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Sample records for cu-nbc composite produced

  1. Process for producing dispersed particulate composite materials

    DOEpatents

    Henager, Jr., Charles H.; Hirth, John P.

    1995-01-01

    This invention is directed to a process for forming noninterwoven dispersed particulate composite products. In one case a composite multi-layer film product comprises a substantially noninterwoven multi-layer film having a plurality of discrete layers. This noninterwoven film comprises at least one discrete layer of a first material and at least one discrete layer of a second material. In another case the first and second materials are blended together with each other. In either case, the first material comprises a metalloid and the second material a metal compound. At least one component of a first material in one discrete layer undergoes a solid state displacement reaction with at least one component of a second material thereby producing the requisite noninterwoven composite film product. Preferably, the first material comprises silicon, the second material comprises Mo.sub.2 C, the third material comprises SiC and the fourth material comprises MoSi.sub.2.

  2. Molybdenum disilicide composites produced by plasma spraying

    SciTech Connect

    Castro, R.G.; Hollis, K.J.; Kung, H.H.; Bartlett, A.H.

    1998-05-25

    The intermetallic compound, molybdenum disilicide (MoSi{sub 2}) is being considered for high temperature structural applications because of its high melting point and superior oxidation resistance at elevated temperatures. The lack of high temperature strength, creep resistance and low temperature ductility has hindered its progress for structural applications. Plasma spraying of coatings and structural components of MoSi{sub 2}-based composites offers an exciting processing alternative to conventional powder processing methods due to superior flexibility and the ability to tailor properties. Laminate, discontinuous and in situ reinforced composites have been produced with secondary reinforcements of Ta, Al{sub 2}O{sub 3}, SiC, Si{sub 3}N{sub 4} and Mo{sub 5}Si{sub 3}. Laminate composites, in particular, have been shown to improve the damage tolerance of MoSi{sub 2} during high temperature melting operations. A review of research which as been performed at Los Alamos National Laboratory on plasma spraying of MoSi{sub 2}-based composites to improve low temperature fracture toughness, thermal shock resistance, high temperature strength and creep resistance will be discussed.

  3. Method of producing particulate-reinforced composites and composites produced thereby

    DOEpatents

    Han, Qingyou; Liu, Zhiwei

    2013-12-24

    A process for producing particle-reinforced composite materials through utilization of an in situ reaction to produce a uniform dispersion of a fine particulate reinforcement phase. The process includes forming a melt of a first material, and then introducing particles of a second material into the melt and subjecting the melt to high-intensity acoustic vibration. A chemical reaction initiates between the first and second materials to produce reaction products in the melt. The reaction products comprise a solid particulate phase, and the high-intensity acoustic vibration fragments and/or separates the reaction products into solid particles that are dispersed in the melt and are smaller than the particles of the second material. Also encompassed are particle-reinforced composite materials produced by such a process.

  4. Method of producing particulate-reinforced composites and composites produced thereby

    SciTech Connect

    Han, Qingyou; Liu, Zhiwei

    2015-12-29

    A process for producing particle-reinforced composite materials through utilization of an in situ reaction to produce a uniform dispersion of a fine particulate reinforcement phase. The process includes forming a melt of a first material, and then introducing particles of a second material into the melt and subjecting the melt to high-intensity acoustic vibration. A chemical reaction initiates between the first and second materials to produce reaction products in the melt. The reaction products comprise a solid particulate phase, and the high-intensity acoustic vibration fragments and/or separates the reaction products into solid particles that are dispersed in the melt and are smaller than the particles of the second material. Also encompassed are particle-reinforced composite materials produced by such a process.

  5. Process for producing a petroleum wax composition

    SciTech Connect

    Jones, R.L.

    1991-04-23

    This patent describes a process for producing a wax composition. It comprises: vacuum distilling a petroleum feed to prepare a 650 distillate heavy intermediate petroleum wax, having a melting point range of from about 155{degrees}F. to about 185{degrees}F., subjecting the heavy intermediate petroleum wax to furfural/duosol solvent extraction, dissolving and crystallizing the heavy intermediate petroleum wax from a methyl ethyl ketone/toluene mixed solvent, dissolving and recrystallizing the heavy intermediate petroleum wax from a methyl ethyl ketone/toluene mixed solvent, percolating the recrystallized heavy intermediate petroleum wax in the molten state through a clay bed; and blending the recrystallized heavy intermediate petroleum wax from about 50 weight percent to about 90 weight percent with from about 10 weight percent to about 30 weight percent of a polymeric compound selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polypropylene and mixtures there of and having a molecular weight of from about 2,000 to about 100,000 and a melt index of from about 1 to about 250{degrees} at 375{degrees}F.

  6. Carbides composite surface layers produced by (PTA)

    SciTech Connect

    Tajoure, Meloud; Tajouri, Ali E-mail: dr.mokhtarphd@yahoo.com; Abuzriba, Mokhtar E-mail: dr.mokhtarphd@yahoo.com; Akreem, Mosbah

    2013-12-16

    The plasma transferred arc technique was applied to deposit a composite layer of nickel base with tungsten carbide in powder form on to surface of low alloy steel 18G2A type according to polish standard. Results showed that, plasma transferred arc hard facing process was successfully conducted by using Deloro alloy 22 plus tungsten carbide powders. Maximum hardness of 1489 HV and minimum dilution of 8.4 % were achieved by using an arc current of 60 A. However, when the current was further increased to 120 A and the dilution increases with current increase while the hardness decreases. Microstructure of the nickel base deposit with tungsten carbide features uniform distribution of reinforcement particles with regular grain shape half - dissolved in the matrix.

  7. Carbides composite surface layers produced by (PTA)

    NASA Astrophysics Data System (ADS)

    Tajoure, Meloud; Tajouri, Ali; Abuzriba, Mokhtar; Akreem, Mosbah

    2013-12-01

    The plasma transferred arc technique was applied to deposit a composite layer of nickel base with tungsten carbide in powder form on to surface of low alloy steel 18G2A type according to polish standard. Results showed that, plasma transferred arc hard facing process was successfully conducted by using Deloro alloy 22 plus tungsten carbide powders. Maximum hardness of 1489 HV and minimum dilution of 8.4 % were achieved by using an arc current of 60 A. However, when the current was further increased to 120 A & the dilution increases with current increase while the hardness decreases. Microstructure of the nickel base deposit with tungsten carbide features uniform distribution of reinforcement particles with regular grain shape half - dissolved in the matrix.

  8. Multilayered titanium-steel composite produced by explosive welding

    NASA Astrophysics Data System (ADS)

    Malyutina, Yu. N.; Skorohod, K. A.; Shevtsova, K. E.; Chesnokova, A. V.

    2015-10-01

    Multilayered titanium-steel composite consisting of alternating high-strength and ductile metallic materials were produced by explosive welding. Different types of weld joints formed in the composite were recognized by methods of microstructural analysis. Wave-shaped and flat geometry of welds are typical of steel and titanium layers, respectively. Structural features such as lack of penetration, shear bands, recrystallized metals and martensitic structure were detected in the vortex and weld-adjacent zones of impacted materials. The impact strength of the layered composite was 65% higher as compared to that of VT23 titanium alloy. A favorable role of interlayers in the multilayered composite has been confirmed by toughness tests.

  9. Composition of Mineral Produced by Dental Mesenchymal Stem Cells

    PubMed Central

    Volponi, A.A.; Gentleman, E.; Fatscher, R.; Pang, Y.W.Y.; Gentleman, M.M.; Sharpe, P.T.

    2015-01-01

    Mesenchymal stem cells isolated from different dental tissues have been described to have osteogenic/odontogenic-like differentiation capacity, but little attention has been paid to the biochemical composition of the material that each produces. Here, we used Raman spectroscopy to analyze the mineralized materials produced in vitro by different dental cell populations, and we compared them with the biochemical composition of native dental tissues. We show that different dental stem cell populations produce materials that differ in their mineral and matrix composition and that these differ from those of native dental tissues. In vitro, BCMP (bone chip mass population), SCAP (stem cells from apical papilla), and SHED (stem cells from human-exfoliated deciduous teeth) cells produce a more highly mineralized matrix when compared with that produced by PDL (periodontal ligament), DPA (dental pulp adult), and GF (gingival fibroblast) cells. Principal component analyses of Raman spectra further demonstrated that the crystallinity and carbonate substitution environments in the material produced by each cell type varied, with DPA cells, for example, producing a more carbonate-substituted mineral and with SCAP, SHED, and GF cells creating a less crystalline material when compared with other dental stem cells and native tissues. These variations in mineral composition reveal intrinsic differences in the various cell populations, which may in turn affect their specific clinical applications. PMID:26253190

  10. Insoluble starch composite foams produced through microwave expansion.

    PubMed

    Deng, Yuzhi; Catchmark, Jeffrey M

    2014-10-13

    An insoluble biocomposite composed of potato starch and chitosan was prepared by microwave treatment. The effect of pH on swelling (liquid absorption) behavior of the composites was investigated at pH 2, pH 6.8 and pH 12. Analysis revealed that the solution uptake ratio of composites depends both on the aqueous pH value and the content of the chitosan. Composites exhibited a relatively high swelling ratio at pH environments lower than the pK(a) of amine groups on chitosan (about 6.3). Glucose analysis by ion exchange chromatography showed that there was little hydrolysis of such composites at low pH. When immersed in the same pH solution, composites with higher chitosan content exhibited higher swelling ratios. The microstructure of composites produced was also investigated by FE-SEM. PMID:25037426

  11. Compositions produced using an in situ heat treatment process

    DOEpatents

    Roes, Augustinus Wilhelmus Maria; Nair, Vijay; Munsterman, Erwin Hunh; Van Bergen, Petrus Franciscus; Van Den Berg, Franciscus Gondulfus Antonius

    2013-05-28

    Methods for treating a subsurface formation and compositions produced therefrom are described herein. At least one method for producing hydrocarbons from a subsurface formation includes providing heat to the subsurface formation using an in situ heat treatment process. One or more formation particles may be formed during heating of the subsurface formation. Fluid that includes hydrocarbons and the formation particles may be produced from the subsurface formation. The formation particles in the produced fluid may include cenospheres and have an average particle size of at least 0.5 micrometers.

  12. Method of producing a hybrid matrix fiber composite

    DOEpatents

    Deteresa, Steven J.; Lyon, Richard E.; Groves, Scott E.

    2006-03-28

    Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites comprised of two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

  13. Process to Produce Iron Nanoparticle Lunar Dust Simulant Composite

    NASA Technical Reports Server (NTRS)

    Hung, Ching-cheh; McNatt, Jeremiah

    2010-01-01

    A document discusses a method for producing nanophase iron lunar dust composite simulant by heating a mixture of carbon black and current lunar simulant types (mixed oxide including iron oxide) at a high temperature to reduce ionic iron into elemental iron. The product is a chemically modified lunar simulant that can be attracted by a magnet, and has a surface layer with an iron concentration that is increased during the reaction. The iron was found to be -iron and Fe3O4 nanoparticles. The simulant produced with this method contains iron nanoparticles not available previously, and they are stable in ambient air. These nanoparticles can be mass-produced simply.

  14. Method of producing particulate-reinforced composites and composties produced thereby

    SciTech Connect

    Han, Qingyou; Liu, Zhiwei

    2013-12-24

    A process for producing particle-reinforced composite materials through utilization of an in situ reaction to produce a uniform dispersion of a fine particulate reinforcement phase. The process includes forming a melt of a first material, and then introducing particles of a second material into the melt and subjecting the melt to high-intenisty acoustic vibration. A chemical reaction initiates between the first and second materials to produce reaction products in the melt. The reaciton products comprise a solide particulate phase, and the high-intensity acoustic vibration fragments and/or separates the reaction products into solid particles that are dispersed in the melt and are smaller than the particles of the second material. Also encompassed are particles-reinforced composite materials produced by such a process.

  15. Resin impregnation process for producing a resin-fiber composite

    NASA Technical Reports Server (NTRS)

    Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

    1994-01-01

    Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

  16. Low energy particle composition. [cosmic rays produced in solar system

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.

    1975-01-01

    A review is given of current knowledge of low-energy cosmic ray particles produced in the solar system. It is argued that the notion that the sun alone can accelerate particles in the solar system must be abandoned in light of evidence that Jupiter and earth may be sources of observed low-energy particles. Measurements of the composition and energy spectra of low-energy particles during quiet times are examined, emphasizing the abundance of protons and helium and of anomalous N, O, and Ne. The abundance of heavy particles (B, C, N, O, Ne, Ca and Fe) of unknown origin in the earth magnetosphere is examined. Reported observations of Jovian electrons are discussed and solar particle events with anomalous compositions (He-3 rich events and Fe rich events) are treated in detail. Nuclear abundances of solar particles, emphasizing their temporal and spatial variations are considered together with the nature of nuclear reaction products in solar flares.

  17. Tailoring of composite wing structures for elastically produced camber deformations

    NASA Technical Reports Server (NTRS)

    Rehfield, Lawrence W.; Chang, Stephen; Zischka, Peter J.; Pickings, Richard D.; Holl, Michael W.

    1991-01-01

    Structural concepts have been created which produce chordwise camber deformation that results in enhanced lift. A wing box can be tailored to utilize these concepts with composites. In attempting to optimize the aerodynamic benefits, it is found that there are two optimum designs that are of interest. There is a 'weight' optimum which corresponds to the maximum lift per unit structural weight. There is also a 'lift' optimum that corresponds to maximum absolute lift. Experience indicates that a large weight penalty accompanies the transition from weight to lift optimum designs. New structural models, the basic deformation mechanisms that are utilized and typical analytical results are presented. It appears that lift enhancements of sufficient magnitude can be produced to render this type of wing tailoring of practical interest.

  18. Tailored composite wings with elastically produced chordwise camber

    NASA Technical Reports Server (NTRS)

    Rehfield, Lawrence W.; Chang, Stephen; Zischka, Peter J.; Pickings, Richard D.; Holl, Michael W.

    1991-01-01

    Four structural concepts were created which produce chordwise camber deformation that results in enhanced lift. A wing box can be tailored to utilize each of these with composites. In attempting to optimize the aerodynamic benefits, researchers found that there are two optimum designs that are of interest. There is a weight optimum which corresponds to the maximum lift per unit structural weight. There is also a lift optimum that corresponds to maximum absolute lift. Experience indicates that a large weight penalty accompanies the transition from weight to lift optimum designs. New structural models, the basic deformation mechanisms that are utilized, and typical analytical results are presented. It appears that lift enhancements of sufficient magnitude can be produced to render this type of wing tailoring of practical interest.

  19. Method for producing heat treated composite nuclear fuel containers

    SciTech Connect

    Rosenbaum, H.S.

    1993-06-29

    A method is described for producing composite constructed nuclear fuel containers for service in water cooled nuclear fission reactors comprising a tubular zirconium alloy casing having a protective lining of a zirconium metal covering the inside surface of the zirconium alloy tubular casing and being metallurgically bonded thereto, consisting essentially of the steps of: heat treating a large diameter zirconium alloy tube comprising a beta-quench treatment of heating the zirconium alloy to a temperature sufficient to recrystallize the zirconium alloy to its beta phase of at least about 970 C and then rapidly cooling the thus heated and recrystallized zirconium alloy tube stock, heat treating a large diameter zirconium metal hollow liner stock comprising a beta-quench treatment of heating the zirconium metal to a temperature sufficient to recrystallize the zirconium metal to its beta phase of at least about 900 C and then rapidly cooling the thus heated and recrystallized zirconium metal hollow liner stock, assembling the heat treated zirconium alloy tube stock and heat treated lining stock with the hollow zirconium metal lining stock inserted inclose fitting contact within the tube stock, metallurgically bonding the tube and liner stocks providing a composite tubular stock unit with the tube stock surrounding the lining stock, and reducing the circumference of the assembled composite tubular stock unit down to a size suitable for service as a lined tubular container for nuclear fuel in a series of progressive reductions in circumference applied in sequence.

  20. Device for producing a fluid stream of varying composition

    DOEpatents

    Moss, Owen R.; Clark, Mark L.; Rossignol, E. John

    1982-01-01

    A device for producing a fluid stream of varying composition comprises a chamber having an inlet at one end and outlet at the other. Between the inlet and outlet there are substantially planar pans or baffles positioned normal to the bulk flow of fluid between the inlet and the outlet. These pans are arranged in pairs. Each pan, except those of the pair most remote from the inlet, is spaced from the walls of the chamber to permit air to flow past it. The pans of each pair are also spaced from each other, in a direction parallel to their planes, leaving an empty space along the mid-plane of the chamber. This produces a circulation and mixing of fluid between the pairs of pans or baffles. A secondary stream of fluid is introduced between two pairs of baffles in the intermediate portion of the chamber, so that the composition of the fluid is different in the portion adjacent to the outlet and the portion adjacent to the inlet. In a specific embodiment, the device is an exposure chamber for experimental animals, and the pans or baffles are catch pans for excrement.

  1. Method of producing exfoliated graphite composite compositions for fuel cell flow field plates

    DOEpatents

    Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

    2014-04-08

    A method of producing an electrically conductive composite composition, which is particularly useful for fuel cell bipolar plate applications. The method comprises: (a) providing a supply of expandable graphite powder; (b) providing a supply of a non-expandable powder component comprising a binder or matrix material; (c) blending the expandable graphite with the non-expandable powder component to form a powder mixture wherein the non-expandable powder component is in the amount of between 3% and 60% by weight based on the total weight of the powder mixture; (d) exposing the powder mixture to a temperature sufficient for exfoliating the expandable graphite to obtain a compressible mixture comprising expanded graphite worms and the non-expandable component; (e) compressing the compressible mixture at a pressure within the range of from about 5 psi to about 50,000 psi in predetermined directions into predetermined forms of cohered graphite composite compact; and (f) treating the so-formed cohered graphite composite to activate the binder or matrix material thereby promoting adhesion within the compact to produce the desired composite composition. Preferably, the non-expandable powder component further comprises an isotropy-promoting agent such as non-expandable graphite particles. Further preferably, step (e) comprises compressing the mixture in at least two directions. The method leads to composite plates with exceptionally high thickness-direction electrical conductivity.

  2. Elemental composition of four farmed fish produced in Portugal.

    PubMed

    Lourenço, Helena M; Afonso, Cláudia; Anacleto, Patrícia; Martins, Maria F; Nunes, Maria L; Lino, Ana R

    2012-11-01

    Farmed gilthead sea bream (Sparus aurata), European sea bass (Dicentrarchus labrax), rainbow trout (Oncorhynchus mykiss) and turbot (Psetta maxima) produced in Portugal were analysed in order to characterize their elemental composition. Atomic absorption (flame and cold vapour) and molecular absorption spectrometry techniques were used to determine all the studied elements. Similar patterns of macro, trace and ultra trace elements were observed for all fish species. The main elements were potassium (K), sodium (Na), phosphorus (P), magnesium (Mg) and calcium (Ca), followed by zinc (Zn), iron (Fe), copper (Cu), chromium (Cr), manganese (Mn) and nickel (Ni). Cadmium (Cd), mercury (Hg) and lead (Pb) concentrations, obtained in this study, allow concluding that these species do not present a hazard for human consumption. In addition, they contain almost all essential elements at concentrations sufficient to suit the dietary reference intake. Nevertheless, P. maxima nutritious trace element content is relatively low compared with the other three species. PMID:22574998

  3. Producibility aspects of advanced composites for an L-1011 Aileron

    NASA Technical Reports Server (NTRS)

    Van Hamersveld, J.; Fogg, L. D.

    1976-01-01

    The design of advanced composite aileron suitable for long-term service on transport aircraft includes Kevlar 49 fabric skins on honeycomb sandwich covers, hybrid graphite/Kevlar 49 ribs and spars, and graphite/epoxy fittings. Weight and cost savings of 28 and 20 percent, respectively, are predicted by comparison with the production metallic aileron. The structural integrity of the design has been substantiated by analysis and static tests of subcomponents. The producibility considerations played a key role in the selection of design concepts with potential for low-cost production. Simplicity in fabrication is a major factor in achieving low cost using advanced tooling and manufacturing methods such as net molding to size, draping, forming broadgoods, and cocuring components. A broadgoods dispensing machine capable of handling unidirectional and bidirectional prepreg materials in widths ranging from 12 to 42 inches is used for rapid layup of component kits and covers. Existing large autoclaves, platen presses, and shop facilities are fully exploited.

  4. 3D nanotube-based composites produced by laser irradiation

    SciTech Connect

    Ageeva, S A; Bobrinetskii, I I; Nevolin, Vladimir K; Podgaetskii, Vitalii M; Selishchev, S V; Simunin, M M; Konov, Vitalii I; Savranskii, V V; Ponomareva, O V

    2009-04-30

    3D nanocomposites have been fabricated through self-assembly under near-IR cw laser irradiation, using four types of multiwalled and single-walled carbon nanotubes produced by chemical vapour deposition, disproportionation on Fe clusters and cathode sputtering in an inert gas. The composites were prepared by laser irradiation of aqueous solutions of bovine serum albumin until the solvent was evaporated off and a homogeneous black material was obtained: modified albumin reinforced with nanotubes. The consistency of the composites ranged from paste-like to glass-like. Atomic force microscopy was used to study the surface morphology of the nanomaterials. The nanocomposites had a 3D quasi-periodic structure formed by almost spherical or toroidal particles 200-500 nm in diameter and 30-40 nm in visible height. Their inner, quasi-periodic structure was occasionally seen through surface microfractures. The density and hardness of the nanocomposites exceed those of microcrystalline albumin powder by 20% and by a factor of 3-5, respectively. (nanostructures)

  5. In-vehicle VOCs composition of unconditioned, newly produced cars.

    PubMed

    Brodzik, Krzysztof; Faber, Joanna; Łomankiewicz, Damian; Gołda-Kopek, Anna

    2014-05-01

    The in-vehicle volatile organic compounds (VOCs) concentrations gains the attention of both car producers and users. In the present study, an attempt was made to determine if analysis of air samples collected from an unconditioned car cabin can be used as a quality control measure. The VOCs composition of in-vehicle air was analyzed by means of active sampling on Carbograph 1TD and Tenax TA sorbents, followed by thermal desorption and simultaneous analysis on flame ionization and mass detector (TD-GC/FID-MS). Nine newly produced cars of the same brand and model were chosen for this study. Within these, four of the vehicles were equipped with identical interior materials and five others differed in terms of upholstery and the presence of a sunroof; one car was convertible. The sampling event took place outside of the car assembly plant and the cars tested left the assembly line no later than 24 hr before the sampling took place. More than 250 compounds were present in the samples collected; the identification of more than 160 was confirmed by comparative mass spectra analysis and 80 were confirmed by both comparison with single/multiple compounds standards and mass spectra analysis. In general, aliphatic hydrocarbons represented more than 60% of the total VOCs (TVOC) determined. Depending on the vehicle, the concentration of aromatic hydrocarbons varied from 12% to 27% of total VOCs. The very short period between car production and sampling of the in-vehicle air permits the assumption that the entire TVOC originates from off-gassing of interior materials. The results of this study expand the knowledge of in-vehicle pollution by presenting information about car cabin air quality immediately after car production. PMID:25079635

  6. Method for producing silicon nitride/silicon carbide composite

    DOEpatents

    Dunmead, Stephen D.; Weimer, Alan W.; Carroll, Daniel F.; Eisman, Glenn A.; Cochran, Gene A.; Susnitzky, David W.; Beaman, Donald R.; Nilsen, Kevin J.

    1996-07-23

    Silicon carbide/silicon nitride composites are prepared by carbothermal reduction of crystalline silica powder, carbon powder and optionally crsytalline silicon nitride powder. The crystalline silicon carbide portion of the composite has a mean number diameter less than about 700 nanometers and contains nitrogen.

  7. Aluminum/alkaline earth metal composites and method for producing

    DOEpatents

    Russell, Alan M; Anderson, Iver E; Kim, Hyong J; Freichs, Andrew E

    2014-02-11

    A composite is provided having an electrically conducting Al matrix and elongated filaments comprising Ca and/or Sr and/or Ba disposed in the matrix and extending along a longitudinal axis of the composite. The filaments initially comprise Ca and/or Sr and/or Ba metal or allow and then may be reacted with the Al matrix to form a strengthening intermetallic compound comprising Al and Ca and/or Sr and/or Ba. The composite is useful as a long-distance, high voltage power transmission conductor.

  8. Composition for producing polyurethane resin at ambient temperature

    SciTech Connect

    Kamatani, Y.; Nishino, K.; Tanaka, M.; Yamazaki, K.

    1984-06-26

    Disclosed is a composition for polyurethane resins which is ordinarily of two-package type and curable at ambient temperature and which comprises an isocyanate component having oxadiazinetrione ring as a curing agent and a polyol component, having in the molecule, at least one of a tertiary amino group, a quaternary ammonium group and a salt-formed carboxyl group as a main component. The composition has excellent curability and provides cured products excellent in adhesiveness and physical properties.

  9. Thermoelectric skutterudite compositions and methods for producing the same

    SciTech Connect

    Ren, Zhifeng; Yang, Jian; Yan, Xiao; He, Qinyu; Chen, Gang; Hao, Qing

    2014-11-11

    Compositions related to skutterudite-based thermoelectric materials are disclosed. Such compositions can result in materials that have enhanced ZT values relative to one or more bulk materials from which the compositions are derived. Thermoelectric materials such as n-type and p-type skutterudites with high thermoelectric figures-of-merit can include materials with filler atoms and/or materials formed by compacting particles (e.g., nanoparticles) into a material with a plurality of grains each having a portion having a skutterudite-based structure. Methods of forming thermoelectric skutterudites, which can include the use of hot press processes to consolidate particles, are also disclosed. The particles to be consolidated can be derived from (e.g., grinded from), skutterudite-based bulk materials, elemental materials, other non-Skutterudite-based materials, or combinations of such materials.

  10. Thermoelectric Skutterudite Compositions and Methods for Producing the Same

    NASA Technical Reports Server (NTRS)

    Ren, Zhifeng (Inventor); Yang, Jian (Inventor); Yan, Xiao (Inventor); He, Qinyu (Inventor); Chen, Gang (Inventor); Hao, Qing (Inventor)

    2014-01-01

    Compositions related to skutterudite-based thermoelectric materials are disclosed. Such compositions can result in materials that have enhanced ZT values relative to one or more bulk materials from which the compositions are derived. Thermoelectric materials such as n-type and p-type skutterudites with high thermoelectric figures-of-merit can include materials with filler atoms and/or materials formed by compacting particles (e.g., nanoparticles) into a material with a plurality of grains each having a portion having a skutterudite-based structure. Methods of forming thermoelectric skutterudites, which can include the use of hot press processes to consolidate particles, are also disclosed. The particles to be consolidated can be derived from (e.g., grinded from), skutterudite-based bulk materials, elemental materials, other non-Skutterudite-based materials, or combinations of such materials.

  11. Laminated structures and methods and compositions for producing same

    DOEpatents

    Fumei, Giancarlo J.; Karabedian, James A.

    1977-04-05

    Methods for bonding two substrates, one of which is polymeric, which comprise coating the surface of at least one substrate with an adhesive composition comprising a major component which is an adhesive for the first substrate and a minor disperse phase which is a solution of a polymer in a solvent for the polymeric substrate and contacting the coated surface of the one substrate with the surface of the other substrate, together with adhesive compositions useful for joining such substrates, laminates so formed, and articles comprised of such laminates.

  12. Compositions produced using an in situ heat treatment process

    SciTech Connect

    Roes, Augustinus Wilhelmus Maria; Nair, Vijay; Munsterman, Erwin Henh; Van Bergen, Petrus Franciscus; Van Den Berg, Franciscus Gondulfus Antonius

    2009-10-20

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for producing hydrocarbons from a subsurface formation includes providing heat to the subsurface formation using an in situ heat treatment process. One or more formation particles may be formed during heating of the subsurface formation. Fluid that includes hydrocarbons and the formation particles may be produced from the subsurface formation. The formation particles in the produced fluid may include cenospheres and have an average particle size of at least 0.5 micrometers.

  13. Method for producing ceramic composition having low friction coefficient at high operating temperatures

    DOEpatents

    Lankford, Jr., James

    1988-01-01

    A method for producing a stable ceramic composition having a surface with a low friction coefficient and high wear resistance at high operating temperatures. A first deposition of a thin film of a metal ion is made upon the surface of the ceramic composition and then a first ion implantation of at least a portion of the metal ion is made into the near surface region of the composition. The implantation mixes the metal ion and the ceramic composition to form a near surface composite. The near surface composite is then oxidized sufficiently at high oxidizing temperatures to form an oxide gradient layer in the surface of the ceramic composition.

  14. Use of microfasteners to produce damage tolerant composite structures

    PubMed Central

    Hallett, Stephen R.

    2016-01-01

    The paper concerns the mechanical performance of continuous fibre/thermosetting polymer matrix composites reinforced in the through-thickness direction with fibrous or metallic rods or threads in order to mitigate against low delamination resistance. Specific illustrations of the effects of microfasteners in reducing delamination crack growth are made for Z-pinned and tufted composites. Response to loading in such ‘structured materials’ is subject to multiple parameters defining their in-plane and out-of-plane properties. Single microfastener mechanical tests are well suited to establish the crack bridging laws under a range of loading modes, from simple delamination crack opening to shear, and provide the basis for predicting the corresponding response of microfastener arrays, within a given material environment. The fundamental experiments on microfasteners can be used to derive analytical expressions to describe the crack bridging behaviour in a general sense, to cover all possible loadings. These expressions can be built into cohesive element constitutive laws in a finite-element framework for modelling the effects of microfastener arrays on the out-of-plane mechanical response of reinforced structural elements, including the effects of known manufacturing imperfections. Such predictive behaviour can then be used to assess structural integrity under complex loading, as part of the component design process. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’. PMID:27242299

  15. Use of microfasteners to produce damage tolerant composite structures.

    PubMed

    Partridge, Ivana K; Hallett, Stephen R

    2016-07-13

    The paper concerns the mechanical performance of continuous fibre/thermosetting polymer matrix composites reinforced in the through-thickness direction with fibrous or metallic rods or threads in order to mitigate against low delamination resistance. Specific illustrations of the effects of microfasteners in reducing delamination crack growth are made for Z-pinned and tufted composites. Response to loading in such 'structured materials' is subject to multiple parameters defining their in-plane and out-of-plane properties. Single microfastener mechanical tests are well suited to establish the crack bridging laws under a range of loading modes, from simple delamination crack opening to shear, and provide the basis for predicting the corresponding response of microfastener arrays, within a given material environment. The fundamental experiments on microfasteners can be used to derive analytical expressions to describe the crack bridging behaviour in a general sense, to cover all possible loadings. These expressions can be built into cohesive element constitutive laws in a finite-element framework for modelling the effects of microfastener arrays on the out-of-plane mechanical response of reinforced structural elements, including the effects of known manufacturing imperfections. Such predictive behaviour can then be used to assess structural integrity under complex loading, as part of the component design process. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242299

  16. /Al-4Cu Composite Material Produced by Squeeze Casting Method

    NASA Astrophysics Data System (ADS)

    Ficici, Ferit

    2014-05-01

    The wear behavior of a weight fraction of particles with up to 30 wt.% in situ AlB2 flakes reinforced in Al-4Cu matrix alloy composites and fabricated by a squeeze casting method was investigated in a pin-on-disk abrasion test instrument against different SiC abrasives at room conditions. Wear tests were performed under the load of 10 N against SiC abrasive papers of 80, 100, and 120 mesh grits. The effects of sliding speed, AlB2 flake content, and abrasive grit sizes on the abrasive wear properties of the matrix alloy and composites have been evaluated. The main wear mechanisms were identified using an optical microscope. The results showed that in situ AlB2 flake reinforcement improved the abrasion resistance against all the abrasives used, and the abrasive wear resistance decreased with an increase in the sliding speed and the abrasive grit size. The wear resistances of the composites were considerably bigger than those of the matrix alloy and increased with increases in in situ AlB2 flake contents.

  17. Uniform composite in a hypermonotectic alloy system and a method for producing the same

    NASA Technical Reports Server (NTRS)

    Grugal, Richard N. (Inventor)

    1993-01-01

    A uniform composite of hypermonotectic composition and a method for producing the same wherein the composition has a plurality of aligned and constrained fibers therein. These fibers serve to uniformly distribute L.sub.11 from the reaction L.sub.I .fwdarw.S.sub.I +L.sub.II.

  18. CHEMICAL COMPOSITION OF PRODUCED WATER AT SOME OFFSHORE OIL PLATFORMS

    EPA Science Inventory

    The effectiveness of produced water treatment was briefly studied in offshore oil and gas extraction operations in Cook Inlet, Alaska, and the Gulf of Mexico. Three offshore oil extraction facilities were examined in the Cook Inlet production field, and seven platforms were studi...

  19. Wear resistance of composite coatings produced by thermal spraying

    SciTech Connect

    Klinskaya, N.A.

    1995-12-31

    Injection of refractory additions (carbides, borides, oxides etc.) into self-fluxing alloys is a well-known technique for their hardening. Nevertheless the matter of influence of refractory components on the structure and characteristics of composite coatings is not studied well enough. This paper presents the results of investigations of gas thermal coatings (plasma and detonation ones) on the base of stellite with refractory components in the form of borides such as CrB{sub 2}, TiB{sub 2}, (TiCr)B{sub 2}. This study is concerned with the influence of refractory additions (carbides, borides, oxides) on the wear resistance sprayed coatings based on self-fluxing alloys NiCrBSi and CoCrBSi.

  20. Characterization of carbides composite surface layers produced by PTA

    NASA Astrophysics Data System (ADS)

    Tajoure, M.; Tajouri, A.

    2015-03-01

    Composite surface layer of nickel base with titanium carbide in powder form was deposited on to surface of low alloy steel 18G2A type according to polish standard by using plasma transferred arc technique. Results showed that, plasma transferred arc hardfacin process was successfully conducted by using PMNICr50P alloy plus titanium carbide powders. Maximum hardness of 754 HV and minimum dilution of 4.6 % were achieved by using an arc current of 80 A. However, when the current was further increased to 120 A& the dilution increases with current increase while the hardness decreases. Microstructure of the nickel base with titanium carbide feature uniform distribution of reinforcement particles with irregular grain shape and relatively small particles size, and regular boundary line between the substrate and over layer with presence of black area along the boundary line. A few micro - porosities are located in the matrix.

  1. Phase Composition and Microstructure of Ti-Nb Alloy Produced by Selective Laser Melting

    NASA Astrophysics Data System (ADS)

    Sharkeev, Yu P.; Eroshenko, A. Yu; Kovalevskaya, Zh G.; Saprykin, A. A.; Ibragimov, E. A.; Glukhov, I. A.; Chimich, M. A.; Uvarkin, P. V.; Babakova, E. V.

    2016-07-01

    The phase composition and microstructure of Ti-Nb alloy produced from composite titanium and niobium powder by selective laser melting (SLM) was studied. Produced monolayered Ti-Nb alloy enhanced the formation of fine-grained and medium-grained zones with homogeneous element composition of 36-38% Nb mass interval. Alloy phase composition responded to β-alloy substrate phase (grain size was 5-7 pm) and non-equilibrium martensite α"- phase (grain size was 0.1-0.7 µm). α"-phase grains were found along β-phase grain boundaries and inside grains, including decreased niobium content. Alloy microhardness varied within 4200-5500 MPa.

  2. Comparison of Chemical Composition of Complex Disinfection Byproduct (DBP) Mixtures Produced by Different Treatment Methods - slides

    EPA Science Inventory

    Analyses of the chemical composition of complex DBP mixtures, produced by different drinking water treatment processes, are essential to generate toxicity data required for assessing their risks to humans. For mixture risk assessments, whole mixture toxicology studies generally a...

  3. Comparison of Chemical Composition of Complex Disinfection Byproduct (DBP) Mixtures Produced by Different Treatment Methods

    EPA Science Inventory

    Analyses of the chemical composition of complex DBP mixtures, produced by different drinking water treatment processes, are essential to generate toxicity data required for assessing their risks to humans. For mixture risk assessments, whole mixture toxicology studies generally a...

  4. Composition of Powders Produced by Electrospark Dispersion of Metal Granules in Water

    NASA Astrophysics Data System (ADS)

    Zhuravkov, S. P.; Lobanova, G. L.; Pustovalov, A. V.; Slyadnikov, P. E.; Nadeina, L. V.

    2016-02-01

    The results of experimental studies of metal powders composition produced by electrospark dispersion according to the scheme “metal electrodes - metal granule loading - distilled water” are given in the paper. With a help of X-ray diffraction analysis and other methods, it was found that chemical and phase composition of dispersion products is determined by affinity of metal to oxygen.

  5. COMPOSITE MATERIALS PRODUCED BY PARTICLE-BONDING WITH GLIADIN AS A GLUE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In our previous report, we introduced a new methodology for the production of biodegradable polymer composites that will potentially replace existing petroleum-based polymers. Unlike conventional techniques that produce polymer composites by mixing the component materials in the extruder at high te...

  6. Feasibility of producing cast-refractory metal-fiber superalloy composites

    NASA Technical Reports Server (NTRS)

    Mcintyre, R. D.

    1973-01-01

    A study was conducted to evaluate the feasibility of direct casting as a practical method for producing cast superalloy tungsten or columbium alloy fiber composites while retaining a high percentage of fiber strength. Fourteen nickel base, four cobalt, and three iron based matrices were surveyed for their degree of reaction with the metal fibers. Some stress-rupture results were obtained at temperatures of 760, 816, 871, and 1093 C for a few composite systems. The feasibility of producing acceptable composites of some cast nickel, cobalt, and iron matrix alloys with tungsten or columbium alloy fibers was demonstrated.

  7. Comparison of meat composition from offspring of cloned and conventionally produced boars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compares the meat composition of the offspring from boars produced by somatic cell nuclear transfer (n=4) to that of the offspring from conventionally produced boars (n=3). In total 89 commercial gilts were artificially inseminated and 61 progressed to term and farrowed. All of the result...

  8. Properties of High Volume Fraction Fly Ash/Al Alloy Composites Produced by Infiltration Process

    NASA Astrophysics Data System (ADS)

    Kountouras, D. T.; Stergioudi, F.; Tsouknidas, A.; Vogiatzis, C. A.; Skolianos, S. M.

    2015-09-01

    In the present study, pressure infiltration is employed to synthesize aluminum alloy 7075-fly ash composites. The microstructure and chemical composition of the fly ash and the produced composite material was examined using optical and scanning electron microscopy, as well as x-ray diffraction. Several properties of the produced composite material were examined and evaluated including macro-hardness, wear, thermal expansion, and corrosion behavior. The wear characteristics of the composite, in the as-cast conditions, were studied by dry sliding wear tests. The corrosion behavior of composite material was evaluated by means of potentiodynamic corrosion experiments in a 3.5 wt.% NaCl solution. The composite specimens exhibit a homogeneous distribution of fly ash particles and present enhanced hardness values, compared to the matrix material. The high volume fraction of the fly ash reinforcement (>40%) in the composite material led to increased wear rates, attributed to the fragmentation of the fly ash particles. However, the presence of fly ash particles in the Al alloy matrix considerably decreased the coefficiency of thermal expansion, while resulting in an altered corrosion mechanism of the composite material with respect to the matrix alloy.

  9. Chemical Composition of Different Botanical Origin Honeys Produced by Sicilian Black Honeybees (Apis mellifera ssp. sicula).

    PubMed

    Mannina, Luisa; Sobolev, Anatoly P; Di Lorenzo, Arianna; Vista, Silvia; Tenore, Gian Carlo; Daglia, Maria

    2015-07-01

    In 2008 a Slow Food Presidium was launched in Sicily (Italy) for an early warning of the risk of extinction of the Sicilian native breed of black honeybee (Apis mellifera L. ssp sicula). Today, the honey produced by these honeybees is the only Sicilian honey produced entirely by the black honeybees. In view of few available data regarding the chemical composition of A. mellifera ssp. sicula honeys, in the present investigation the chemical compositions of sulla honey (Hedysarum coronarium L.) and dill honey (Anethum graveolens L.) were studied with a multimethodological approach, which consists of HPLC-PDA-ESI-MSn and NMR spectroscopy. Moreover, three unifloral honeys (lemon honey (obtained from Citrus limon (L.) Osbeck), orange honey (Citrus arantium L.), and medlar honey (Eriobotrya japonica (Thunb.) Lindl)), with known phenol and polyphenol compositions, were studied with NMR spectroscopy to deepen the knowledge about sugar and amino acid compositions. PMID:25730368

  10. Surface finish produced on three resin composites by new polishing systems.

    PubMed

    St-Georges, Annie J; Bolla, Marc; Fortin, Daniel; Muller-Bolla, Michelle; Thompson, Jeffrey Y; Stamatiades, Perry J

    2005-01-01

    This study evaluated the surface finish of three direct resin composites polished with three different systems. Disk-shaped specimens (n=16 per material; phi=8.0 mm x h=2.0 mm) were formed in a stainless steel mold by packing uncured material, either a hybrid composite (Z250, 3M ESPE) or two micro-hybrid composites (Point 4, Kerr; Esthet-X, Dentsply), and light-cured from the top and the bottom surfaces with a light-emitting diode (LED) curing unit (NRG, Dentsply). After storing the specimens in deionized water at 37 degrees C for seven days, one side of each specimen was finished through 1200-grit SiC abrasive (Buehler). Five specimens of each resin composite were randomly assigned to one of the three polishing systems (Identoflex, Kerr; Pogo, Dentsply; Sof-Lex, 3M ESPE). Manufacturers' instructions were followed during the polishing procedures. The average surface roughness (Ra) was determined by generating tracings across the polished surface of each disk using a scanning profilometer (Surfanalyzer System 5000, Federal Products Co). The results were analyzed by Kruskal-Wallis and Mann and Whitney tests (p < or = 0.05). The smoothest surfaces were produced with the celluloid strip (control group) on all the resin composites tested. The aluminum oxide disks (Sof-Lex) produced a statistically equivalent surface finish (Ra) on the three resin composites. The lowest mean roughness values were recorded with diamond micropolisher disks (PoGo) on the hybrid composite (Z250). Overall, the two new polishing systems, Identoflex and PoGo, created a comparable surface finish to that produced by the Sof-Lex system on all three resin composites. PMID:16268393

  11. Method for the production of cementitious compositions and aggregate derivatives from said compositions, and cementitious compositions and aggregates produced thereby

    DOEpatents

    Minnick, L. John

    1983-01-01

    The present invention relates to a method for preparing synthetic shaped cementitious compositions having high quality even without the addition of high energy binders, such as portland cement, through the use of the spent residue from a fluidized combustion bed of the type wherein limestone particles are suspended in a fluidized medium and sulfur oxides are captured, and pulverized coal fly ash.

  12. Marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS)

    PubMed Central

    CORREA, Luciano Ribeiro; BORGES, Alexandre Luiz Souto; GUIMARÃES, Heloisa Bailly; ALMEIDA, Elis Regina Nunes; POSKUS, Laiza Tatiana; SILVA, Eduardo Moreira

    2015-01-01

    Marginal integrity is one of the most crucial aspects involved in the clinical longevity of resin composite restorations. Objective To analyze the marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS). Material and Methods A base composite (B) was produced with an organic matrix with UDMA/TEGDMA and 70 wt.% of barium borosilicate glass particles. To produce the model composite, 25 wt.% of UDMA were replaced by POSS (P25). The composites P90 and TPH3 (TP3) were used as positive and negative controls, respectively. Marginal integrity (%MI) was analyzed in bonded class I cavities. The volumetric polymerization shrinkage (%VS) and the polymerization shrinkage stress (Pss - MPa) were also evaluated. Results The values for %MI were as follows: P90 (100%) = TP3 (98.3%) = B (96.9%) > P25 (93.2%), (p<0.05). The %VS ranged from 1.4% (P90) to 4.9% (P25), while Pss ranged from 2.3 MPa (P90) to 3.9 MPa (B). For both properties, the composite P25 presented the worst results (4.9% and 3.6 MPa). Linear regression analysis showed a strong positive correlation between %VS and Pss (r=0.97), whereas the correlation between Pss and %MI was found to be moderate (r=0.76). Conclusions The addition of 25 wt.% of POSS in methacrylate organic matrix did not improve the marginal integrity of class I restorations. Filtek P90 showed lower polymerization shrinkage and shrinkage stress when compared to the experimental and commercial methacrylate composite. PMID:26537714

  13. Method of producing a ceramic fiber-reinforced glass-ceramic matrix composite

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P. (Inventor)

    1994-01-01

    A fiber-reinforced composite composed of a BaO-Al2O3-2SiO2 (BAS) glass ceramic matrix is reinforced with CVD silicon carbide continuous fibers. A slurry of BAS glass powders is prepared and celsian seeds are added during ball melting. The slurry is cast into tapes which are cut to the proper size. Continuous CVD-SiC fibers are formed into mats of the desired size. The matrix tapes and the fiber mats are alternately stacked in the proper orientation. This tape-mat stack is warm pressed to produce a 'green' composite. The 'green' composite is then heated to an elevated temperature to burn out organic constituents. The remaining interim material is then hot pressed to form a silicon carbide fiber-reinforced celsian (BAS) glass-ceramic matrix composite which may be machined to size.

  14. Process for producing metal oxide superconductor-polymer composites and composites thereby formed

    SciTech Connect

    Chien, J.C.W.

    1990-06-05

    This patent describes a process for producing copper based metal oxide superconductors having continuous foam-like morphology. It comprises: co-dissolving solutions other than metal oxides containing metal ions with a polymer or copolymer in an organic solvent in which the solutions and polymer or copolymer are soluble and of a polar organic solvent type selected from the group consisting of dimethyl formamide, dimethacetamide N-methyl pyrolidone and sulfolan, the the polymer or copolymer being selected from the group consisting of (poly)acrylic acid, (poly)methacrylic acid (poly)styrene sulfonic acid, and copolymers of malonic acid, citraconic acid, acrylonitriles, E-caprolactam, cyclic ethers and cyclic acetals having metal complexing or chelating functional pendant substituents, and a copolymer of vinyl acetate and acrylic acid, and the metals being of the type susceptible of forming high transition temperature metal oxide superconductors with at least some selected from the group consisting of Y, Ba, La and Sr.

  15. Composite geochemical database for coalbed methane produced water quality in the Rocky Mountain region.

    PubMed

    Dahm, Katharine G; Guerra, Katie L; Xu, Pei; Drewes, Jörg E

    2011-09-15

    Coalbed methane (CBM) or coalbed natural gas (CBNG) is an unconventional natural gas resource with large reserves in the United States (US) and worldwide. Production is limited by challenges in the management of large volumes of produced water. Due to salinity of CBM produced water, it is commonly reinjected into the subsurface for disposal. Utilization of this nontraditional water source is hindered by limited knowledge of water quality. A composite geochemical database was created with 3255 CBM wellhead entries, covering four basins in the Rocky Mountain region, and resulting in information on 64 parameters and constituents. Database water composition is dominated by sodium bicarbonate and sodium chloride type waters with total dissolved solids concentrations of 150 to 39,260 mg/L. Constituents commonly exceeding standards for drinking, livestock, and irrigation water applications were total dissolved solids (TDS), sodium adsorption ratio (SAR), temperature, iron, and fluoride. Chemical trends in the basins are linked to the type of coal deposits, the rank of the coal deposits, and the proximity of the well to fresh water recharge. These water composition trends based on basin geology, hydrogeology, and methane generation pathway are relevant to predicting water quality compositions for beneficial use applications in CBM-producing basins worldwide. PMID:21790201

  16. Method of producing a silicon carbide fiber reinforced strontium aluminosilicate glass-ceramic matrix composite

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P. (Inventor)

    1995-01-01

    A SrO-Al2O3-2SrO2 (SAS) glass ceramic matrix is reinforced with CVD SiC continuous fibers. This material is prepared by casting a slurry of SAS glass powder into tapes. Mats of continuous CVD-SiC fibers are alternately stacked with the matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite. Organic constituents are burned out of the 'green' composite, and the remaining interim material is hot pressed.

  17. Characterization of Vc-Vb Particles Reinforced Fe-Based Composite Coatings Produced by Laser Cladding

    NASA Astrophysics Data System (ADS)

    Qu, K. L.; Wang, X. H.; Wang, Z. K.

    2016-03-01

    In situ synthesized VC-VB particles reinforced Fe-based composite coatings were produced by laser beam melting mixture of ferrovanadium (Fe-V) alloy, boron carbide (B4C), CaF2 and Fe-based self-melting powders. The results showed that VB particles with black regular and irregular blocky shape and VC with black flower-like shape were uniformly distributed in the coatings. The type, amount, and size of the reinforcements were influenced by the content of FeV40 and B4C powders. Compared to the substrate, the hardness and wear resistance of the composite coatings were greatly improved.

  18. Method for producing melt-infiltrated ceramic composites using formed supports

    DOEpatents

    Corman, Gregory Scot; Brun, Milivoj Konstantin; McGuigan, Henry Charles

    2003-01-01

    A method for producing shaped articles of ceramic composites provides a high degree of dimensional tolerance to these articles. A fiber preform is disposed on a surface of a stable formed support, a surface of which is formed with a plurality of indentations, such as grooves, slots, or channels. Precursors of ceramic matrix materials are provided to the fiber preform to infiltrate from both sides of the fiber preform. The infiltration is conducted under vacuum at a temperature not much greater than a melting point of the precursors. The melt-infiltrated composite article substantially retains its dimension and shape throughout the fabrication process.

  19. Factors that control the stable carbon isotopic composition of methane produced in an anoxic marine sediment

    NASA Technical Reports Server (NTRS)

    Alperin, M. J.; Blair, Neal E.; Albert, D. B.; Hoehler, T. M.; Martens, C. S.

    1993-01-01

    The carbon isotopic composition of methane produced in anoxic marine sediment is controlled by four factors: (1) the pathway of methane formation, (2) the isotopic composition of the methanogenic precursors, (3) the isotope fractionation factors for methane production, and (4) the isotope fractionation associated with methane oxidation. The importance of each factor was evaluated by monitoring stable carbon isotope ratios in methane produced by a sediment microcosm. Methane did not accumulate during the initial 42-day period when sediment contained sulfate, indicating little methane production from 'noncompetitive' substrates. Following sulfate depletion, methane accumulation proceeded in three distinct phases. First, CO2 reduction was the dominant methanogenic pathway and the isotopic composition of the methane produced ranged from -80 to -94 per thousand. The acetate concentration increased during this phase, suggesting that acetoclastic methanogenic bacteria were unable to keep pace with acetate production. Second, acetate fermentation became the dominant methanogenic pathway as bacteria responded to elevated acetate concentrations. The methane produced during this phase was progressively enriched in C-13, reaching a maximum delta(C-13) value of -42 per thousand. Third, the acetate pool experienced a precipitous decline from greater than 5 mM to less than 20 micro-M and methane production was again dominated by CO2 reduction. The delta(C-13) of methane produced during this final phase ranged from -46 to -58 per thousand. Methane oxidation concurrent with methane production was detected throughout the period of methane accumulation, at rates equivalent to 1 to 8 percent of the gross methane production rate. Thus methane oxidation was too slow to have significantly modified the isotopic signature of methane. A comparison of microcosm and field data suggests that similar microbial interactions may control seasonal variability in the isotopic composition of methane

  20. Biomechanical model produced from light-activated dental composite resins: a holographic analysis

    NASA Astrophysics Data System (ADS)

    Pantelić, Dejan; Vasiljević, Darko; Blažić, Larisa; Savić-Šević, Svetlana; Murić, Branka; Nikolić, Marko

    2013-11-01

    Light-activated dental composites, commonly applied in dentistry, can be used as excellent material for producing biomechanical models. They can be cast in almost any shape in an appropriate silicone mold and quickly solidified by irradiation with light in the blue part of the spectrum. In that way, it is possible to obtain any number of nearly identical casts. The models can be used to study the behavior of arbitrary structure under mechanical loads. To test the technique, a simple mechanical model of the tooth with a mesio-occluso-distal cavity was manufactured. Composite resin restoration was placed inside the cavity and light cured. Real-time holographic interferometry was used to analyze the contraction of the composite resin and its effect on the surrounding material. The results obtained in the holographic experiment were in good agreement with those obtained using the finite element method.

  1. Composite ECM-alginate microfibers produced by microfluidics as scaffolds with biomineralization potential.

    PubMed

    Angelozzi, Marco; Miotto, Martina; Penolazzi, Letizia; Mazzitelli, Stefania; Keane, Timothy; Badylak, Stephen F; Piva, Roberta; Nastruzzi, Claudio

    2015-11-01

    A novel approach to produce artificial bone composites (microfibers) with distinctive features mimicking natural tissue was investigated. Currently proposed inorganic materials (e.g. apatite matrixes) lack self-assembly and thereby limit interactions between cells and the material. The present work investigates the feasibility of creating "bio-inspired materials" specifically designed to overcome certain limitations inherent to current biomaterials. We examined the dimensions, morphology, and constitutive features of a composite hydrogel which combined an alginate based microfiber with a gelatin solution or a particulate form of urinary bladder matrix (UBM). The effectiveness of the composite microfibers to induce and modulate osteoblastic differentiation in three-dimensional (3D) scaffolds without altering the viability and morphological characteristics of the cells was investigated. The present study describes a novel alginate microfiber production method with the use of microfluidics. The microfluidic procedure allowed for precise tuning of microfibers which resulted in enhanced viability and function of embedded cells. PMID:26249575

  2. Metallic layered composite materials produced by explosion welding: Structure, properties, and structure of the transition zone

    NASA Astrophysics Data System (ADS)

    Mal'tseva, L. A.; Tyushlyaeva, D. S.; Mal'tseva, T. V.; Pastukhov, M. V.; Lozhkin, N. N.; Inyakin, D. V.; Marshuk, L. A.

    2014-10-01

    The structure, morphology, and microhardness of the transition zone in multilayer metallic composite joints are studied, and the cohesion strength of the plates to be joined, the mechanical properties of the formed composite materials, and fracture surfaces are analyzed. The materials to be joined are plates (0.1-1 mm thick) made of D16 aluminum alloy, high-strength maraging ZI90-VI (03Kh12N9K4M2YuT) steel, BrB2 beryllium bronze, and OT4-1 titanium alloy. Composite materials made of different materials are shown to be produced by explosion welding. The dependence of the interface shape (smooth or wavelike) on the physicomechanical properties of the materials to be joined is found. The formation of a wavelike interface is shown to result in the formation of intense-mixing regions in transition zones. Possible mechanisms of layer adhesion are discussed.

  3. Oxygen isotope composition of sulfate produced during microbial sulfur oxidation: A pathway-specific fingerprint?

    NASA Astrophysics Data System (ADS)

    Pjevac, P.; Brunner, B.; Mußmann, M.

    2012-04-01

    The oxidation of zero-valent sulfur such as elemental sulfur (S0) is an important energy source in many marine habitats including deep-sea vents, pelagic redox-clines and coastal surface sediments. Many microorganisms oxidize elemental sulfur to sulfate to gain reducing power. This transformation is catalyzed by a few known enzymatic pathways such as the reverse dissimilatory sulfite reductase (rDSR)-aprAB/Sor pathway or the Sox multienzyme pathway. The isotopic composition of oxygen and sulfur in produced sulfate (δ34S and δ18O) is determined by the isotope composition of the reactants, the ratio between forward and backward fluxes of enzymatically catalyzed reaction steps, and by kinetic and equilibrium isotopic fractionation. We hypothesize that the activity of distinct oxidation pathways is reflected in different δ34S and particularly, in unique δ18O isotopic fingerprints in the produced sulfate. To test our hypothesis we grew pure cultures of photo- and chemoautotrophic sulfur-oxidizing microorganisms of different phylogenetic origin with S0 as sole source of reducing power and determined the sulfur and oxygen isotope composition of the produced sulfate. The identification of characteristic isotope fingerprints for each sulfur oxidation pathway could serve as a tool to estimate and deduce the importance of certain enzymatic pathways and sulfur-oxidizing microorganisms in the environment.

  4. Microstructure and Fracture Toughness of FeNiCr-TiC Composite Produced by Thermite Reaction

    NASA Astrophysics Data System (ADS)

    Xi, Wenjun; Shi, Chaoliang

    The microstructures of the FeNiCr-TiC composite produced by the rapid solidification thermite process were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The effects of aging treatment on the microstructure and fracture toughness of the composite were examined. Results showed that the FeNiCr-TiC composite was composed of ferrite (α-FeNiCr), TiC and NiAl (β phase). TiC particles in the matrix were in the shape of polygon and uniformly distributed, and their size was less than 3 µm. The β phase was coherent with the ferrite matrix, and its average size was about 50 nm. The fracture toughness of composite was 22 MPa·m1/2 without aging. When the aging temperature was below 600°C, the fracture toughness of the composite had higher plateau values and reached the maximum of 32 MPa·m1/2 at aging temperature 500°C due to the precipitation of NiAl phase on the nanometer scale. The fracture toughness decreased rapidly aged at 650°C, and then kept homology value in the range of 700 to 900°C, which was attributed to the precipitation of needle-shaped carbide (Cr/Fe)7C3 at the grain boundaries.

  5. Low-magnesium calcite produced by coralline algae in seawater of Late Cretaceous composition.

    PubMed

    Stanley, Steven M; Ries, Justin B; Hardie, Lawrence A

    2002-11-26

    Shifts in the MgCa ratio of seawater driven by changes in midocean ridge spreading rates have produced oscillations in the mineralogy of nonskeletal carbonate precipitates from seawater on time scales of 10(8) years. Since Cambrian time, skeletal mineralogies of anatomically simple organisms functioning as major reef builders or producers of shallow marine limestones have generally corresponded in mineral composition to nonskeletal precipitates. Here we report on experiments showing that the ambient MgCa ratio actually governs the skeletal mineralogy of some simple organisms. In modern seas, coralline algae produce skeletons of high-Mg calcite (>4 mol % MgCO(3)). We grew three species of these algae in artificial seawaters having three different MgCa ratios. All of the species incorporated amounts of Mg into their skeletons in proportion to the ambient MgCa ratio, mimicking the pattern for nonskeletal precipitation. Thus, the algae calcified as if they were simply inducing precipitation from seawater through their consumption of CO(2) for photosynthesis; presumably organic templates specify the calcite crystal structure of their skeletons. In artificial seawater with the low MgCa ratio of Late Cretaceous seas, the algae in our experiments produced low-Mg calcite (<4 mol % MgCO(3)), the carbonate mineral formed by nonskeletal precipitation in those ancient seas. Our results suggest that many taxa that produce high-Mg calcite today produced low-Mg calcite in Late Cretaceous seas. PMID:12399549

  6. Fluid motions and compositional gradients produced by crystallization or melting at vertical boundaries

    NASA Astrophysics Data System (ADS)

    Turner, J. Stewart; Gustafson, Lewis B.

    1981-12-01

    The results of a continuing series of laboratory experiments, designed to model the fluid motions which accompany crystallization, are both described and related in a preliminary way to prototype flows in magma chambers. Previous experiments have demonstrated the importance of compositional inhomogeneity, produced by crystallization and melting in a thermal gradient and coupled with double-diffusive effects, in driving convective flows which result in thermal and compositional stratification in an originally homogeneous fluid. The present experiments examine effects produced in tanks cooled at the side, by the upward flow of a less dense boundary layer depleted in the crystallizing component as crystals grow on the side wall. These processes are examined in simple two and three component aqueous systems (H 2O-Na 2CO 3, H 2O-Na 2CO 3-K 2CO 3, H 2O-CuSO 4-Na 2SO 4) with one and two crystallizing phases. In each of these systems, an initially downward flow of a cooled boundary layer against the side wall is reversed as crystallization commences and depletes the boundary layer in the crystallizing component. Accumulation of this cooler but lighter depleted fluid at the top of the chamber produces thermal and compositional layering by a "filling box" mechanism, partly modified by interchange between the boundary layer and the convecting layers outside. When more than one component is present in the solution, the crystallization process produces a differentiated fluid column, i.e. one with compositional gradients which are different for each of the components. The compositional and thermal distributions within the fluid change with time, but finally appear to reach a steady state. These distributions are the integrated result of compositional changes produced by crystallization from a thin boundary layer, a small proportion of the bulk fluid which evolves in composition and temperature independently of the bulk fluid, in a manner controlled by the dynamics of the system

  7. Invited review: organic and conventionally produced milk-an evaluation of factors influencing milk composition.

    PubMed

    Schwendel, B H; Wester, T J; Morel, P C H; Tavendale, M H; Deadman, C; Shadbolt, N M; Otter, D E

    2015-02-01

    Consumer perception of organic cow milk is associated with the assumption that organic milk differs from conventionally produced milk. The value associated with this difference justifies the premium retail price for organic milk. It includes the perceptions that organic dairy farming is kinder to the environment, animals, and people; that organic milk products are produced without the use of antibiotics, added hormones, synthetic chemicals, and genetic modification; and that they may have potential benefits for human health. Controlled studies investigating whether differences exist between organic and conventionally produced milk have so far been largely equivocal due principally to the complexity of the research question and the number of factors that can influence milk composition. A main complication is that farming practices and their effects differ depending on country, region, year, and season between and within organic and conventional systems. Factors influencing milk composition (e.g., diet, breed, and stage of lactation) have been studied individually, whereas interactions between multiple factors have been largely ignored. Studies that fail to consider that factors other than the farming system (organic vs. conventional) could have caused or contributed to the reported differences in milk composition make it impossible to determine whether a system-related difference exists between organic and conventional milk. Milk fatty acid composition has been a central research area when comparing organic and conventional milk largely because the milk fatty acid profile responds rapidly and is very sensitive to changes in diet. Consequently, the effect of farming practices (high input vs. low input) rather than farming system (organic vs. conventional) determines milk fatty acid profile, and similar results are seen between low-input organic and low-input conventional milks. This confounds our ability to develop an analytical method to distinguish organic from

  8. Homogeneous metal matrix composites produced by a modified stir-casting technique

    SciTech Connect

    Kennedy, A.R.; McCartney, D.G.; Wood, J.V.

    1995-12-31

    Al-based metal matrix composites have been made by a novel liquid processing route which is not only cheap and versatile but produces composites with extremely uniform distributions of the reinforcing phase. Particles of TiB{sub 2}, TiC and B{sub 4}C have been spontaneously incorporated, that is without the use of external mechanical agitation, into Al and Al-alloy melts in volume fractions as high as 0.3. This has been achieved through the use of wetting agents which produce K-Al-F based slags on the melt surface. Spontaneous particle entry and the chemistry of the slag facilitate the generation of good distributions of the reinforcing phase in the solidified composite castings. Non-clustered, near homogeneous distributions have been achieved irrespective of the casting conditions and the volume fraction, type or size of the reinforcement. The majority of the reinforcement becomes engulfed into the solid metal grains during solidification rather than, what is more commonly the case, being pushed to the inter-granular regions. This intra-granular distribution of the reinforcement is likely to improve the mechanical properties of the material.

  9. Wear characteristics of Al-AlN composites produced in-situ by nitrogenation

    NASA Astrophysics Data System (ADS)

    Pradhan, S.; Jena, S. K.; Patnaik, S. C.; Swain, P. K.; Majhi, J.

    2015-02-01

    In the present scenario most of the parts used in automobile and aerospace industries are made of composites. Aluminium metal has a very high strength to weight ratio. Al-AlN metal matrix composites have excellent mechanical properties like good wear resistance, high hardness and high strength to weight ratio which are obtained from low density of aluminium and high hardness and wear resistance of AlN. Therefore, use of Al-AlN MMC leads to advantages in automobile industries as it reduces fuel consumption and gives better structural strength. The composites can be produced ex-situ by introducing AlN as reinforcement into the metal matrix and in- situ by nitrogenation process. In the present process Al-AlN composites were fabricated by treating molten aluminium with a mixture of CaO and NH4Cl and held at temperature range at 750-930°C and then cast into a metal mould. Addition of CaO to NH4Cl is found to have a more pronounced effect as a nitrogenation agent in comparison with NH4Cl in the molten aluminium in the temperature range of 700- 1000°C. Castings of aluminium and Al-AlN composites were prepared by mixing different ratios of aluminium and NH4Cl, at different casting temperatures and holding time. Wear resistance and hardness of the samples were determined, and microstructure studies were carried out. The composite formed using higher amount of NH4Cl had higher hardness and wear resistance.

  10. Degradation of Al/SiCp composites produced with rice-hull ash and aluminum cans.

    PubMed

    Escalera-Lozano, R; Gutiérrez, C A; Pech-Canul, M A; Pech-Canul, M I

    2008-01-01

    The use of recycling aluminum from beverage containers and rice-hull ash (RHA) offers to be an attractive alternative for the economic production of Al/SiCp composites. However, corrosion phenomena in the composites represent technological barriers yet to be resolved before they can be exploited to their full potential. A simple methodology involving characterization by XRD, SEM, EDX, FTIR and ICP was designed in order to investigate the causes of the rapid degradation in a humid environment of Al/SiCp composites produced with RHA and aluminum cans. Results reveal that the use of RHA was beneficial to avoid degradation through the formation and subsequent hydration of the Al4C3 phase. However with condensed moisture acting as an electrolyte, localized corrosion took place with aggressive damage manifested by the disintegration of the composite into a powdery mixture. The relevant corrosion mechanism was mainly attributed to microgalvanic coupling between the Mg2Si intermetallic compound and the matrix (although other phases such as SiC, Si, MgAl2O4 could also work as microcathodes). PMID:17320370

  11. Structural and compositional characterization of the adhesive produced by reef building oysters.

    PubMed

    Alberts, Erik M; Taylor, Stephen D; Edwards, Stephanie L; Sherman, Debra M; Huang, Chia-Ping; Kenny, Paul; Wilker, Jonathan J

    2015-04-29

    Oysters have an impressive ability to overcome difficulties of life within the stressful intertidal zone. These shellfish produce an adhesive for attaching to each other and building protective reef communities. With their reefs often exceeding kilometers in length, oysters play a major role in balancing the health of coastal marine ecosystems. Few details are available to describe oyster adhesive composition or structure. Here several characterization methods were applied to describe the nature of this material. Microscopy studies indicated that the glue is comprised of organic fiber-like and sheet-like structures surrounded by an inorganic matrix. Phospholipids, cross-linking chemistry, and conjugated organics were found to differentiate this adhesive from the shell. Symbiosis in material synthesis could also be present, with oysters incorporating bacterial polysaccharides into their adhesive. Oyster glue shows that an organic-inorganic composite material can provide adhesion, a property especially important when constructing a marine ecosystem. PMID:25843147

  12. Effect of Milling Parameters on Microstructure of Ti/Al Composite Powder Produced by Discus Milling

    NASA Astrophysics Data System (ADS)

    Raynova, S.; Cao, P.; Gabbitas, B.; Zhang, D.

    The motivation of this research is to develop a process for producing Ti/Al composite powders that enable synthesis of a single-phase TiAl intermetallic bulk material, which is then used as a target for physical vapour deposition (PVD) coating. This study reports the effects of milling time, amount of process control agent (PCA) added as well as the powder-to-medium ratio on the microstructure of the Ti/Al composite powder. Optical microscopy and scanning electron microscopy (SEM) were used to evaluate the level of mixing and the resulting powder particle size. X-ray diffraction analysis and differential thermal analysis were used for determining the phase constituents and the solid state reaction temperature of the as-milled powders.

  13. Composition and methods of preparation of target material for producing radionuclides

    SciTech Connect

    Seropeghin, Yurii D; Zhuikov, Boris L

    2013-05-28

    A composition suitable for use as a target containing antimony to be irradiated by accelerated charged particles (e.g., by protons to produce tin-117m) comprises an intermetallic compound of antimony and titanium which is synthesized at high-temperature, for example, in an arc furnace. The formed material is powdered and melted in an induction furnace, or heated at high gas pressure in gas static camera. The obtained product has a density, temperature stability, and heat conductivity sufficient to provide an appropriate target material.

  14. CARBON FIBRE COMPOSITE MATERIALS PRODUCED BY GAMMA RADIATION INDUCED CURING OF EPOXY RESINS

    SciTech Connect

    Dispenza, C.; Spadaro, G.; Alessi, S.

    2008-08-28

    It is well known that ionizing radiation can initiate polymerization of suitable monomers for many applications. In this work an epoxy difunctional monomer has been used as matrix of a carbon fibre composite in order to produce materials through gamma radiation, for aerospace and advanced automotive applications. Radiation curing has been performed at different absorbed doses and, as comparison, also thermal curing of the same monomer formulations has been done. Furthermore some irradiated samples have been also subjected to a post irradiation thermal curing in order to complete the polymerization reactions. The properties of the cured materials have been studied by moisture absorption isotherms, dynamic mechanical thermal analysis and mechanical flexural tests.

  15. Methods of refining natural oils, and methods of producing fuel compositions

    DOEpatents

    Firth, Bruce E.; Kirk, Sharon E.

    2015-10-27

    A method of refining a natural oil includes: (a) providing a feedstock that includes a natural oil; (b) reacting the feedstock in the presence of a metathesis catalyst to form a metathesized product that includes olefins and esters; (c) passivating residual metathesis catalyst with an agent that comprises nitric acid; (d) separating the olefins in the metathesized product from the esters in the metathesized product; and (e) transesterifying the esters in the presence of an alcohol to form a transesterified product and/or hydrogenating the olefins to form a fully or partially saturated hydrogenated product. Methods for suppressing isomerization of olefin metathesis products produced in a metathesis reaction, and methods of producing fuel compositions are described.

  16. Methods of refining natural oils and methods of producing fuel compositions

    DOEpatents

    Firth, Bruce E; Kirk, Sharon E; Gavaskar, Vasudeo S

    2015-11-04

    A method of refining a natural oil includes: (a) providing a feedstock that includes a natural oil; (b) reacting the feedstock in the presence of a metathesis catalyst to form a metathesized product that includes olefins and esters; (c) passivating residual metathesis catalyst with an agent selected from the group consisting of phosphorous acid, phosphinic acid, and a combination thereof; (d) separating the olefins in the metathesized product from the esters in the metathesized product; and (e) transesterifying the esters in the presence of an alcohol to form a transesterified product and/or hydrogenating the olefins to form a fully or partially saturated hydrogenated product. Methods for suppressing isomerization of olefin metathesis products produced in a metathesis reaction, and methods of producing fuel compositions are described.

  17. Composition, Structure and Functional Properties of Protein Concentrates and Isolates Produced from Walnut (Juglans regia L.)

    PubMed Central

    Mao, Xiaoying; Hua, Yufei

    2012-01-01

    In this study, composition, structure and the functional properties of protein concentrate (WPC) and protein isolate (WPI) produced from defatted walnut flour (DFWF) were investigated. The results showed that the composition and structure of walnut protein concentrate (WPC) and walnut protein isolate (WPI) were significantly different. The molecular weight distribution of WPI was uniform and the protein composition of DFWF and WPC was complex with the protein aggregation. H0 of WPC was significantly higher (p < 0.05) than those of DFWF and WPI, whilst WPI had a higher H0 compared to DFWF. The secondary structure of WPI was similar to WPC. WPI showed big flaky plate like structures; whereas WPC appeared as a small flaky and more compact structure. The most functional properties of WPI were better than WPC. In comparing most functional properties of WPI and WPC with soybean protein concentrate and isolate, WPI and WPC showed higher fat absorption capacity (FAC). Emulsifying properties and foam properties of WPC and WPI in alkaline pH were comparable with that of soybean protein concentrate and isolate. Walnut protein concentrates and isolates can be considered as potential functional food ingredients. PMID:22408408

  18. Method for producing solid or hollow spherical particles of chosen chemical composition and of uniform size

    DOEpatents

    Hendricks, Charles D.

    1988-01-01

    A method is provided for producing commercially large quantities of high melting temperature solid or hollow spherical particles of a predetermined chemical composition and having a uniform and controlled size distribution. An end (18, 50, 90) of a solid or hollow rod (20, 48, 88) of the material is rendered molten by a laser beam (14, 44, 82). Because of this, there is no possibility of the molten rod material becoming contaminated with extraneous material. In various aspects of the invention, an electric field is applied to the molten rod end (18, 90), and/or the molten rod end (50, 90) is vibrated. In a further aspect of the invention, a high-frequency component is added to the electric field applied to the molten end of the rod (90). By controlling the internal pressure of the rod, the rate at which the rod is introduced into the laser beam, the environment of the process, the vibration amplitude and frequency of the molten rod end, the electric field intensity applied to the molten rod end, and the frequency and intensity of the component added to the electric field, the uniformity and size distribution of the solid or hollow spherical particles (122) produced by the inventive method is controlled. The polarity of the electric field applied to the molten rod end can be chosen to eliminate backstreaming electrons, which tend to produce run-away heating in the rod, from the process.

  19. A mechanism on why slower polymerization of a dental composite produces lower contraction stress.

    PubMed

    Feng, L; Suh, B I

    2006-07-01

    It has been well documented that the rate of polymerization of a dental composite often affects its polymerization contraction stress. In most cases, a slower cure produces a lower stress. To investigate the mechanism behind this, we prepared an unfilled dimethacrylate resin sample and photocured it using two light irradiances, both with the same total irradiation energy. We measured the polymerization-induced shrinkage from the unbonded surface of a class I restoration, contraction stress, extent of polymerization, and flexural modulus. The resin specimens cured under the two irradiances achieved the same extent of polymerization and developed an identical amount of shrinkage from the unbonded surface. But those cured under the lower irradiance possessed a lower contraction stress and a lower flexural modulus than those cured under the higher irradiance. We demonstrated that the stress level did not respond to the extent of viscous flow of the curing resin because the slower polymerization did not produce more shrinkage from the unbonded surface. Instead, the lower stress is likely due to a lower modulus of the cured resin. To explain why the cured resin with an identical extent of polymerization can have different moduli, we proposed that slower polymerization produces a higher level of structural inhomogeneity, which reduces the rigidity of the cured resin. PMID:16470813

  20. Composites of thermoplastic starch and nanoclays produced by extrusion and thermopressing.

    PubMed

    Müller, Carmen M O; Laurindo, João Borges; Yamashita, Fabio

    2012-06-20

    The aim of this study was to produce thermoplastic starch (TPS) films and to enhance their properties by reinforcing them with hydrophilic and hydrophobic nanoclays. TPS films were prepared by extrusion and thermopressing, and their crystallinity, water vapor permeability (WVP), and mechanical properties were studied. The hydrophilic nanoclay lowered the material WVP due to the formation of an intercalated composite. The hydrophobic nanoclays increased the rigidity of the films but did not alter the tensile strength. The blending of nanoclays with thermoplastic starch modifies the mechanical properties and WVP, and these changes are strongly associated with the dispersion of nanoclay in the polymer matrix. The dispersion, in turn, depends on the compatibility of the matrix and the nanoclay in terms of the hygroscopicity and the concentration in which the nanoclay is used. The addition of nanoclays to starch-based films is a promising way to enhance them for industrial manufacture. PMID:24750751

  1. Interfacial reaction in cast WC particulate reinforced titanium metal matrix composites coating produced by laser processing

    NASA Astrophysics Data System (ADS)

    Liu, Dejian; Hu, Peipei; Min, Guoqing

    2015-06-01

    Laser injection of ceramic particle was conducted to produce particulate reinforced metal matrix composites (MMCs) coating on Ti-6Al-4V alloy. Cast WC particle (WCp) was used as injection reinforcement to avoid excessive release of carbon atoms into the melt pool. The interfaces and boundaries between WC and Ti matrix were investigated by electron microscopy study. Compared with single crystal WCp, cast WCp was an appropriate solution to control the reaction products (TiC) in the matrix and the total amount of reaction products was significantly reduced. Irregular-shape reaction layers were formed around cast WCp. The reaction layers consist of a W2C layer and a mixed layer of W and TiC. Such reaction layers are effective in load transfer under an external load.

  2. The stress relaxation characteristics of composite matrices etched to produce nanoscale surface features.

    PubMed

    Mirani, Rahul D; Pratt, Jonathan; Iyer, Pooja; Madihally, Sundararajan V

    2009-02-01

    Many synthetic and xenogenic natural matrices have been explored in tissue regeneration, however, they lack either mechanical strength or cell colonization characteristics found in natural tissue. Moreover natural matrices such as small intestinal submucosa (SIS) lack sample to sample homogeneity, leading to unpredictable clinical outcomes. This work explored a novel fabrication technique by blending together the useful characteristics of synthetic and natural polymers to form a composite structure by using a NaOH etching process that produces nanoscale surface features. The composite scaffold was formed by sandwiching a thin layer of PLGA between porous layers of gelatin-chitosan. The etching process increased the surface roughness of PLGA membrane, allowing easy spreading of the hydrophilic gelatin-chitosan solution on its hydrophobic surface and reducing the scaffold thickness by nearly 50% than otherwise. The viscoelastic properties of the scaffold, an area of mechanical analysis which remains largely unexplored in tissue regeneration was assessed. Stress relaxation experiments of the "ramp and hold" type performed at variable ranges of temperature (25 degrees C and 37 degrees C), loading rates (3.125% s(-1) and 12.5% s(-1)) and relaxation times (60 s, 100 s and 200 s) found stress relaxation to be sensitive to temperature and the loading rate but less dependent on the relaxation time. Stress relaxation behavior of the composite matrix was compared with SIS structures at 25 degrees C (hydrated), 3.125% s(-1) loading rate and 100 s relaxation time which showed that the synthetic matrix was found to be strain softening as compared to the strain hardening behavior exhibited by SIS. Popularly used quasi-linear viscoelastic (QLV) model to describe biomechanics of soft tissues was utilized. The QLV model predicted the loading behavior with an average error of 3%. The parameters of the QLV model predicted using nonlinear regression analysis appear to be in concurrence

  3. Method and apparatus for producing composites of materials exhibiting thermoplastic properties

    DOEpatents

    Garvey, Raymond E.; Grostick, Edmund T.

    1992-01-01

    A mobile device for the complete consolidation of layers of material which exhibit thermoplastic properties for the formation of a composite of the layers upon a complex contoured substrate. The principal of the device is to provide heating into the molten temperature range of the thermoplastic material, applying sufficient pressure to the layers to cause flow of the plastic for a time sufficient to achieve full consolidation of the layers, and quickly cooling the structure to prevent delamination or other non-consolidation action. In the preferred form, there is an element to deposit a layer of the mateiral against another layer in close proximity. The two layers are pre-heated to near the melting temperature, and then further heated into the melting temperature range as they are brought into intimate contact with sufficient pressure to cause flow of the plastic for a time sufficient to achieve the full consolidation. The structure is then cooled. The mechanism for the application of pressure is selected such that the layers can be deformed to conform to a complex contour. In the preferred form, this pressurization is produced using a compliant hood that supplies both the pressure and at least a portion of the melting temperature, as well as the cooling. The apparatus, and method of operation, are described relative to the use of fiber-reinforced PEEK in the making of fully-consolidated composites. Other applications are discussed.

  4. Process of high temperature synthesis in producing composite carbide powders for thermally sprayed coatings

    NASA Astrophysics Data System (ADS)

    Szymański, K.; Formanek, B.

    2011-05-01

    The paper presents the characterization of powders containing hard phases of chromium carbides in a NiCr matrix, intended for thermal spraying coatings. The synthesized composite powder containing hard phases and plastic matrix, produced in high-temperature synthesis with chosen powder metallurgy processes has been presented. Commercial materials, such as NiCr- CrxCy, are fabricated by means of agglomeration and sintering method. Processes of high temperature synthesis of Cr3C2, Cr7C3, Cr23C6 carbides combined with NiCr powder mechanical alloying are presented in the article. Parameters of the carbides synthesis were determined in the reactive -protective atmosphere. In the rotation- vibration mill, processes were conducted using grinding and appropriate mechanical alloying at variable amplitude. The standard and synthesized powders were thermally sprayed by HVOF method in Jet Kote II and Diamond Jet system. The structure and phase composition of the powders and coatings were determined by: light and scanning microscopy, X-ray phase analysis (RTG) and energy dispersive X-ray analysis (EDX). The structure and wear properties of HVOF sprayed coatings containing chromium carbides has been presented. The thermally sprayed coatings are characterized of wear resistance in abrasion and erosion tests. The sprayed coatings characterized high resistance in wear conditions.

  5. Experimentally Produced Spinel Rims on Ca-Al-Rich Inclusion Bulk Compositions

    NASA Technical Reports Server (NTRS)

    Paque, Julie M.; Le, L.; Lofgren, G. E.

    1998-01-01

    Most Ca-Al-rich inclusions (CAls) from Allende are surrounded by a series of mineralogically distinct rim layers. Proposed modes of formation for these layers include flash heating, evaporation, and condensation. The innermost of these rim layers is generally spinel (SP), in some cases intergrown with perovskite (PV), and commonly containing varying amounts of secondary iron increasing towards the edge of the CAI. The SP or SP+PV rim is not always contiguous with the other rim layers, indicating that it is probably the result of a separate event. We have produced continuous SP rims on synthetic analogs representing Type A/B1, average Type B, and Type B2 bulk compositions by reheating a solid glass experimental charge to subliquidus crystallization temperatures. This experimental result is consistent with the formation of chondrules; and CAIs by more than one sequence of heating and cooling. Previous work indicated that prior crystallization events produced observable effects in the texture and chemistry of the final run product. Information on the nature of the heating/cooling cycles experienced by CAls and chondrules is important in modeling the environment of their formation. Additional information is contained in the original extended abstract.

  6. High- and low-temperature-stable thermite composition for producing high-pressure, high-velocity gases

    DOEpatents

    Halcomb, Danny L.; Mohler, Jonathan H.

    1990-10-16

    A high- and low-temperature-stable thermite composition for producing high-pressure and high-velocity gases comprises an oxidizable metal, an oxidizing reagent, and a high-temperature-stable gas-producing additive selected from the group consisting of metal carbides and metal nitrides.

  7. Nanoscale Mineralogy and Composition of Experimental Regolith Agglutinates Produced under Asteroidal Impact Conditions

    NASA Technical Reports Server (NTRS)

    Christoffersen, Roy; Cintala, M. J.; Keller, L. P.; See, T. H.; Horz, F.

    2013-01-01

    On the Moon, the energetics of smaller impactors and the physical/chemical characteristics of the granular regolith target combine to form a key product of lunar space weathering: chemically reduced shock melts containing optically-active nanophase Fe metal grains (npFe0) [1]. In addition to forming the optically dark glassy matrix phase in lunar agglutinitic soil particles [1], these shock melts are becoming increasingly recognized for their contribution to optically active patina coatings on a wide range of exposed rock and grain surfaces in the lunar regolith [2]. In applying the lessons of lunar space weathering to asteroids, the potential similarities and differences in regolith-hosted shock melts on the Moon compared to those on asteroids has become a topic of increasing interest [3,4]. In a series of impact experiments performed at velocities applicable to the asteroid belt [5], Horz et al. [6] and See and Horz [7] have previously shown that repeated impacts into a gabbroic regolith analog target can produce melt-welded grain aggregates morphologically very similar to lunar agglutinates [6,7]. Although these agglutinate-like particles were extensively analyzed by electron microprobe and scanning electron microscopy (SEM) as part of the original study [7], a microstructural and compositional comparison of these aggregates to lunar soil agglutinates at sub-micron scales has yet to be made. To close this gap, we characterized a representative set of these aggregates using a JEOL 7600 field-emission scanning electron microscope (FE-SEM), and JEOL 2500SE field-emission scanning transmission electron microscope (FE-STEM) both optimized for energy dispersive X-ray spectroscopy (EDX) compositional spectrum imaging at respective analytical spatial resolutions of 0.5 to 1 micron, and 2 to 4 nm.

  8. Nutritional composition of "gari" analog produced from cassava (Manihot esculenta) and cocoyam (Colocasia esculenta) tuber.

    PubMed

    Bamidele, Oluwaseun P; Ogundele, Femi G; Ojubanire, Basirat A; Fasogbon, Mofoluwaso B; Bello, Olayide W

    2014-11-01

    Physicochemical properties ofgari analog produced from coprocessing of Cassava (Manihot esculenta Crantz) and Cocoyam (Colocasia esculenta) were investigated. Cassava tuber and cocoyam were coprocessed at different percentages before frying separately. Proximate composition, mineral content, antinutritional factors, and sensory evaluation of various samples were determined. The results showed that the moisture content of all the samples was in the same range (7.28 ± 0.30 to 7.78 ± 0.14%). The protein content (1.57 ± 0.14 to 4.43 ± 0.16), ash (1.89 ± 0.10 to 2.15 ± 0.30), and crude fiber (1.53 ± 0.50 to 2.19 ± 0.10%) showed a significant increase with increase in the level of cocoyam substitution. The fat and carbohydrate content decreased with an increase in cocoyam level. The mineral contents of the samples increased with an increase in cocoyam content with sample F having the highest value of potassium, followed by samples E and D (68 mg/100 g, 35 mg/100 g, and 24 mg/100 g). The antinutritional factors of all the samples were at very low concentration while samples B, C, and D competed favorably with sample A (control) in sensory evaluation. In conclusion, coprocessing of cassava and cocoyam improved the nutritional quality of thegari produced with high level of acceptance from the taste panelist. PMID:25493189

  9. Organic and inorganic composition and microbiology of produced waters from Pennsylvania shale gas wells

    USGS Publications Warehouse

    Akob, Denise M.; Cozzarelli, Isabelle M.; Dunlap, Darren S.; Rowan, Elisabeth L.; Lorah, Michelle M.

    2015-01-01

    Hydraulically fractured shales are becoming an increasingly important source of natural gas production in the United States. This process has been known to create up to 420 gallons of produced water (PW) per day, but the volume varies depending on the formation, and the characteristics of individual hydraulic fracture. PW from hydraulic fracturing of shales are comprised of injected fracturing fluids and natural formation waters in proportions that change over time. Across the state of Pennsylvania, shale gas production is booming; therefore, it is important to assess the variability in PW chemistry and microbiology across this geographical span. We quantified the inorganic and organic chemical composition and microbial communities in PW samples from 13 shale gas wells in north central Pennsylvania. Microbial abundance was generally low (66–9400 cells/mL). Non-volatile dissolved organic carbon (NVDOC) was high (7–31 mg/L) relative to typical shallow groundwater, and the presence of organic acid anions (e.g., acetate, formate, and pyruvate) indicated microbial activity. Volatile organic compounds (VOCs) were detected in four samples (∼1 to 11.7 μg/L): benzene and toluene in the Burket sample, toluene in two Marcellus samples, and tetrachloroethylene (PCE) in one Marcellus sample. VOCs can be either naturally occurring or from industrial activity, making the source of VOCs unclear. Despite the addition of biocides during hydraulic fracturing, H2S-producing, fermenting, and methanogenic bacteria were cultured from PW samples. The presence of culturable bacteria was not associated with salinity or location; although organic compound concentrations and time in production were correlated with microbial activity. Interestingly, we found that unlike the inorganic chemistry, PW organic chemistry and microbial viability were highly variable across the 13 wells sampled, which can have important implications for the reuse and handling of these fluids

  10. Clustering effects in 48Cr composite nuclei produced via the 24Mg+24Mg reaction

    NASA Astrophysics Data System (ADS)

    Di Nitto, A.; Vardaci, E.; Brondi, A.; La Rana, G.; Cinausero, M.; Gelli, N.; Moro, R.; Nadtochy, P. N.; Prete, G.; Vanzanella, A.

    2016-04-01

    The nuclear properties of 48Cr composite α -like nuclei produced at 60 MeV of excitation energy via the 24Mg+24Mg reaction were investigated. This excitation energy corresponds to a resonance with a narrow width (170 keV) observed in the elastic and inelastic channels, which was interpreted as a highly deformed state. To gain insight on the deformation of this state exclusive measurements of light charged particles were carried out with 8 π LP apparatus at Laboratori Nazionali di Legnaro and compared to statistical model predictions. The measured of α -particle energy spectra, α -evaporation residues, α -α , and α -α -α correlations indicate the limitation of the rotating liquid drop model in describing the nuclear shape of the compound nucleus along the decay cascade. To reproduce the full set of experimental data very elongated nuclear shapes had to be considered, with an axis ratio 3 :1 at the resonance angular momentum. This large deformation is consistent with previous findings for α -like nuclei and with the predictions of the cranked cluster model.

  11. Chemically produced nanostructured ODS-lanthanum oxide-tungsten composites sintered by spark plasma

    NASA Astrophysics Data System (ADS)

    Yar, Mazher Ahmed; Wahlberg, Sverker; Bergqvist, Hans; Salem, Hanadi G.; Johnsson, Mats; Muhammed, Mamoun

    2011-01-01

    High purity W and W-0.9La 2O 3 (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous solutions. High resolution electron microscopy investigations revealed that the tungstate particles were coated with oxide precipitates. The precursor powder was reduced to tungsten metal with dispersed lanthanum oxide. Powders were consolidated by spark plasma sintering (SPS) at 1300 and 1400 °C to suppress grain growth during sintering. The final grain size relates to the SPS conditions, i.e. temperature and heating rate, regardless of the starting powder particle size. Scanning electron microscopy revealed that oxide phases were mainly accumulated at grain boundaries while the tungsten matrix constituted of nanosized sub-grains. The transmission electron microscopy revealed that the tungsten grains consist of micron-scale grains and finer sub-grains. EDX analysis confirmed the presence of W in dispersed oxide phases with varying chemical composition, which evidenced the presence of complex oxide phases (W-O-La) in the sintered metals.

  12. Pyrolysis temperature induced changes in characteristics and chemical composition of biochar produced from conocarpus wastes.

    PubMed

    Al-Wabel, Mohammad I; Al-Omran, Abdulrasoul; El-Naggar, Ahmed H; Nadeem, Mahmoud; Usman, Adel R A

    2013-03-01

    Conocarpus wastes were pyrolyzed at different temperatures (200–800 °C) to investigate their impact on characteristics and chemical composition of biochars. As pyrolysis temperature increased, ash content, pH, electrical conductivity, basic functional groups, carbon stability, and total content of C, N, P, K, Ca, and Mg increased while biochar yield, total content of O, H and S, unstable form of organic C and acidic functional groups decreased. The ratios of O/C, H/C, (O + N)/C, and (O + N + S)/C tended to decrease with temperature. The data of Fourier transformation infrared indicate an increase in aromaticity and a decrease in polarity of biochar produced at a high temperature. With pyrolysis temperature, cellulose loss and crystalline mineral components increased, as indicated by X-ray diffraction analysis and scanning electron microscope images. Results suggest that biochar pyrolized at high temperature may possess a higher carbon sequestration potential when applied to the soil compared to that obtained at low temperature. PMID:23376202

  13. Properties of SiC-SiC composites produced using CVR converted graphite cloth to SiC cloth

    SciTech Connect

    Kowbel, W.; Kyriacou, C.; Gao, F.; Bruce, C.A.; Withers, J.C.

    1995-10-01

    Nicalon fiber is the primary reinforcement in SiC-SiC composites currently produced by a variety of techniques including CVI and polymer infiltration. Low strength retention at high temperatures of the Nicalon fibers limits the choice of manufacturing processes which can be employed to produce low cost SiC-SiC composites. MER has developed a new SiC reinforcement based upon a conversion of low cost carbon fabric to SiC via a Chemical Vapor Reaction (CVR) process. This new SiC filaments exhibit an excellent creep resistance at temperatures up to 1,600 C. Several SiC-SiC composites were fabricated using graphite fabric converted to SiC fabric utilizing the CVR process combined with a slurry infiltration and CVI densification. A correlation between processing conditions, microstructure and properties of the SiC-SiC composites are discussed in detail.

  14. Gastric Composite Tumor of Alpha Fetoprotein-Producing Carcinoma/Hepatoid Adenocarcinoma and Endocrine Carcinoma with Reference to Cellular Phenotypes

    PubMed Central

    Suzuki, Akira; Koide, Naohiko; Kitazawa, Masato; Mochizuka, Akiyoshi; Ota, Hiroyoshi; Miyagawa, Shinichi

    2012-01-01

    Alpha-fetoprotein-producing carcinoma (AFPC)/hepatoid adenocarcinoma (HAC) and neuroendocrine carcinoma (NEC) are uncommon in the stomach. Composite tumors consisting of these carcinomas and their histologic phenotypes are not well known. Between 2002 and 2007, to estimate the prevalence of composite tumors consisting of tubular adenocarcinoma, AFPC/HAC and NEC, we reviewed specimens obtained from 294 consecutive patients treated surgically for gastric cancer. We examined histological phenotype of tumors of AFPC or NEC containing the composite tumor by evaluating immunohistochemical expressions of MUC2, MUC5AC, MUC6, CDX2, and SOX2. Immunohistochemically, AFPC/HAC dominantly showed the intestinal or mixed phenotype, and NEC frequently showed the gastric phenotype. In the composite tumor, the tubular and hepatoid components showed the gastric phenotype, and the neuroendocrine component showed the mixed type. The unique composite tumor predominantly showed the gastric phenotype, and the hepatoid and neuroendocrine components were considered to be differentiated from the tubular component. PMID:22482081

  15. Preparation and properties of the Ni-Al/Fe-Al intermetallics composite coating produced by plasma cladding

    NASA Astrophysics Data System (ADS)

    Zhang, Li-Min; Liu, Bang-Wu; Sun, Dong-Bai

    2011-12-01

    A novel approach to produce an intermetallic composite coating was put forward. The microstructure, microhardness, and dry-sliding wear behavior of the composite coating were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrum (EDS) analysis, microhardness test, and ball-on-disc wear experiment. XRD results indicate that some new phases FeAl, Fe0.23Ni0.77Al, and Ni3Al exit in the composite coating with the Al2O3 addition. SEM results show that the coating is bonded with carbon steel metallurgically and exhibits typical rapid directional solidification structures. The Cr7C3 carbide and intermetallic compounds co-reinforced composite coating has a high average hardness and exhibits an excellent wear resistance under dry-sliding wear test compared with the Cr7C3 carbide-reinforced composite coating. The formation mechanism of the intermetallic compounds was also investigated.

  16. Simple and mass-produced mechanochemical preparation of graphene nanosheet/polyaniline composite assisted with bifunctional ionic liquid

    NASA Astrophysics Data System (ADS)

    Lu, Xiangjun; Dou, Hui

    2016-05-01

    Graphene nanosheet/polyaniline (GNS/PANI) composite was prepared by a simple and mass-produced mechanochemical method, where the functionalized ionic liquid 1-(3-sulfonic acid) propyl-3-methylimidazolium hydrogen sulfate conducts as not only the dispersant of GNS but also the dopant of PANI. The GNS/PANI composite characterized by Fourier transformation infrared spectra, UV-Vis spectra and X-ray diffraction shows that the resulting PANI in composite is in its doped, conductive emeraldine oxidation state. Scanning electron microscope images reveal that the GNS/PANI composite with PANI uniformly coated on the surface of GNS is randomly stacking. Compared with pure PANI, the GNS/PANI composite has higher electrical conductivity, better thermal stability and electrochemical activity due to the presence of GNS.

  17. Novel recycling of nonmetal particles from waste printed wiring boards to produce porous composite for sound absorbing application.

    PubMed

    Sun, Zhixing; Shen, Zhigang; Zhang, Xiaojing; Ma, Shulin

    2014-01-01

    Nonmetal materials take up about 70 wt% of waste printed wiring boards (WPWB), which are usually recycled as low-value fillers or even directly disposed by landfill dumping and incineration. In this research, a novel reuse ofthe nonmetals to produce porous composites for sound absorbing application was demonstrated. The manufacturing process, absorbing performance and mechanical properties of the composites were studied. The results show that the high porous structure of the composites leads to an excellent sound absorption ability in broad-band frequency range. Average absorption coefficient of above 0.4 can be achievedby the composite in the frequency range from 100 to 6400 Hz. When the particle size is larger than 0.2 mm, the absorption ability of the composite is comparable to that of commercial wood-fibre board and urea-formaldehyde foam. Mechanical analysis indicates that the porous composites possess sufficient structural strength for self-sustaining applications. All the results indicate that producing sound absorbing composite with nonmetal particles from WPWB provides an efficient and profitable way for recycling this waste resource and can resolve both the environment pollution and noise pollution problems. PMID:24701924

  18. Characterization of composites fabricated from discontinuous random carbon fiber thermoplastic matrix sheets produced by a paper making process

    NASA Astrophysics Data System (ADS)

    Ducote, Martin Paul, Jr.

    In this thesis, a papermaking process was used to create two randomly oriented, high performance composite material systems. The primary objective of this was to discover the flexural properties of both composite systems and compare those to reported results from other studies. In addition, the process was evaluated for producing quality, randomly oriented composite panels. Thermoplastic polymers have the toughness and necessary strength to be alternatives to thermosets, but with the promise of lower cycle times and increased recyclability. The wet-lay papermaking process used in this study produces a quality, randomly oriented thermoplastic composite at low cycle times and simple production. The materials chosen represent high performance thermoplastics and carbon fibers. Short chopped carbon fiber filled Nylon 6,6 and PEEK composites were created at varying fiber volume fractions. Ten nylon based panels and five PEEK based panels were subjected to 4-point flexural testing. In several of the nylon-based panels, flexural testing was done in multiple direction to verify the in-plane isotropy of the final composite. The flexural strength performance of both systems showed promise when compared to equivalent products currently available. The flexural modulus results were less than expected and further research should be done into possibly causes. Overall, this research gives good insight into two high performance engineering composites and should aid in continued work.

  19. Nitrogen Isotope Composition of Thermally Produced NOx from Various Fossil-Fuel Combustion Sources.

    PubMed

    Walters, Wendell W; Tharp, Bruce D; Fang, Huan; Kozak, Brian J; Michalski, Greg

    2015-10-01

    The nitrogen stable isotope composition of NOx (δ(15)N-NOx) may be a useful indicator for NOx source partitioning, which would help constrain NOx source contributions in nitrogen deposition studies. However, there is large uncertainty in the δ(15)N-NOx values for anthropogenic sources other than on-road vehicles and coal-fired energy generating units. To this end, this study presents a broad analysis of δ(15)N-NOx from several fossil-fuel combustion sources that includes: airplanes, gasoline-powered vehicles not equipped with a three-way catalytic converter, lawn equipment, utility vehicles, urban buses, semitrucks, residential gas furnaces, and natural-gas-fired power plants. A relatively large range of δ(15)N-NOx values was measured from -28.1‰ to 8.5‰ for individual exhaust/flue samples that generally tended to be negative due to the kinetic isotope effect associated with thermal NOx production. A negative correlation between NOx concentrations and δ(15)N-NOx for fossil-fuel combustion sources equipped with selective catalytic reducers was observed, suggesting that the catalytic reduction of NOx increases δ(15)N-NOx values relative to the NOx produced through fossil-fuel combustion processes. Combining the δ(15)N-NOx measured in this study with previous published values, a δ(15)N-NOx regional and seasonal isoscape was constructed for the contiguous U.S., which demonstrates seasonal and regional importance of various NOx sources. PMID:26332865

  20. Nano-fabricated superconducting radio-frequency composites, method for producing nano-fabricated superconducting rf composites

    DOEpatents

    Norem, James H.; Pellin, Michael J.

    2013-06-11

    Superconducting rf is limited by a wide range of failure mechanisms inherent in the typical manufacture methods. This invention provides a method for fabricating superconducting rf structures comprising coating the structures with single atomic-layer thick films of alternating chemical composition. Also provided is a cavity defining the invented laminate structure.

  1. MASBAL: A computer program for predicting the composition of nuclear waste glass produced by a slurry-fed ceramic melter

    SciTech Connect

    Reimus, P.W.

    1987-07-01

    This report is a user's manual for the MASBAL computer program. MASBAL's objectives are to predict the composition of nuclear waste glass produced by a slurry-fed ceramic melter based on a knowledge of process conditions; to generate simulated data that can be used to estimate the uncertainty in the predicted glass composition as a function of process uncertainties; and to generate simulated data that can be used to provide a measure of the inherent variability in the glass composition as a function of the inherent variability in the feed composition. These three capabilities are important to nuclear waste glass producers because there are constraints on the range of compositions that can be processed in a ceramic melter and on the range of compositions that will be acceptable for disposal in a geologic repository. MASBAL was developed specifically to simulate the operation of the West Valley Component Test system, a commercial-scale ceramic melter system that will process high-level nuclear wastes currently stored in underground tanks at the site of the Western New York Nuclear Services Center (near West Valley, New York). The program is flexible enough, however, to simulate any slurry-fed ceramic melter system. 4 refs., 16 figs., 5 tabs.

  2. Media composition and incubation temperature affect Congo red dye affinity of Shiga toxin-producing Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Escherichia coli biofilm formation is dependent on curli fimbriae and cellulose, and the expression of both varies among Shiga toxin-producing E. coli (STEC). Curli and cellulose expression are often identified by their affinity for Congo red dye (CR) but media composition and incubation...

  3. Conducting and non-conducting biopolymer composites produced by particle bonding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this report, we introduce two types of processes for the production of biopolymer composites: one is fabricated by bonding biopolymers with corn protein or wheat protein and the other by bonding starch with a synthetic polymer. These two types of biopolymer composites make use of the strong bon...

  4. Utilizing fly ash particles to produce low-cost metal matrix composites

    SciTech Connect

    Withers, G.

    2008-07-01

    Metal matrix composites (MMCs) are a blend of fine ceramic particles mixed with metals such as aluminium or magnesium. Fly ash is considerably cheaper than ceramics; aluminium-fly ash composites cost less than 60% of conventional aluminium-SiC composites making them attractive to automakers striving for lower weight and cheaper materials for brake rotors or brake drums. Ultalite.com has consulted with US researchers to to find the optimum requirements of the fly ash needed to make MMCs. Particle size 20-40 microns, low calcium oxide content and spherical particles were identified. The desired particles once extracted are stirred into molten aluminum and the resulting composite is into ingots for shipment to a casting facility. Dynamometer testing has shown that aluminium-fly ash composite brake drums have better performance and wear than cast iron drums. 6 figs., 1 tab.

  5. Moon - Possible nature of the body that produced the Imbrian Basin, from the composition of Apollo 14 samples.

    NASA Technical Reports Server (NTRS)

    Ganapathy, R.; Laul, J. C.; Morgan, J. W.; Anders, E.

    1972-01-01

    Soils from the Apollo 14 site contain nearly three times as much meteoritic material as soils from the Apollo 11, Apollo 12, and Luna 16 sites. Part of this material consists of the ubiquitous micrometeorite component, of primitive (carbonaceous-chondrite-like) composition. The remainder, seen most conspicuously in coarse glass and norite fragments, has a decidedly fractionated composition, with volatile elements less than one-tenth as abundant as siderophiles. This material seems to be debris of the Cyprus-sized planetesimal that produced the Imbrian Basin. Compositionally this planetesimal has no exact counterpart among known meteorite classes, though group IVA irons come close. It also resembles the initial composition of the earth as postulated by the two-component model. Apparently the Imbrian planetesimal was an earth satellite swept up by the moon during tidal recession or capture, or an asteroid deflected by Mars into terrestrial space.

  6. Effect of HNT on the Microstructure, Thermal and Mechanical Properties of Al/FACS-HNT Composites Produced by GPI

    NASA Astrophysics Data System (ADS)

    Siewiorek, A.; Malczyk, P.; Sobczak, N.; Sobczak, J. J.; Czulak, A.; Kozera, R.; Gude, M.; Boczkowska, A.; Homa, M.

    2016-07-01

    To develop an optimised manufacturing method of fly ash-reinforced metal matrix composites, the preliminary tests were performed on the cenospheres selected from fly ash (FACS) with halloysite nanotubes (HNTs) addition. The preform made out of FACS with and without the addition of HNT (with 5 and 10 wt.%) has been infiltrated by the pure aluminium (Al) via adapted gas pressure infiltration process. This paper reveals the influence of HNT addition on the microstructure (analysis was done by computed tomography and scanning electron microscopy combined with energy-dispersive x-ray spectroscopy), thermal properties (thermal expansion coefficient, thermal conductivity and specific heat) and the mechanical properties (hardness and compression test) of manufactured composites. The analysis of structure-property relationships for Al/FACS-HNT composites produced shows that the addition of 5 wt.% of HNT to FACS preform contributes to receiving of the best mechanical and structural properties of investigated composites.

  7. Ceramics reinforced metal base composite coatings produced by CO II laser cladding

    NASA Astrophysics Data System (ADS)

    Yang, Xichen; Wang, Yu; Yang, Nan

    2008-03-01

    Due to the excellent performance in high strength, anti-temperature and anti-wear, ceramics reinforced metal base composite material was used in some important fields of aircraft, aerospace, automobile and defense. The traditional bulk metal base composite materials are the expensive cost, which is limited in its industrial application. Development of laser coating of ceramics reinforced metal base composite is very interesting in economy. This paper is focused on three laser cladding ceramics coatings of SiC particle /Al matrix , Al IIO 3 powder/ Al matrix and WC + Co/mild steel matrix. Powder particle sizes are of 10-60μm. Chemical contents of aluminum matrix are of 3.8-4.0% Cu, 1.2-1.8% Mg, 0.3-0.99% Mn and balance Al. 5KW CO II laser, 5 axes CNC table, JKF-6 type powder feeder and co-axis feeder nozzle are used in laser cladding. Microstructure and performance of laser composite coatings have been respectively examined with OM,SEM and X-ray diffraction. Its results are as follows : Microstructures of 3C-,6H- and 5H- SiC particles + Al + Al 4SiC 4 + Si in SiC/Al composite, hexagonal α-Al IIO 3 + cubic γ-Al IIO 3 + f.c.c Al in Al IIO 3 powder/ Al composite and original WC particles + separated WC particles + eutectic WC + γ-Co solid solution + W IIC particles in WC + Co/steel coatings are respectively recognized. New microstructures of 5H-SiC in SiC/Al composite, cubic γ-Al IIO 3 in Al IIO 3 composite and W IIC in WC + Co/ steel composite by laser cladding have been respectively observed.

  8. Modification of Chemically Exfoliated Graphene to Produce Efficient Piezoresistive Polystyrene-Graphene Composites

    NASA Astrophysics Data System (ADS)

    Nasirpouri, Farzad; Pourmahmoudi, Hassan; Abbasi, Farhang; Littlejohn, Samuel; Chauhan, Ashok S.; Nogaret, Alain

    2015-10-01

    We report the chemical exfoliation of grapheneoxide from graphite and its subsequent reduction to graphene nanosheets (GN) to obtain highly conducting composites of graphene sheets in a polymer matrix. The effect of using graphite nanoparticles or flakes as precursors, and different drying methods, was investigated to obtain multilayer graphene sheets of atomically controlled thickness, which was essential to optimizing their dispersion in a polystyrene (PS) polymer matrix. In situ emulsion polymerization of the styrene monomer in the presence of GN was performed to obtain thin composite films with highly uniform dispersion and fewer graphene layers when GN were obtained from graphite flakes then freeze drying. The highest electrical conductivity of PS-GN composites was ~0.01 S/m for a graphene filling fraction of 2%. The piezoresistance of the PS-GN composites was evaluated and used in pressure sensor arrays with pressure field imaging capability.

  9. /SiCp Reinforced Composites Produced by Pressure-Assisted Aluminum Infiltration

    NASA Astrophysics Data System (ADS)

    Altinkök, Necat

    2014-06-01

    This study investigates Al2O3/SiCp-Al composites fabricated by pressure-assisted liquid-metal infiltration techniques and modified alumina/SiC particle preforms. The infiltration was achieved successfully; microstructure and mechanical properties of the composites were examined. An experimental design based on the Taguchi technique was used to acquire the data and investigate the mechanical properties of the hybrid composites. An orthogonal array and analysis of variance were employed to investigate the influence of test parameters such as infiltration temperature and infiltration pressure. It was found that the infiltration temperature was the most effective factor in increasing the mechanical properties of hybrid Al2O3/SiCp composite.

  10. High strength-high conductivity Cu--Fe composites produced by powder compaction/mechanical reduction

    DOEpatents

    Verhoeven, John D.; Spitzig, William A.; Gibson, Edwin D.; Anderson, Iver E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an "in-situ" Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite.

  11. In vitro degradation and cytotoxicity of Mg/Ca composites produced by powder metallurgy.

    PubMed

    Zheng, Y F; Gu, X N; Xi, Y L; Chai, D L

    2010-05-01

    Mg/Ca (1 wt.%, 5 wt.%, 10 wt.% Ca) composites were prepared from pure magnesium and calcium powders using the powder metallurgy method, aiming to enlarge the addition of Ca content without the formation of Mg(2)Ca. The microstructures, mechanical properties and cytotoxicities of Mg/Ca composite samples were investigated. The corrosion of Mg/Ca composites in Dulbecco's modified Eagle's medium (DMEM) for various immersion intervals was studied by electrochemical impedance spectroscopy measurements and environmental scanning electron microscope, with the concentrations of released Mg and Ca ions in DMEM for various immersion time intervals being measured. It was shown that the main constitutional phases were Mg and Ca, which were uniformly distributed in the Mg matrix. The ultimate tensile strength (UTS) and elongation of experimental composites decreased with increasing Ca content, and the UTS of Mg/1Ca composite was comparable with that of as-extruded Mg-1Ca alloy. The corrosion potential increased with increasing Ca content, whereas the current density and the impedance decreased. It was found that the protective surface film formed quickly at the initial immersion stage. With increasing immersion time, the surface film became compact, and the corrosion rate of Mg/Ca composites slowed down. The surface film consisted mainly of CaCO(3), MgCO(3)x3H(2)O, HA and Mg(OH)(2) after 72 h immersion in DMEM. Mg/1Ca and Mg/5Ca composite extracts had no significant toxicity (p>0.05) to L-929 cells, whereas Mg/10Ca composite extract induced approximately 40% reduced cell viability. PMID:19815098

  12. High strength-high conductivity Cu-Fe composites produced by powder compaction/mechanical reduction

    DOEpatents

    Verhoeven, J.D.; Spitzig, W.A.; Gibson, E.D.; Anderson, I.E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an ''in-situ'' Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite. 5 figures.

  13. Sb/O nano-composites produced via Spark Discharge Generation for Li-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Simonin, L.; Lafont, U.; Tabrizi, N.; Schmidt-Ott, A.; Kelder, E. M.

    Spark Discharge Generation (SDG) was used to produce powders of 10-20 nm of Sb and antimony oxides. Different composite materials with different textures were obtained either with an amorphous passive layer of antimony oxide or with crystalline cubic Sb 2O 3. The composition and shape of the different mixtures, depending on the production and collection conditions, were analysed via XRD and HRTEM coupled with EDX. The effect of the nature and the content of the oxides on the electrode performances were studied using Swagelok cells, cycled galvanostatically with a MACCOR cycler.

  14. Influence of sulfides on the tribological properties of composites produced by pulse electric current sintering

    NASA Astrophysics Data System (ADS)

    Kim, Seung Ho

    2014-01-01

    Self-lubricating Al2O3-15wt% ZrO2 composites with sulfides, such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) serving as solid lubricants, were fabricated by using the pulse electric current sintering (PECS) technique. The coefficient of friction (COF) of the Al2O3-15wt% ZrO2 composite without/with sulfides was in the range of 0.37-0.48 and 0.27-0.49, respectively. As the amount of sulfides increased, the COF and the wear rate decreased. The reduction in COF and wear rate of the sulfide-containing composite is caused by a reduction in shear stresses between the specimen and the tribological medium due to the formation of a lubricating film resulting from the lamellar structure of sulfides located on the worn surface.

  15. Process to produce titanium diboride whiskers as reinforcement for metal and ceramic composites

    SciTech Connect

    Withers, J.C.; Loutfy, R.O.; Lee, C.T.

    1988-10-01

    The objective of the Phase I program was to establish the feasibility of producing TiB2 whiskers. Two approaches were investigated. High temperature carbothermic reduction of titanium and boron compounds produced TiB2 platelets, and using excess B to limit the growth on the basal plane, platelets with thickness of 1.5 microns and 10 microns length and width were produced. The dimensions are ideal for reinforcing metal and intermetallics. Vapor-solid (VS) and Vapor-Liquid-Solid (VLS) TiB2 whiskers were produced via the low temperature hydrogen reduction of TiCl4 and BCl3, using Au and/or Au/Pd catalyst over a wide temperature range. VS whiskers with a diameter of 1.5 - 3.0 microns and aspect ratio of 20-40 were produced at temperatures between 1050 C and 1250 C. The whiskers are ideal for metal and intermetallic reinforcement.

  16. Composites from maleated polyolefin-grafted wood particles produced via reactive extrusion

    NASA Astrophysics Data System (ADS)

    Carlborn, Karana

    This study examined the concept of using a reactive extrusion process to develop a new, formaldehyde-free binding system for wood composite products. The surfaces of wood particles were modified by grafting maleated polyethylene (MAPE) and maleated polypropylene (MAPP) compounds through a continuous reactive extrusion process. MAPE content was varied to study the effect of material composition on grafting efficiency, while extruder barrel temperatures and rotational screw speeds were varied to evaluate the effects of processing conditions on the modification of wood particles. Polymer molecular weight effects were followed using MAPP with different molecular weights. Efficiency of the modification was assessed using FTIR. 13C NMR and XPS surface analysis techniques, along with a titrimetric analysis to verify the esterification reaction between the wood particles and maleated polyolefins. Composite panels were made from wood particles modified with MAPE and MAPP binding agents under two different manufacturing methods. Specific contrasts of (i) base resin type, PE vs. PP, (ii) molecular weight/maleic anhydride content in MAPP binding agents, and (iii) the manufacturing methods (reactive extrusion vs. hot press) were investigated to determine the effects of these factors on the physico-mechanical properties of the composites. Finally, a response surface method using a Box-Behnken design was constructed to statistically model and optimize the material compositions-processing conditions-mechanical property relationships of formaldehyde-free wood composite panels. FTIR, 13C NMR, XPS and titration data confirmed the grafting of maleated polyolefins onto wood particles through an esterification reaction, while the level of grafting of MAPE onto wood particles was determined to be a function of the MAPE concentration. However, there was no significant difference in grafting efficiency at different extrusion processing conditions; rather all of the conditions resulted in

  17. Compositions of corrosion-resistant Fe-based amorphous metals suitable for producing thermal spray coatings

    DOEpatents

    Farmer, Joseph C.; Wong, Frank M. G.; Haslam, Jeffery J.; Ji, Xiaoyan; Day, Sumner D.; Blue, Craig A.; Rivard, John D. K.; Aprigliano, Louis F.; Kohler, Leslie K.; Bayles, Robert; Lemieux, Edward J.; Yang, Nancy; Perepezko, John H.; Kaufman, Larry; Heuer, Arthur; Lavernia, Enrique J.

    2013-07-09

    A method of coating a surface comprising providing a source of amorphous metal that contains manganese (1 to 3 atomic %), yttrium (0.1 to 10 atomic %), and silicon (0.3 to 3.1 atomic %) in the range of composition given in parentheses; and that contains the following elements in the specified range of composition given in parentheses: chromium (15 to 20 atomic %), molybdenum (2 to 15 atomic %), tungsten (1 to 3 atomic %), boron (5 to 16 atomic %), carbon (3 to 16 atomic %), and the balance iron; and applying said amorphous metal to the surface by a spray.

  18. Compositions of corrosion-resistant Fe-based amorphous metals suitable for producing thermal spray coatings

    DOEpatents

    Farmer, Joseph C; Wong, Frank M.G.; Haslam, Jeffery J; Ji, Xiaoyan; Day, Sumner D; Blue, Craig A; Rivard, John D.K.; Aprigliano, Louis F; Kohler, Leslie K; Bayles, Robert; Lemieux, Edward J; Yang, Nancy; Perepezko, John H; Kaufman, Larry; Heuer, Arthur; Lavernia, Enrique J

    2013-09-03

    A method of coating a surface comprising providing a source of amorphous metal that contains manganese (1 to 3 atomic %), yttrium (0.1 to 10 atomic %), and silicon (0.3 to 3.1 atomic %) in the range of composition given in parentheses; and that contains the following elements in the specified range of composition given in parentheses: chromium (15 to 20 atomic %), molybdenum (2 to 15 atomic %), tungsten (1 to 3 atomic %), boron (5 to 16 atomic %), carbon (3 to 16 atomic %), and the balance iron; and applying said amorphous metal to the surface by a spray.

  19. Effects of Kernel Composition and Starch Structure on Ethanol Yield Produced from Dry-Grind Corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives of this study were to understand how the composition of kernels (i.e., starch, protein, and lipid contents) and the starch structure of dry-grind corn affected the enzyme hydrolysis of starch and the ethanol yield during yeast fermentation. Four lines of corn, designated, 05GEM06031, 06G...

  20. One step process for producing dense aluminum nitride and composites thereof

    DOEpatents

    Holt, J. Birch; Kingman, Donald D.; Bianchini, Gregory M.

    1989-01-01

    A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

  1. One step process for producing dense aluminum nitride and composites thereof

    DOEpatents

    Holt, J.B.; Kingman, D.D.; Bianchini, G.M.

    1989-10-31

    A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1,000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

  2. An efficient process for producing economical and eco-friendly cotton textile composites for mobile industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mobile industry comprised of airplanes, automotives, and ships uses enormous quantities of various types of textiles. Just a few decades ago, most of these textile products and composites were made with woven or knitted fabrics that were mostly made with the then only available natural fibers, i...

  3. Composition of Extracellular Polymeric Substances (EPS) produced by Flavobacterium columnare isolated from tropical fish in Brazil

    PubMed Central

    de Alexandre Sebastião, Fernanda; Pilarski, Fabiana; Lemos, Manoel Victor Franco

    2013-01-01

    Thirty nine isolates of Flavobacterium columnare from Brazilian fish farms had their carbohydrate composition of EPS evaluated by high efficiency liquid chromatography, using the phenol-sulfuric acid method of EPS. The occurrence of capsules on F. columnare cells was not directly related to biofilm formation, and the predominant monosaccharide is glucose. PMID:24516426

  4. The composition and functional properties of whey protein concentrates produced from buttermilk are comparable with those of whey protein concentrates produced from skimmed milk.

    PubMed

    Svanborg, Sigrid; Johansen, Anne-Grethe; Abrahamsen, Roger K; Skeie, Siv B

    2015-09-01

    The demand for whey protein is increasing in the food industry. Traditionally, whey protein concentrates (WPC) and isolates are produced from cheese whey. At present, microfiltration (MF) enables the utilization of whey from skim milk (SM) through milk protein fractionation. This study demonstrates that buttermilk (BM) can be a potential source for the production of a WPC with a comparable composition and functional properties to a WPC obtained by MF of SM. Through the production of WPC powder and a casein- and phospholipid (PL)-rich fraction by the MF of BM, sweet BM may be used in a more optimal and economical way. Sweet cream BM from industrial churning was skimmed before MF with 0.2-µm ceramic membranes at 55 to 58°C. The fractionations of BM and SM were performed under the same conditions using the same process, and the whey protein fractions from BM and SM were concentrated by ultrafiltration and diafiltration. The ultrafiltration and diafiltration was performed at 50°C using pasteurized tap water and a membrane with a 20-kDa cut-off to retain as little lactose as possible in the final WPC powders. The ultrafiltrates were subsequently spray dried, and their functional properties and chemical compositions were compared. The amounts of whey protein and PL in the WPC powder from BM (BMWPC) were comparable to the amounts found in the WPC from SM (SMWPC); however, the composition of the PL classes differed. The BMWPC contained less total protein, casein, and lactose compared with SMWPC, as well as higher contents of fat and citric acid. No difference in protein solubility was observed at pH values of 4.6 and 7.0, and the overrun was the same for BMWPC and SMWPC; however, the BMWPC made less stable foam than SMWPC. PMID:26142868

  5. Cold Regime interannual variability of primary and secondary producer community composition in the southeastern Bering Sea.

    PubMed

    Stauffer, Beth A; Miksis-Olds, Jennifer; Goes, Joaquim I

    2015-01-01

    Variability of hydrographic conditions and primary and secondary productivity between cold and warm climatic regimes in the Bering Sea has been the subject of much study in recent years, while interannual variability within a single regime and across multiple trophic levels has been less well-documented. Measurements from an instrumented mooring on the southeastern shelf of the Bering Sea were analyzed for the spring-to-summer transitions within the cold regime years of 2009-2012 to investigate the interannual variability of hydrographic conditions, primary producer biomass, and acoustically-derived secondary producer and consumer abundance and community structure. Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column. Primary producer biomass was more tightly coupled to hydrographic conditions in 2012 than in 2009 or 2011, and shallow and mid-column phytoplankton blooms tended to occur independent of one another. There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year. Phytoplankton blooms stimulated different populations of secondary producers in each year, and summer consumer populations appeared to determine dominant populations in the subsequent spring. Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years. The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given changing

  6. Cold Regime Interannual Variability of Primary and Secondary Producer Community Composition in the Southeastern Bering Sea

    PubMed Central

    Stauffer, Beth A.; Miksis-Olds, Jennifer; Goes, Joaquim I.

    2015-01-01

    Variability of hydrographic conditions and primary and secondary productivity between cold and warm climatic regimes in the Bering Sea has been the subject of much study in recent years, while interannual variability within a single regime and across multiple trophic levels has been less well-documented. Measurements from an instrumented mooring on the southeastern shelf of the Bering Sea were analyzed for the spring-to-summer transitions within the cold regime years of 2009–2012 to investigate the interannual variability of hydrographic conditions, primary producer biomass, and acoustically-derived secondary producer and consumer abundance and community structure. Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column. Primary producer biomass was more tightly coupled to hydrographic conditions in 2012 than in 2009 or 2011, and shallow and mid-column phytoplankton blooms tended to occur independent of one another. There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year. Phytoplankton blooms stimulated different populations of secondary producers in each year, and summer consumer populations appeared to determine dominant populations in the subsequent spring. Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years. The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given

  7. Variation in the volatile oil composition of Eucalyptus citriodora produced by hydrodistillation and supercritical fluid extraction techniques.

    PubMed

    Mann, Tavleen S; Babu, G D Kiran; Guleria, Shailja; Singh, Bikram

    2013-04-01

    This work reports variations in the yields and quality of volatiles produced from Eucalyptus citriodora leaves by different hydrodistillation (HD) and supercritical carbon dioxide extraction (SCE) techniques. HD techniques (1.5%) produced higher yields compared to SCE (0.7%). Citronellal, the major component, was maximum in the extract produced by SCE (79%) followed by oil produced by water-steam distillation (WSD) (72.6%) and water distillation (WD) (62.4%) techniques. Chemical composition of glycoside-bound volatiles produced by acid hydrolysis during HD was found to be very different from free volatiles, although in a minor quantity. The extent of artefact formation and release of aglycones was more profound in the bound volatile oil produced by WD than WSD. Highest oxygenated monoterpenes were found in SCE and WSD (93% each) followed by WD (91.4%). Although the SCE produced lower yields than the HD techniques, its extract is superior in quality in terms of higher concentration of citronellal. PMID:22559719

  8. Structure and blood compatibility of highly oriented PLA/MWNTs composites produced by solid hot drawing.

    PubMed

    Li, Zhengqiu; Zhao, Xiaowen; Ye, Lin; Coates, Phil; Caton-Rose, Fin; Martyn, Michasel

    2014-03-01

    Highly oriented poly(lactic acid) (PLA)/multi-walled carbon nanotubes (MWNTs) composites were fabricated through solid hot drawing technology in an effort to improve the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. It was found that proper MWNTs content and drawing orientation can improve the tensile strength and modulus of PLA dramatically. With the increase in draw ratio, the cold crystallization peak became smaller, and the glass transition and the melting peak of PLA moved to high temperature, while the crystallinity increased, and the grain size decreased, indicating the stress-induced crystallization of PLA during drawing. MWNTs showed a nucleation effect on PLA, leading to the rise in the melting temperature, increase in crystallinity and reduction of spherulite size for the composites. Moreover, the intensity of (002) diffraction of MWNTs increased with draw ratio, indicating that MWNTs were preferentially aligned and oriented during drawing. Microstructure observation demonstrated that PLA matrix had an ordered fibrillar bundle structure, and MWNTs in the composite tended to align parallel to the drawing direction. In addition, the dispersion of MWNTs in PLA was also improved by orientation. Introduction of MWNTs and drawing orientation could significantly enhance the blood compatibility of PLA by prolonging kinetic clotting time, reducing hemolysis ratio and platelet activation. PMID:23733838

  9. Composition of proteoglycan fragments from hyaline cartilage produced by granulocytes in a model of frustrated phagocytosis.

    PubMed

    Liszt, F; Schnittker-Schulze, K; Stuhlsatz, H W; Greiling, H

    1991-02-01

    An in vitro model of frustrated phagocytosis was developed in which granulocytes interact with well-defined slices of hyaline cartilage. The composition of the purified proteoglycan fragments released from the cartilage slices by N-formyl-methionyl-leucyl-phenylalanine-stimulated granulocytes was studied after 30, 60 and 90 min incubation time. It was shown that the proteoglycan fragments do not change their composition during incubation. The only change observed during incubation was an increase in the quantity of the fragments. The protein content of the proteoglycan fragments is 7.0-8.6%, corresponding to a peptide chain of 24-28 amino acids, and the relative molecular mass of the total fragment is Mr = 37,600-39,200. On average, each proteoglycan fragment contains two chondroitin sulphate chains (Mr = 22,000-22,400), every fourth fragment contains a keratan sulphate chain (Mr = 7000-7200) and every seventh to eighth contains an O-glycosidic oligosaccharide, whereas no N-glycosidic oligosaccharide could be detected. The results of the disaccharide analysis show that the galactosaminoglycan chains contain 76.2-83.6% chondroitin 4-sulphate, 12.9-19.4% chondroitin 6-sulphate, 3.5-3.8% chondroitin and no dermatan sulphate. Since composition and relative molecular mass of the chondroitin sulphate and keratan sulphate chains from the proteoglycan fragments resemble those of native proteoglycans, the conclusion may be drawn that the degeneration of the proteoglycans occurs by proteases that attack preferably the chondroitin sulphate-rich region of the core protein. This is the first inflammation model of joint destruction, which demonstrates the elution of soluble specific proteoglycan degradation products of defined size. PMID:1904780

  10. Internal zone growth method for producing metal oxide metal eutectic composites

    DOEpatents

    Clark, Grady W.; Holder, John D.; Pasto, Arvid E.

    1980-01-01

    An improved method for preparing a cermet comprises preparing a compact having about 85 to 95 percent theoretical density from a mixture of metal and metal oxide powders from a system containing a eutectic composition, and inductively heating the compact in a radiofrequency field to cause the formation of an internal molten zone. The metal oxide particles in the powder mixture are effectively sized relative to the metal particles to permit direct inductive heating of the compact by radiofrequency from room temperature. Surface melting is prevented by external cooling or by effectively sizing the particles in the powder mixture.

  11. Phase composition and structure of femtosecond laser-produced oxide layer on VT6 alloy surface

    NASA Astrophysics Data System (ADS)

    Kolobov, Yu R.; Zhidkov, M. V.; Golosov, E. V.; Vershinina, T. N.; Kudryashov, S. I.; Makarov, S. V.; Ionin, A. A.; Ligachev, A. E.

    2016-07-01

    The influence of femtosecond laser irradiation on the formation of an oxide layer on the surface of VT6 titanium alloy (Ti–6Al–4V) is studied. The structure, chemical and phase composition have been studied by x-ray diffraction, and scanning and transmission electron microscopy. The formation features of an oxide layer, which contains TiO2-rutile, TiO2-anatase Al2TiO5-aluminum titanate, Ti3O5-titanium oxide and TiO-titanium monoxide on the femtosecond laser-irradiation modified surface have been analyzed.

  12. FNDC5 is produced in the stomach and associated to body composition

    PubMed Central

    Barja-Fernández, S.; Folgueira, C.; Castelao, C.; Al-Massadi, O.; Bravo, S. B.; Garcia-Caballero, T.; Leis, R.; Pardo, M.; Casanueva, F. F.; Seoane, L. M.

    2016-01-01

    The fibronectin type III domain-containing protein 5 (FNDC5) discovered in 2002 has recently gained attention due to its potential role in protecting against obesity. In rat, no data exist regarding FNDC5 production and regulation in the stomach. The aim of the present work was to determine the expression of FNDC5 in the rat stomach and its potential regulation by body composition. The present data shows FNDC5 gene expression in the gastric mucosa. Immunohistochemical studies found FNDC5 immunopositivity in chief cells of gastric tissue. By the use of three different antibodies FNDC5 was found expressed in gastric mucosa and secreted by the stomach. The rate of gastric FNDC5 secretion parallels the circulating levels of FNDC5. The body fat mass increase after intervention with high fat diet coincided with a decrease in the secretion of FNDC5 from the stomach and a diminution in the FNDC5 circulating levels. In summary, the present data shows, for the first time, the expression of FNDC5 in the stomach of rats and its regulation by body composition, suggesting a potential role of gastric FNDC5 in energy homeostasis. PMID:26961074

  13. FNDC5 is produced in the stomach and associated to body composition.

    PubMed

    Barja-Fernández, S; Folgueira, C; Castelao, C; Al-Massadi, O; Bravo, S B; Garcia-Caballero, T; Leis, R; Pardo, M; Casanueva, F F; Seoane, L M

    2016-01-01

    The fibronectin type III domain-containing protein 5 (FNDC5) discovered in 2002 has recently gained attention due to its potential role in protecting against obesity. In rat, no data exist regarding FNDC5 production and regulation in the stomach. The aim of the present work was to determine the expression of FNDC5 in the rat stomach and its potential regulation by body composition. The present data shows FNDC5 gene expression in the gastric mucosa. Immunohistochemical studies found FNDC5 immunopositivity in chief cells of gastric tissue. By the use of three different antibodies FNDC5 was found expressed in gastric mucosa and secreted by the stomach. The rate of gastric FNDC5 secretion parallels the circulating levels of FNDC5. The body fat mass increase after intervention with high fat diet coincided with a decrease in the secretion of FNDC5 from the stomach and a diminution in the FNDC5 circulating levels. In summary, the present data shows, for the first time, the expression of FNDC5 in the stomach of rats and its regulation by body composition, suggesting a potential role of gastric FNDC5 in energy homeostasis. PMID:26961074

  14. Approach to In- Situ Producing Reinforcing Phase Within an Active-Transient Liquid Phase Bond Seam for Aluminum Matrix Composite

    NASA Astrophysics Data System (ADS)

    Zhang, Guifeng; Liao, Xianjin; Chen, Bo; Zhang, Linjie; Zhang, Jianxun

    2015-06-01

    To optimize the braze composition design route for aluminum matrix composite, the feasibility of in situ producing reinforcing phase within the transient liquid phase bond seam matrix, by adding active melting point increaser (MPI, e.g., Ti) together with general melting point depressant (MPD, e.g., Cu) into the interlayer, was demonstrated. For SiC p /A356 composite, by comparing the wettability, joint microstructure, joint shear strength, and fracture path for the developed Al-19Cu-1Ti, Al-19Cu, Al-33Cu-1Ti, Al-33Cu (wt pct), and commercial Cu foils as interlayer, the feasibility of in situ producing reinforcing phase within the bond seam by adding Ti was demonstrated. Especially for Al-19Cu-1Ti active braze, small and dispersed ternary aluminide of Al-Si-Ti phase was obtained within the bond seam as in situ reinforcement, leading to a favorable fracture path within SiC p /A356, not along the initial interface or within the bond seam. For the formation mechanism of the in situ reinforcing phase of MPI-containing intermetallic compound within the bond seam, a model of repeating concentration-precipitation-termination-engulfment during isothermal solidification is proposed.

  15. Sputter-produced plasma as a measure of satellite surface composition - The Cassini mission

    NASA Technical Reports Server (NTRS)

    Johnson, R. E.; Sittler, E. C., Jr.

    1990-01-01

    Measurements of the co-orbiting neutral cloud or the plasma produced by sputtering of the icy Saturnian satellites can be used to determine the relative abundance of a minority surface species which would be difficult to determine from reflectance spectra. This is due to the fact that the sputter source rates, hence the plasma supply rates, are directly proportional to the bulk concentrations of mixed solids or clathrates, although the surface grains may be depleted in the most volatile species.

  16. Microstructure and Waer Resistance of a Composite Gr/Al2O3/Al Produced by Reciprocating Extrusion

    NASA Astrophysics Data System (ADS)

    Zhang, Z. M.; Zhu, G. P.; Xu, C. J.; Hu, B.

    A reciprocating extrusion process was used to produce graphite and alumina reinforced pure aluminium composite. The graphite particles (0 5vol%), alumina particles (10 vol%) and pure aluminium particles (balanced) were dehydrated separately at 70°C in vacuum for 3 hours, and then mixed together. A round billet with 50 mm in diameter was prepared by hot pressing at 350°C with the mixed particles and then extruded to a fully-consolidated goblet-like sample at 480°C and 430MPa by reciprocating extrusion. The results showed that all reinforced particles were refined and uniformly distributed in the matrix by reciprocation extrusion severe plastic deformation. The presence of graphite particles caused the reduction in the friction coefficient and wear rate of the Gr/Al2O3/Al composite. Compared with the composite prepared only by alumina particles (10 vol%) and pure aluminium particles, the friction coefficient and wear rate of the Gr/Al2O3/Al composite, which contains 5vol% graphite and 10vol% alumina particles, decreased 45.3% and 33.5%, respectively, and thereafter it displays an excellent combination of low friction coefficient (0.37) and wear rate (2.2×10-7mm3/(N.m)), and appears to be more promising.

  17. Nanoscale compositional banding in binary thin films produced by ion-assisted deposition

    SciTech Connect

    Mark Bradley, R.

    2013-12-14

    During the ion-assisted deposition of a binary material, the ion beam can induce the formation of nanoscale ripples on the surface of the growing thin film and compositional banding within its bulk. We demonstrate that this remains true even if the curvature dependence of the sputter yields and ballistic mass redistribution are negligible, and the two atomic species are completely miscible. The concentration of the species with the lower of the two sputter yields is higher at the crests of the ripples than at their troughs. Depending on the angles of incidence of the two atomic species, the incident flux of atoms with the higher sputter yield can either stabilize or destabilize the initially flat surface of the thin film.

  18. Graphite immobilisation in iron phosphate glass composite materials produced by microwave and conventional sintering routes

    NASA Astrophysics Data System (ADS)

    Mayzan, M. Z. H.; Stennett, M. C.; Hyatt, N. C.; Hand, R. J.

    2014-11-01

    An investigation of microwave and conventional processing of iron phosphate based graphite glass composite materials as potential wasteforms for the immobilisation of irradiated graphite is reported. For the base iron phosphate glass, full reaction of the raw materials and formation of a glass melt occurs with consequent removal of porosity at 8 min microwave processing. When graphite is present, iron phosphate crystalline phases are formed with higher levels of residual porosity than in the sample prepared using conventional sintering under argon. It is found that graphite reacts with the microwave field when in powder form but this reaction is minimised when the graphite is incorporated into a pellet, and that the graphite also impedes sintering of the glass. Mössbauer spectroscopy indicates that reduction of iron also occurs with concomitant graphite oxidation. Conventionally sintered samples had lower porosities than the equivalent microwaved ones.

  19. Composition of the gases associated with the magmas that produced rocks 15016 and 15065

    NASA Technical Reports Server (NTRS)

    Barker, C.

    1974-01-01

    Gases may be trapped in crystallizing minerals in many different ways but gas analyses can provide geologically meaningful information only if the gases can be related to their specific locations in the host mineral. The gases trapped in glass inclusions can be representative samples of the gases associated with the magma adjacent to the mineral at the time it crystallized. Analyses of the gases in glass inclusions in gabbro 15065,44 and basalt 15016,48 show that in both cases the gases in the parent magma started with a composition close to 46% oxygen, 42% carbon and 12% hydrogen and became more water-rich as crystallization progressed. This enrichment is probably due to a selective removal of the less soluble carbon compounds into the vapor phase. Some of the volatile components may react with the rock as temperature falls to give siderite and possibly hydrous phases.

  20. Strontium ranelate changes the composition and crystal structure of the biological bone-like apatite produced in osteoblast cell cultures.

    PubMed

    Querido, William; Campos, Andrea P C; Martins Ferreira, Erlon H; San Gil, Rosane A S; Rossi, Alexandre M; Farina, Marcos

    2014-09-01

    We evaluate the effects of strontium ranelate on the composition and crystal structure of the biological bone-like apatite produced in osteoblast cell cultures, a system that gave us the advantage of obtaining mineral samples produced exclusively during treatment. Cells were treated with strontium ranelate at concentrations of 0.05 and 0.5 mM Sr(2+). Mineral substances were isolated and analyzed by using a combination of methods: Fourier transform infrared spectroscopy, solid-state (1)H nuclear magnetic resonance, X-ray diffraction, micro-Raman spectroscopy and energy dispersive X-ray spectroscopy. The minerals produced in all cell cultures were typical bone-like apatites. No changes occurred in the local structural order or crystal size of the minerals. However, we noticed several relevant changes in the mineral produced under 0.5 mM Sr(2+): (1) increase in type-B CO3 (2-) substitutions, which often lead to the creation of vacancies in Ca(2+) and OH(-) sites; (2) incorporation of Sr(2+) by substituting slightly less than 10 % of Ca(2+) in the apatite crystal lattice, resulting in an increase in both lattice parameters a and c; (3) change in the PO4 (3-) environments, possibly because of the expansion of the lattice; (4) the Ca/P ratio of this mineral was reduced, but its (Ca+Sr)/P ratio was the same as that of the control, indicating that its overall cation/P ratio was preserved. Thus, strontium ranelate changes the composition and crystal structure of the biological bone-like apatite produced in osteoblast cell cultures. PMID:24859219

  1. Surface layer composition of titania produced by various methods. The change of layer state under illumination

    NASA Astrophysics Data System (ADS)

    Zakharenko, V.; Daibova, E.; Kosova, N.; Zmeeva, O.

    2016-01-01

    The comparative analysis of experimental data over titanium dioxide powders prepared by various ways under ambient air is carried out. The results over TiO2 prepared by high-temperature heating of anatase, produced by burning of titanium micro particles and grinding of rutile crystal are used for that comparison. Water and carbon dioxide were the main products released from the surface of the titania powders. It was found that under UV irradiation absorbed by titania, in absent oxygen, water effectively reacts with lattice oxygen of titanium dioxide.

  2. Compositional, nutritional, and functional characteristics of instant teas produced from low- and high-quality black teas.

    PubMed

    Alasalvar, Cesarettin; Pelvan, Ebru; Ozdemir, Kübra Sultan; Kocadağlı, Tolgahan; Mogol, Burçe Ataç; Paslı, Ayça Ayfer; Ozcan, Nihat; Ozçelik, Beraat; Gökmen, Vural

    2013-08-01

    Two types of instant teas produced from low- and high-quality black teas were examined for their proximate composition, dietary fiber, minerals, water-soluble vitamins, total phenolic content, various antioxidant assays, phenolics (flavanols, condensed phenolics, and phenolic acids), alkaloids, and carotenoids as well as taste-active compounds (sugars, organic acids, and free amino acids). Some variations, albeit to different extents, were observed (p < 0.05) among these parameters between instant teas produced from low- and high-quality black teas. With respect to proximate composition, carbohydrate was the predominant component (56.68-59.84 g/100 g), followed by protein (19.31-19.86 g/100 g). Ash, moisture, and, to a lesser extent, dietary fiber and fat were also present in both instant teas. Thirteen minerals, four water-soluble vitamins, six flavanols, two alkaloids, three condensed phenolics, one phenolic acid, and one carotenoid were identified. Total phenolic content varied between 17.35 and 17.82 g of gallic acid equivalents (GAE)/100 g instant tea. With regard to antioxidant activities, three different assays such as oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC), and cupric ion reducing antioxidant capacity (CUPRAC) were measured. No significant differences (p > 0.05) in total phenolic, ORAC, TEAC, and CUPRAC contents between low- and high-quality instant teas were observed. With regard to taste-active compounds, 3 sugars, 5 organic acids, and 18 free amino acids were positively identified, of which fructose, tannic acid, and theanine predominated, respectively. The present work suggests that despite some differences, instant teas produced from low- and high-quality black teas should not be distinguished on the basis of their compositional, nutritional, and functional characteristics as well as taste-active compounds. PMID:23837397

  3. Evaluation of the micronutrient composition of plant foods produced by organic and conventional agricultural methods.

    PubMed

    Hunter, Duncan; Foster, Meika; McArthur, Jennifer O; Ojha, Rachel; Petocz, Peter; Samman, Samir

    2011-07-01

    The aim of the present analysis was to evaluate the micronutrient content of plant foods produced by organic and conventional agricultural methods. Studies were identified from a search of electronic databases (1980-2007, inclusive) as well as manual searches. A total of 66 studies (describing 1440 micronutrient comparisons) were identified. Thirty-three studies (908 comparisons) satisfied the screening criteria which considered cultivar, harvesting, and soil conditions. In studies that satisfied the screening criteria, the absolute levels of micronutrients were higher in organic foods more often than in conventional foods (462 vs 364 comparisons, P=0.002), and the total micronutrient content, expressed as a percent difference, was higher in organic (+5.7%, P<0.001) as compared to conventionally grown produce. The micronutrient content of food groups was more frequently reported to be higher for organic vegetables and legumes compared to their conventional counterparts (vegetables, 267 vs 197, P<0.001; legumes, 79 vs 46, P=0.004). This trend was supported by a mean percent difference in micronutrient content favoring organic vegetables (+5.9%, P<0.001) and legumes (+5.7%, P<0.001). Further research is required to determine the effect of organic agricultural methods on a broader range of nutrients and their potential impact on health. PMID:21929333

  4. Producers and scroungers: feeding-type composition changes with group size in a socially foraging spider.

    PubMed

    Dumke, Marlis; Herberstein, Marie E; Schneider, Jutta M

    2016-04-13

    In groups of socially foraging animals, feeding behaviour may change with group size in response to varying cost-benefit trade-offs. Numerous studies have described group-size effects on group-average feeding behaviour, particularly emphasizing an increase in scrounging incidence for larger groups, where individuals (scroungers) feed from the food sources others (producers) discovered. However, individual variation in feeding behaviour remains unconsidered in the vast majority of these studies even though theoretical models predict individuals to specialize in feeding tactic and anticipate higher scrounger-type frequencies in larger groups. We combined group-level and individual-level analyses of group-size effects on social foraging in the subsocial spiderAustralomisidia ergandros Lending novel experimental support to model predictions, we found that individuals specialize in feeding tactic and that higher scrounging and lower producing incidence in larger groups were mediated through shifts in the ratio of feeding types. Further, feeding-type specialization was not explained by innate individual differences in hunting ability as all feeding types were equally efficient in prey capture when foraging alone. Context adaptivity of feeding behaviour might allow this subsocial species to succeed under varying socioecological conditions. PMID:27075253

  5. Study of composition and morphology features of alumina producing waste for its application in road building technologies

    NASA Astrophysics Data System (ADS)

    Shepelev, Igor; Bochkov, Nikolay; Zhyzhaev, Anatoly

    2016-01-01

    The research of component composition of complex mineral binder material obtained using non-toxic alumina producing waste was performed. The strength characteristics of road mixtures and binder mineral product structure were studied. The technology of subgrade building on the basis of nepheline slime, gypsum-anhydrite waste and dust from cleaning collectors of electrostatic gas treatment systems of calcination furnaces of Achinsk alumina plant was developed and experimentally tested. It provides beside of part of waste utilization also increasing of strength properties and frost resistance of road mixtures.

  6. Comparison of the structural and chemical composition of two unique micro/nanostructures produced by femtosecond laser interactions on nickel

    SciTech Connect

    Zuhlke, Craig A.; Anderson, Troy P.; Alexander, Dennis R.

    2013-09-16

    The structural and chemical composition of two unique microstructures formed on nickel, with nanoscale features, produced using femtosecond laser surface processing (FLSP) techniques is reported in this paper. These two surface morphologies, termed mounds and nanoparticle-covered pyramids, are part of a larger class of self-organized micro/nanostructured surfaces formed using FLSP. Cross-sections of the structures produced using focused ion beam milling techniques were analyzed with a transmission electron microscope. Both morphologies have a solid core with a layer of nanoparticles on the surface. Energy dispersive X-ray spectroscopy by scanning transmission electron microscopy studies reveal that the nanoparticles are a nickel oxide, while the core material is pure nickel.

  7. Process of producing a ceramic matrix composite article and article formed thereby

    DOEpatents

    Corman, Gregory Scot; McGuigan, Henry Charles; Brun, Milivoj Konstantin

    2010-05-04

    A CMC article and process for producing the article to have a layer on its surface that protects a reinforcement material within the article from damage. The method entails providing a body containing a ceramic reinforcement material in a matrix material that contains a precursor of a ceramic matrix material. A fraction of the reinforcement material is present and possibly exposed at a surface of the body. The body surface is then provided with a surface layer formed of a slurry containing a particulate material but lacking the reinforcement material of the body. The body and surface layer are heated to form the article by converting the precursor within the body to form the ceramic matrix material in which the reinforcement material is contained, and by converting the surface layer to form the protective layer that covers any fraction of the reinforcement material exposed at the body surface.

  8. *d13C composition of primary producers and role of detritus in a freshwater coastal ecosystem

    USGS Publications Warehouse

    Keough, J.R.; Hagley, C.A.; Sierszen, M.

    1998-01-01

    Stable-isotope ratio signatures of primary producers in a coastal wetland and in adjacent offshore waters of western Lake Superior indicated that phytoplankton are the primary source of carbon for the grazing food web of this ecosystem. This study outlines the possible roles of other autotrophs in this regard. Isotopic signatures of macrophytes reflected their life-form-associated constraints on diffusion of inorganic carbon. Data indicated that differences between wetland and lake phytoplankton may be explained by the isotopic signatures of their dissolved inorganic carbon (DIC) sources. Results of an in situ experiment showed that respiration associated with macrophyte decomposition is capable of enriching surrounding water with significant amounts of *d13C-depleted DIC and lowering the net *d13C ratio of DIC in water in low-turbulence situations. The *d13C ratio for wetland phytoplankton may be depleted relative to pelagic algae because the fixed carbon is derived from decomposing detritus.

  9. Process of producing a ceramic matrix composite article and article formed thereby

    DOEpatents

    Corman, Gregory Scot; McGuigan, Henry Charles; Brun, Milivoj Konstantin

    2011-10-25

    A CMC article and process for producing the article to have a layer on its surface that protects a reinforcement material within the article from damage. The method entails providing a body containing a ceramic reinforcement material in a matrix material that contains a precursor of a ceramic matrix material. A fraction of the reinforcement material is present and possibly exposed at a surface of the body. The body surface is then provided with a surface layer formed of a slurry containing a particulate material but lacking the reinforcement material of the body. The body and surface layer are heated to form the article by converting the precursor within the body to form the ceramic matrix material in which the reinforcement material is contained, and by converting the surface layer to form the protective layer that covers any fraction of the reinforcement material exposed at the body surface.

  10. Composition of the excimer laser-induced plume produced during LASIK refractive surgery

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Liu, Yun; Mayo, George L.; Baribeau, Alan D.; Starck, Tomy; Bankhead, Tom

    2003-07-01

    Because of concerns about potential hazards to surgical personnel of the plume associated with laser refractive surgery, this study was performed to characterize the composition of such plumes. Filter elements were removed from the smoke evacuator of a VISX S3 excimer laser (filter pore size ~0.3 microns) and from a Mastel Clean Room ( filter pore size ~0.2 microns) used with a LADARVISION excimer laser. The filters from both laser systems captured the laser-induced plumes from multiple, routine, LASIK patient procedures. Some filters were processed for scanning electron microscopy, while others were extracted with methanol and chloroform for biochemical analysis. Both the VISX "Final Air" filter and the Mastel "Clean Room" filter captured material that was not observed in filters that had clean operating room air only passed through them. In the VISX system, air flows through the filter unit parallel to the filter matrix. SEM analysis showed these filters captured discrete particles of 0.3 to 3.0 microns in size. In the Mastel Clean Room unit, air flows orthogonally through the filter, and the filter matrix was heavily layered with captured debris so that individual particles were not readily distinguished. Amino acid analysis and gel electrophoresis of extracted material revealed proteinaceous molecules as large as 5000 molecular weight. Such large molecules in the laser plume are not predicted by the existing theory of photochemical ablation. The presence of relatively large biomolecules may constitute a risk of allergenic reactions in personnel exposed to the plume, and also calls into question the precise mechanism of excimer laser photochemical ablation. Supported by the RMG Research Endowment, and Research to Prevent Blindness

  11. Mechanisms of formation of nonlinear optical light guide structures in metal cluster composites produced by ion beam implantation

    SciTech Connect

    Sarkisov, S.S.; Williams, E.K.; Curley, M.; Smith, C.C.; Ila, D.; Venkateswarlu, P.; Poker, D.B.; Hensley, D.K.

    1997-11-01

    Ion implantation has been shown to produce a high density of metal colloids in glasses and crystalline materials. The high-precipitate volume fraction and small size of metal nanoclusters formed leads to values for the third-order susceptibility much greater than those for metal doped solids. This has stimulated interest in use of ion implantation to make nonlinear optical materials. On the other side, LiNbO{sub 3} has proved to be a good material for optical waveguides produced by MeV ion implantation. Light confinement in these waveguides is produced by refractive index step difference between the implanted region and the bulk material. Implantation of LiNbO{sub 3} with MeV metal ions can therefore result into nonlinear optical waveguide structures with great potential in a variety of device applications. The authors describe linear and nonlinear optical properties of a waveguide structure in LiNbO{sub 3}-based composite material produced by silver ion implantation in connection with mechanisms of its formation.

  12. Effects of Carbon Allotropic Forms on Microstructure and Thermal Properties of Cu-C Composites Produced by SPS

    NASA Astrophysics Data System (ADS)

    Pietrzak, K.; Sobczak, N.; Chmielewski, M.; Homa, M.; Gazda, A.; Zybała, R.; Strojny-Nędza, A.

    2016-02-01

    Combination of extreme service conditions and complex thermomechanical loadings, e.g., in electronics or power industry, requires using advanced materials with unique properties. Dissipation of heat generated during the operation of high-power electronic elements is crucial from the point of view of their efficiency. Good cooling conditions can be guaranteed, for instance, with materials of very high thermal conductivity and low thermal expansion coefficient, and by designing the heat dissipation system in an accurate manner. Conventional materials such as silver, copper, or their alloys, often fail to meet such severe requirements. This paper discusses the results of investigations connected with Cu-C (multiwall carbon nanotubes (MWNTs), graphene nanopowder (GNP), or thermally reduced graphene oxide (RGO)) composites, produced using the spark plasma sintering technique. The obtained composites are characterized by uniform distribution of a carbon phase and high relative density. Compared with pure copper, developed materials are characterized by similar thermal conductivity and much lower values of thermal expansion coefficient. The most promising materials to use as heat dissipation elements seems to be copper-based composites reinforced by carbon nanotubes (CNTs) and GNP.

  13. Methods for Producing High-Performance Silicon Carbide Fibers, Architectural Preforms, and High-Temperature Composite Structures

    NASA Technical Reports Server (NTRS)

    DiCarlo, James A. (Inventor); Yun, Hee-Mann (Inventor)

    2014-01-01

    Methods are disclosed for producing architectural preforms and high-temperature composite structures containing high-strength ceramic fibers with reduced preforming stresses within each fiber, with an in-situ grown coating on each fiber surface, with reduced boron within the bulk of each fiber, and with improved tensile creep and rupture resistance properties tier each fiber. The methods include the steps of preparing an original sample of a preform formed from a pre-selected high-strength silicon carbide ceramic fiber type, placing the original sample in a processing furnace under a pre-selected preforming stress state and thermally treating the sample in the processing furnace at a pre-selected processing temperature and hold time in a processing gas having a pre-selected composition, pressure, and flow rate. For the high-temperature composite structures, the method includes additional steps of depositing a thin interphase coating on the surface of each fiber and forming a ceramic or carbon-based matrix within the sample.

  14. The functional TiO2-biodegradable plastic composite material produced by HVOF spraying process.

    PubMed

    Bang, Hee-Seon; Bang, Han-Sur; Lee, Yoon-Ki

    2007-11-01

    Photocatalytic TiO2 coatings on bio-degradable plastic(polybutylene succinate: PBS) were prepared by HVOF spraying using three kinds of agglomerated powders (P200: 200 nm, P30: 30 nm, P7: 7 nm). The microstructures of the coatings were characterized with SEM and XRD analysis, and the photocatalytic efficiency of the coatings was evaluated by photo degradation of gaseous acetaldehyde. For both the HVOF sprayed P200 and P30 coatings, high anatase ratio of 100% was achieved, regardless of the fuel gas pressure. On the other hand, for the HVOF sprayed P7 coating, the anatase ratio decreased from 100% to 49.1% with increasing fuel gas pressure. This decrease may be attributed to the much higher susceptibility to heat of the 7 nm agglomerated powders than the 30 nm and 200 nm agglomerated powders. In terms of the photocatalytic efficiency, HVOF sprayed P200 and P30 coatings seemed to outperform the P7 coatings because of their higher anatase ratios. However, the HVOF sprayed P7 coatings did not show photocatalytic activity possibly because of the extremely small reaction surface area to the photo-catalytic activity and low anatase ratio. Therefore, the present study found that functional PBS plastic with photocatalytic performance could be produced by spraying of ceramics such as TiO2. PMID:18047069

  15. Enzymatic activities produced by mixed Saccharomyces and non-Saccharomyces cultures: relationship with wine volatile composition.

    PubMed

    Maturano, Yolanda Paola; Assof, Mariela; Fabani, María Paula; Nally, María Cristina; Jofré, Viviana; Rodríguez Assaf, Leticia Anahí; Toro, María Eugenia; Castellanos de Figueroa, Lucía Inés; Vazquez, Fabio

    2015-11-01

    During certain wine fermentation processes, yeasts, and mainly non-Saccharomyces strains, produce and secrete enzymes such as β-glucosidases, proteases, pectinases, xylanases and amylases. The effects of enzyme activity on the aromatic quality of wines during grape juice fermentation, using different co-inoculation strategies of non-Saccharomyces and Saccharomyces cerevisiae yeasts, were assessed in the current study. Three strains with appropriate enological performance and high enzymatic activities, BSc562 (S. cerevisiae), BDv566 (Debaryomyces vanrijiae) and BCs403 (Candida sake), were assayed in pure and mixed Saccharomyces/non-Saccharomyces cultures. β-Glucosidase, pectinase, protease, xylanase and amylase activities were quantified during fermentations. The aromatic profile of pure and mixed cultures was determined at the end of each fermentation. In mixed cultures, non-Saccharomyces species were detected until day 4-5 of the fermentation process, and highest populations were observed in MSD2 (10% S. cerevisiae/90% D. vanrijiae) and MSC1 (1% S. cerevisiae/99% C. sake). According to correlation and multivariate analysis, MSD2 presented the highest concentrations of terpenes and higher alcohols which were associated with pectinase, amylase and xylanase activities. On the other hand, MSC1 high levels of β-glucosidase, proteolytic and xylanolytic activities were correlated to esters and fatty acids. Our study contributes to a better understanding of the effect of enzymatic activities by yeasts on compound transformations that occur during wine fermentation. PMID:26386703

  16. Investigation of defectiveness of multiwalled carbon nanotubes produced with Fe-Co catalysts of different composition

    NASA Astrophysics Data System (ADS)

    Bokova-Sirosh, Sofya N.; Kuznetsov, Vladimir L.; Romanenko, Anatoly I.; Kazakova, Mariya A.; Krasnikov, Dmitry V.; Tkachev, Evgeniy N.; Yuzyuk, Yury I.; Obraztsova, Elena D.

    2016-01-01

    We have performed a study of CVD multiwalled carbon nanotubes (MWCNTs) produced with Fe-Co catalysts with a variable ratio of active metals. The Raman data were considered in combination with the temperature dependence of MWCNT conductivity. The data analysis is based on the point that the value of I2D/ID ratio correlates with the graphene fragment size. The fragments are considered as building blocks of MWCNTs. We showed that MWCNT defectiveness depends on the ratio of bimetallic active components in the Fe-Co catalyst. Thus, the ratio of I2D/ID increases and the D-mode intensity decreases while the Fe content in the catalyst increases. This also points to the reduction of defect number in the bigger graphene fragments. These results correlate with the data on conductivity temperature dependence. Namely, the increase of Fe content in the active component of the Fe-Co catalyst results in the increase of charge carrier concentration, which, in turn, indicates a decrease in MWCNT defectiveness.

  17. Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

    PubMed Central

    Nabok, Alexei; Davis, Frank; Higson, Séamus P J

    2016-01-01

    Summary In this paper we detail a novel semi-automated method for the production of graphene by sonochemical exfoliation of graphite in the presence of ionic surfactants, e.g., sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB). The formation of individual graphene flakes was confirmed by Raman spectroscopy, while the interaction of graphene with surfactants was proven by NMR spectroscopy. The resulting graphene–surfactant composite material formed a stable suspension in water and some organic solvents, such as chloroform. Graphene thin films were then produced using Langmuir–Blodgett (LB) or electrostatic layer-by-layer (LbL) deposition techniques. The composition and morphology of the films produced was studied with SEM/EDX and AFM. The best results in terms of adhesion and surface coverage were achieved using LbL deposition of graphene(−)SDS alternated with polyethyleneimine (PEI). The optical study of graphene thin films deposited on different substrates was carried out using UV–vis absorption spectroscopy and spectroscopic ellipsometry. A particular focus was on studying graphene layers deposited on gold-coated glass using a method of total internal reflection ellipsometry (TIRE) which revealed the enhancement of the surface plasmon resonance in thin gold films by depositing graphene layers. PMID:26977378

  18. Characterisation of thin films of graphene-surfactant composites produced through a novel semi-automated method.

    PubMed

    Walch, Nik J; Nabok, Alexei; Davis, Frank; Higson, Séamus P J

    2016-01-01

    In this paper we detail a novel semi-automated method for the production of graphene by sonochemical exfoliation of graphite in the presence of ionic surfactants, e.g., sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB). The formation of individual graphene flakes was confirmed by Raman spectroscopy, while the interaction of graphene with surfactants was proven by NMR spectroscopy. The resulting graphene-surfactant composite material formed a stable suspension in water and some organic solvents, such as chloroform. Graphene thin films were then produced using Langmuir-Blodgett (LB) or electrostatic layer-by-layer (LbL) deposition techniques. The composition and morphology of the films produced was studied with SEM/EDX and AFM. The best results in terms of adhesion and surface coverage were achieved using LbL deposition of graphene(-)SDS alternated with polyethyleneimine (PEI). The optical study of graphene thin films deposited on different substrates was carried out using UV-vis absorption spectroscopy and spectroscopic ellipsometry. A particular focus was on studying graphene layers deposited on gold-coated glass using a method of total internal reflection ellipsometry (TIRE) which revealed the enhancement of the surface plasmon resonance in thin gold films by depositing graphene layers. PMID:26977378

  19. Bacterial diversity and composition in major fresh produce growing soils affected by physiochemical properties and geographic locations.

    PubMed

    Ma, Jincai; Ibekwe, A Mark; Yang, Ching-Hong; Crowley, David E

    2016-09-01

    Microbial diversity of agricultural soils has been well documented, but information on leafy green producing soils is limited. In this study, we investigated microbial diversity and community structures in 32 (16 organic, 16 conventionally managed soils) from California (CA) and Arizona (AZ) using pyrosequencing, and identified factors affecting bacterial composition. Results of detrended correspondence analysis (DCA) and dissimilarity analysis showed that bacterial community structures of conventionally managed soils were similar to that of organically managed soils; while the bacterial community structures in soils from Salinas, California were different (P<0.05) from those in soils from Yuma, Arizona and Imperial Valley, California. Canonical correspondence analysis (CCA) and artificial neural network (ANN) analysis of bacterial community structures and soil variables showed that electrical conductivity (EC), clay content, water-holding capacity (WHC), pH, total nitrogen (TN), and organic carbon (OC) significantly (P<0.05) correlated with microbial communities. CCA based variation partitioning analysis (VPA) showed that soil physical properties (clay, EC, and WHC), soil chemical variables (pH, TN, and OC) and sampling location explained 16.3%, 12.5%, and 50.9%, respectively, of total variations in bacterial community structure, leaving 13% of the total variation unexplained. Our current study showed that bacterial community composition and diversity in major fresh produce growing soils from California and Arizona is a function of soil physiochemical characteristics and geographic distances of sampling sites. PMID:27135583

  20. Iron isotope composition of particles produced by UV-femtosecond laser ablation of natural oxides, sulfides, and carbonates.

    PubMed

    d'Abzac, Francois-Xavier; Beard, Brian L; Czaja, Andrew D; Konishi, Hiromi; Schauer, James J; Johnson, Clark M

    2013-12-17

    The need for femtosecond laser ablation (fs-LA) systems coupled to MC-ICP-MS to accurately perform in situ stable isotope analyses remains an open question, because of the lack of knowledge concerning ablation-related isotopic fractionation in this regime. We report the first iron isotope analysis of size-resolved, laser-induced particles of natural magnetite, siderite, pyrrhotite, and pyrite, collected through cascade impaction, followed by analysis by solution nebulization MC-ICP-MS, as well as imaging using electron microscopy. Iron mass distributions are independent of mineralogy, and particle morphology includes both spheres and agglomerates for all ablated phases. X-ray spectroscopy shows elemental fractionation in siderite (C-rich agglomerates) and pyrrhotite/pyrite (S-rich spheres). We find an increase in (56)Fe/(54)Fe ratios of +2‰, +1.2‰, and +0.8‰ with increasing particle size for magnetite, siderite, and pyrrhotite, respectively. Fe isotope differences in size-sorted aerosols from pyrite ablation are not analytically resolvable. Experimental data are discussed using models of particles generation by Hergenröder and elemental/isotopic fractionation by Richter. We interpret the isotopic fractionation to be related to the iron condensation time scale, dependent on its saturation in the gas phase, as a function of mineral composition. Despite the isotopic variations across aerosol size fractions, total aerosol composition, as calculated from mass balance, confirms that fs-LA produces a stoichiometric sampling in terms of isotopic composition. Specifically, both elemental and isotopic fractionation are produced by particle generation processes and not by femtosecond laser-matter interactions. These results provide critical insights into the analytical requirements for laser-ablation-based stable isotope measurements of high-precision and accuracy in geological samples, including the importance of quantitative aerosol transport to the ICP. PMID

  1. Quantity, composition and water contamination potential of ash produced under different wildfire severities.

    PubMed

    Santín, Cristina; Doerr, Stefan H; Otero, Xosé L; Chafer, Chris J

    2015-10-01

    Wildfires frequently threaten water quality through the transfer of eroded ash and soil into rivers and reservoirs. The ability to anticipate risks for water resources from wildfires is fundamental for implementing effective fire preparedness plans and post-fire mitigation measures. Here we present a new approach that allows quantifying the amount and characteristics of ash generated under different wildfire severities and its respective water contamination potential. This approach is applied to a wildfire in an Australian dry sclerophyll eucalypt forest, but can be adapted for use in other environments. The Balmoral fire of October 2013 affected 12,694 ha of Sydney's forested water supply catchment. It produced substantial ash loads that increased with fire severity, with 6, 16 and 34 Mg ha(-1) found in areas affected by low, high and extreme fire severity, respectively. Ash bulk density was also positively related to fire severity. The increase with fire severity in the total load and bulk density of the ash generated is mainly attributed to a combination of associated increases in (i) total amount of fuel affected by fire and (ii) contribution of charred mineral soil to the ash layer. Total concentrations of pollutants and nutrients in ash were mostly unrelated to fire severity and relatively low compared to values reported for wildfire ash in other environments (e.g. 4.0-7.3mg As kg(-1); 2.3-4.1 B mg kg(-1); 136-154 P mg kg(-1)). Solubility of the elements analysed was also low, less than 10% of the total concentration for all elements except for B (6-14%) and Na (30-50%). This could be related to a partial loss of soluble components by leaching and/or wind erosion before the ash sampling (10 weeks after the fire and before major ash mobilisation by water erosion). Even with their relatively low concentrations of potential pollutants, the substantial total ash loads found here represent a water contamination risk if transported into the hydrological network

  2. Fundamental and molecular composition characteristics of biochars produced from sugarcane and rice crop residues and by-products.

    PubMed

    Jeong, Chang Yoon; Dodla, Syam K; Wang, Jim J

    2016-01-01

    Biochar conversion of sugarcane and rice harvest residues provides an alternative for managing these crop residues that are traditionally burned in open field. Sugarcane leaves, bagasse, rice straw and husk were converted to biochar at four pyrolysis temperatures (PTs) of 450 °C, 550 °C, 650 °C, and 750 °C and evaluated for various elemental, molecular and surface properties. The carbon content of biochars was highest for those produced at 650-750 °C. Biochars produced at 550 °C showed the characteristics of biochar that are commonly interpreted as being stable in soil, with low H/C and O/C ratios and pyrolysis fingerprints dominated by aromatic and polyaromatic hydrocarbons. At 550 °C, all biochars also exhibited maximum CEC values with sugarcane leaves biochar (SLB) > sugarcane bagasse biochar (SBB) > rice straw biochar (RSB) > rice husk biochar (RHB). The pore size distribution of biochars was dominated by pores of 20 nm and high PT increased both smaller and larger than 50 nm pores. Water holding capacity of biochars increased with PT but the magnitude of the increase was limited by feedstock types, likely related to the hydrophobicity of biochars as evident by molecular composition, besides pore volume properties of biochars. Py-GC/MS analysis revealed a clear destruction of lignin with decarboxylation and demethoxylation at 450 °C and dehydroxylation at above 550 °C. Overall, biochar molecular compositions became similar as PT increased, and the biochars produced at 550 °C demonstrated characteristics that have potential benefit as soil amendment for improving both C sequestration and nutrient dynamics. PMID:26058554

  3. Composite Bacterial Hopanoids and Their Microbial Producers across Oxygen Gradients in the Water Column of the California Current

    PubMed Central

    Ugalde, Juan A.; Hogle, Shane L.; Allen, Eric E.; Aluwihare, Lihini I.

    2013-01-01

    Hopanoids are pentacyclic triterpenoid lipids produced by many prokaryotes as cell membrane components. The structural variations of composite hopanoids, or bacteriohopanepolyols (BHPs), produced by various bacterial genera make them potentially useful molecular biomarkers of bacterial communities and metabolic processes in both modern and ancient environments. Building on previous work suggesting that organisms in low-oxygen environments are important contributors to BHP production in the marine water column and that there may be physiological roles for BHPs specific to these environments, this study investigated the relationship between trends in BHP structural diversity and abundance and the genetic diversity of BHP producers for the first time in a low-oxygen environment of the Eastern Tropical North Pacific. Amplification of the hopanoid biosynthesis gene for squalene hopene cyclase (sqhC) indicated far greater genetic diversity than would be predicted by examining BHP structural diversity alone and that greater sqhC genetic diversity exists in the marine environment than is represented by cultured representatives and most marine metagenomes. In addition, the genetic relationships in this data set suggest microaerophilic environments as potential “hot spots” of BHP production. Finally, structural analysis of BHPs showed that an isomer of the commonly observed BHP bacteriohopanetetrol may be linked to a producer that is more abundant in low-oxygen environments. Results of this study increase the known diversity of BHP producers and provide a detailed phylogeny with implications for the role of hopanoids in modern bacteria, as well as the evolutionary history of hopanoid biosynthesis, both of which are important considerations for future interpretations of the marine sedimentary record. PMID:24077702

  4. Spray dried double emulsions containing procyanidin-rich extracts produced by premix membrane emulsification: effect of interfacial composition.

    PubMed

    Berendsen, Rikkert; Güell, Carme; Ferrando, Montserrat

    2015-07-01

    Spray drying of procyanidin-loaded W1/O/W2 emulsions produced by premix membrane emulsification (ME) enabled to produce microcapsules containing procyanidins. The interface of the emulsion droplets prior to spray drying was stabilized with several hydrophilic emulsifiers (whey protein (WPI), WPI-carboxylmethyl cellulose, WPI-gum Arabic, and WPI-chitosan). Their effect on procyanidin encapsulation efficiency, water activity, moisture and oil content, and microcapsule size distribution was investigated. Furthermore, the microstructure and droplet size distribution of redispersed microcapsules were analyzed. Although premix ME produced W1/O/W2 emulsions with a narrow droplet size distribution regardless the hydrophilic emulsifier (main peak of droplet size distribution around 9 μm), microcapsules after spray drying and double emulsions after redispersion showed profound differences in sizes depending on the interfacial composition. WPI-CMC stabilized microcapsules not only showed the highest procyanidin content (5.3 g kg(-1)) but also gave the narrowest particle size distribution with the lowest particle size for both microcapsules and the corresponding emulsions after rehydration (7.7 and 9.9 μm respectively). PMID:25704709

  5. Chemical composition, pretreatments and saccharification of Senna siamea (Lam.) H.S. Irwin & Barneby: An efficient biomass producing tree legume.

    PubMed

    Mund, Nitesh K; Dash, Debabrata; Barik, Chitta R; Goud, Vaibhav V; Sahoo, Lingaraj; Mishra, Prasannajit; Nayak, Nihar R

    2016-05-01

    Protocols were developed for efficient release of glucose from the biomass of Senna siamea, one of the highly efficient biomass producing tree legumes. Composition of mature, 1year and 2years coppice biomass were analysed. For the hydrolysis of the glucan, two pretreatments, cellulose solvent- and organic solvent-based lignocellulose fractionation (COSLIF) and alkali (sodium hydroxide) were used; COSLIF (85% phosphoric acid, 45min incubation at 50°C) pretreated mature biomass exhibited best result in which 88.90% glucose released after 72h of incubation with the use of 5 filter paper units (FPU) of cellulase and 10 international units (IU) of β-glucosidase per gram of glucan. Of the biomass of different particle sizes (40-200mesh) used for saccharification, 40-60mesh shown the maximum glucose release. COSLIF pretreated mature, 1year and 2years coppice biomass showed equivalent glucose release profiles. PMID:26890795

  6. Compositional variation of sialon phase produced after carbothermal reduction and nitridation of vermiculite-polyacrylonitrile intercalation compound

    SciTech Connect

    Aviles, M.A.; Sanchez-Soto, P.J.; Justo, A.; Perez-Rodriguez, J.L. . Instituto de Ciencia de Materiales)

    1994-10-01

    Vermiculite (Al-Mg hydrated layer silicate) has been used as raw material for the synthesis of nitrogen ceramics in the Si-Al-Mg-O-N system in the presence of carbon. Successive intercalation of butylammonium cation and acrylonitrile, followed by polymerization and cyclization of the polymer and thermal treatment under nitrogen flow, have produced the carbothermal reduction and reactive nitridation of the precursor, yielding [beta]-Si[sub 3]N[sub 4] and [beta]-sialon as nitrided phases. Thermal evolution of the intercalated samples from 1,000 C to 1,500 C has been studied by XRD and IR spectroscopy. The composition variation of sialon phase was found to be a function of heating temperature and soaking time at 1,400 C. These facts were explained on the basis of a complex vapor-liquid-solid mechanism.

  7. Composition of Secondary Organic Aerosols Produced by Photo-Oxidation of Biomass Burning Emissions in a Smog Chamber

    NASA Astrophysics Data System (ADS)

    Desyaterik, Y.; Sullivan, A.; Hennigan, C. J.; Robinson, A. L.; Collett, J. L.

    2009-12-01

    Knowledge of the chemical composition of atmospheric organic aerosols (OA) is essential for accurate representation of OA in air quality and climate models. Both the sources of OA and their properties and effects remain poorly understood. In particular, we still know relatively little about the atmospheric formation of secondary organic aerosols (SOA). There is growing interest in the impact of biomass burning emissions on air quality, human health, and radiative forcing. Through a series of experiments, we are working to quantify changes in the chemical composition of wood smoke particles as a result of photochemical aging under well-controlled laboratory conditions. One specific objective of this study is to identify markers for biomass burning SOA and test whether these markers can be used in atmospheric samples to quantify SOA formation from aging of biomass burning emissions. We analyzed SOA generated in a smog chamber by photooxidation of smoke produced by burning oak wood. In order to initiate photochemistry, the chamber was irradiated with UV light. Aqueous extracts of collected aerosol samples were analyzed with Electrospray Ionization Time-of-Flight Mass Spectrometry. The high mass accuracy of these measurements reduces ambiguity in the assignment of elemental compositions for observed ions. Analysis has shown that primary oak smoke aerosol includes products of the thermal decomposition of cellulose (levoglucosan, cyclotene etc.) and lignin (guaiacol and syringol derivatives, mostly aldehydes and alcohols). After 2 hours of aging at typical summertime hydroxyl radical concentrations, the aerosol mass increased 2.5 fold due to the production of secondary organic aerosol. Mass spectra of the secondary organic aerosol formed are dominated by organic nitrates (nitrophenol, nitrocresol, nitrocatechol, and nitroguaiacol) and aromatic acids (benzoic acid, mono and di-hydroxybenzoic acid). Both nitrates and acids most likely are formed due to oxidation of the

  8. Mercury stable isotopic compositions in coals from major coal producing fields in China and their geochemical and environmental implications.

    PubMed

    Yin, Runsheng; Feng, Xinbin; Chen, Jiubin

    2014-05-20

    Total mercury (Hg) concentrations (THg) and stable mercury isotopic compositions were measured in coal samples (n = 61) from major coal producing fields in China. The THg concentrations in coals ranged from 0.05 to 0.78 μg g(-1), with a geometric mean of 0.22 μg g(-1). Hg isotopic compositions in coals showed large variations both in mass-dependent fractionation (MDF, δ(202)Hg: -2.36 to -0.14‰) and mass-independent fractionation (MIF, Δ(199)Hg: -0.44 to +0.38‰). The MIF signatures in coals may reveal important information on the coal-forming conditions (e.g., humic and sapropelic). The Δ(199)Hg/Δ(201)Hg of ∼1 determined in coals indicated that a portion of Hg has been subjected to photoreduction process prior to being incorporated to coals. On the basis of THg, Hg isotopic signatures, and other geological factors (e.g., total ash content and total sulfur content), the potential sources of Hg in coals from different coal producing regions were estimated. The main source of Hg in coals from southwestern China and eastern part of northern China is likely geogenic Hg, whereas the source of Hg in coals from other parts of northern China is mainly biogenic Hg. Finally, we estimated that Hg emission from coal combustion in China is characterized by diagnostic Hg isotopic signatures (δ(202)Hg: ∼-0.70‰ and Δ(199)Hg: ∼-0.05‰). The present study demonstrates that Hg isotopes can serve as a tool in understanding the sources and transformation of Hg in coals and may also be used as a tracer to quantify Hg emissions from coal combustion. PMID:24742360

  9. High damping Al-Fe-Mo-Si/Zn-Al composites produced by rapidly solidified powder metallurgy process

    SciTech Connect

    Li, P.Y.; Dai, S.L.; Chai, S.C.; Li, Y.R.

    2000-05-10

    The metallic materials commonly used in aircraft and aerospace fields, such as aluminum and titanium alloys, steels, etc., show extremely low damping capacity (usually of the order of or less than 10{sup {minus}3}). Thus, some problems related to vibration may emerge and influence the reliability, safety and life of airplanes, satellites, etc. It has been reported that almost two thirds of errors for rockets and satellites are related to vibration and noise. One effective way to solve these vibration-related problems is to adopt high damping metallic materials. Conventional high damping alloys exhibit damping capacity above 10{sup {minus}2}, however, their densities are usually great than 5 x 10{sup 3} kg m{sup {minus}3}, or their strengths are less than 200 MPa (for alloys based on dislocation damping), making them impossible to be applied to aircraft and aerospace areas. Recently, some low-density high-damping metal/metal composites based on aluminum and high damping alloys have been developed in Beijing Institute of Aeronautical Materials (BIAM) by the rapidly solidified power metallurgy process. This paper aims to report the properties of the composites based on a high temperature Al-Fe-Mo-Si alloy and a high damping Zn-Al alloy, and compare them with that of 2618-T61 alloy produced by the ingot metallurgy process.

  10. Effects of oxidizing medium on the composition, morphology and optical properties of copper oxide nanoparticles produced by pulsed laser ablation

    NASA Astrophysics Data System (ADS)

    Gondal, M. A.; Qahtan, Talal F.; Dastageer, M. A.; Saleh, Tawfik A.; Maganda, Yasin W.; Anjum, D. H.

    2013-12-01

    Pulsed laser ablation in liquid (PLAL) with 532 nm wavelength laser with 5 ns pulse duration is used to produce the nanostructure copper oxide and the effects of oxidizing media (deionized water and hydrogen peroxide) on the composition, morphology and optical properties of the product materials produced by PLAL were studied. XRD and TEM studies indicate that in the absence of hydrogen peroxide, the product material is in two phases (Cu/Cu2O) with the spherical nanoparticle structure, whereas in the presence of hydrogen peroxide in the liquid medium, the product material revealed other two phases (Cu/CuO) with nanorod-like structure. The optical studies revealed a considerable red shift (3.34-2.5 eV) in the band gap energy in the case of hydrogen peroxide in the liquid medium in PLAL synthesis compared to the one in the absence of it. Also the product material in the presence of hydrogen peroxide in the liquid medium showed a reduced photoluminescence intensity indicating the reduced electron-hole recombination rate. The red shift in the band gap energy and the reduced electron-hole recombination rate make the product material an ideal photocatalyst to harvest solar radiation for various applications. The most relevant signals on the FTIR spectrum for the samples are the absorption bands in the region between 450 and 700 cm-1 which are the characteristics bands of coppersbnd oxygen bonds. The reported laser ablation approach for the synthesis of Cu2O and CuO nanoparticles has the advantages of being clean method with controlled particle properties.

  11. Nutritional composition of “gari” analog produced from cassava (Manihot esculenta) and cocoyam (Colocasia esculenta) tuber

    PubMed Central

    Bamidele, Oluwaseun P; Ogundele, Femi G; Ojubanire, Basirat A; Fasogbon, Mofoluwaso B; Bello, Olayide W

    2014-01-01

    Physicochemical properties ofgari analog produced from coprocessing of Cassava (Manihot esculenta Crantz) and Cocoyam (Colocasia esculenta) were investigated. Cassava tuber and cocoyam were coprocessed at different percentages before frying separately. Proximate composition, mineral content, antinutritional factors, and sensory evaluation of various samples were determined. The results showed that the moisture content of all the samples was in the same range (7.28 ± 0.30 to 7.78 ± 0.14%). The protein content (1.57 ± 0.14 to 4.43 ± 0.16), ash (1.89 ± 0.10 to 2.15 ± 0.30), and crude fiber (1.53 ± 0.50 to 2.19 ± 0.10%) showed a significant increase with increase in the level of cocoyam substitution. The fat and carbohydrate content decreased with an increase in cocoyam level. The mineral contents of the samples increased with an increase in cocoyam content with sample F having the highest value of potassium, followed by samples E and D (68 mg/100 g, 35 mg/100 g, and 24 mg/100 g). The antinutritional factors of all the samples were at very low concentration while samples B, C, and D competed favorably with sample A (control) in sensory evaluation. In conclusion, coprocessing of cassava and cocoyam improved the nutritional quality of thegari produced with high level of acceptance from the taste panelist. PMID:25493189

  12. Characterization of five typical agave plants used to produce mezcal through their simple lipid composition analysis by gas chromatography.

    PubMed

    Martínez-Aguilar, Juan Fco; Peña-Alvarez, Araceli

    2009-03-11

    Five agave plants typically used in Mexico for making mezcal in places included in the Denomination of Origin (Mexican federal law that establishes the territory within which mezcal can be produced) of this spirit were analyzed: Agave salmiana ssp. crassispina, A. salmiana var. salmiana, Agave angustifolia, Agave cupreata, and Agave karwinskii. Fatty acid and total simple lipid profiles of the mature heads of each plant were determined by means of a modified Bligh-Dyer extraction and gas chromatography. Sixteen fatty acids were identified, from capric to lignoceric, ranging from 0.40 to 459 microg/g of agave. Identified lipids include free fatty acids, beta-sitosterol, and groups of mono-, di-, and triacylglycerols, their total concentration ranging from 459 to 992 microg/g of agave. Multivariate analyses performed on the fatty acid profiles showed a close similarity between A. cupreata and A. angustifolia. This fact can be ascribed to the taxa themselves or differences in growing conditions, an issue that is still to be explored. These results help to characterize the agaves chemically and can serve to relate the composition of mezcals from various states of Mexico with the corresponding raw material. PMID:19216532

  13. Carriage of Enterobacteria Producing Extended-Spectrum β-Lactamases and Composition of the Gut Microbiota in an Amerindian Community.

    PubMed

    Gosalbes, María José; Vázquez-Castellanos, Jorge F; Angebault, Cécile; Woerther, Paul-Louis; Ruppé, Etienne; Ferrús, María Loreto; Latorre, Amparo; Andremont, Antoine; Moya, Andrés

    2016-01-01

    Epidemiological and individual risk factors for colonization by enterobacteria producing extended-spectrum beta-lactamases (E-ESBL) have been studied extensively, but whether such colonization is associated with significant changes in the composition of the rest of the microbiota is still unknown. To address this issue, we assessed in an isolated Amerindian Guianese community whether intestinal carriage of E-ESBL was associated with specificities in gut microbiota using metagenomic and metatranscriptomic approaches. While the richness of taxa of the active microbiota of carriers was similar to that of noncarriers, the taxa were less homogeneous. In addition, species of four genera, Desulfovibrio, Oscillospira, Parabacteroides, and Coprococcus, were significantly more abundant in the active microbiota of noncarriers than in the active microbiota of carriers, whereas such was the case only for species of Desulfovibrio and Oscillospira in the total microbiota. Differential genera in noncarrier microbiota could either be associated with resistance to colonization or be the consequence of the colonization by E-ESBL. PMID:26552974

  14. Carriage of Enterobacteria Producing Extended-Spectrum β-Lactamases and Composition of the Gut Microbiota in an Amerindian Community

    PubMed Central

    Gosalbes, María José; Vázquez-Castellanos, Jorge F.; Angebault, Cécile; Woerther, Paul-Louis; Ruppé, Etienne; Ferrús, María Loreto; Latorre, Amparo

    2015-01-01

    Epidemiological and individual risk factors for colonization by enterobacteria producing extended-spectrum beta-lactamases (E-ESBL) have been studied extensively, but whether such colonization is associated with significant changes in the composition of the rest of the microbiota is still unknown. To address this issue, we assessed in an isolated Amerindian Guianese community whether intestinal carriage of E-ESBL was associated with specificities in gut microbiota using metagenomic and metatranscriptomic approaches. While the richness of taxa of the active microbiota of carriers was similar to that of noncarriers, the taxa were less homogeneous. In addition, species of four genera, Desulfovibrio, Oscillospira, Parabacteroides, and Coprococcus, were significantly more abundant in the active microbiota of noncarriers than in the active microbiota of carriers, whereas such was the case only for species of Desulfovibrio and Oscillospira in the total microbiota. Differential genera in noncarrier microbiota could either be associated with resistance to colonization or be the consequence of the colonization by E-ESBL. PMID:26552974

  15. Lipid Classes, Fatty Acid Composition, and Glycerolipid Molecular Species of the Red Alga Gracilaria vermiculophylla, a Prostaglandin-Producing Seaweed.

    PubMed

    Honda, Masaki; Ishimaru, Takashi; Itabashi, Yutaka

    2016-01-01

    The red alga Gracilaria vermiculophylla is a well-known producer of prostaglandins, such as PGE2 and PGF2α. In this study, the characteristics of glycerolipids as substrates of prostaglandin production were clarified, and the lipid classes, fatty acid composition, and glycerolipid molecular species were investigated in detail. The major lipid classes were monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and sulfoquinovosyldiacylglycerol (SQDG), as well as phosphatidylcholine (PC), which accounted for 43.0% of the total lipid profile. Arachidonic acid (20:4n-6), a prostaglandin precursor, and palmitic acid (16:0) were the predominant fatty acids in the total lipid profile. The 20:4n-6 content was significantly high in MGDG and PC (more than 60%), and the 16:0 content was significantly high in DGDG and SQDG (more than 50%). Chiral-phase high-performance liquid chromatography determined that fatty acids were esterified at the sn-1 and sn-2 positions of those lipids. The main glycerolipid molecular species were 20:4n-6/20:4n-6 (sn-1/sn-2) for MGDG (56.5%) and PC (40.0%), and 20:4n-6/16:0 for DGDG (75.4%) and SQDG (58.4%). Thus, it was considered that the glycerolipid molecular species containing one or two 20:4n-6 were the major substrates for prostaglandin production in G. vermiculophylla. PMID:27581490

  16. The wear properties of in-situ 7075 Al-Ti composites produced by powder metallurgy route

    NASA Astrophysics Data System (ADS)

    Ay, H.; Özyurek, D.; Yıldırım, M.; Bostan, B.

    2016-04-01

    In this study, the wear properties of in-situ 7075 Al-Ti composites produced by powder metallurgy route were investigated. Different amount of Ti (2, 4, 6 %) added to gas atomized 7075 Al alloy powders and they were mixed in turbula with 47rpm for 45 minutes. Then the mixed powders were pre-shaped by press under 600 MPa pressure. The samples were cooled in the furnace after sintered at 580 °C for 4 hours in the atmosphere controlled furnace. Standard metallographic process such as grinding, polishing and etching were applied to sintered samples. The hardness values were measured. Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) examines were carried out. The wear tests were performed in a pin-on disc type wear apparatus with 1 ms-1 sliding speed at six different sliding distance (500-3000 m) under 30 N loads. As a result of studies, hardness values were increased with increasing Ti content, in addition the weight losses were decreased with increasing Ti amount.

  17. Biochemical composition and changes of extracellular polysaccharides (ECPS) produced during microphytobenthic biofilm development (Marennes-Oléron, France).

    PubMed

    Pierre, Guillaume; Graber, Marianne; Rafiliposon, Beby Alibay; Dupuy, Christine; Orvain, Francis; De Crignis, Margot; Maugard, Thierry

    2012-01-01

    The main goal of this work was to study the dynamics and biochemical composition of extracellular polysaccharides (ECPS), a fraction of the extracellular polymeric substances (EPS) produced during the development of a microphytobenthic biofilm in a European intertidal mudflat (Marennes-Oléron Bay, France) during winter. Microphytobenthic biomass was surveyed during four consecutive emersion periods to confirm the biofilm growth. Bacteria abundance was also checked considering the importance of heterotrophic bacteria observed by various authors in the dynamics of EPS. Various colorimetric assays, coupled to biochemical chromatographic analysis, were used to characterize the three main fractions of extracted EPS: colloidal, bound, and residual. The monosaccharide distribution of colloidal ECPS highlighted their role of carbon source for bacteria (>50% of glucose) even if no increase of colloidal carbohydrate amounts was observed during the tidal exposure. Bound ECPS were composed of deoxy or specific sugars (30% rhamnose) and uronic acids (18% galacturonic acid). Their levels and dynamics could be correlated to the development of the microphytobenthic biofilm, enhancing the stabilization of the sediment or increasing binding forces accordingly. Residual fractions, containing refractory bound ECPS and other internal polymeric substances, were composed of various carbohydrates. The high ratio of glucose in these fractions (18% to 43%) was interesting, as it was once attributed to colloidal sugars due to poor extraction procedures. Finally, the presence of inositol (15%) was significant since no author has highlighted it before, knowing that inositol is a major growth factor for heterotrophic bacteria. PMID:22001998

  18. Investigation of the Microstructure and the Mechanical Properties of Cu-NiC Composite Produced by Accumulative Roll Bonding and Coating Processes

    NASA Astrophysics Data System (ADS)

    Shabani, Ali; Toroghinejad, Mohammad Reza

    2015-12-01

    In the present study, Cu-1.8 wt.% NiC (nickel coating) composite was produced by the combination of two methods, including accumulative roll bonding (ARB) and electroplating processes. Electroplating process was done on copper strips in order to produce a nickel-particle-reinforced composite. Microstructure, texture, and the mechanical properties of the produced composite were evaluated during various cycles of ARB using optical and scanning electron microscopes, x-ray diffraction, microhardness, and tensile tests. In addition, the results were compared with Cu-Cu and also Cu-NiS (nickel sheet) samples. It was found that nickel layers were fractured from the first cycle of the process, and nickel fragments were distributed in the copper matrix as the number of cycles was increased. Variation of orientation density of α-, β-, and τ-fibers for the produced composite was examined in different cycles. Microhardness for different elements in different cycles of Cu-NiC was also evaluated. Also, the investigation of the mechanical properties showed that by proceeding the ARB process, the tensile strength of the produced Cu-NiC and Cu-Cu samples was increased. However, improvement in the mechanical properties of composite samples was more noticeable due to the reinforcing effect of nickel particles. The elongation of composite samples showed a decrease in the primary cycles, unlike Cu-Cu ones; however, it was then increased. Finally, by using scanning electron microscopy, the fracture surfaces of Cu-NiC composite were studied to disclose the fracture mechanism of the samples.

  19. nTiO₂ induced changes in intracellular composition and nutrient stoichiometry in primary producer--cyanobacteria.

    PubMed

    Cherchi, Carla; Miljkovic, Milos; Diem, Max; Gu, April Z

    2015-04-15

    The widely and increasing use of nano-titanium dioxide (nTiO2) has led to its release in the environment and concerns of consequent impact on aquatic eco-relevant biota. Previous studies indicated possible physiological changes (i.e., nitrogen storage) induced by nano-titanium dioxide (nTiO2) exposure in algae, which will likely have ecological implications. This study investigated the short- (96 h) and long-term (21 days) ecotoxic impact of environmentally relevant nTiO2 concentrations on the cellular biochemical pools and nutrient stoichiometry in the nitrogen-fixing cyanobacteria Anabaena variabilis. Changes in nutrient element ratios and cellular composition were analyzed using both chemical elemental analysis and Fourier Transform Infrared (FT-IR) spectroscopy. Chemical elemental analysis showed that exposure to nTiO2 at varying dose concentrations and exposure duration led to statistically significant changes in intracellular C:N, C:P and N:P stoichiometries compared with those in the controls. In general, there seemed to be a decreasing trends of cellular C:N ratio and increase in the cellular C:P and N:P ratios with the increasing level of nTiO2 exposure. Further FT-IR analysis results revealed both temporal and dose-dependent change patterns of major macromolecules, including protein, lipids, nucleic acids and carbohydrates, in A. variabilis upon nTiO2 exposure. The relative ratio of amide II, lipids, nucleic acids and carbohydrates to the cellular protein content (quantified as amide I stretch) changed significantly within the initial 96 h of exposure and, both the magnitude of changes and levels of recovery seemed to be nTiO2 dose-dependent. This study, for the first time, demonstrated that the intracellular composition and nutrient stoichiometry changes could be induced by long-term and short-term exposures to nTiO2 to primary producers, which may have ecological implications for interspecies equilibriums and community dynamics in aquatic ecosystems

  20. Optimization of permeate flux produced by solar energy driven membrane distillation process using central composite design approach.

    PubMed

    Bouguecha, Salah T; Boubakri, Ali; Aly, Samir E; Al-Beirutty, Mohammad H; Hamdi, Mohamed M

    2016-01-01

    Membrane distillation (MD) is considered as a relatively high-energy requirement. To overcome this drawback, it is recommended to couple the MD process with solar energy as the renewable energy source in order to provide heat energy required to optimize its performance to produce permeate flux. In the present work, an original solar energy driven direct contact membrane distillation (DCMD) pilot plant was built and tested under actual weather conditions at Jeddah, KSA, in order to model and optimize permeate flux. The dependency of permeate flux on various operating parameters such as feed temperature (46.6-63.4°C), permeate temperature (6.6-23.4°C), feed flow rate (199-451L/h) and permeate flow rate (199-451L/h) was studied by response surface methodology based on central composite design approach. The analysis of variance (ANOVA) confirmed that all independent variables had significant influence on the model (where P-value <0.05). The high coefficient of determination (R(2) = 0.9644 and R(adj)(2) = 0.9261) obtained by ANOVA demonstrated good correlation between experimental and predicted values of the response. The optimized conditions, determined using desirability function, were T(f) = 63.4°C, Tp = 6.6°C, Q(f) = 451L/h and Q(p) = 451L/h. Under these conditions, the maximum permeate flux of 6.122 kg/m(2).h was achieved, which was close to the predicted value of 6.398 kg/m(2).h. PMID:27386986

  1. The composition of corn oil produced after fermentation via centrifugation in a commercial dry grind ethanol process

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to examine the chemical composition of corn oil obtained via centrifugation after fermentation of corn to make fuel ethanol, and compare its composition to that of corn germ oil (commercial corn oil) and experimental corn oils. The levels of free fatty acids in the post fermen...

  2. Microstructure and Crystallographic Texture Variations in the Friction-Stir-Welded Al-Al2O3-B4C Metal Matrix Composite Produced by Accumulative Roll Bonding

    NASA Astrophysics Data System (ADS)

    Mohammadnezhad, Mahyar; Shamanian, Morteza; Zabolian, Azam; Taheri, Mahshid; Javaheri, Vahid; Navidpour, Amir Hossein; Nezakat, Majid; Szpunar, Jerzy A.

    2015-12-01

    In this research, ultrafine-grained sheets of aluminum matrix composite (Al-Al2O3-B4C) were produced by accumulative roll bonding ARB technique. As-received, ultrafine-grained aluminum composite sheets were joined by friction-stir welding. The microstructure, crystallographic texture, and Vickers hardness in the weld zones were investigated. Electron backscattered diffraction results revealed occurrence of dynamic recrystallization and demonstrated existence of different grain orientations within the weld nugget. Produced composite plates illustrated rotated cubic texture. Moreover, in the nugget, a well-recrystallized grain structure having characteristic strong shear texture component finally developed. However, the texture result in the heat-affected zone illustrated rotated cubic and Goss components that related to the effect of heat input. Friction-stir welding refined the grain size in the weld zone. The hardness also improved with the peak hardness being observed towards the advancing stir welding side.

  3. PROCESSING, MICROSTRUCTURE AND MECHANICAL PROPERTY CORRELATION IN Al-B4C SURFACE COMPOSITE PRODUCED VIA FRICTION STIR PROCESSING

    SciTech Connect

    Komarasamy, Mageshwari; Mishra, Rajiv S.; Baumann, John A.; Grant, Glenn J.; Hovanski, Yuri

    2013-01-29

    Friction stir processing (FSP) was employed to prepare surface composites (SC) composed of B4C particles in 5024 Al matrix. The processing parameters, such as hole pattern and geometry,and the number of FSP passes, were optimized to obtain uniform powder distribution. The micrographs revealed a homogeneous distribution of the particles with good interfacial bonding. The hardness of the composite was uniform across the processed region which again indicates the uniformity of powder distribution. The modulus of the surface composite was measured using strain gage and showed a significant improvement. This improvement in modulus lies in the load sharing capability from the soft matrix to the hard particles.

  4. Hydrothermal Preparation and Characterization of TiO2 /BiVO4 Composite Catalyst and its Photolysis of Water to Produce Hydrogen.

    PubMed

    Jian, Zicong; Huang, Shaobin; Cao, Yaya; Zhang, Yongqing

    2016-05-01

    In the present work, bismuth vanadate composited photocatalysts were synthesized and characterized. X-ray diffractometry and Raman results showed that the particles were well crystallized, and formed by the complex of monoclinic BiVO4 and TiO2 . On electron microscopy, the photocatalyst exhibited high crystallization, agglutination and irregular shape, and was surrounded by numerous TiO2 particles. The study of surface areas showed that the specific surface area of 30-BiVO4 /TiO2 composited was 112 m(2) ·g(-1) , which was nearly 10 times that of pure BiVO4 . The ultraviolet-visible diffuse reflectance spectra indicated the composited photocatalyst were activated in visible light. The activity of photocatalytic water splitting was studied. The results showed that monomer BiVO4 photocatalyst was not able to produce hydrogen under any light source. BiVO4 /TiO2 composited photocatalysts, however, were capable of generating hydrogen. Under UV light irradiation for 120 min, 1 g catalyst dispersed in 50 mL deionized water produced almost 1 mL hydrogen, such that the productivity of hydrogen was higher than that of P25-TiO2 . Photocatalytic decomposition of water under visible light also confirmed that the BiVO4 /TiO2 composited photocatalyst had the ability of water splitting. PMID:26849995

  5. Influence of the Processing Route in the Microstructure and Mechanical Properties of NiAl/TiB2 Composites Produced by Combustion Synthesis

    NASA Astrophysics Data System (ADS)

    Torres, Ricardo D.; Lepienski, Carlos M.; Moore, John J.; Reimanis, Ivar E.

    2009-04-01

    In this work, dense NiAl/TiB2 composites with varying amounts of TiB2 were produced by combustion synthesis routes. The morphology of the TiB2 phase in the composite has been modified by changing the reactants in the initial powder mixture. In the first processing route, NiAl and TiB2 phases were obtained from Ni, Al, Ti, and B elemental powders. In the second processing route, TiB2 was added, instead of Ti and B, along with Ni and Al to produce NiAl and TiB2 phases. The XRD performed on the products of both processing routes confirmed that the synthesized phases were indeed TiB2 and NiAl. The NiAl grain size is smaller for the composites obtained in the first processing route. In addition, the first processing route leads to clusters of TiB2 submicron particles in which the matrix is either TiB2 or NiAl depending on the starting composition. The second processing route results in less dense composites in which the matrix is the NiAl and the TiB2 exists as dispersed platelets. The hardness ( H) and Young’s modulus ( E) were observed to be higher for composites produced by the first processing route. This difference in the mechanical properties is caused by the difference in microstructure, as well as the difference in porosity between the two processing routes.

  6. Preparation of a new-style composite containing a key bioflocculant produced by Pseudomonas aeruginosa ZJU1 and its flocculating effect on harmful algal blooms.

    PubMed

    Sun, Peng-Fei; Lin, Hui; Wang, Guan; Lu, Li-Ling; Zhao, Yu-Hua

    2015-03-01

    A novel composite consisting of clay, bioflocculant, and inorganic flocculant was designed, and its flocculating effect on harmful algal blooms (HABs) was studied in this study. The extracellular polymeric substances (EPS), produced with a yield of 3.58±0.11 g/L by a newly isolated Pseudomonas aeruginosa ZJU1, was indicated to be a key component in the composite. The components and functional groups of the EPS were analyzed, and it showed that polysaccharides, proteins, and nucleic acids are the main components; polar functional groups in the EPS are responsible for its flocculating activity. The novel composite was optimized by the response surface methodology and after optimization, the optical components and contents of the composite were Kaolin 2.38 g/L, CaCl2 0.28 g/L, KAl(SO4)2 0.09 g/L, and EPS 1.75 mg/L. The flocculating rates of the composite were tested, and it could rapidly reach 100±0.13% within 2 min when OD680 of Microcystis aeruginosa was 0.1; it could reach 100±0.08% within 5 min for OD680 of M. aeruginosa in HABs up to 1.0. These results suggest that the novel composite will be a highly efficient material for the treatment of HABs caused by M. aeruginosa. PMID:25463236

  7. Effect of milling time and CNT concentration on hardness of CNT/Al{sub 2024} composites produced by mechanical alloying

    SciTech Connect

    Perez-Bustamante, R.; Perez-Bustamante, F.; Estrada-Guel, I.; Licea-Jimenez, L.; Miki-Yoshida, M.; Martinez-Sanchez, R.

    2013-01-15

    Carbon nanotube/2024 aluminum alloy (CNT/Al{sub 2024}) composites were fabricated with a combination of mechanical alloying (MA) and powder metallurgy routes. Composites were microstructurally and mechanically evaluated at sintering condition. A homogeneous dispersion of CNTs in the Al matrix was observed by a field emission scanning electron microscopy. High-resolution transmission electron microscopy confirmed not only the presence of well dispersed CNTs but also needle-like shape aluminum carbide (Al{sub 4}C{sub 3}) crystals in the Al matrix. The formation of Al{sub 4}C{sub 3} was suggested as the interaction between the outer shells of CNTs and the Al matrix during MA process in which crystallization took place after the sintering process. The mechanical behavior of composites was evaluated by Vickers microhardness measurements indicating a significant improvement in hardness as function of the CNT content. This improvement was associated to a homogeneous dispersion of CNTs and the presence of Al{sub 4}C{sub 3} in the aluminum alloy matrix. - Highlights: Black-Right-Pointing-Pointer The 2024 aluminum alloy was reinforced by CNTs by mechanical alloying process. Black-Right-Pointing-Pointer Composites were microstructural and mechanically evaluated after sintering condition. Black-Right-Pointing-Pointer The greater the CNT concentration, the greater the hardness of the composites. Black-Right-Pointing-Pointer Higher hardness in composites is achieved at 20 h of milling. Black-Right-Pointing-Pointer The formation of Al{sub 4}C{sub 3} does not present a direct relationship with the milling time.

  8. Field emission characteristics study for ZnO/Ag and ZnO/CNTs composites produced by DC electrophoresis

    NASA Astrophysics Data System (ADS)

    Yu, Ling-min; Zhu, Chang-chun

    2009-07-01

    A simple controllable method is reported for the coating of ZnO nanowires with Ag nanoparticles and ZnO/carbon nanotubes (CNTs) composite. It has been achieved through DC electrophoresis AgNO 3 electrolyte and CNTs in the presence of isopropanol dispersion of ZnO nanowires. In the present work, the influence of Ag nanoparticles and CNTs on the field emission properties of the composite materials is studied. The results of this research demonstrate a remarkable enhancement of field emission current of ZnO nanowires in case of CNTs mixture and Ag nanoparticles coating.

  9. Enhanced toughness and stable crack propagation in a novel tungsten fibre-reinforced tungsten composite produced by chemical vapour infiltration

    NASA Astrophysics Data System (ADS)

    Riesch, J.; Höschen, T.; Linsmeier, Ch; Wurster, S.; You, J.-H.

    2014-04-01

    Tungsten is a promising candidate for the plasma-facing components of a future fusion reactor, but its use is strongly restricted by its inherent brittleness. An innovative concept to overcome this problem is tungsten fibre-reinforced tungsten composite. In this paper we present the first mechanical test of such a composite material using a sample containing multiple fibres. The in situ fracture experiment was performed in a scanning electron microscope for close observation of the propagating crack. Stable crack propagation accompanied with rising load bearing capacity is observed. The fracture toughness is estimated using the test results and the surface observation.

  10. Seed composition, seedling emergence and early seeding vigour of red kidney bean seed produced at elevated temperature and Carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding effects of temperature and carbon dioxide (CO2) on seed quality is important under present and future climates. The objective was to determine the effects of elevated growth temperature and CO2 during seed-filling of parent plants on seed composition and ensuing seedling emergence and ...

  11. Detergent composition comprising a cellulase containing cell-free fermentate produced from microorganism ATCC 55702 or mutant thereof

    DOEpatents

    Dees, H. Craig

    1998-01-01

    Bacteria which produce large amounts of a cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

  12. Detergent composition comprising a cellulase containing cell-free fermentate produced from microorganism ATCC 55702 or mutant thereof

    DOEpatents

    Dees, H.C.

    1998-07-14

    Bacteria which produce large amounts of a cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

  13. Special Features of the Mechanical Characteristics of Al-Al2O3 Composites Produced By Explosive Compaction of Powders Under Shock-Wave Deformation

    NASA Astrophysics Data System (ADS)

    Zhukov, I. A.; Garkushin, G. V.; Vorozhtsov, S. A.; Khrustalyov, A. P.; Razorenov, S. V.; Kvetinskaya, A. V.; Promakhov, V. V.; Zhukov, A. S.

    2016-01-01

    The results obtained from investigations into the special features inherent in the mechanical characteristics (Hugoniot elastic limit and spall strength) observed under shock-wave loading of Al-Al2O3 composite samples produced by an explosive powder compaction technique are presented. Embedding 10 wt.% of aluminum oxide in the aluminum matrix has been found to increase the Hugoniot elastic limit as opposed to the commercialgrade AD1(Al 1013) aluminum alloy.

  14. Composition.

    ERIC Educational Resources Information Center

    Nemanich, Donald, Ed.

    1974-01-01

    The articles in this special issue of the "Illinois English Bulletin" concern the state of composition instruction at the secondary and college levels. The titles and authors are "Monologues or Dialogues? A Plea for Literacy" by Dr. Alfred J. Lindsey, "Teaching Composition: Curiouser and Curiouser" by Denny Brandon, and "Teaching Writing to High…

  15. Composition surveys of test gas produced by a hydrogen-oxygen-air burner. [for supersonic ramjet engine

    NASA Technical Reports Server (NTRS)

    Eggers, J. M.

    1974-01-01

    As a result of the need for a uniform hot gas test stream for fuel injector development for hydrogen fueled supersonic combustion ramjet engines, an experimental study of injector configuration effect on exit flow uniformity of a hydrogen fueled oxygen replenished, combustion burner was made. Measurements used to investigate the burner nozzle exit profiles were pitot and gas sample measurements. Gas composition and associated temperature profiles were reduced to an acceptable level by burner injector modifications. The effect of the injector modifications was to redistribute the hydrogen fuel, increase the air pressure drop, promote premixing of the oxygen and air, and establish a uniform flow pattern where the oxygen-air mixture comes into contact with the hydrogen fuel. The most sensitive phenomenon which affected the composition profiles was the uniformity of the air distribution supplied to the combustion chamber.

  16. Microstructure and mechanical properties of Al-nano ZrO II composites produced by casting route

    NASA Astrophysics Data System (ADS)

    Karimi, M.; Baharvandi, H. R.; Abdizadeh, H.; Pak Beyrami, B.; Mobarhan Bonab, M. A.

    2007-07-01

    Aluminum metal matrix composites (AMCs) are regarded as candidate materials for aerospace and automotive applications owning to their superior properties, such as high specific modulus specifically at high temperatures, good strength and low wear rates. AMCs have been prepared by liquid metal route such as pressureless infiltration, squeeze casting, stir casting, spray forming, etc. Each of these processes has their own advantages and limitations. The choice of the fabrication techniques is dictated by production cost, process efficiency, the quality desired in the product and their applications. AMCs cast from the liquid state are of interest because of their relatively low processing cost and ease in manufacturing. In the present project, Aluminum A356 and zirconia nano particles were selected as raw materials. Zirconia nano particles were founded to be a promising candidate due to its high hardness, high modulus of elasticity and excellent thermal stability. Samples of composites was made at different amount of zirconia's particles (0, 1.5, 2.5, 5vol %) and temperature of casting were 800, 850 and 950°C. Microstructure of composite specimens was examined using SEM and optical microscopy. Chemical composition was investigated by XRD method. Physical properties such as density and porosity were determined by Archimedes and image analyzing methods. Mechanical properties such as tensile strength, hardness and toughness were determined. The experimental results show that the mechanical properties like tensile strength and hardness markedly improved by adding zirconia nano particles. The maximum was for samples with 5vol% of nano particles were casted at 850°C. Fracture toughness decreased by addition of zirconia nano particles.

  17. Mechanical, thermal and morphological characterization of polycarbonate/oxidized carbon nanofiber composites produced with a lean 2-step manufacturing process.

    PubMed

    Lively, Brooks; Kumar, Sandeep; Tian, Liu; Li, Bin; Zhong, Wei-Hong

    2011-05-01

    In this study we report the advantages of a 2-step method that incorporates an additional process pre-conditioning step for rapid and precise blending of the constituents prior to the commonly used melt compounding method for preparing polycarbonate/oxidized carbon nanofiber composites. This additional step (equivalent to a manufacturing cell) involves the formation of a highly concentrated solid nano-nectar of polycarbonate/carbon nanofiber composite using a solution mixing process followed by melt mixing with pure polycarbonate. This combined method yields excellent dispersion and improved mechanical and thermal properties as compared to the 1-step melt mixing method. The test results indicated that inclusion of carbon nanofibers into composites via the 2-step method resulted in dramatically reduced ( 48% lower) coefficient of thermal expansion compared to that of pure polycarbonate and 30% lower than that from the 1-step processing, at the same loading of 1.0 wt%. Improvements were also found in dynamic mechanical analysis and flexural mechanical properties. The 2-step approach is more precise and leads to better dispersion, higher quality, consistency, and improved performance in critical application areas. It is also consistent with Lean Manufacturing principles in which manufacturing cells are linked together using less of the key resources and creates a smoother production flow. Therefore, this 2-step process can be more attractive for industry. PMID:21780388

  18. Enterolignan Producing Phenotypes are Associated with Increased Gut Microbial Diversity and Altered Composition in Premenopausal Women in the United States

    PubMed Central

    Hullar, Meredith A. J.; Lancaster, Samuel M.; Li, Fei; Tseng, Elizabeth; Beer, Karlyn; Atkinson, Charlotte; Wähälä, Kristiina; Copeland, Wade K.; Randolph, Timothy W.; Newton, Katherine M.; Lampe, Johanna W.

    2014-01-01

    Background Lignans in plant foods are metabolized by gut bacteria to the enterolignans, enterodiol (END) and enterolactone (ENL). Enterolignans have biologic activities important to the prevention of cancer and chronic diseases. We examined the composition of the gut microbial community (GMC) as a contributor to human enterolignan exposure. Methods We evaluated the association between the GMC in stool, urinary enterolignan excretion, and diet from a 3-day food record in 115 premenopausal (ages 40–45 y) women in the United States. Urinary enterolignans were measured using GC/MS. The GMC was evaluated using 454 pyrosequencing of the 16S rRNA gene. Sequences were aligned in SILVA (www.arb-silva.de). Operational taxonomic units (OTU) were identified at 97% sequence similarity. Taxonomic classification was performed and alpha and beta diversity in relationship to ENL production were assessed. Multivariate analysis and regression were used to model the association between enterolignan excretion and the GMC. Bacteria associated with ENL production were identified using univariate analysis and ridge regression. Results After adjusting for dietary fiber intake and adiposity, we found a significant positive association between ENL excretion and either the GMC (p=0.0007), or the diversity of the GMC (p=0.01). The GMC associated with high ENL production was distinct (UNIFRAC, p<0.003, MRPP) and enriched in Moryella spp., Acetanaerobacterium spp., Fastidiosipila spp., and Streptobacillus spp. Conclusion Diversity and composition of the GMC are associated with increased human exposure to enterolignans. Impact Differences in gut microbial diversity and composition explain variation in gut metabolic processes that impact environmental exposures and influences human health. PMID:25542830

  19. Crack initiation and propagation behavior of WC particles reinforced Fe-based metal matrix composite produced by laser melting deposition

    NASA Astrophysics Data System (ADS)

    Wang, Jiandong; Li, Liqun; Tao, Wang

    2016-08-01

    It is generally believed that cracks in metal matrix composites (MMC) parts manufacturing are crucial to the reliable material properties, especially for the reinforcement particles with high volume fraction. In this paper, WC particles (WCp) reinforced Fe-based metal matrix composites (WCp/Fe) were manufactured by laser melting deposition (LMD) technology to investigate the characteristics of cracks formation. The section morphology of composites were analyzed by optical microscope (OM), and microstructure of WCp, matrix and interface were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), in order to study the crack initiation and propagation behavior under different laser process conditions. The temperature of materials during the laser melting deposition was detected by the infrared thermometer. The results showed that the cracks often appeared after five layers laser deposition in this experiment. The cracks crossed through WC particles rather than the interface, so the strength of interface obtained by the LMD was relatively large. When the thermal stress induced by high temperature gradient during LMD and the coefficient of thermal expansion mismatch between WC and matrix was larger than yield strength of WC, the cracks would initiate inside WC particle. Cracks mostly propagated along the eutectic phases whose brittleness was very large. The obtained thin interface was beneficial to transmitting the stress from particle to matrix. The influence of volume fraction of particles, laser power and scanning speed on cracks were investigated. This paper investigated the influence of WC particles size on cracks systematically, and the smallest size of cracked WC in different laser processing parameters was also researched.

  20. Lignocellulose Nanofiber-Reinforced Polystyrene Produced from Composite Microspheres Obtained in Suspension Polymerization Shows Superior Mechanical Performance.

    PubMed

    Ballner, Daniel; Herzele, Sabine; Keckes, Jozef; Edler, Matthias; Griesser, Thomas; Saake, Bodo; Liebner, Falk; Potthast, Antje; Paulik, Christian; Gindl-Altmutter, Wolfgang

    2016-06-01

    A facile approach to obtaining cellulose nanofiber-reinforced polystyrene with greatly improved mechanical performance compared to unreinforced polystyrene is presented. Cellulose nanofibers were obtained by mechanical fibrillation of partially delignified wood (MFLC) and compared to nanofibers obtained from bleached pulp. Residual hemicellulose and lignin imparted amphiphilic surface chemical character to MFLC, which enabled the stabilization of emulsions of styrene in water. Upon suspension polymerization of styrene from the emulsion, polystyrene microspheres coated in MFLC were obtained. When processed into polymer sheets by hot-pressing, improved bending strength and superior impact toughness was observed for the polystyrene-MFLC composite compared to the un-reinforced polystyrene. PMID:27163488

  1. Comparative Protein Composition Analysis of Goat Milk Produced by the Alpine and Saanen Breeds in Northeastern Brazil and Related Antibacterial Activities

    PubMed Central

    da Costa, Whyara Karoline Almeida; de Souza, Evandro Leite; Beltrão-Filho, Edvaldo Mesquita; Vasconcelos, Gracy Kelly Vieira; Santi-Gadelha, Tatiane; de Almeida Gadelha, Carlos Alberto; Franco, Octavio Luiz; Magnani, Marciane

    2014-01-01

    The protein composition of goat milk differs between goat breeds and could present regional trends. The aim of this study was to comparatively analyze the protein composition of goat milk produced by the Alpine and Saanen breeds in northeastern Brazil and to evaluate the antibacterial activity of its protein fractions. SDS-PAGE, 2-DE electrophoresis and RP-HPLC analyses revealed the absence of αs1-casein in the milk of both breeds and no differences between the αs2-casein, β-casein, β-lactoglobulin and α-lactalbumin profiles. The amounts of soluble proteins and β-casein hydrolysis residues were higher in Saanen milk. Only the protein fraction containing the largest amounts of casein (F60–90%) inhibited bacterial growth, with MIC values between 50 and 100 mg/mL. This study describe for the first time three important points about the goat milk protein of two Brazilian goat breeders: absence of α-s1 casein in the protein profile, differences between the milk protein composition produced by goats of Alpine and Saanen breeders and antibacterial activity of unbroken proteins (casein-rich fraction) present in these milk. PMID:24675996

  2. Composites

    SciTech Connect

    Chou, T.; McCullough, R.L.; Pipes, R.B.

    1986-10-01

    The degree of control over material properties that is typified by hybrid composites is transforming engineering design. In part because homogeneous materials such as metals and alloys do not offer comparable control, specifying a material and designing a component have traditionally taken place separately. As composites begin to replace traditional materials in fields and such as aerospace, component design and the specification of a material are merging and becoming aspects of a single process. The controllable microstructure of a composite allows it to be tailored to match the distribution of stresses to which it will be subject. At the same time components must come to reflect the distinctive nature of composites: their directional properties and the intricate forms they can be given through processes such as injection molding, filament winding and three-dimensional weaving. The complexity inherent in conceiving components and their materials at the same time suggests engineering design will grow increasingly dependent on computers and multidisciplinary teams. Such an approach will harness the full potential of composites for the technologies of the future. 10 figures.

  3. Nutritional composition of fufu analog flour produced from Cassava root (Manihot esculenta) and Cocoyam (Colocasia esculenta) tuber.

    PubMed

    Bamidele, Oluwaseun P; Fasogbon, Mofoluwaso B; Oladiran, Dolapo A; Akande, Ebunoluwa O

    2015-11-01

    Nutritional properties of fufu analog produced from co-processing of cassava and cocoyam were studied. Cassava and cocoyam were fermented for 72 h, dried to obtain fufu flour. Proximate, functional, minerals, antinutritional factor, pasting properties, and sensory evaluation of various samples were determined. The results revealed that the moisture contents of the samples showed significant difference from control with values between 6.50 and 7.30%. The protein contents (1.68-4.98%), ash (1.84-4.01%), and crude fiber (1.42-4.56%) showed significant increase with increasing level of cocoyam, while the crude fat and carbohydrate reduced with increase in cocoyam. The minerals also increased with increase in cocoyam level with sample E having the highest value of Magnesium (32.15 mg/100 g). The antinutritional factors were very low and the pasting properties revealed the importance of cocoyam in the fufu analog produced. In conclusion, fufu produced from co-processing of cassava and cocoyam has more nutritional qualities than the common fufu made from cassava alone. PMID:26788301

  4. Composition, Reactivity and Regulation of Extracellular Metal-Reducing Structures (Bacterial Nanowires) Produced by Dissimilatory Metal - Reducing Bacteria

    SciTech Connect

    Beveridge, Terrance J.

    2004-06-01

    Approach. Previously, using conventional and cryoTEM techniques, surface physicochemistry assays, NMR structural analysis, etc., we showed that the structure and composition of Shewanella's lipopolysaccharide (LPS) and capsular polysaccharide (PS) significantly determined overall cell surface physicochemistry. In our study a strong correlation between such macroscopic parameters as surface electronegativity, hydrophobicity or hydrophilicity, and bacterial adhesion to hematite was observed. Rough LPS strains exhibited more than an order higher affinity and maximal sorption capacity to hematite when compared to encapsulated strains. These general trends, however, characterize bacterial adhesion only as a bulk process, being unable to reveal finer mechanisms taking place at the level of an individual cell. Cell surface physicochemical and structural heterogeneity suggests much more complex interactions at the bacterial-mineral interface than predicted by such approaches operating within macroscopic parameters.

  5. Recovery and purification of chitosanase produced by Bacillus cereus using expanded bed adsorption and central composite design.

    PubMed

    de Araújo, Nathália Kelly; Pimentel, Vanessa Carvalho; da Silva, Nayane Macedo Portela; de Araújo Padilha, Carlos Eduardo; de Macedo, Gorete Ribeiro; Dos Santos, Everaldo Silvino

    2016-02-01

    This study presents a system for expanded bed adsorption for the purification of chitosanase from broth extract in a single step. A chitosanase-producing strain was isolated and identified as Bacillus cereus C-01 and used to produce chitosanases. The expanded bed adsorption conditions for chitosanase purification were optimized statistically using STREAMLINE(TM) DEAE and a homemade column (2.6 × 30.0 cm). Dependent variables were defined by the quality criteria purification factor (P) and enzyme yield to optimize the chromatographic process. Statistical analyses showed that the optimum conditions for the maximum P were 150 cm/h load flow velocity, 6.0 cm settled bed height, and 7.36 cm distributor height. Distributor height had a strong influence on the process, considerably affecting both the P and enzyme yield. Optimizing the purification variables resulted in an approximately 3.66-fold increase in the P compared with the value under nonoptimized conditions. This system is promising for the recovery of chitosanase from B. cereus C-01 and is economically viable because it promotes the reduction steps. PMID:26638991

  6. A new methodology to calculate the environmental protection index (Ep). A case study applied to a company producing composite materials.

    PubMed

    Siracusa, G; La Rosa, A D; Sterlini, S E

    2004-12-01

    Environmental indicators can be used as a first stage in progress towards comprehensive environmental impact measures [J. Environ. Manage 65/3 (2002) 285]. In this article, we develop a 'pollutant interaction matrix method' that allows calculation of a global environmental protection index (Ep) in order to verify the eco-compatibility of an industrial activity. Two methods are proposed for the Ep index evaluation (which represents the numerical measure of the environmental sustainability): the Direct Method (Epd) and the Weighted Method (Epw). Both methods need to define, in the whole industrial process, homogeneous sectors (defined as construction sites where activities of the same type are carried out). Furthermore, for each activity a set of parameters (t, duration of pollution effect, P, quantity of pollutant produced,G, hazard of the pollutant) are required to evaluate the relative pollution index Y. All indices calculations were carried out using a set of matrices. The correct use of Ep evaluation provides an improvement in the total environmental performance of companies because it points out possible critical operations in each homogeneous sector which require solutions. The methodology is applied to evaluate the environmental pollution risk of a company that produces polymer materials and to improve their environmental performance. The results obtained show that the whole productive process has a low environmental impact factor. Nevertheless the applied methodology puts in evidence some processes that generate local pollution in specific areas of the factory and which could be dangerous for the workers' health. PMID:15531386

  7. Corrosion Resistance of Laser Produced in-situ Particle Reinforced Fe-matrix Composite Coating with High Nickel Content on Spheroidal Graphite Cast Iron

    NASA Astrophysics Data System (ADS)

    Qiwen, W.; Mingxing, M.; Cunyuan, P.; Xiaohui, Y.; Weiming, Z.

    Fe-matrix composite coatings reinforced by in-situ particles with high nickel content were produced on QT450-10 by laser alloying. Coatings with different microstructure proportions and particle distributions were obtained by the adjustment of the content of Ni, Ti and Zr in the alloying powder and the laser parameters. The influence of the content of Ni and the particle distribution on coating's corrosion resistance is studied, which is revealed by the electrochemical characteristics. The results indicate that the alloying coating with more content of nickel and less particles get corroded much harder with a higher corrosion rate.

  8. Improved manufacturing technology for producing porous Nafion for high-performance ionic polymer–metal composite actuators

    NASA Astrophysics Data System (ADS)

    Zhao, Dongxu; Li, Dichen; Wang, Yanjie; Chen, Hualing

    2016-07-01

    The current actuation performance of ionic polymer–metal composites (IPMCs) limits their further application in the aerospace, energy, and optics fields, among others. To overcome this issue, we developed a freeze-drying process to generate Nafion membranes with a porous structure, the characteristics of which were investigated using thermogravimetric analysis, Fourier transform infrared spectrometry, field-emission scanning electron microscopy, and water uptake tests. The pores fabricated using the developed freeze-drying process had a diameter of approximately 270 nm, and a porosity of nearly 40.45%. The displacement and the central angle were introduced as variables to evaluate the bending deformation of an IPMC actuator based on the porous Nafion membrane. Compared with conventional actuators, this IPMC actuator showed an increase in displacement of 4963.6% at 2 V, and an increase in central angle of 73.35% at 3 V. Although the blocking forces of this IPMC actuator decreased to some extent, it was confirmed that the integrated actuation performance, which was evaluated using the strain energy density increment, was improved. The performance of the IPMC actuator was enhanced as a result of the porous Nafion structure manufactured using the developed freeze-drying process.

  9. Composition, Reactivity and Regulation of Extracellular Metal-Reducing Structures (Bacterial Nanowires) Produced by Dissimilatory Metal - Reducing Bacteria.

    SciTech Connect

    Beveridge, Terrance J; Whitfield, Christopher

    2013-03-06

    This is the final technical report for the project. There were two objectives in the proposal. The first was to describe the composition and function of electrically conductive appendages, known as bacterial nanowires, which resemble pili but are longer and are electrically conductive. They were first identified on the dissimilatory metal-reducing bacteria (DMRB), Shewanella and Geobacter. Specifically, this project investigated the role of these structures in: (i) the reductive transformation of iron oxides as solid phase electron acceptors; (ii) the use of as uranium as a dissolved electron acceptor to form nanocrystalline particles of uraninite upon reduction. The Beveridge group investigated these processes using advanced cryo-transmission electron microscopy (cryoTEM) to visualize the points of connection between the distal ends of nanowires and the effect they have on solid phase Fe minerals. At the same time, immuno-electron microscopy was applied in an attempt to identify where metal reductases and cytochromes are located on the cell surface, or in the nanowires. The second objective was to define the surface physicochemistry of Shewanella spp. in an attempt to decipher how weak bonding (electrostatics and hydrophobicity) affects the adherence of the bacteria to Fe oxides. This bonding could be dictated by the chemistry of lipopolysaccharide (LPS), or the presence/absence of capsular polysaccharide.

  10. Composition and concentration of hydrocarbons in sediment samples from the oil producing area of the East Shetland Basin, Scotland.

    PubMed

    Russell, M; Webster, L; Walsham, P; Packer, G; Dalgarno, E J; McIntosh, A D; Fryer, R J; Moffat, C F

    2008-04-01

    The East Shetland Basin is one of the areas that the Fisheries Research Services (FRS) has concentrated on to assess the possible impacts of oil exploration and production on the marine environment. A stratified random survey of the sediment was carried out in 2002. TOCs were low across the basin and were positively correlated with grain size. The total PAH concentrations (2- to 6-ring parent and alkylated PAHs, including the 16 US EPA PAHs) were less than 150 microg kg(-1) dry weight and their composition indicated a predominantly pyrolytic input to the basin in 2002. Minor unresolved complex mixtures in the n-alkane profiles indicated a slight petrogenic input but further examination of the biomarkers (hopanes and steranes) showed a mixed North Sea and Middle Eastern source. The Middle Eastern source is likely due to inputs from shipping activity, as it is widely used as bunker fuel. Grid surveys were carried out in 1986, 1988-89 and 1994 and areas were selected for which there was data for all the historic grid surveys and the 2002 stratified random survey. Although referring to only a small part of the East Shetland Basin, comparison with these historic surveys shows clearly that the concentrations of Forties crude oil equivalents and total PAH concentrations were highest in 1988-89 and by 2002 had returned to concentrations the same as or less than observed in the original survey in 1986. PMID:18385878

  11. Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers.

    PubMed

    Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

    2014-02-14

    Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10,000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm(-2). The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices. PMID:24434798

  12. A solvothermal method to produce RGO-Fe3O4 hybrid composite for fast chromium removal from aqueous solution

    NASA Astrophysics Data System (ADS)

    Zhou, Li; Deng, Huiping; Wan, Junli; Shi, Jun; Su, Tong

    2013-10-01

    A simple one step solvotermal strategy using non-toxic and cost-effective precursors has been developed to prepare reduced graphene oxide (RGO)-Fe3O4 non-nanocomposite for removal of Cr(VI). Compared with the nano-adsorbent, the RGO-Fe3O4 hybrid particles with size larger than 100 nm can reduce cell toxicity in water treatment processes. The structure, surface and magnetic characteristics of the non-nanocomposite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and Vibrating sample magnetometer (VSM). The RGO-Fe3O4 composite with the highest loading of Fe3O4 demonstrates the fastest removal of 500 μg/L Cr(VI) which can reach 85% within 5 min at neutral pH. The adsorption kinetics follows the pseudo-second-order model and the adosorbent exhibits better Cr(VI) removal efficiency in water at low pH. However, the removal efficiency of Cr(VI) decreased when common hazardous ions were added in water. The large saturation magnetization (41.12 emu/g) of the synthesized non-nanoparticles allows fast separation of the adsorbent from water. The RGO-Fe3O4 non-nanocomposite could be utilized as an efficient, stable, less toxic and magnetically separable adsorbent for environmental cleanup.

  13. Composition and morphology characterization of exopolymeric substances produced by the PAH-degrading fungus of Mucor mucedo.

    PubMed

    Jia, Chunyun; Li, Xiaojun; Allinson, Graeme; Liu, Changfeng; Gong, Zongqiang

    2016-05-01

    To explore the role of exopolymeric substances (EPS) in the process of polycyclic aromatic hydrocarbons (PAH) biodegradation, the characteristics of EPS isolated from a PAH-degrading fungus were investigated firstly by spectrometric determination, microscopic observation, Fourier transform-infrared spectroscopy (FT-IR), and three-dimensional excitation-emission matrix fluorescence spectroscopy (3D-EEM), and then the PAH-degrading ability of isolated EPS was evaluated. The EPS compositions and morphology varied significantly with the extraction methods. EPS were mainly composed of proteins, carbohydrate, and humic-like substances, and the cation exchange resin (CER)-extracted EPS were granular while other EPS samples were all powders. Heating was the most effective treatment method, followed by the CER, centrifugation, and ultrasonication methods. However, 3D-EEM data demonstrated that heating treatment makes the mycelia lyse the most. Overall, therefore, the CER was the best EPS extraction method for Mucor mucedo (M. mucedo). The PAH degradation results indicated that 87 % of pyrene and 81 % of benzo[a]pyrene (B[a]P) were removed by M. mucedo over 12 days and 9 % more pyrene and 7 % more B[a]P were reduced after CER-extracted EPS addition of 465 mg l(-1). The investigation of EPS characterization and EPS enhancing PAH biodegradation is the premise for further in-depth exploration of the role of EPS contribution to PAH biodegradation. PMID:26782320

  14. Acute chlorine gas exposure produces transient inflammation and a progressive alteration in surfactant composition with accompanying mechanical dysfunction.

    PubMed

    Massa, Christopher B; Scott, Pamela; Abramova, Elena; Gardner, Carol; Laskin, Debra L; Gow, Andrew J

    2014-07-01

    Acute Cl2 exposure following industrial accidents or military/terrorist activity causes pulmonary injury and severe acute respiratory distress. Prior studies suggest that antioxidant depletion is important in producing dysfunction, however a pathophysiologic mechanism has not been elucidated. We propose that acute Cl2 inhalation leads to oxidative modification of lung lining fluid, producing surfactant inactivation, inflammation and mechanical respiratory dysfunction at the organ level. C57BL/6J mice underwent whole-body exposure to an effective 60ppm-hour Cl2 dose, and were euthanized 3, 24 and 48h later. Whereas pulmonary architecture and endothelial barrier function were preserved, transient neutrophilia, peaking at 24h, was noted. Increased expression of ARG1, CCL2, RETLNA, IL-1b, and PTGS2 genes was observed in bronchoalveolar lavage (BAL) cells with peak change in all genes at 24h. Cl2 exposure had no effect on NOS2 mRNA or iNOS protein expression, nor on BAL NO3(-) or NO2(-). Expression of the alternative macrophage activation markers, Relm-α and mannose receptor was increased in alveolar macrophages and pulmonary epithelium. Capillary surfactometry demonstrated impaired surfactant function, and altered BAL phospholipid and surfactant protein content following exposure. Organ level respiratory function was assessed by forced oscillation technique at 5 end expiratory pressures. Cl2 exposure had no significant effect on either airway or tissue resistance. Pulmonary elastance was elevated with time following exposure and demonstrated PEEP refractory derecruitment at 48h, despite waning inflammation. These data support a role for surfactant inactivation as a physiologic mechanism underlying respiratory dysfunction following Cl2 inhalation. PMID:24582687

  15. Acute Chlorine Gas Exposure Produces Transient Inflammation and a Progressive Alteration in Surfactant Composition with Accompanying Mechanical Dysfunction

    PubMed Central

    Massa, Christopher B; Scott, Pamela; Abramova, Elena; Gardner, Carol; Laskin, Debra L; Gow, Andrew J

    2014-01-01

    Acute Cl2 exposure following industrial accidents or military/terrorist activity causes pulmonary injury and severe acute respiratory distress. Prior studies suggest that antioxidant depletion is important in producing dysfunction, however a pathophysiologic mechanism has not been elucidated. We propose that acute Cl2 inhalation leads to oxidative modification of lung lining fluid, producing surfactant inactivation, inflammation and mechanical respiratory dysfunction at the organ level. C57BL/6J mice underwent whole-body exposure to an effective 60 ppm-hour Cl2 dose, and were sacrificed 3, 24 and 48 hours later. Whereas pulmonary architecture and endothelial barrier function were preserved, transient neutrophilia, peaking at 24 hours, was noted. Increased expression of ARG1, CCL2, RETLNA, IL-1b, and PTGS2 genes was observed in bronchoalveolar lavage (BAL) cells with peak change in all genes at 24 hours. Cl2 exposure had no effect on NOS2 mRNA or iNOS protein expression, nor on BAL NO3− or NO2−. Expression of the alternative macrophage activation markers, Relm-α and mannose receptor was increased in alveolar macrophages and pulmonary epithelium. Capillary surfactometry demonstrated impaired surfactant function, and altered BAL phospholipid and surfactant protein content following exposure. Organ level respiratory function was assessed by forced oscillation technique at 5 end expiratory pressures. Cl2 exposure had no significant effect on either airway or tissue resistance. Pulmonary elastance was elevated with time following exposure and demonstrated PEEP refractory derecruitment at 48 hours, despite waning inflammation. These data support a role for surfactant inactivation as a physiologic mechanism underlying respiratory dysfunction following Cl2 inhalation. PMID:24582687

  16. Biochemical composition of haemagglutinin-based influenza virus-like particle vaccine produced by transient expression in tobacco plants.

    PubMed

    Le Mauff, François; Mercier, Geneviève; Chan, Philippe; Burel, Carole; Vaudry, David; Bardor, Muriel; Vézina, Louis-Philippe; Couture, Manon; Lerouge, Patrice; Landry, Nathalie

    2015-06-01

    Influenza virus-like particles (VLPs) are noninfectious particles resembling the influenza virus representing a promising vaccine alternative to inactivated influenza virions as antigens. Medicago inc. has developed a plant-based VLP manufacturing platform allowing the large-scale production of GMP-grade influenza VLPs. In this article, we report on the biochemical compositions of these plant-based influenza candidate vaccines, more particularly the characterization of the N-glycan profiles of the viral haemagglutinins H1 and H5 proteins as well as the tobacco-derived lipid content and residual impurities. Mass spectrometry analyses showed that all N-glycosylation sites of the extracellular domain of the recombinant haemagglutinins carry plant-specific complex-type N-glycans having core α(1,3)-fucose, core β(1,2)-xylose epitopes and Lewis(a) extensions. Previous phases I and II clinical studies have demonstrated that no hypersensibility nor induction of IgG or IgE directed against these glycans was observed. In addition, this article showed that the plant-made influenza vaccines are highly pure VLPs preparations while detecting no protein contaminants coming either from Agrobacterium or from the enzymes used for the enzyme-assisted extraction process. In contrast, VLPs contain few host cell proteins and glucosylceramides associated with plant lipid rafts. Identification of such raft markers, together with the type of host cell impurity identified, confirmed that the mechanism of VLP formation in planta is similar to the natural process of influenza virus assembly in mammals. PMID:25523794

  17. Abundance, depth distribution, and composition of aerobic bacteriochlorophyll a-producing bacteria in four basins of the central Baltic Sea.

    PubMed

    Salka, Ivette; Moulisová, Vladimíra; Koblízek, Michal; Jost, Günter; Jürgens, Klaus; Labrenz, Matthias

    2008-07-01

    The abundance, vertical distribution, and diversity of aerobic anoxygenic phototrophic bacteria (AAP) were studied at four basins of the Baltic Sea. AAP were enumerated by infrared epifluorescence microscopy, and their diversity was analyzed by using pufM gene clone libraries. In addition, numbers of CFU containing the pufM gene were determined, and representative strains were isolated. Both approaches indicated that AAP reached maximal abundance in the euphotic zone. Maximal AAP abundance was 2.5 x 10(5) cells ml(-1) (11% of total prokaryotes) or 1.0 x 10(3) CFU ml(-1) (9 to 10% of total CFU). Environmental pufM clone sequences were grouped into 11 operational taxonomic units phylogenetically related to cultivated members of the Alpha-, Beta-, and Gammaproteobacteria. In spite of varying pufM compositions, five clones were present in all libraries. Of these, Jannaschia-related clones were always found in relative abundances representing 25 to 30% of the total AAP clones. The abundances of the other clones varied. Clones potentially affiliated with typical freshwater Betaproteobacteria sequences were present at three Baltic Sea stations, whereas clones grouping with Loktanella represented 40% of the total cell numbers in the Gotland Basin. For three alphaproteobacterial clones, probable pufM phylogenetic relationships were supported by 16S rRNA gene analyses of Baltic AAP isolates, which showed nearly identical pufM sequences. Our data indicate that the studied AAP assemblages represented a mixture of marine and freshwater taxa, thus characterizing the Baltic Sea as a "melting pot" of abundant, polyphyletic aerobic photoheterotrophic bacteria. PMID:18502937

  18. Composites

    NASA Astrophysics Data System (ADS)

    Taylor, John G.

    The Composites market is arguably the most challenging and profitable market for phenolic resins aside from electronics. The variety of products and processes encountered creates the challenges, and the demand for high performance in critical operations brings value. Phenolic composite materials are rendered into a wide range of components to supply a diverse and fragmented commercial base that includes customers in aerospace (Space Shuttle), aircraft (interiors and brakes), mass transit (interiors), defense (blast protection), marine, mine ducting, off-shore (ducts and grating) and infrastructure (architectural) to name a few. For example, phenolic resin is a critical adhesive in the manufacture of honeycomb sandwich panels. Various solvent and water based resins are described along with resin characteristics and the role of metal ions for enhanced thermal stability of the resin used to coat the honeycomb. Featured new developments include pultrusion of phenolic grating, success in RTM/VARTM fabricated parts, new ballistic developments for military vehicles and high char yield carbon-carbon composites along with many others. Additionally, global regional market resin volumes and sales are presented and compared with other thermosetting resin systems.

  19. Acute chlorine gas exposure produces transient inflammation and a progressive alteration in surfactant composition with accompanying mechanical dysfunction

    SciTech Connect

    Massa, Christopher B.; Scott, Pamela; Abramova, Elena; Gardner, Carol; Laskin, Debra L.; Gow, Andrew J.

    2014-07-01

    Acute Cl{sub 2} exposure following industrial accidents or military/terrorist activity causes pulmonary injury and severe acute respiratory distress. Prior studies suggest that antioxidant depletion is important in producing dysfunction, however a pathophysiologic mechanism has not been elucidated. We propose that acute Cl{sub 2} inhalation leads to oxidative modification of lung lining fluid, producing surfactant inactivation, inflammation and mechanical respiratory dysfunction at the organ level. C57BL/6J mice underwent whole-body exposure to an effective 60 ppm-hour Cl{sub 2} dose, and were euthanized 3, 24 and 48 h later. Whereas pulmonary architecture and endothelial barrier function were preserved, transient neutrophilia, peaking at 24 h, was noted. Increased expression of ARG1, CCL2, RETLNA, IL-1b, and PTGS2 genes was observed in bronchoalveolar lavage (BAL) cells with peak change in all genes at 24 h. Cl{sub 2} exposure had no effect on NOS2 mRNA or iNOS protein expression, nor on BAL NO{sub 3}{sup −} or NO{sub 2}{sup −}. Expression of the alternative macrophage activation markers, Relm-α and mannose receptor was increased in alveolar macrophages and pulmonary epithelium. Capillary surfactometry demonstrated impaired surfactant function, and altered BAL phospholipid and surfactant protein content following exposure. Organ level respiratory function was assessed by forced oscillation technique at 5 end expiratory pressures. Cl{sub 2} exposure had no significant effect on either airway or tissue resistance. Pulmonary elastance was elevated with time following exposure and demonstrated PEEP refractory derecruitment at 48 h, despite waning inflammation. These data support a role for surfactant inactivation as a physiologic mechanism underlying respiratory dysfunction following Cl{sub 2} inhalation. - Highlights: • Effect of 60 ppm*hr Cl{sub 2} gas on lung inflammation and mechanical function examined. • Pulmonary inflammation is transient and minor.

  20. Functional properties of ‘Ti50Ni50-Ti49.3Ni50.7’ shape memory composite produced by explosion welding

    NASA Astrophysics Data System (ADS)

    Belyaev, S.; Rubanik, V.; Resnina, N.; Rubanik, V., Jr.; Lomakin, I.

    2014-08-01

    A bimetal composite, Ti50Ni50-Ti49.3Ni50.7, was produced by explosion welding, causing a Martensitic transformation. The functional properties of these objects were studied. It was found that explosion welding partially depressed the Martensitic transformation; however, a subsequent annealing resulted in the recovery of the kinetics of Martensitic transformations. Moreover, a variation in the annealing temperature allowed the control of a sequence of Martensitic transformations in the Ni-rich layer. The influence of the ratio of the equiatomic TiNi layer thickness to the total thickness of the bimetal composite on the recoverable strain was studied, and it was found that the maximum recoverable strain was observed when the thickness of the equiatomic TiNi layer was approximately equal to 55% of the total thickness of the sample. Functional properties were studied in the bimetal composite using the optimal ratio of the layer’s thickness. It was found that the value of the recoverable strain depended on the value of the residual strain as well as the sequence of the Martensitic transformations that occurred in the Ni-rich TiNi layer.

  1. Microhardness and microstructure evolution of TiB2 reinforced Inconel 625/TiB2 composite produced by selective laser melting

    NASA Astrophysics Data System (ADS)

    Zhang, Baicheng; Bi, Guijun; Nai, Sharon; Sun, Chen-nan; Wei, Jun

    2016-06-01

    In this study, micron-size TiB2 particles were utilized to reinforce Inconel 625 produced by selective laser melting. Exceptional microhardness 600-700 HV0.3 of the composite was obtained. In further investigation, the microstructure and mechanical properties of Inconel 625/TiB2 composite can be significantly influenced by addition of TiB2 particles during SLM. It was found that the long directional columnar grains observed from SLM-processed Inconel 625 were totally changed to fine dendritic matrix due to the addition of TiB2 particles. Moreover, with laser energy density (LED) of 1200 J/m, a Ti, Mo rich interface around TiB2 particles with fine thickness can be observed by FESEM and EDS. The microstructure evolution can be determined by different laser energy density (LED): under 1200 J/m, γ phase in dendrite grains; under 600 J/m, γ phase in combination of dendritic and acicular grains; under 400 J/m, γ phase acicular grains. Under optimized LED 1200 J/m, the dynamic nanohardness (8.62 GPa) and elastic modulus (167 GPa) of SLM-processed Inconel 625/TiB2 composite are higher compared with those of SLM-processed Inconel 625 (3.97 GPa and 135 GPa, respectively).

  2. Composite titanium nitride layers produced on the AZ91D magnesium alloy by a hybrid method including hydrothermal modification of the layer

    NASA Astrophysics Data System (ADS)

    Tacikowski, M.; Grzonka, J.; Płociński, T.; Jakieła, R.; Pisarek, M.; Wierzchoń, T.

    2015-08-01

    The microstructure and properties of the composite TiN-Ti-Al type titanium nitride surface layer with a sub-layer of titanium and aluminium produced on AZ91D magnesium alloy using a hybrid PVD method including final sealing by hydrothermal treatment were investigated. The results were analysed in terms of the microstructure-properties correlation, to approach the role of the sub-layers and the mechanisms involved in the properties improvement. The microstructure investigations indicate that the composite titanium nitride layers are tight and have nano-crystalline, diffusive character and multi zone microstructure of the type TixOy-TiN-Ti-Al-Al3Mg2-Al12Mg17. The significant corrosion resistance improvement of the AZ91D alloy obtained using the sealed composite titanium nitride layers was found to be the result of a synergistic mechanism which combined hydrothermal treatment of the layer with an action of aluminium sub-layer which is critical to make the sealing effective. The diffusive bonding via Mg-Al zone improves adhesion and the load bearing capacity of titanium nitride layers in wear conditions.

  3. Lipid composition in a strain of Bacillus subtilis, a producer of iturin A lipopeptides that are active against uropathogenic bacteria.

    PubMed

    Bernat, Przemysław; Paraszkiewicz, Katarzyna; Siewiera, Paulina; Moryl, Magdalena; Płaza, Grażyna; Chojniak, Joanna

    2016-10-01

    Urinary tract infections are a common disease in humans. Therefore, new methods are needed to destroy biofilms that are formed by uropathogens. Iturin A lipopeptides (LPs) C14 and C15 are potent biosurfactants synthetized by the Bacillus subtilis I'1a strain. The biological activity of extracted LPs was confirmed by examining extracts from I'1a cultures against uropathogenic bacteria that had been isolated from biofilms on urinary catheters. Compared with cultures of DSM 3257, which produce surfactin at a relatively low level, the extract obtained from strain I'1a exhibited a greater inhibitory effect against both planktonic and sessile forms of Escherichia coli, Serratia marcescens, Enterobacter cloacae, Proteus mirabilis, Citrobacter freundii and Enterococcus faecalis. Moreover, cyclic LP biosurfactants may disturb the integrity of cytoplasmic membranes; therefore, we investigated the effects of synthetized LPs on fatty acids and phospholipids of B. subtilis. LPs and lipids were analyzed using GC-MS, LC-MS/MS and MALDI-TOF/TOF techniques. Compared with B. subtilis DSM 3257, membranes of the I'1a strain were characterized by an increased amount of anteiso fatty acids and a ten-fold higher ratio of phosphatidylglycerol (PG)-to-phosphatidylethanolamine (PE). Interestingly, in cultures of B. subtilis DSM 3257 supplemented with LP extracts of the I'1a strain, the PG-to-PE ratio was fourfold higher, and the amount of anteiso fatty acids was also increased. PMID:27550437

  4. Optimization of chemical compositions in low-carbon Al-killed enamel steel produced by ultra-fast continuous annealing

    SciTech Connect

    Dong, Futao; Du, Linxiu; Liu, Xianghua; Xue, Fei

    2013-10-15

    The influence of Mn,S and B contents on microstructural characteristics, mechanical properties and hydrogen trapping ability of low-carbon Al-killed enamel steel was investigated. The materials were produced and processed in a laboratory and the ultra-fast continuous annealing processing was performed using a continuous annealing simulator. It was found that increasing Mn,S contents in steel can improve its hydrogen trapping ability which is attributed by refined ferrite grains, more dispersed cementite and added MnS inclusions. Nevertheless, it deteriorates mechanical properties of steel sheet. Addition of trace boron results in both good mechanical properties and significantly improved hydrogen trapping ability. The boron combined with nitrogen segregating at grain boundaries, cementite and MnS inclusions, provides higher amount of attractive hydrogen trapping sites and raises the activation energy for hydrogen desorption from them. - Highlights: • We study microstructures and properties in low-carbon Al-killed enamel steel. • Hydrogen diffusion coefficients are measured to reflect fish-scale resistance. • Manganese improves hydrogen trapping ability but decrease deep-drawing ability. • Boron improves both hydrogen trapping ability and deep-drawing ability. • Both excellent mechanical properties and fish-scale resistance can be matched.

  5. On the role of processing parameters in producing Cu/SiC metal matrix composites via friction stir processing: Investigating microstructure, microhardness, wear and tensile behavior

    SciTech Connect

    Barmouz, Mohsen; Besharati Givi, Mohammad Kazem; Seyfi, Javad

    2011-01-15

    The main aim of this study is to produce copper reinforced metal matrix composite (MMC) layers using micron sized SiC particles via friction stir processing (FSP) in order to enhance surface mechanical properties. Microstructural evaluation using optical microscopy (OM) and scanning electron microscopy (SEM) indicated that an increase in traverse speed and a decrease in rotational speed cause a reduction in the grain size of stir zone (SZ) for the specimens friction stir processed (FSPed) without SiC particles. With the aim of determining the optimum processing parameters, the effect of traverse speed as the main processing variable on microstructure and microhardness of MMC layers was investigated. Higher traverse speeds resulted in poor dispersion of SiC particles and consequently reduced the microhardness values of MMC layers. It was found that upon addition of SiC particles, wear properties were improved. This behavior was further supported by SEM images of wear surfaces. Results demonstrated that the microcomposite produced by FSP exhibited enhanced wear resistance and higher average friction coefficient in comparison with pure copper. Tensile properties and fracture characteristics of the specimens FSPed with and without SiC particles and pure copper were also evaluated. According to the results, the MMC layer produced by FSP showed lower strength and elongation than pure copper while a remarkable elongation was observed for FSPed specimen without SiC particles. Research Highlights: {yields} Decrease in traverse speed leads to good dispersion of SiC particles in composites. {yields} No distinct TMAZ in side regions of SZ of FSPed specimens with SiC particles. {yields} Microhardness of FSPed specimens with SiC particles shows a remarkable increase. {yields} Reinforcement of Cu with SiC particles improves wear and friction behavior of surface. {yields} A weak bonding in tensile due to probable agglomeration for SiC containing samples.

  6. The Effects of Trimethylamine and Organic Matter Additions on the Stable Carbon Isotopic Composition of Methane Produced in Hypersaline Microbial Mat Environments

    NASA Astrophysics Data System (ADS)

    Kelley, C. A.; Nicholson, B. E.; Beaudoin, C. S.; Detweiler, A. M.; Bebout, B.

    2014-12-01

    Methane production has been observed in a number of hypersaline environments, and it is generally thought that this methane is produced through the use of non-competitive substrates, such as the methylamines, methanol and dimethylsulfide. The stable carbon isotopic composition of the produced methane has suggested that the methanogens are operating under conditions of substrate limitation. We investigated substrate limitation in gypsum-hosted endoevaporite and soft mat hypersaline environments by the additions of trimethylamine, a non-competitive substrate for methanogenesis, and dried microbial mat, a source of natural organic matter. The δ13C values of the methane produced after amendments were compared to those in unamended control vials. At all hypersaline sites investigated, the δ13C values of the methane produced in the amended vials were statistically lower (by 10 to 71 ‰) than the unamended controls, supporting the hypothesis of substrate limitation at these sites. When substrates were added to the incubation vials, the methanogens within the vials fractionated carbon isotopes to a greater degree, resulting in the production of more 13C-depleted methane. Trimethylamine-amended samples produced lower methane δ13C values than the mat-amended samples. This difference in the δ13C values between the two types of amendments could be due to differences in isotope fractionation associated with the dominant methane production pathway (or substrate used) within the vials, with trimethylamine being the main substrate used in the trimethylamine-amended vials. We hypothesize that increased natural organic matter in the mat-amended vials would increase fermentation rates, leading to higher H2 concentrations and increased CO2/H2 methanogenesis.

  7. Composites

    NASA Astrophysics Data System (ADS)

    Chmielewski, M.; Nosewicz, S.; Pietrzak, K.; Rojek, J.; Strojny-Nędza, A.; Mackiewicz, S.; Dutkiewicz, J.

    2014-11-01

    It is commonly known that the properties of sintered materials are strongly related to technological conditions of the densification process. This paper shows the sintering behavior of a NiAl-Al2O3 composite, and its individual components sintered separately. Each kind of material was processed via the powder metallurgy route (hot pressing). The progress of sintering at different stages of the process was tested. Changes in the microstructure were examined using scanning and transmission electron microscopy. Metal-ceramics interface was clean and no additional phases were detected. Correlation between the microstructure, density, and mechanical properties of the sintered materials was analyzed. The values of elastic constants of NiAl/Al2O3 were close to intermetallic ones due to the volume content of the NiAl phase particularly at low densities, where small alumina particles had no impact on the composite's stiffness. The influence of the external pressure of 30 MPa seemed crucial for obtaining satisfactory stiffness for three kinds of the studied materials which were characterized by a high dense microstructure with a low number of isolated spherical pores.

  8. The composition analysis and preliminary cultivation optimization of a PHA-producing microbial consortium with xylose as a sole carbon source.

    PubMed

    Huang, Luokun; Liu, Chang; Liu, Yingjie; Jia, Xiaoqiang

    2016-06-01

    This work aimed at using xylose as sole substrate, and combining feast-famine process with Nile blue staining as well as denaturing gradient gel electrophoresis (DGGE) analysis to screen polyhydroxyalkanoate (PHA)-producing bacteria from waste activated sludge (WAS). Composition changes of the microbial consortium during domestication were analyzed by DGGE, and the results indicated that there were mainly four classes of bacteria in the final stable system, which were γ-Proteobacteria, Cellvibrio sp., an uncultured bacterium and Pseudomonas sp., respectively. After preliminary optimization, the optimal conditions for the microbial consortium to produce PHA were also obtained as follows: temperature 33°C, pH 8, xylose concentration 2.4g/L, C/N ratio 160 and C/P ratio 125. The final PHA accumulation was up to 31% of dry cell weight (DCW), compared to 23.8% of the original consortia. Though our process is at the very beginning and the PHA yield is relatively low, producing PHA from xylose by using microbial consortia is a promising way to save the PHA production cost. PMID:27021696

  9. Towards an organic palaeosalinity proxy: the effect of salinity, growth rate and growth phase on the hydrogen isotopic composition of alkenones produced by haptophyte algae

    NASA Astrophysics Data System (ADS)

    Chivall, David; M'Boule, Daniela; Schouten, Stefan; Sinninghe Damsté, Jaap S.; van der Meer, Marcel T. J.

    2013-04-01

    Palaeosalinity is one of the most important oceanographic parameters which currently cannot be quantified with reasonable accuracy from sedimentary records. Schouten et al.1 established that the fractionation of hydrogen isotopes between growth water and alkenones produced by the haptophyte algae Emiliania huxleyi and Gephyrocapsa oceanica is salinity dependent. As such, the δD values of alkenones recovered from sediment cores can be used to reconstruct variations in palaeo- sea surface salinity.2 However, to accurately determine absolute palaeosalinity requires a better constraining of the relationship between this hydrogen fractionation, salinity and other parameters such as growth rate and growth phase. Here, we present results from our ongoing work to constrain the relationship between the fractionation factor αalkenone-water, salinity, growth rate and growth phase for the major alkenone-producing haptophytes. In batch cultures of different strains of the open-ocean haptophyte E. huxleyi sampled during the exponential growth phase, αC37alkenone-growthwater increases by between 0.0022 and 0.0033 per unit increase in salinity. A similar relationship is observed in batch cultures of the coastal haptophyte Isochrysis galbana, where α increases with each unit of salinity by 0.0019 - slightly less than for E. huxleyi. However, absolute αC37alkenone-growthwater values vary strongly between species suggesting that species composition has a strong impact on the δD value of alkenones. The fractionation factor for alkenones produced by batch cultures of I. galbana is affected by growth phase: the rate of change of αC37alkenone-growthwater with each unit of salinity decreases from 0.0019 in the exponential phase to 0.0010 during the stationary phase. We also show the effect of varying growth rate over the range 0.2-0.8 day-1 on the fractionation factor for alkenones produced by E. huxleyi grown in continuous culture. These data show that alkenone δD can be used to

  10. Characterization of polyphenols, sugars, and other polar compounds in persimmon juices produced under different technologies and their assessment in terms of compositional variations.

    PubMed

    Jiménez-Sánchez, Cecilia; Lozano-Sánchez, Jesús; Marti, Nuria; Saura, Domingo; Valero, Manuel; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

    2015-09-01

    Persimmon juice is emerging in the global juice market as a new wholesome commercial juice that could effectively complement a healthy diet, given the epidemiological evidence linking a diet rich in fruits and vegetables with reduced incidences of chronic diseases. However, little data are available on the persimmon-juice composition or on the effect of the technological treatment employed for its production. The present work performs a complete qualitative analytical characterization through high-performance liquid chromatography coupled to electrospray time-of-flight mass spectrometry (HPLC-DAD-ESI-TOF/MS) of the diverse persimmon juices produced under different technologies in a pilot plant (clarification, astringency removal, flash vacuum expansion, centrifugation and pasteurization) in order to evaluate the effect of the different production procedures on the polar chemical profile of persimmon juice. Persimmon-juice extracts have been found to be a source of sugars, protein derivatives, organic acids, vitamins, and polyphenols, including simple polyphenols (phenolic acids and flavonoids) and polymerized flavan-3-ols. A marked influence of processing on the composition of the juices has been noticed. Extracts 3 and 7 (undergoing the combinations of clarification and centrifugation, and astringency removal, centrifugation and pasteurization, respectively) contained more polyphenols, which may help reduce risk of chronic diseases. PMID:25842339

  11. Evidence for a reversible drought induced shift in the species composition of mycotoxin producing Fusarium head blight pathogens isolated from symptomatic wheat heads.

    PubMed

    Beyer, Marco; Pogoda, Friederike; Pallez, Marine; Lazic, Joëlle; Hoffmann, Lucien; Pasquali, Matias

    2014-07-16

    Fusarium species are fungal plant pathogens producing toxic secondary metabolites such as deoxynivalenol (DON), 15-acetyl-deoxynivalenol (15AcDON) and nivalenol (NIV). In Luxembourg, the Fusarium species composition isolated from symptomatic winter wheat heads was dominated by Fusarium graminearum sensu stricto strains (genetic 15AcDON chemotype) between the years 2009 and 2012, except for 2011, when Fusarium culmorum strains (genetic NIV chemotype) dominated the pathogen complex. Previous reports indicated that F. graminearum sensu stricto (genetic 15AcDON chemotype) was also most frequently isolated from randomly sampled winter wheat kernels including symptomatic as well as asymptomatic kernels in 2007 and 2008. The annual precipitation (average of 10 weather stations scattered across the country) decreased continuously from 924.31mm in 2007 over 917.15mm in 2008, to 843.38mm in 2009, 736.24mm in 2010, and 575.09mm in 2011. In 2012, the annual precipitation increased again to 854.70mm. Hardly any precipitation was recorded around the time of wheat anthesis in the years 2010 and 2011, whereas precipitation levels >50mm within the week preceding anthesis plus the week post anthesis were observed in the other years. The shift to genetic NIV chemotype F. culmorum strains in 2011 was accompanied by a very minor elevation of average NIV contents (2.9ngg(-1)) in the grain. Our data suggest that high NIV levels in Luxembourgish winter wheat are at present rather unlikely, because the indigenous F. culmorum strains with the genetic NIV chemotype seem to be outcompeted under humid in vivo conditions by F. graminearum DON producing strains on the one hand and seem to be inhibited - even though to a lower extent than DON producing strains - under dry in vivo conditions on the other hand. PMID:24859190

  12. Targeted mutation of Δ12 and Δ15 desaturase genes in hemp produce major alterations in seed fatty acid composition including a high oleic hemp oil.

    PubMed

    Bielecka, Monika; Kaminski, Filip; Adams, Ian; Poulson, Helen; Sloan, Raymond; Li, Yi; Larson, Tony R; Winzer, Thilo; Graham, Ian A

    2014-06-01

    We used expressed sequence tag library and whole genome sequence mining to identify a suite of putative desaturase genes representing the four main activities required for production of polyunsaturated fatty acids in hemp seed oil. Phylogenetic-based classification and developing seed transcriptome analysis informed selection for further analysis of one of seven Δ12 desaturases and one of three Δ15 desaturases that we designate CSFAD2A and CSFAD3A, respectively. Heterologous expression of corresponding cDNAs in Saccharomyces cerevisiae showed CSFAD2A to have Δx+3 activity, while CSFAD3A activity was exclusively at the Δ15 position. TILLING of an ethyl methane sulphonate mutagenized population identified multiple alleles including non-sense mutations in both genes and fatty acid composition of seed oil confirmed these to be the major Δ12 and Δ15 desaturases in developing hemp seed. Following four backcrosses and sibling crosses to achieve homozygosity, csfad2a-1 was grown in the field and found to produce a 70 molar per cent high oleic acid (18:1(Δ9) ) oil at yields similar to wild type. Cold-pressed high oleic oil produced fewer volatiles and had a sevenfold increase in shelf life compared to wild type. Two low abundance octadecadienoic acids, 18:2(Δ6,9) and 18:2(Δ9,15), were identified in the high oleic oil, and their presence suggests remaining endogenous desaturase activities utilize the increased levels of oleic acid as substrate. Consistent with this, CSFAD3A produces 18:2(Δ9,15) from endogenous 18:1(Δ9) when expressed in S. cerevisiae. This work lays the foundation for the development of additional novel oil varieties in this multipurpose low input crop. PMID:24506492

  13. Inhibitory effects of various essential oils and individual components against extended-spectrum beta-lactamase (ESBL) produced by Klebsiella pneumoniae and their chemical compositions.

    PubMed

    Orhan, Ilkay Erdogan; Ozcelik, Berrin; Kan, Yüksel; Kartal, Murat

    2011-10-01

    In the current study, in vitro inhibitory activity of several essential oils obtained from the cultivated plants, Foeniculum vulgare, Mentha piperita and M. spicata, Ocimum basilicum, Origanum majorana, O. onites, O. vulgare, Satureja cuneifolia, and a number of individual essential oil components of terpene and aromatic types were screened against 10 isolated strains of Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL) enzyme, which makes this microorganism quite resistant against the antibiotics: trimetoprime-sulfametoksazol, sulbactam-ampicilin, clavulonate-amoxicilin, ceftriaxon, cefepime, imipenem, ceftazidime, tobramicine, gentamisine, ofloxacin, and ciprofloksasin. All of the essential oils and the components exerted a remarkable inhibition ranging between 32 and 64 μg/mL against all of these strains as strong as the references (ampicilin and oflaxocin) inhibiting at 32 μg/mL. Besides, chemical compositions of the essential oils were elucidated by gas chromatography-mass spectrometry (GC-MS). The essential oils and the pure components widely found in essential oils screened herein have shown remarkable inhibition against ESBL-producing K. pneumoniae strains, which leads to the suggestion that they may be used as food preservatives for this purpose. Practical Application:  The essential oils obtained from Foeniculum vulgare, Mentha piperita and M. spicata, O.cimum basilicum, Origanum majorana, O. onites, O. vulgare, and Satureja cuneifolia as well as common essential oil components have shown notable inhibitory effects against 10 isolated strains of Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL) enzyme and they might be used as food preservative or ingredient. PMID:22417594

  14. The N-glycan on Asn54 affects the atypical N-glycan composition of plant-produced interleukin-22, but does not influence its activity.

    PubMed

    Wilbers, Ruud H P; Westerhof, Lotte B; Reuter, Lauri J; Castilho, Alexandra; van Raaij, Debbie R; Nguyen, Dieu-Linh; Lozano-Torres, Jose L; Smant, Geert; Hokke, Cornelis H; Bakker, Jaap; Schots, Arjen

    2016-02-01

    Human interleukin-22 (IL-22) is a member of the IL-10 cytokine family that has recently been shown to have major therapeutic potential. IL-22 is an unusual cytokine as it does not act directly on immune cells. Instead, IL-22 controls the differentiation, proliferation and antimicrobial protein expression of epithelial cells, thereby maintaining epithelial barrier function. In this study, we transiently expressed human IL-22 in Nicotiana benthamiana plants and investigated the role of N-glycosylation on protein folding and biological activity. Expression levels of IL-22 were up to 5.4 μg/mg TSP, and N-glycan analysis revealed the presence of the atypical Lewis A structure. Surprisingly, upon engineering of human-like N-glycans on IL-22 by co-expressing mouse FUT8 in ΔXT/FT plants a strong reduction in Lewis A was observed. Also, core α1,6-fucoylation did not improve the biological activity of IL-22. The combination of site-directed mutagenesis of Asn54 and in vivo deglycosylation with PNGase F also revealed that N-glycosylation at this position is not required for proper protein folding. However, we do show that the presence of a N-glycan on Asn54 contributes to the atypical N-glycan composition of plant-produced IL-22 and influences the N-glycan composition of N-glycans on other positions. Altogether, our data demonstrate that plants offer an excellent tool to investigate the role of N-glycosylation on folding and activity of recombinant glycoproteins, such as IL-22. PMID:26059044

  15. Compositional Grading in an Impact-produced Spherule Bed, Barberton Greenstone Belt, South Africa: A Key to Condensation History of Rock Vapor Clouds

    NASA Technical Reports Server (NTRS)

    Krull, A. E.; Lowe, D. R.; Byerly, G. R.

    2003-01-01

    The chemical and physical processes by which spherules form during the condensation of impact-produced rock vapor clouds are poorly understood. Although efforts have been made to model the processes of spherule formation, there is presently a paucity of field data to constrain the resulting theoretical models. The present study examines the vertical compositional variability in a single early Archean spherule bed in the Barberton Greenstone Belt (BGB), South Africa, in order to better identify the process by which impact vapor clouds condense and spherules form and accumulate. The BGB spherule beds are suitable for this type of study because of their great thickness, often exceeding 25cm of pure spherules, due to the massive sizes of the impactors. Two main problems complicate analysis of vertical compositional variability of graded spherule beds: (1) differential settling of particles in both the vapor and water column due to density and size differences and (2) turbulence within the vapor cloud. The present study compares sections of spherule bed S3 from four different depositional environments in the Barberton Greenstone Belt: (1) The Sheba Mine section (SAF-381) was deposited under fairly low energy conditions in deep water, providing a nice fallout sequence, and also has abundant Ni-rich spinels; (2) Jay's Chert section (SAF-380) was deposited in subaerial to shallow-water conditions with extensive post-depositional reworking by currents. The spherules also have preserved spinels; (3) the Loop Road section (loc. SAF-295; samp. KSA-7) was moderately reworked and has only rare preservation of spinels; and (4) the shallow-water Barite Syncline section (loc. SAF-206; samp KSA-1) has few to no spinels preserved and is not reworked. Although all of the spherule beds have been altered by silica diagenesis and K-metasomatism, most of the compositional differences between these sections appear to reflect their diagenetic histories, possibly related to their differing

  16. Betalain and betaine composition of greenhouse- or field-produced beetroot ( Beta vulgaris L.) and inhibition of HepG2 cell proliferation.

    PubMed

    Lee, Eun Jin; An, Dami; Nguyen, Chau T T; Patil, Bhimanagouda S; Kim, Jeongyun; Yoo, Kil Sun

    2014-02-12

    The composition of betalain, red or yellow pigments, and betaine (trimethylglycine or glycinebetaine) of nine beetroot ( Beta vulgaris L.) cultivars produced in the greenhouse or field was studied. Inhibition of HepG2 cell proliferation by betanin and betaine was also tested. Four predominant betalains, two betacyanins (betanin and isobetanin) and two betaxanthins (vulgaxanthin I and miraxanthin V), were isolated and quantified. Betanin and vulgaxanthin I were the major compounds in red and yellow beetroot extracts, respectively, and they comprised >90% of the betalain content in the tested cultivars. The total betalain content of beetroots produced from the field was between 650 and 800 μg/g fresh weight, approximately 25% higher than those from the greenhouse. The betaine content of the beetroot grown in the field was between 3.0 and 4.8 mg/g fresh weight, approximately 20% higher than in plants from the greenhouse. There was great variation among the cultivars with respect to their contents of betalains and betaine. In vitro cancer cell cytotoxicity was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay on HepG2 cells after exposure to betanin and betaine at concentrations ranging from 0 to 400 μg/mL and from 0 to 800 μg/mL for 48 h, respectively. Betanin resulted in a 49% inhibition of HepG2 cell proliferation at 200 μg/mL, and betaine yielded a 25% inhibition at 800 μg/mL, implying a higher cytotoxicity of betanin compared with betaine. The results indicated that the contents of health-beneficial compounds in beetroots, betalains and betaine, could be increased by modifying the growing conditions and that betanin and betaine extracted from beetroots had some anticancer effects against HepG2 cells. PMID:24467616

  17. Compositional and sensory differences of products of sweet-cream and whey buttermilk produced by microfiltration, diafiltration, and supercritical CO2.

    PubMed

    Olabi, A; Jinjarak, S; Jiménez-Flores, R; Walker, J H; Daroub, Hamza

    2015-06-01

    The objectives of this work were to assess the compositional properties and sensory characteristics of ingredients produced by treating sweet-cream and whey-cream buttermilks with microfiltration (MF), diafiltration (DF), and supercritical CO2 (SFE) extraction. Sweet-cream buttermilk (CBM) and buttermilk resulting from churning the residual fat from whey processing (whey buttermilk, WBM) were used. Using MF or microfiltration followed by diafiltration (MF-DF), we obtained resulting retentates that were dried and then were subjected to SFE treatment. Control buttermilks, SFE resulting products, and MF and MF-DF SFE and all treated retentates products totaled 16 samples (2 types×4 treatments×2 batches). Eleven trained panelists assessed samples using descriptive analysis. Sweet-cream buttermilk was higher in protein and lactose, whereas the WBM had similar total protein, mainly β-LG and α-LA but very low lactose. The resulting samples in order of concentration for fat and lactose were control samples>SFE treated>MF treated>DF=MF-SFE and DF-SFE. Sodium dodecyl sulfate-PAGE protein profiling showed negligible casein for WBM versus CBM and less whey proteins for CBM versus WBM, as expected. Whey buttermilk was more yellow, salty, sour, and rancid than CBM. Regarding the treatments, significant differences were obtained on homogeneity, opacity, rancid odor, cardboard and sour flavors, sweet and salty tastes, viscosity, and mouthcoating, where SFE-treated samples showed lowest rancid odor and cardboard flavor. PMID:25864057

  18. Continuous esterification to produce biodiesel by SPES/PES/NWF composite catalytic membrane in flow-through membrane reactor: experimental and kinetic studies.

    PubMed

    Shi, Wenying; He, Benqiao; Cao, Yuping; Li, Jianxin; Yan, Feng; Cui, Zhenyu; Zou, Zhiqun; Guo, Shiwei; Qian, Xiaomin

    2013-02-01

    A novel composite catalytic membrane (CCM) was prepared from sulfonated polyethersulfone (SPES) and polyethersulfone (PES) blend supported by non-woven fabrics, as a heterogeneous catalyst to produce biodiesel from continuous esterification of oleic acid with methanol in a flow-through mode. A kinetic model of esterification was established based on a plug-flow assumption. The effects of the CCM structure (thickness, area, porosity, etc.), reaction temperature and the external and internal mass transfer resistances on esterification were investigated. The results showed that the CCM structure had a significant effect on the acid conversion. The external mass transfer resistance could be neglected when the flow rate was over 1.2 ml min(-1). The internal mass transfer resistance impacted on the conversion when membrane thickness was over 1.779 mm. An oleic acid conversion kept over 98.0% for 500 h of continuous running. The conversions obtained from the model are in good agreement with the experimental data. PMID:23232226

  19. Characterization of SiC f/SiC and CNT/SiC composite materials produced by liquid phase sintering

    NASA Astrophysics Data System (ADS)

    Lee, J. K.; Lee, S. P.; Cho, K. S.; Byun, J. H.; Bae, D. S.

    2011-10-01

    This paper dealt with the microstructure and mechanical properties of SiC based composites reinforced with different reinforcing materials. The composites were fabricated using reinforcing materials of carbon nanotubes (CNT) and Tyranno Lox-M SiC chopped fibers. The volume fraction of carbon nanotubes was also varied in this composite system. An Al 2O 3-Y 2O 3 powder mixture was used as a sintering additive in the consolidation of the SiC matrix. The characterization of the composites was investigated by means of SEM and three point bending tests. These composites showed a dense morphology of the matrix region, by the creation of a secondary phase. The composites reinforced with SiC chopped fibers possessed a flexural strength of about 400 MPa at room temperature. The flexural strength of the carbon nanotubes composites had a tendency to decrease with increased volume fraction of the reinforcing material.

  20. Winter-summer nutrient composition linkage to algae-produced toxins in shellfish at a eutrophic coastal lagoon (Óbidos lagoon, Portugal)

    NASA Astrophysics Data System (ADS)

    Pereira, Patrícia; Botelho, Maria João; Cabrita, Maria Teresa; Vale, Carlos; Moita, Maria Teresa; Gonçalves, Célia

    2012-10-01

    The current work examines the linkage of pronounced winter-summer fluctuations on the nutrient composition with phytoplankton assemblages and mussel toxicity produced by the presence of toxic dinoflagellates. The work was performed at the Óbidos lagoon, a coastal eutrophic ecosystem that is permanently connected to an area characterized by frequent upwelling episodes. The lagoon and adjoining coastal area exhibit recurrent incidents of diarrhetic and paralytic shellfish poisoning. The conclusions are based on: (1) inorganic and organic nutrients at five sites of the lower, middle and upper Óbidos lagoon, and inorganic nutrients at two sites of the adjacent coastal area; biannual campaigns were performed in winter and summer between 2006 and 2010; (2) phytoplankton assemblages at three sites of the lagoon (located at lower and upper areas) in winter and summer of 2009; (3) algae-derived toxicity of wild mussels from the lower lagoon and coastal area, on a 1-2 week time scale, over 2006 and 2009. Nutrient molar ratios in Óbidos lagoon contrast between winter and summer. The lower median ratios DIN:P (31 and 0.8) and Si:P (11 and 3.3) in summer reflect the excess of phosphate. Excess was mainly attributed to phosphorus regeneration in sediments of the upper lagoon with accentuated symptoms of eutrophication. Dissolved organic nitrogen and dissolved organic phosphorus were also higher in summer, particularly in this area. No significant winter-summer differences were recorded for nutrient ratios in the adjacent coastal area. Phytoplankton assemblages pointed to a winter-summer contrast characterized by a shift of non-siliceous-based phytoplankton to diatoms. The toxic dinoflagellate species (Gymnodinium catenatum, Dinophysis cf. acuminata and Dinophysis acuta), presumably imported from the adjacent coast following upwelling episodes in summer, were observed in the lower lagoon. In summer of the two surveyed years, toxins produced by dinoflagellates occurred in

  1. Producing docosahexaenoic acid (DHA)-rich algae from biodiesel-derived crude glycerol: effects of impurities on DHA production and algal biomass composition.

    PubMed

    Pyle, Denver J; Garcia, Rafael A; Wen, Zhiyou

    2008-06-11

    Crude glycerol is the primary byproduct of the biodiesel industry. Producing docosahexaenoic acid (DHA, 22:6 n-3) through fermentation of the alga Schizochytrium limacinum on crude glycerol provides a unique opportunity to utilize a large quantity of this byproduct. The objective of this work is to investigate the effects of impurities contained in the crude glycerol on DHA production and algal biomass composition. Crude glycerol streams were obtained from different biodiesel refineries. All of the glycerol samples contained methanol, soaps, and various elements including calcium, phosphorus, potassium, silicon, sodium, and zinc. Both methanol and soap were found to negatively influence algal DHA production; these two impurities can be removed from culture medium by evaporation through autoclaving (for methanol) and by precipitation through pH adjustment (for soap). The glycerol-derived algal biomass contained 45-50% lipid, 14-20% protein, and 25% carbohydrate, with 8-13% ash content. Palmitic acid (C16:0) and DHA were the two major fatty acids in the algal lipid. The algal biomass was rich in lysine and cysteine, relative to many common feedstuffs. Elemental analysis by inductively coupled plasma showed that boron, calcium, copper, iron, magnesium, phosphorus, potassium, silicon, sodium, and sulfur were present in the biomass, whereas no heavy metals (such as mercury) were detected in the algal biomass. Overall, the results show that crude glycerol was a suitable carbon source for algal fermentation. The crude glycerol-derived algal biomass had a high level of DHA and a nutritional profile similar to that of commercial algal biomass, suggesting a great potential for using crude glycerol-derived algae in omega-3-fortified food or feed. PMID:18465872

  2. Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 glass ceramic-aluminum containing austenitic stainless steel composite body and a method of producing the same

    DOEpatents

    Cassidy, Roger T.

    1990-05-01

    The present invention relates to a hermetically sealed Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 glass ceramic-aluminum containing stainless steel composite body and a method of producing the body. The composite body includes an oxide interfacial region between the glass ceramic and metal, wherein the interfacial region consists essentially of an Al.sub.2 O.sub.3 layer. The interfacial Al.sub.2 O.sub.3 region includes constituents of both the metal and glass ceramic.

  3. High temperature mechanical properties of a {beta}-Si{sub 3}N{sub 4} whisker reinforced aluminium alloy composite produced by squeeze casting

    SciTech Connect

    Tochigi, Isao; Imai, Tsunemichi; Ai, Kyosuke

    1995-06-01

    The {beta}-Si{sub 3}N{sub 4}w/6061 Al composite was fabricated by the squeeze casting and extruded with the extrusion ratios of 44 and 100 at 773 K. Its tensile strength and superplastic characteristics were investigated and the following results were obtained: (1) the {beta}-Si{sub 3}N{sub 4}w/6061 Al composite exhibits the tensile strengths of about 400 MPa at room temperature and of about 250 MPa at 773 K; (2) the m value of the composite pulled at 818 K is 0.33 in the strain rate range from 0.02 up to 1.0 s{sup {minus}1}; (3) the total elongation of the composite becomes about 173 % at the strain rate of 0.02 s{sup {minus}1} even in the case of the high volume fraction of 0.25; (4) no reaction product on the surface of {beta}-Si{sub 3}N{sub 4} whisker after removing a matrix by etching was detected except AlN; (5) the fracture surface of the composite includes the melt matrix and small filaments, which shows that interfacial sliding should promote HSRS in addition to fine grain boundary sliding.

  4. Bollgard II cotton: compositional analysis and feeding studies of cottonseed from insect-protected cotton (Gossypium hirsutum L.) producing the Cry1Ac and Cry2Ab2 proteins.

    PubMed

    Hamilton, Kathryn A; Pyla, Paul D; Breeze, Matthew; Olson, Tammy; Li, Menghe; Robinson, Edwin; Gallagher, Sean P; Sorbet, Roy; Chen, Yin

    2004-11-17

    Bollgard II cotton event 15985 producing the Cry1Ac and Cry2Ab2 proteins has been developed by genetic modification to broaden the spectrum of insects to which the plant is tolerant and to provide an insect resistance management tool to impede the onset of resistance. The purpose of this study was to evaluate the composition and nutrition of Bollgard II cotton, relative to the use for food and animal feed, compared to that of conventional cotton varieties. Compositional analyses were conducted to measure proximate, fiber, amino acid, fatty acid, gossypol, and mineral contents of cottonseed from a total of 14 U.S. field sites over two years. Compositional analysis results showed that the cottonseed and cottonseed oil from Bollgard II cotton were comparable in their composition to those of the conventional control cotton line and other commercial varieties. The composition data are supported by nutritional safety studies conducted with dairy cows, catfish, and quail. Results from these studies showed that Bollgard II performed similarly to the conventional control cotton varieties. These data demonstrate that Bollgard II cotton is compositionally and nutritionally equivalent to conventional cotton varieties. These data support the conclusion that Bollgard II cotton is as safe and nutritious as conventional cotton for food and feed use. PMID:15537305

  5. Cure Cycle Design Methodology for Fabricating Reactive Resin Matrix Fiber Reinforced Composites: A Protocol for Producing Void-free Quality Laminates

    NASA Technical Reports Server (NTRS)

    Hou, Tan-Hung

    2014-01-01

    For the fabrication of resin matrix fiber reinforced composite laminates, a workable cure cycle (i.e., temperature and pressure profiles as a function of processing time) is needed and is critical for achieving void-free laminate consolidation. Design of such a cure cycle is not trivial, especially when dealing with reactive matrix resins. An empirical "trial and error" approach has been used as common practice in the composite industry. Such an approach is not only costly, but also ineffective at establishing the optimal processing conditions for a specific resin/fiber composite system. In this report, a rational "processing science" based approach is established, and a universal cure cycle design protocol is proposed. Following this protocol, a workable and optimal cure cycle can be readily and rationally designed for most reactive resin systems in a cost effective way. This design protocol has been validated through experimental studies of several reactive polyimide composites for a wide spectrum of usage that has been documented in the previous publications.

  6. Microstructure and wear resistance of Al2O3-M7C3/Fe composite coatings produced by laser controlled reactive synthesis

    NASA Astrophysics Data System (ADS)

    Tan, Hui; Luo, Zhen; Li, Yang; Yan, Fuyu; Duan, Rui

    2015-05-01

    Based on the principle of thermite reaction of Al and Fe2O3 powders, the Al2O3 ceramic reinforced Fe-based composite coatings were fabricated on a steel substrate by laser controlled reactive synthesis and cladding. The effects of different additions of thermite reactants on the phase transition, microstructure evolution, microhardness and wear resistance of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Vickers microhardness and block-on-ring wear test, respectively. The results show that Al2O3 ceramic and M7C3 carbide are in situ synthesized via the laser controlled reactive synthesis. The Al2O3 ceramic and M7C3 carbides prefer to distribute along the γ-Fe phase boundary continuously, which separates the γ-Fe matrix and is beneficial to the grain refinement. With the increase of thermite reactants, the amount of Al2O3 ceramic and M7C3 carbide in the composite coatings increases gradually. Moreover the cladding layer changes from dendritic structure to columnar structure and martensite structure in the heat affected zone becomes coarse. The increased thermite reactants improve the microhardness and wear resistance of the in situ composite coatings obviously and enhance the hardness of the heat affected zone, which should be ascribed to the grain refinement, ceramic and carbide precipitation and solid solution strengthening.

  7. Tribological Behavior of Aluminum Alloy AlSi10Mg-TiB2 Composites Produced by Direct Metal Laser Sintering (DMLS)

    NASA Astrophysics Data System (ADS)

    Lorusso, Massimo; Aversa, Alberta; Manfredi, Diego; Calignano, Flaviana; Ambrosio, Elisa Paola; Ugues, Daniele; Pavese, Matteo

    2016-06-01

    Direct metal laser sintering (DMLS) is an additive manufacturing technique for the production of parts with complex geometry and it is especially appropriate for structural applications in aircraft and automotive industries. Aluminum-based metal matrix composites (MMCs) are promising materials for these applications because they are lightweight, ductile, and have a good strength-to-weight ratio This paper presents an investigation of microstructure, hardness, and tribological properties of AlSi10Mg alloy and AlSi10Mg alloy/TiB2 composites prepared by DMLS. MMCs were realized with two different compositions: 10% wt. of microsize TiB2, 1% wt. of nanosize TiB2. Wear tests were performed using a pin-on-disk apparatus on the prepared samples. Performances of AlSi10Mg samples manufactured by DMLS were also compared with the results obtained on AlSi10Mg alloy samples made by casting. It was found that the composites displayed a lower coefficient of friction (COF), but in the case of microsize TiB2 reinforcement the wear rate was higher than with nanosize reinforcements and aluminum alloy without reinforcement. AlSi10Mg obtained by DMLS showed a higher COF than AlSi10Mg obtained by casting, but the wear rate was higher in the latter case.

  8. Effect of surfactant concentration in the electrolyte on the tribological properties of nickel-tungsten carbide composite coatings produced by pulse electro co-deposition

    NASA Astrophysics Data System (ADS)

    Kartal, Muhammet; Uysal, Mehmet; Gul, Harun; Alp, Ahmet; Akbulut, Hatem

    2015-11-01

    A nickel plating bath containing WC particles was used to obtain hard and wear-resistant particle reinforced Ni/WC MMCs on steel surfaces for anti-wear applications. Copper substrates were used for electro co-deposition of Ni matrix/WC with the particle size of <1 μm tungsten carbide reinforcements. The influence of surfactant (sodium dodecyl sulfate, SDS) concentration on particle distribution, microhardness and wear resistance of composite coatings has been studied. The nickel films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of the surfactant on the zeta potential, co-deposition and distribution of WC particles in the nickel matrix, as well as the tribological properties of composite coatings were also investigated. The tribological behaviors of the electrodeposited WC composite coatings sliding against M50 steel ball (Ø 10 mm) were examined on a CSM Instrument. All friction and wear tests were performed without lubrication at room temperature and in the ambient air (relative humidity 55-65%).

  9. Producing Docosahexaenoic Acid (DHA)-Rich Algae from Biodiesel-Derived Crude Glycerol: Effects of Impurities on DHA Production and Algal Biomass Composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crude glycerol is the primary byproduct of the biodiesel industry. Producing docosahexaenoic acid (DHA, 22:6 n-3) through fermentation of the alga Schizochytrium limacinum on crude glycerol provides a unique opportunity to utilize a large quantity of this byproduct. The objective of this work is to...

  10. Characteristics of Ti(C, N)/TiB composite layer on Ti-6Al-4V alloy produced by laser surface melting

    NASA Astrophysics Data System (ADS)

    Zeng, Xian; Yamaguchi, Tomiko; Nishio, Kazumasa

    2016-06-01

    A Ti(C, N)/TiB reinforced titanium matrix composite layer was successfully in-situ synthesized by laser melting on Ti-6Al-4V alloy surface with Ti-BN-C mixed powder, aiming at improving the wear resistance. The microstructure, chemical composition, hardness and wear behavior were analyzed. The results showed that, the cross sectional microstructure can be clearly divided into three parts, which were the laser melted layer, heat affected zone and non-affected zone. The reinforcements in laser melted layer consisted of dendritic TiC0.3N0.7 phases and fine-structure TiB phases. The matrix in laser melted layer was in a two-phase structure, being composed of platelet α titanium and intergranular β titanium. The hardness was increased from 320 HV in the substrate to 450-550 HV in the modified layer. The wear resistance was improved that, the wear volume loss of the laser treated sample was approximately half of the as received Ti-6Al-4V alloy after 8 h wear test.

  11. Association of Composite IS26-sul3 Elements with Highly Transmissible IncI1 Plasmids in Extended-Spectrum-β-Lactamase-Producing Escherichia coli Clones from Humans▿

    PubMed Central

    Curiao, Tânia; Cantón, Rafael; Garcillán-Barcia, M. Pilar; de la Cruz, Fernando; Baquero, Fernando; Coque, Teresa M.

    2011-01-01

    The association of an IS440-sul3 platform with Tn21 class 1 integrons carried by IncI1 plasmids encoding extended-spectrum β-lactamases (ESBLs; mainly SHV-12 and CTX-M-14) among worldwide Escherichia coli clones of phylogroups A (ST10, ST23, and ST46), B1 (ST155, ST351, and ST359), and D/B2 (ST131) is reported. An in silico comparative analysis of sul3 elements available in the GenBank database shows the evolution of sul3 platforms by hosting different transposable elements facilitating the potential genesis of IS26 composite transposons and further insertion element-mediated promoted arrangements. PMID:21343460

  12. The Optical Properties of Cu-Ni Nanoparticles Produced via Pulsed Laser Dewetting of Ultrathin Films: The Effect of Nanoparticle Size and Composition on the Plasmon Response

    SciTech Connect

    Wu, Yeuyeng; Fowlkes, Jason Davidson; Rack, Philip D

    2011-01-01

    Thin film Cu-Ni alloys ranging from 2-8nm were synthesized and their optical properties were measured as-deposited and after a laser treatment which dewet the films into arrays of spatially correlated nanoparticles. The resultant nanoparticle size and spacing are attributed to laser induced spinodal dewetting process. The evolution of the spinodal dewetting process is investigated as a function of the thin film composition which ultimately dictates the size distribution and spacing of the nanoparticles. The optical measurements of the copper rich alloy nanoparticles reveal a signature absorption peak suggestive of a plasmonic peak which red-shifts with increasing nanoparticle size and blue shifts and dampens with increasing nickel concentration.

  13. Highly flexible transparent self-healing composite based on electrospun core-shell nanofibers produced by coaxial electrospinning for anti-corrosion and electrical insulation

    NASA Astrophysics Data System (ADS)

    An, Seongpil; Liou, Minho; Song, Kyo Yong; Jo, Hong Seok; Lee, Min Wook; Al-Deyab, Salem S.; Yarin, Alexander L.; Yoon, Sam S.

    2015-10-01

    Coaxial electrospinning was used to fabricate two types of core-shell fibers: the first type with liquid resin monomer in the core and polyacrylonitrile in the shell, and the second type with liquid curing agent in the core and polyacrylonitrile in the shell. These two types of core-shell fibers were mutually entangled and embedded into two flexible transparent matrices thus forming transparent flexible self-healing composite materials. Such materials could be formed before only using emulsion electrospinning, rather than coaxial electrospinning. The self-healing properties of such materials are associated with release of healing agents (resin monomer and cure) from nanofiber cores in damaged locations with the subsequent polymerization reaction filing the micro-crack with polydimethylsiloxane. Transparency of these materials is measured and the anti-corrosive protection provided by them is demonstrated in electrochemical experiments.

  14. Influence of the HVOF Gas Composition on the Thermal Spraying of WC-Co Submicron Powders (-8 + 1 μm) to Produce Superfine Structured Cermet Coatings

    NASA Astrophysics Data System (ADS)

    Tillmann, W.; Vogli, E.; Baumann, I.; Matthaeus, G.; Ostrowski, T.

    2008-12-01

    Thermal spraying technology represents a novel and promising approach to protect forming tools with complex surfaces and highest shape accuracy against abrasive wear and galling. However, due to high or nonuniform layer thicknesses or inappropriate surface roughness conventional coarse-structured coatings are not suitable to achieve this aim. The application of novel submicron or nanoscaled feedstock materials in the thermal spray process can provide the deposition of cermet coatings with significantly improved characteristics and is recently of great interest in science and industry. In this collaborative study, the feeding and HVOF spraying of WC-Co submicron powders (-8 + 1 μm) have been investigated to manufacture superfine structured, wear resistant, near-net-shape coatings with improved macroscopic properties and smooth surfaces. The influences of varying HVOF gas compositions on the spray process and the coating properties have been analyzed.

  15. Microstructure, microhardness, phase analysis and chemical composition of laser remelted FeB-Fe2B surface layers produced on Vanadis-6 steel

    NASA Astrophysics Data System (ADS)

    Bartkowska, Aneta; Swadźba, Radosław; Popławski, Mikołaj; Bartkowski, Dariusz

    2016-12-01

    The paper presents the study results of the diffusion boronized layer and their laser modification. Diffusion boronized processes were carried out on Vanadis-6 steel at 900 °C for 5 h. Boronized layers were characterized by dual-phase microstructure consisting of iron borides having a microhardness in the range from 1800 to 1400 HV. The laser heat treatment was carried out using CO2 laser after diffusion boronizing process. The research goals of this paper was analysis of microstructure, microhardness as well as phase and chemical composition of boronized layers after laser modification. Microstructure of boronized layer after laser modification consisted of remelted zone, heat affected zone and substrate. Remelted zone was characterized by microstructure consisted of boron-martensite eutectic. In this zone, the phases of borides and carbides were detected. Boronized layers after laser modification were characterized by the mild gradient of microhardness from surface to the substrate.

  16. Partial melting to produce high-silica rhyolites of a young bimodal suite: compositional constraints among rhyolites, basalts, and metamorphic xenoliths from the Harney Basin, Oregon

    NASA Astrophysics Data System (ADS)

    Streck, Martin J.

    2002-08-01

    The Rattlesnake Ash Flow Tuff from eastern Oregon includes lithic fragments (xenoliths) of which metasedimentary or metavolcanic lithologies around the vent area in the Harney Basin are samples of the concealed crust. Metasedimentary xenoliths are volcanic lithic to feldspathic graywackes that could be sampling lithologies similar to arc-related terranes to the north that have accreted during Mesozoic time along the Oregon Pacific margin. The importance of finding metaxenoliths in the Rattlesnake Tuff is that they are the first basement samples of southeastern Oregon possibly representative of larger portions of the concealed crust from which voluminous Rattlesnake Tuff and other rhyolites were initially generated during partial melting with subsequent evolution through fractional crystallization. High Ba/Rb ratios of ~30 and La/Yb of ~6.5 of least-evolved Rattlesnake Tuff high-silica rhyolites in combination with other low concentrations of some incompatible trace elements preclude the derivation of least-evolved Rattlesnake Tuff high-silica rhyolite from local low-silica rhyolites through fractionation, which suggests instead that some chemical characteristics could be nearly unmodified signatures derived from partial melting. Rattlesnake metamorphic xenoliths and primitive basalt lavas (HAOT) have the most compatible chemistries as source rock for partial melting among a large range of other local rock compositions. Compositional evidence, comparison with literature data of experimental melts derived from laboratory experiments, and modeling of required effective partition coefficients indicate that least-evolved Rattlesnake Tuff rhyolite was likely generated during dehydration melting of mafic crust at melt percentage ranging from ~5 to 10% with residues as observed in experiments with abundant pyroxene and plagioclase.

  17. Effect of particle concentration on the structure and tribological properties of submicron particle SiC reinforced Ni metal matrix composite (MMC) coatings produced by electrodeposition

    NASA Astrophysics Data System (ADS)

    Gül, H.; Kılıç, F.; Uysal, M.; Aslan, S.; Alp, A.; Akbulut, H.

    2012-03-01

    In the present work, a nickel sulfate bath containing SiC submicron particles between 100 and 1000 nm was used as the plating electrolyte. The aim of this work is to obtain Ni-SiC metal matrix composites (MMCs) reinforced with submicron particles on steel surfaces with high hardness and wear resistance for using in anti-wear applications such as dies, tools and working parts for automobiles and vehicles. The influence of the SiC content in the electrolyte on particle distribution, microhardness and wear resistance of nano-composite coatings was studied. During the electroplating process, the proper stirring speed was also determined for sub-micron SiC deposition with Ni matrix. The Ni films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The depositions were controlled to obtain a specific thickness (between 50 and 200 μm) and volume fraction of the particles in the matrix (between 0.02 and 0.10). The hardness of the coatings was measured to be 280-571 HV depending on the particle volume in the Ni matrix. The tribological behaviors of the electrodeposited SiC nanocomposite coatings sliding against an M50 steel ball (Ø 10 mm) were examined on a tribometer. All the friction and wear tests were performed without lubrication at room temperature and in the ambient air (with a relative humidity of 55-65%). The results showed that the wear resistance of the nanocomposites was approximately 2-2.2 times more than those of unreinforced Ni.

  18. Use of D-T-produced fast neutrons for in vivo body composition analysis: a reference method for nutritional assessment in the elderly.

    PubMed

    Kehayias, J J

    2004-05-01

    Body composition has become the main outcome of many nutritional intervention studies including osteoporosis, malnutrition, obesity, AIDS, and aging. Traditional indirect body composition methods developed with healthy young adults do not apply to the elderly or diseased. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments. Non-bone phosphorus for muscle is measured by the (31)P(n, alpha)(28)Al reaction, and nitrogen for protein via the (14)N(n,2n)(13)N fast neutron reaction. Inelastic neutron scattering is used to measure total body carbon and oxygen. Body fat is derived from carbon after correcting for contributions from protein, bone, and glycogen. Carbon-to-oxygen ratio (C/O) is used to measure the distribution of fat and lean tissue in the body and to monitor small changes of lean mass. A sealed, D-T neutron generator is used for the production of fast neutrons. Carbon and oxygen mass and their ratio are measured in vivo at a radiation exposure of less than 0.06 mSv. Gamma-ray spectra are collected using large BGO detectors and analyzed for the 4.43 MeV state of carbon and 6.13 MeV state of oxygen, simultaneously with the irradiation. P and N analysis by delayed fast neutron activation is performed by transferring the patient to a shielded room equipped with an array of NaI(Tl) detectors. A combination of measurements makes possible the assessment of the "quality" of fat-free mass. The neutron generator system is used to evaluate the efficacy of new treatments, to study mechanisms of lean tissue depletion with aging, and to investigate methods for preserving function and quality of life in the elderly. It is also used as a reference method for the validation of portable instruments of nutritional assessment. PMID:14747891

  19. Novel, band-controlled metal oxide compositions for semiconductor-mediated photocatalytic splitting of water to produce H{sub 2}

    SciTech Connect

    Gupta, Narendra M.

    2013-02-05

    Semiconductor-mediated photo-catalytic dissociation of water offers a unique opportunity for the production of H{sub 2}, a sustainable source of energy. More efficient and chemically stable photo-catalysts, however, remain a vital requirement for commercial viability of this process. The recent research in my group has focused on the synthesis of several new metal oxide (MO) photo-catalysts, such as: LaInO{sub 3}, GaFeO{sub 3}, InVO{sub 4}, In{sub 2}TiO{sub 5} and nanotubular TiO{sub 2}. These samples of controlled grain morphology have been synthesized by using different synthesis protocols and with and without coating of a noble metal co-catalyst. The doping of an impurity, either at cationic or at anionic lattice site, has helped in the tailoring of band structure and making these oxides visible-light-sensitive. Our study has revealed that the surface characteristics, grain morphology, band structure, and doping-induced lattice imperfections control the photo-physical properties and overall photo-catalytic water splitting activity of these metal/MO composites [1-6]. We have demonstrated that, besides promoting certain charge-transfer steps, metal-semiconductor interfaces influence the adsorption of water molecules and their subsequent interaction with photo-generated electron-hole pair at the catalyst surface. The role played by the above-mentioned micro-structural properties in photo-catalytic water splitting process will be discussed.

  20. Overexpression of the olive acyl carrier protein gene (OeACP1) produces alterations in fatty acid composition of tobacco leaves.

    PubMed

    De Marchis, Francesca; Valeri, Maria Cristina; Pompa, Andrea; Bouveret, Emmanuelle; Alagna, Fiammetta; Grisan, Simone; Stanzione, Vitale; Mariotti, Roberto; Cultrera, Nicolò; Baldoni, Luciana; Bellucci, Michele

    2016-02-01

    Taking into account that fatty acid (FA) biosynthesis plays a crucial role in lipid accumulation in olive (Olea europaea L.) mesocarp, we investigated the effect of olive acyl carrier protein (ACP) on FA composition by overexpressing an olive ACP cDNA in tobacco plants. The OeACP1.1A cDNA was inserted in the nucleus or in the chloroplast DNA of different tobacco plants, resulting in extensive transcription of the transgenes. The transplastomic plants accumulated lower olive ACP levels in comparison to nuclear-transformed plants. Moreover, the phenotype of the former plants was characterized by pale green/white cotyledons with abnormal chloroplasts, delayed germination and reduced growth. We suggest that the transplastomic phenotype was likely caused by inefficient olive ACP mRNA translation in chloroplast stroma. Conversely, total lipids from leaves of nuclear transformants expressing high olive ACP levels showed a significant increase in oleic acid (18:1) and linolenic acid (18:3), and a concomitant significant reduction of hexadecadienoic acid (16:2) and hexadecatrienoic acid (16:3). This implies that in leaves of tobacco transformants, as likely in the mesocarp of olive fruit, olive ACP not only plays a general role in FA synthesis, but seems to be specifically involved in chain length regulation forwarding the elongation to C18 FAs and the subsequent desaturation to 18:1 and 18:3. PMID:26560313

  1. Effect of reciprocating sliding speed on the tribological performance of nano SiC(p) reinforced Ni-metal matrix composites produced by electrocodeposition.

    PubMed

    Gül, H; Akbulut, H; Aslan, S; Alp, A

    2012-12-01

    In the present work, Ni/SiC metal matrix composite (MMC) coatings were prepared from a modified Watt's type electrolyte containing nano-SiC particles by direct current (DC) plating method to increase wear resistance of the electro co-deposited Ni. SiC nano particles with average particle size of 0, 1-1 microm were co-deposited with nickel matrix on the steel substrates. For this purpose, several studies were carried out to optimize deposition parameters for specific applications. The depositions were controlled to obtain the specific thickness (between 175-200 microm) and particle volume fraction in the matrix (between 0.03 and 0.10). The hardness of the resultant coatings was measured and found to be 280-571 HV depending on the particle concentration in the electrolyte and therefore, particle volume in the Ni matrix. The tribological tests were performed by a reciprocating ball-on disk apparatus sliding against M50 steel ball (Ø10 mm). All the friction and wear tests were performed under the unlubricated conditions at room temperature and in the ambient air (relative humidity 55-65%). The wear tests were carried out at different sliding velocities of 50 mm/s, 100 mm/s and 150 mm/s by using a constant dead load of 1.0 N. It was detected that increasing sliding speed resulted to increase wear rate but decreasing friction coefficient due to change in wear mechanism. Increasing sliding speed showed formation of tribo induced oxides up to 20 g/l SiC(p) in the electrolyte and wear mechanism was controlled by temperature induced fatigue wear. Further increase in the SiC(p) in the electrolyte caused an abrasive type of the wear. PMID:23447960

  2. Abundance, Depth Distribution, and Composition of Aerobic Bacteriochlorophyll a-Producing Bacteria in Four Basins of the Central Baltic Sea▿ †

    PubMed Central

    Salka, Ivette; Moulisová, Vladimíra; Koblížek, Michal; Jost, Günter; Jürgens, Klaus; Labrenz, Matthias

    2008-01-01

    The abundance, vertical distribution, and diversity of aerobic anoxygenic phototrophic bacteria (AAP) were studied at four basins of the Baltic Sea. AAP were enumerated by infrared epifluorescence microscopy, and their diversity was analyzed by using pufM gene clone libraries. In addition, numbers of CFU containing the pufM gene were determined, and representative strains were isolated. Both approaches indicated that AAP reached maximal abundance in the euphotic zone. Maximal AAP abundance was 2.5 × 105 cells ml−1 (11% of total prokaryotes) or 1.0 × 103 CFU ml−1 (9 to 10% of total CFU). Environmental pufM clone sequences were grouped into 11 operational taxonomic units phylogenetically related to cultivated members of the Alpha-, Beta-, and Gammaproteobacteria. In spite of varying pufM compositions, five clones were present in all libraries. Of these, Jannaschia-related clones were always found in relative abundances representing 25 to 30% of the total AAP clones. The abundances of the other clones varied. Clones potentially affiliated with typical freshwater Betaproteobacteria sequences were present at three Baltic Sea stations, whereas clones grouping with Loktanella represented 40% of the total cell numbers in the Gotland Basin. For three alphaproteobacterial clones, probable pufM phylogenetic relationships were supported by 16S rRNA gene analyses of Baltic AAP isolates, which showed nearly identical pufM sequences. Our data indicate that the studied AAP assemblages represented a mixture of marine and freshwater taxa, thus characterizing the Baltic Sea as a “melting pot” of abundant, polyphyletic aerobic photoheterotrophic bacteria. PMID:18502937

  3. Transfer, composition and technological characterization of the lactic acid bacterial populations of the wooden vats used to produce traditional stretched cheeses.

    PubMed

    Scatassa, Maria Luisa; Gaglio, Raimondo; Macaluso, Giusi; Francesca, Nicola; Randazzo, Walter; Cardamone, Cinzia; Di Grigoli, Antonino; Moschetti, Giancarlo; Settanni, Luca

    2015-12-01

    The biofilms of 12 wooden vats used for the production of the traditional stretched cheeses Caciocavallo Palermitano and PDO Vastedda della valle del Belìce were investigated. Salmonella spp. and Listeria monocytogenes were never detected. Total coliforms were at low numbers with Escherichia coli found only in three vats. Coagulase-positive staphylococci (CPS) were below the enumeration limit, whereas lactic acid bacteria (LAB) dominated the surfaces of all vats. In general, the dominance was showed by coccus LAB. Enterococci were estimated at high numbers, but usually between 1 and 2 Log cycles lower than other LAB. LAB populations were investigated at species and strain level and for their technological properties relevant in cheese production. Eighty-five strains were analysed by a polyphasic genetic approach and allotted into 16 species within the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Streptococcus. Enterococcus faecium was found in all wooden vats and the species most frequently isolated were Enterococcus faecalis, Lactococcus lactis, Leuconostoc mesenteroides, Pediococcus acidilactici and Streptococcus thermophilus. The study of the quantitative data on acidification rate, autolysis kinetics, diacetyl production, antibacterial compound generation and proteolysis by cluster and principal component analysis led to the identification of some strains with promising dairy characteristics. Interestingly, a consistent percentage of LAB was bacteriocin-like inhibitory substances (BLIS) producer. Thus, the microbial biofilms of the wooden vats analysed in this study might contribute actively to the stability of the final cheeses. PMID:26338114

  4. Protein composition, plasmin activity and cheesemaking properties of cows' milk produced at two altitudes from hay of lowland and high-alpine origins.

    PubMed

    Leiber, Florian; Nigg, Daniel; Kunz, Carmen; Scheeder, Martin R L; Wettstein, Hans-Rudolf; Kreuzer, Michael

    2005-02-01

    The influence of high altitude, alpine origin of the forage and roughage-only diets on milk protein content and composition, plasmin activity and cheesemaking properties was investigated. There were four treatment groups, each consisting of six dairy cows in early to mid-lactation. Two groups were fed only with hay ad libitum either at 2000 m or at 400 m a.s.l. One group, kept in the lowlands, was pair-fed to the alpine-site group and another group received a mixed diet of silages, hay and concentrates. Two hay types, harvested either at the alpine site or in the lowlands, were offered to all cows fed with hay alone, following a change-over design in three periods each of 3 weeks. In the respective third week, milk was sampled at every milking. Hay of alpine origin significantly reduced milk protein, in particular whey proteins, which is why the casein number increased. kappa-Casein proportion in total casein was reduced and its glycosylation was increased by the alpine hay. The apparent plasminogen-derived activity was reduced when alpine hay was given, but apparent plasmin activity and rennet coagulation properties of the milk were not affected by hay type. Independent of hay type, the high altitude group showed a significantly reduced milk protein content, lower glycosylation of kappa-casein and impaired rennet coagulation properties. For several of the traits, the trend was the same in the pair-fed group. There was no effect of altitude on apparent plasmin activity. Hay-alone v. the mixed diet resulted initially in marked declines in milk protein content but did not impair cheesemaking properties. Thus the extensive diet without concentrates, typical of high-alpine conditions, contributed less to the overall effect of extensive alpine v. intensive lowland feeding systems than hay quality and altitude did. In conclusion, certain positive influences of the alpine sojourn of cows on cheese processing quality are overruled by the major adverse impact of lower milk

  5. Rapid Eye Movement Sleep Deprivation Produces Long-Term Detrimental Effects in Spatial Memory and Modifies the Cellular Composition of the Subgranular Zone

    PubMed Central

    Soto-Rodriguez, Sofia; Lopez-Armas, Gabriela; Luquin, Sonia; Ramos-Zuñiga, Rodrigo; Jauregui-Huerta, Fernando; Gonzalez-Perez, Oscar; Gonzalez-Castañeda, Rocio E.

    2016-01-01

    . Highlight Sleep deprivation affects spatial memory and proliferation in the dentate gyrus. To date it is unknown whether these deleterious effects are persistent over a long period of time. We analyzed the effects of sleep deprivation in the hippocampus after 21 days of recovery sleep. Our findings indicate that after sleep recovery, the detrimental effects of SD can be observed for at least 2 weeks, as shown by a reduction in memory performance, changes in the hippocampal cellular composition and higher apoptotic rate over a long period of time. PMID:27303266

  6. Rapid Eye Movement Sleep Deprivation Produces Long-Term Detrimental Effects in Spatial Memory and Modifies the Cellular Composition of the Subgranular Zone.

    PubMed

    Soto-Rodriguez, Sofia; Lopez-Armas, Gabriela; Luquin, Sonia; Ramos-Zuñiga, Rodrigo; Jauregui-Huerta, Fernando; Gonzalez-Perez, Oscar; Gonzalez-Castañeda, Rocio E

    2016-01-01

    . Highlight Sleep deprivation affects spatial memory and proliferation in the dentate gyrus. To date it is unknown whether these deleterious effects are persistent over a long period of time. We analyzed the effects of sleep deprivation in the hippocampus after 21 days of recovery sleep. Our findings indicate that after sleep recovery, the detrimental effects of SD can be observed for at least 2 weeks, as shown by a reduction in memory performance, changes in the hippocampal cellular composition and higher apoptotic rate over a long period of time. PMID:27303266

  7. Project Produce

    ERIC Educational Resources Information Center

    Wolfinger, Donna M.

    2005-01-01

    The grocery store produce section used to be a familiar but rather dull place. There were bananas next to the oranges next to the limes. Broccoli was next to corn and lettuce. Apples and pears, radishes and onions, eggplants and zucchinis all lay in their appropriate bins. Those days are over. Now, broccoli may be next to bok choy, potatoes beside…

  8. Composition of natural gas and crude oil produced from 10 wells in the Lower Silurian "Clinton" Sandstone, Trumbull County, Ohio: Chapter G.7 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Burruss, Robert A.; Ryder, Robert T.

    2014-01-01

    Natural gases and associated crude oils in the “Clinton” sandstone, Medina Group sandstones, and equivalent Tuscarora Sandstone in the northern Appalachian basin are part of a regional, continuous-type or basin-centered accumulation. The origin of the hydrocarbon charge to regional continuoustype accumulations is poorly understood. We have analyzed the molecular and stable isotopic composition of gases and oils produced from 10 wells in the “Clinton” sandstone in Trumbull County, Ohio, in an initial attempt to identify the characteristics of the accumulated fluids. The analyses show that the fluids have remarkably uniform compositions that are similar to previously published analyses of oils (Cole and others, 1987) and gases (Laughrey and Baldasarre, 1998) in Early Silurian reservoirs elsewhere in Ohio; however, geochemical parameters in the oils and gases suggest that the fluids have experienced higher levels of thermal stress than the present-day burial conditions of the reservoir rocks. The crude oils have an unusual geochemical characteristic: they do not contain detectable levels of sterane and triterpane biomarkers. The origin of these absences is unknown.

  9. New nano-sized Al2O3-BN coating 3Y-TZP ceramic composites for CAD/CAM-produced all-ceramic dental restorations. Part I. Fabrication of powders.

    PubMed

    Yang, Se Fei; Yang, Li Qiang; Jin, Zhi Hao; Guo, Tian Wen; Wang, Lei; Liu, Hong Chen

    2009-06-01

    Partially sintered 3 mol % yttria-stabilized tetragonal zirconium dioxide (ZrO(2), zirconia) polycrystal (3Y-TZP) ceramics are used in dental posterior restorations with computer-aided design-computer-aided manufacturing (CAD/CAM) techniques. High strength is acquired after sintering, but shape distortion of preshaped compacts during their sintering is inevitable. The aim of this study is to fabricate new machinable ceramic composites with strong mechanical properties that are fit for all-ceramic dental restorations. Aluminum oxide (Al(2)O(3))-coated 3Y-TZP powders were first prepared by the heterogeneous precipitation method starting with 3Y-TZP, Al(NO(3))(3) . 9H(2)O, and ammonia, then amorphous boron nitride (BN) was produced and the as-received composite powders were coated via in situ reaction with boric acid and urea. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to analyze the status of Al(2)O(3)-BN on the surface of the 3Y-TZP particles. TEM micrographs show an abundance of Al(2)O(3) particles and amorphous BN appearing uniformly on the surface of the 3Y-TZP particles after the coating process. The size of the Al(2)O(3) particles is about 20 nm. The XRD pattern shows clearly the peak of amorphous BN among the peaks of ZrO(2). PMID:19223246

  10. Impact produced stress waves in composites

    SciTech Connect

    Clements, B.; Johnson, J.; Addessio, F.; Hixson, R.

    1997-05-01

    The Nonhomogenized Dynamic Method of Cells (NHDMOC) is used to study the propagation of stress waves through laminates. The accuracy of the theory is tested by applying it to a plate-impact experiment and checking its ability to resolve a propagation shock wave front. The theory is then compared to Lagrangian hydrodynamic calculations, where it is found that the NHDMOC consistently requires less fine spatial and temporal grids, and less artificial viscosity to control numerical noise. The theory is then used to treat the impact of an epoxy-graphite bilaminate. When the viscoelastic properties of the epoxy are accounted for, the theory agrees well with the experiment.

  11. A Method to Produce and Purify Full-Length Recombinant Alpha Dystroglycan: Analysis of N- and O-Linked Monosaccharide Composition in CHO Cells with or without LARGE Overexpression

    PubMed Central

    Yoon, Jung Hae; Xu, Rui; Martin, Paul

    2013-01-01

    α dystroglycan (αDG) is part of the dystrophin-associated glycoprotein (DAG) complex, a series of cytoskeletal, transmembrane, and membrane-associated proteins that serve to link the extracellular matrix (ECM) surrounding individual skeletal myofibers to the intracellular F-actin cytoskeleton. Glycosylation and ECM protein binding to αDG are regulated by a number of genes that, when defective, give rise to congenital or limb-girdle forms of muscular dystrophy termed dystroglycanopathies. One such dystroglycanopathy gene is LARGE. Here, we describe a method to produce and purify full-length, furin-resistant, recombinant αDG from CHO cells and CHO cells overexpressing LARGE (CHO-LARGE). In addition, we analyze the O- and N-linked monosaccharide composition of such proteins. αDG purified from CHO-LARGE cells had increased molar content of xylose and fucose relative to CHO, while no significant changes were found in N-linked monosaccharides. Glucuronic acid could not be quantified by the methods used. These studies describe a method to produce and purify the milligram amounts of αDG needed for certain biochemical methods, including monosaccharide analysis. Key words: Dystroglycan, muscular dystrophy, xylose, fucose, laminin, LARGE Correspondence: Paul.Martin@nationwidechildrens.org PMID:23390591

  12. Method of producing cyclohexasilane compounds

    SciTech Connect

    Elangovan, Arumugasamy; Anderson, Kenneth; Boudjouk, Philip R; Schulz, Douglas L

    2015-03-10

    A method of preparing a cyclohexasilane compound from trichlorosilane is provided. The method includes contacting trichlorosilane with a reagent composition to produce a compound containing a tetradecahalocyclohexasilane dianion, such as a tetradecachlorocyclohexasilane dianion. The reagent composition typically includes (a) tertiary polyamine ligand; and (b) a deprotonating reagent, such as a tertiary amine having a pKa of at least about 10.5. Methods of converting the tetradecahalocyclohexasilane dianion-containing compound to cyclohexasilane or a dodecaorganocyclohexasilane are also provided.

  13. Composite Golf Clubs

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Babcock & Wilcox Co. under a partnership with Marshall Space Flight Center, produced composite materials, originally from the shuttle program, for improving golf clubs. Company used Marshall Space Flight Center's data summary file summarizing typical processing techniques and mechanical and physical properties of graphite and boron- reinforced composite materials. Reinforced composites provide combination of shaft rigidity and flexibility that provide maximum distance.

  14. Photoimageable composition

    DOEpatents

    Dentinger, Paul; Krafick, Karen L.; Simison, Kelby Liv

    2005-02-22

    The use of photoacid generators including an alkoxyphenylphenyliodonium salt and/or bis(t-butylphenyl)iodonium salt in a photoimageable composition helps improve resolution. Suitable photoimageable compositions includes: (a) a multifuctional polymeric epoxy resin that is dissolved in an organic solvent wherein the epoxy resin comprises oligomers of bisphenol A that is quantitatively protected by glycidyl ether and wherein the oligomers have an average functionality that ranges from about 3 to 12; and a photoacid generator comprising an alkoxyphenylphenyliodonium salt and/or bis(t-butylphenyl)iodonium salt. Preferred alkoxyphenylphenyliodonium salts include 4-octyloxyphenyl phenyliodonium hexafluoroantimonate and 4-methoxyphenyl phenyliodonium hexafluoroantimonate. The photoimageable composition is particularly suited for producing high aspect ratio microstructures.

  15. Photoimageable composition

    DOEpatents

    Simison, Kelby Liv; Dentinger, Paul

    2003-11-11

    The use of selected buffering amines in a photoimageable composition prevents process bias which with conventional photoresists causes designed features to be distorted, especially in corners and high resolution features. It is believed that the amines react with the catalysts, e.g., photoacids, generated to create an inert salt. The presence of the amines also increases resolution. Suitable photoimageable compositions includes: (a) a multifunctional polymeric epoxy resin that is dissolved in an organic solvent wherein the epoxy resin comprises oligomers of bisphenol A that is quantitatively protected by glycidyl ether and wherein the oligomers have an average functionality that ranges from about 3 to 12; (b) a photoactive compound; and (c) an amine that is selected from the group consisting of triisobutylamine, 1,8-bis(dimethylamino)naphthalene (also known as PROTON SPONGET.TM.), 2,2'-diazabicyclo[2.2.2] octane and mixtures thereof. The photoimageable composition is particularly suited for producing high aspect ratio metal microstructures.

  16. Nano-composite materials

    DOEpatents

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland

    2010-05-25

    Nano-composite materials are disclosed. An exemplary method of producing a nano-composite material may comprise co-sputtering a transition metal and a refractory metal in a reactive atmosphere. The method may also comprise co-depositing a transition metal and a refractory metal composite structure on a substrate. The method may further comprise thermally annealing the deposited transition metal and refractory metal composite structure in a reactive atmosphere.

  17. Method for manufacturing lightning strike mitigation composites

    NASA Technical Reports Server (NTRS)

    Vaidyanathan, K. Ranji (Inventor); Campbell, Jeffrey (Inventor)

    2012-01-01

    A method for manufacturing a composite material utilizes a tooling material having a desired shape. The surface of the tooling material is coated with a composite film that includes a conductive filler material. A composite composition is introduced into contact with the surface of the tooling material to form a desired shape. The composite composition is processed to produce the composite material, and the composite material has a conductive composite surface layer that includes the conductive filler material.

  18. Method of producing a chemical hydride

    DOEpatents

    Klingler, Kerry M.; Zollinger, William T.; Wilding, Bruce M.; Bingham, Dennis N.; Wendt, Kraig M.

    2007-11-13

    A method of producing a chemical hydride is described and which includes selecting a composition having chemical bonds and which is capable of forming a chemical hydride; providing a source of a hydrocarbon; and reacting the composition with the source of the hydrocarbon to generate a chemical hydride.

  19. Method of producing hydrogen, and rendering a contaminated biomass inert

    DOEpatents

    Bingham, Dennis N [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID

    2010-02-23

    A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

  20. Electrically conductive cellulose composite

    DOEpatents

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  1. Starch-filled polymer composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report describes the development of degradable polymer composites that can be made at room temperature without special equipments. The developed composites are made from ethyl cyanoacrylate and starch. The polymer composites produced by this procedure contain 60 wt% of starch with compressive s...

  2. Honeycomb-laminate composite structure

    NASA Technical Reports Server (NTRS)

    Gilwee, W. J., Jr.; Parker, J. A. (Inventor)

    1977-01-01

    A honeycomb-laminate composite structure was comprised of: (1) a cellular core of a polyquinoxaline foam in a honeycomb structure, and (2) a layer of a noncombustible fibrous material impregnated with a polyimide resin laminated on the cellular core. A process for producing the honeycomb-laminate composite structure and articles containing the honeycomb-laminate composite structure is described.

  3. Suite versus composite statistics

    USGS Publications Warehouse

    Balsillie, J.H.; Tanner, W.F.

    1999-01-01

    Suite and composite methodologies, two statistically valid approaches for producing statistical descriptive measures, are investigated for sample groups representing a probability distribution where, in addition, each sample is probability distribution. Suite and composite means (first moment measures) are always equivalent. Composite standard deviations (second moment measures) are always larger than suite standard deviations. Suite and composite values for higher moment measures have more complex relationships. Very seldom, however, are they equivalent, and they normally yield statistically significant but different results. Multiple samples are preferable to single samples (including composites) because they permit the investigator to examine sample-to-sample variability. These and other relationships for suite and composite probability distribution analyses are investigated and reported using granulometric data.

  4. Producing biofuels using polyketide synthases

    DOEpatents

    Katz, Leonard; Fortman, Jeffrey L; Keasling, Jay D

    2013-04-16

    The present invention provides for a non-naturally occurring polyketide synthase (PKS) capable of synthesizing a carboxylic acid or a lactone, and a composition such that a carboxylic acid or lactone is included. The carboxylic acid or lactone, or derivative thereof, is useful as a biofuel. The present invention also provides for a recombinant nucleic acid or vector that encodes such a PKS, and host cells which also have such a recombinant nucleic acid or vector. The present invention also provides for a method of producing such carboxylic acids or lactones using such a PKS.

  5. Methods for producing reinforced carbon nanotubes

    DOEpatents

    Ren, Zhifen; Wen, Jian Guo; Lao, Jing Y.; Li, Wenzhi

    2008-10-28

    Methods for producing reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials are disclosed. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

  6. Composite Tank Development

    NASA Technical Reports Server (NTRS)

    DeLay, Thomas K.

    2000-01-01

    This paper presents viewgraphs on composite tank development. There is a need for oxidizer tanks and reliable, lightweight fuel. The need for cost-effective and scalable manufacturing is also evident. In order to achieve these goals, tooling methods for tank development must be applied, methods for producing easily adaptable and scalable vessel liners must be developed, insulation layer or protective barriers for containers must be manufactured, and an appropriate fiber/resin system for composite overwrap structures must be identified.

  7. Hybrid matrix fiber composites

    DOEpatents

    Deteresa, Steven J.; Lyon, Richard E.; Groves, Scott E.

    2003-07-15

    Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites include two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

  8. Composite foam structures

    NASA Technical Reports Server (NTRS)

    Williams, Brian E. (Inventor); Brockmeyer, Jerry (Inventor); Tuffias, Robert H. (Inventor)

    2005-01-01

    A composite rigid foam structure that has a skin or coating on at least one of its surfaces. The skin is formed in situ by thermal spray techniques. The skin is bonded substantially throughout the surface of the porous substrate to the peripheries of the pores. The skin on the average does not penetrate the surface of the substrate by more than the depth of about 2 to 5 pores. Thus, thermal spraying the skin onto the rigid foam produces a composite that is tightly and uniformly bonded together without unduly increasing the weight of the composite structure. Both thermal conductivity and bonding are excellent.

  9. History and modern applications of nano-composite materials carrying GA/cm2 current density due to a Bose-Einstein Condensate at room temperature produced by Focused Electron Beam Induced Processing for many extraordinary novel technical applications

    NASA Astrophysics Data System (ADS)

    Koops, Hans W. P.

    2015-12-01

    The discovery of Focused Electron Beam Induced Processing and early applications of this technology led to the possible use of a novel nanogranular material “Koops-GranMat®” using Pt/C and Au/C material. which carries at room temperature a current density > 50 times the current density which high TC superconductors can carry. The explanation for the characteristics of this novel material is given. This fact allows producing novel products for many applications using Dual Beam system having a gas supply and X.Y.T stream data programming and not using GDSII layout pattern control software. Novel products are possible for energy transportation. -distribution.-switching, photon-detection above 65 meV energy for very efficient energy harvesting, for bright field emission electron sources used for vacuum electronic devices like amplifiers for HF electronics, micro-tubes, 30 GHz to 6 THz switching amplifiers with signal to noise ratio >10(!), THz power sources up to 1 Watt, in combination with miniaturized vacuum pumps, vacuum gauges, IR to THz detectors, EUV- and X-Ray sources. Since focusing electron beam induced deposition works also at low energy, selfcloning multibeam-production machines for field emitter lamps, displays, multi-beam - lithography, - imaging, and - inspection, energy harvesting, and power distribution with switches controlling field-emitter arrays for KA of currents but with < 100 V switching voltage are possible. Finally the replacement of HTC superconductors and its applications by the Koops-GranMat® having Koops-Pairs at room temperature will allow the investigation devices similar to Josephson Junctions and its applications now called QUIDART (Quantum interference devices at Room Temperature). All these possibilities will support a revolution in the optical, electric, power, and electronic technology.

  10. Fungi producing significant mycotoxins.

    PubMed

    2012-01-01

    Mycotoxins are secondary metabolites of microfungi that are known to cause sickness or death in humans or animals. Although many such toxic metabolites are known, it is generally agreed that only a few are significant in causing disease: aflatoxins, fumonisins, ochratoxin A, deoxynivalenol, zearalenone, and ergot alkaloids. These toxins are produced by just a few species from the common genera Aspergillus, Penicillium, Fusarium, and Claviceps. All Aspergillus and Penicillium species either are commensals, growing in crops without obvious signs of pathogenicity, or invade crops after harvest and produce toxins during drying and storage. In contrast, the important Fusarium and Claviceps species infect crops before harvest. The most important Aspergillus species, occurring in warmer climates, are A. flavus and A. parasiticus, which produce aflatoxins in maize, groundnuts, tree nuts, and, less frequently, other commodities. The main ochratoxin A producers, A. ochraceus and A. carbonarius, commonly occur in grapes, dried vine fruits, wine, and coffee. Penicillium verrucosum also produces ochratoxin A but occurs only in cool temperate climates, where it infects small grains. F. verticillioides is ubiquitous in maize, with an endophytic nature, and produces fumonisins, which are generally more prevalent when crops are under drought stress or suffer excessive insect damage. It has recently been shown that Aspergillus niger also produces fumonisins, and several commodities may be affected. F. graminearum, which is the major producer of deoxynivalenol and zearalenone, is pathogenic on maize, wheat, and barley and produces these toxins whenever it infects these grains before harvest. Also included is a short section on Claviceps purpurea, which produces sclerotia among the seeds in grasses, including wheat, barley, and triticale. The main thrust of the chapter contains information on the identification of these fungi and their morphological characteristics, as well as factors

  11. METHOD OF PRODUCING NEUTRONS

    DOEpatents

    Imhoff, D.H.; Harker, W.H.

    1964-01-14

    This patent relates to a method of producing neutrons in which there is produced a heated plasma containing heavy hydrogen isotope ions wherein heated ions are injected and confined in an elongated axially symmetric magnetic field having at least one magnetic field gradient region. In accordance with the method herein, the amplitude of the field and gradients are varied at an oscillatory periodic frequency to effect confinement by providing proper ratios of rotational to axial velocity components in the motion of said particles. The energetic neutrons may then be used as in a blanket zone containing a moderator and a source fissionable material to produce heat and thermal neutron fissionable materials. (AEC)

  12. Emotional Subjects for Composition.

    ERIC Educational Resources Information Center

    Micciche, Laura R.

    Metaphors such as "gypsy academics,""freeway flyers," and "contingent laborers," ascribed by compositionists to their work and its conditions, comment on the low status of composition specialists and teachers in academic hierarchies. Work is the activity around which a profession forms, and, as such, it produces emotional dispositions compatible…

  13. Hybrid composite laminate structures

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Lark, R. F. (Inventor)

    1977-01-01

    An invention which relates to laminate structures and specifically to essentially anisotropic fiber composite laminates is described. Metal foils are selectively disposed within the laminate to produce increased resistance to high velocity impact, fracture, surface erosion, and other stresses within the laminate.

  14. Electrocatalyst compositions

    DOEpatents

    Mallouk, Thomas E.; Chan, Benny C.; Reddington, Erik; Sapienza, Anthony; Chen, Guoying; Smotkin, Eugene; Gurau, Bogdan; Viswanathan, Rameshkrishnan; Liu, Renxuan

    2001-09-04

    Compositions for use as catalysts in electrochemical reactions are described. The compositions are alloys prepared from two or more elemental metals selected from platinum, molybdenum, osmium, ruthenium, rhodium, and iridium. Also described are electrode compositions including such alloys and electrochemical reaction devices including such catalysts.

  15. Coal markets squeeze producers

    SciTech Connect

    Ryan, M.

    2005-12-01

    Supply/demand fundamentals seem poised to keep prices of competing fossil fuels high, which could cushion coal prices, but increased mining and transportation costs may squeeze producer profits. Are markets ready for more volatility?

  16. Track recording plastic compositions

    NASA Technical Reports Server (NTRS)

    Tarle, Gregory (Inventor)

    1983-01-01

    Improved nuclear track recording plastic compositions are provided which exhibit greatly decreased surface roughness when etched to produce visible tracks of energetic nuclear particles which have passed into and/or through said plastic. The improved compositions incorporate a small quantity of a phthalic acid ester into the major plastic component which is derived from the polymerization of monomeric di-ethylene glycol bis allyl carbonate. Di-substituted phthalic acid esters are preferred as the added component, with the further perference that the ester substituent has a chain length of 2 or more carbon atoms. The inclusion of the phthalic acid ester to an extent of from about 1-2% by weight of the plastic compositions is sufficient to drastically reduce the surface roughness ordinarily produced when the track recording plastic is contacted by etchants.

  17. Olympic Scoring of English Compositions

    ERIC Educational Resources Information Center

    Follman, John; Panther, Edward

    1974-01-01

    Examines empirically the efficacy of utilizing Olympic diving and gymnastic scoring systems for grading graduate students' English compositions. Results indicated that such scoring rules do not produce ratings different in reliability or in level from conventional letter grades. (ED)

  18. Producer quality assurance programs.

    PubMed

    Kla, J; Tollefson, L

    1999-03-01

    Essentially all animal commodity organizations have established quality assurance programs designed to ensure food safety and quality. Most of these programs were originally implemented to address problems with veterinary drug residues. Many of the current programs have or plan to include food safety critical control points with specific guidelines on how to control or reduce pathogen load. The continued focus placed on food safety by today's consumer demands that American producers ensure that their commodities are wholesome, safe, and of high quality in order to remain competitive in the global marketplace. Veterinarians should recognize that it is important to encourage food animal producers to participate in quality assurance programs for their clients' economic health and for food safety and protection of public health. Commodities certified as being produced under good production practices or by producers certified as following a recognized and validated quality assurance program often bring a premium price. Also, some slaughter establishments are beginning to require producers to be certified as practicing under a recognized quality assurance program before animals are accepted for processing. This practice is being driven partially by the demands placed on slaughter establishments by the US Department of Agriculture's implementation of the Pathogen Reduction, Hazard Analysis and Critical Control Point Systems regulation. Regardless of why producer trade association quality assurance programs have come into existence, veterinarians should promote the programs as an excellent mechanism to help ensure everyone's goal of a safe, wholesome food supply. PMID:10088219

  19. Ultraviolet and thermally stable polymer compositions

    NASA Technical Reports Server (NTRS)

    Adamson, M. J.; Gloria, H. R.; Goldsberry, R. E.; Reinisch, R. F.

    1972-01-01

    Copolymers, produced from aromatic substituted aromatic azine-siloxane compositions, are thermally stable, solar ultraviolet light non-degradable by wavelengths shorter than those reaching earth surface.

  20. Alumina-based ceramic composite

    DOEpatents

    Alexander, Kathleen B.; Tiegs, Terry N.; Becher, Paul F.; Waters, Shirley B.

    1996-01-01

    An improved ceramic composite comprising oxide ceramic particulates, nonoxide ceramic particulates selected from the group consisting of carbides, borides, nitrides of silicon and transition metals and mixtures thereof, and a ductile binder selected from the group consisting of metallic, intermetallic alloys and mixtures thereof is described. The ceramic composite is made by blending powders of the ceramic particulates and the ductile to form a mixture and consolidating the mixture of under conditions of temperature and pressure sufficient to produce a densified ceramic composite.

  1. Layered Composite Analysis Capability

    NASA Technical Reports Server (NTRS)

    Narayanaswami, R.; Cole, J. G.

    1985-01-01

    Laminated composite material construction is gaining popularity within industry as an attractive alternative to metallic designs where high strength at reduced weights is of prime consideration. This has necessitated the development of an effective analysis capability for the static, dynamic and buckling analyses of structural components constructed of layered composites. Theoretical and user aspects of layered composite analysis and its incorporation into CSA/NASTRAN are discussed. The availability of stress and strain based failure criteria is described which aids the user in reviewing the voluminous output normally produced in such analyses. Simple strategies to obtain minimum weight designs of composite structures are discussed. Several example problems are presented to demonstrate the accuracy and user convenient features of the capability.

  2. Advanced composites in Japan

    NASA Technical Reports Server (NTRS)

    Diefendorf, R. Judd; Hillig, William G.; Grisaffe, Salvatore J.; Pipes, R. Byron; Perepezko, John H.; Sheehan, James E.

    1994-01-01

    The JTEC Panel on Advanced Composites surveyed the status and future directions of Japanese high-performance ceramic and carbon fibers and their composites in metal, intermetallic, ceramic, and carbon matrices. Because of a strong carbon and fiber industry, Japan is the leader in carbon fiber technology. Japan has initiated an oxidation-resistant carbon/carbon composite program. With its outstanding technical base in carbon technology, Japan should be able to match present technology in the U.S. and introduce lower-cost manufacturing methods. However, the panel did not see any innovative approaches to oxidation protection. Ceramic and especially intermetallic matrix composites were not yet receiving much attention at the time of the panel's visit. There was a high level of monolithic ceramic research and development activity. High temperature monolithic intermetallic research was just starting, but notable products in titanium aluminides had already appeared. Matrixless ceramic composites was one novel approach noted. Technologies for high temperature composites fabrication existed, but large numbers of panels or parts had not been produced. The Japanese have selected aerospace as an important future industry. Because materials are an enabling technology for a strong aerospace industry, Japan initiated an ambitious long-term program to develop high temperature composites. Although just starting, its progress should be closely monitored in the U.S.

  3. Pyrolysis process for producing fuel gas

    NASA Technical Reports Server (NTRS)

    Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

    2007-01-01

    Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

  4. Parallelization of photocatalytic gas-producing reactions

    NASA Astrophysics Data System (ADS)

    Khnayzer, Rony S.; Martin, Douglas R.; Codding, Charles L.; Castellano, Felix N.

    2015-03-01

    High-throughput screening has been widely utilized in the pharmaceutical and manufacturing industry targeting the development of new molecules and materials for numerous applications. To enable more rapid progress in photocatalytic water-splitting reactions, the construction of high-throughput combinatorial photoreactors enabling the parallel optimization of relevant compositions under varieties of experimental conditions seems appropriate. This contribution describes a 16-photoreactor apparatus permitting the kinetic evaluation of photocatalytic gas-producing reactions using head-space pressure, gas chromatography, and mass spectrometry operating in parallel, illustrated with molecular-based homogeneous photocatalytic H2-generating compositions.

  5. Manufacturing and producibility technology

    NASA Technical Reports Server (NTRS)

    Hankins, J. D.; Dreshfield, R. L.

    1985-01-01

    Activities of the manufacturing/producibility working group within the Advanced High-Pressure O2/H2 Technology Program are summarized. The objectives of the M/P working group are: to develop and evaluate process and manufacturing techniques for advanced propulsion hardware design and selected materials; and to optimize the producibility of (SSME) components and assemblies by improved performance, increased life, greater reliability, and/or reduced cost. The technologies being developed include: plasma arc, laser, and inertia welding; combustion chamber and turbine blade coatings; coating processes; high performance alloy electroforming; and process control technology.

  6. Phosphazene polymer containing composites and method for making phosphazene polymer containing composites

    DOEpatents

    Allen, Charles A.; Grey, Alan E.; McCaffrey, Robert R.; Simpson, Brenda M.; Stone, Mark L.

    1994-01-01

    A composite is produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite.

  7. Phosphazene polymer containing composites and method for making phosphazene polymer containing composites

    DOEpatents

    Allen, Charles A.; Grey, Alan E.; McCaffrey, Robert R.; Simpson, Brenda M.; Stone, Mark L.

    1994-05-03

    A composite is produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite.

  8. Producing superhydrophobic roof tiles

    NASA Astrophysics Data System (ADS)

    Carrascosa, Luis A. M.; Facio, Dario S.; Mosquera, Maria J.

    2016-03-01

    Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic-inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie-Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol-gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a ‘green’ product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie-Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating.

  9. Producing CD-ROMs.

    ERIC Educational Resources Information Center

    Hyams, Peter, Ed.

    1992-01-01

    This issue presents 11 articles that address issues relating to the production of CD-ROMs. Highlights include current uses of CD-ROM; standards; steps involved in producing CD-ROMs, including data capture, conversion, and tagging, product design, and indexing; authoring; selecting indexing and retrieval software; costs; multimedia CD-ROMs; and…

  10. Producer/Consumer Image

    ERIC Educational Resources Information Center

    Englander, Meryl E.; Marsh, John

    1977-01-01

    The work ethic and the success of a system based increasingly upon consumerism has created an image of man in which the quality of life is measured in terms of quantity and ownership of goods; in ethics and attitude, our system of education is creating an ideally receptive population for the producer-consumer society. (JD)

  11. PRODUCING HIGH CORN YIELDS.

    ERIC Educational Resources Information Center

    Illinois Univ., Urbana. Coll. of Agriculture.

    RESOURCE MATERIAL ON CORN PRODUCTION FOR HIGH SCHOOL VOCATIONAL AGRICULTURE AND ADULT FARMER CLASSES WAS DESIGNED BY A STATE LEVEL GROUP OF SUBJECT MATTER SPECIALISTS, TEACHER EDUCATORS, SUPERVISORS, AND TEACHERS TO HELP SOLVE PROBLEMS THAT CONFRONT CORN PRODUCERS AT PLANTING TIME. THE SUBJECT MATTER CONCERNS PLANTING TIME, DEPTH, ROW WIDTH,…

  12. Top Hispanic Degree Producers

    ERIC Educational Resources Information Center

    Diverse: Issues in Higher Education, 2012

    2012-01-01

    This article presents a list of the top 100 producers of associate, bachelor's and graduate degrees awarded to minority students based on research conducted by Dr. Victor M.H. Borden, professor of educational leadership and policy students at the Indiana University Bloomington. For the year 2012, the listings focus on Hispanic students. Data for…

  13. Producing superhydrophobic roof tiles.

    PubMed

    Carrascosa, Luis A M; Facio, Dario S; Mosquera, Maria J

    2016-03-01

    Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic-inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie-Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol-gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a 'green' product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie-Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating. PMID:26854839

  14. Carbapenemase-Producing Enterobacteriaceae

    PubMed Central

    Doi, Yohei; Paterson, David L.

    2015-01-01

    Carbapenemase-producing Enterobacteriaceae (CPE) were almost nonexistent up to the 1990s, but are today encountered routinely in hospitals and other healthcare facilities in many countries including the United States. KPC-producing Klebsiella pneumoniae was the first to emerge and spread globally and is endemic in the United States, Israel, Greece, and Italy. Recently, NDM-producing Enterobacteriaceae and OXA-48-producing K. pneumoniae appear to be disseminating from South Asia and Northern Africa, respectively. They are almost always resistant to all β-lactams including carbapenems and many other classes. Mortality from invasive CPE infections reaches up to 40%. To obtain the maximal benefit from the limited options available, dosing of antimicrobial agents should be optimized based on pharmacokinetic data, especially for colistin and carbapenems. In addition, multiple observational studies have associated combination antimicrobial therapy with lower mortality compared with monotherapy for these infections. The outcomes appear to be especially favorable when patients are treated with a carbapenem and a second agent such as colistin, tigecycline, and gentamicin, but the best approach is yet to be defined. PMID:25643272

  15. Chemical milling solution produces smooth surface finish on aluminum

    NASA Technical Reports Server (NTRS)

    Lorenzen, H. C.

    1966-01-01

    Elementary sulfur mixed into a solution of caustic soda and salts produces an etchant which will chemically mill end-grain surfaces on aluminum plate. This composition results in the least amount of thickness variation and pitting.

  16. Composite Materials

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Composites are lighter and stronger than metals. Aramid fibers like Kevlar and Nomex were developed by DuPont Corporation and can be combined in a honeycomb structure which can give an airplane a light, tough structure. Composites can be molded into many aerodynamic shapes eliminating rivets and fasteners. Langley Research Center has tested composites for both aerospace and non-aerospace applications. They are also used in boat hulls, military shelters, etc.

  17. Composites review

    NASA Technical Reports Server (NTRS)

    Hordonneau, A.

    1987-01-01

    The properties and applications of composite materials are reviewed. Glass, carbon, Kevlar, ceramic, whisker, and metal fibers are discussed along with polyester, epoxy, polyimide, Peek, carbon, ceramic, and metal matrices. The quantitative distribution of high technology fiber in various applications is given. The role of aerospace industry in the development and promotion of composite utilization is discussed. Consumption trends indicate a rapid development of the composite market.

  18. Energetic composites

    DOEpatents

    Danen, Wayne C.; Martin, Joe A.

    1993-01-01

    A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application.

  19. Energetic composites

    DOEpatents

    Danen, W.C.; Martin, J.A.

    1993-11-30

    A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application. 3 figures.

  20. Composite floorpan

    SciTech Connect

    Frutiger, R.L.; Baskar, S.

    1993-02-01

    Composite applications for automotive components have been a topic of increased interest. Some applications--load-bearing composites such as bumpers and leaf springs--have been implemented successfully in production vehicles. On the other hand, semi-structural load-bearing composites such as floorpans have not been investigated as extensively for stiffness, strength, and durability. Past studies have used structural composites to achieve parts consolidation in van crossmembers. A rear floorpan has also been demonstrated in composites. A hybrid vehicle structure consisting of a composite passenger module on a steel frame has been proposed. Assessments of the energy management of full composite front structures have also been reported. There remains a need to assess structural composites for a major load-bearing panel with real-vehicle packaging and design requirements; a floorplan is one such application. This design concept might be used in a space-frame vehicle structure in which composite panels could be used to complete the structure and provide additional torsional rigidity while meeting local strength and stiffness requirements.

  1. Water treatment technology for produced water.

    PubMed

    Szép, Angéla; Kohlheb, Robert

    2010-01-01

    Large amounts of produced water are generated during oil and gas production. Produced water, as it is known in the oil industry, is briny fluid trapped in the rock of oil reservoirs. The objective of this study was to test produced waters from a Montana USA oilfield using a mobile station to design a plant to cost efficiently treat the produced water for agricultural irrigation. We used combined physical and chemical treatment of produced water in order to comply with reuse and discharge limits. This mobile station consists of three stages: pretreatments, membrane filtration and post treatment. Two spiral-wound membrane units were employed and the rejections of various constituents were examined. The performance of two membranes, 20 kDa weight cut-off (MWCO) ultrafiltration and a polyamide-composite reverse osmosis membrane was investigated. The mobile station effectively decreased conductivity by 98%, COD by 100% and the SAR by 2.15 mgeqv(0.5) in the produced water tested in this study. Cost analysis showed that the treatment cost of produced water is less expensive than to dispose of it by injection and this treated water may be of great value in water-poor regions. We can conclude that the mobile station provided a viable and cost-effective result to beneficial use of produced water. PMID:21076224

  2. Method of producing a high pressure gas

    DOEpatents

    Bingham, Dennis N.; Klingler, Kerry M.; Zollinger, William T.

    2006-07-18

    A method of producing a high pressure gas is disclosed and which includes providing a container; supplying the container with a liquid such as water; increasing the pressure of the liquid within the container; supplying a reactant composition such as a chemical hydride to the liquid under pressure in the container and which chemically reacts with the liquid to produce a resulting high pressure gas such as hydrogen at a pressure of greater than about 100 pounds per square inch of pressure; and drawing the resulting high pressure gas from the container.

  3. Solar proton produced neon in shergottite meteorites

    NASA Technical Reports Server (NTRS)

    Garrison, D. H.; Rao, M. N.; Bogard, D. D.

    1994-01-01

    Cosmogenic radionuclides produced by near-surface, nuclear interactions of energetic solar protons (approx. 10-100 MeV) were reported in several lunar rocks and a very small meteorites. We recently documented the existence and isotopic compositions of solar-produced (SCR) Ne in two lunar rocks. Here we present the first documented evidence for SCR Ne in a meteorite, ALH77005, which was reported to contain SCR radionuclides. Examination of literature data for other shergottites suggests that they may also contain a SCR Ne component. The existence of SCR Ne in shergottites may be related to a Martian origin.

  4. Method for producing small hollow spheres

    DOEpatents

    Hendricks, C.D.

    1979-01-09

    Method is disclosed for producing small hollow spheres of glass, metal or plastic, wherein the sphere material is mixed with or contains as part of the composition a blowing agent which decomposes at high temperature (T [approx gt] 600 C). As the temperature is quickly raised, the blowing agent decomposes and the resulting gas expands from within, thus forming a hollow sphere of controllable thickness. The thus produced hollow spheres (20 to 10[sup 3] [mu]m) have a variety of application, and are particularly useful in the fabrication of targets for laser implosion such as neutron sources, laser fusion physics studies, and laser initiated fusion power plants. 1 fig.

  5. Method for producing small hollow spheres

    DOEpatents

    Hendricks, Charles D. [Livermore, CA

    1979-01-09

    Method for producing small hollow spheres of glass, metal or plastic, wherein the sphere material is mixed with or contains as part of the composition a blowing agent which decomposes at high temperature (T .gtorsim. 600.degree. C). As the temperature is quickly raised, the blowing agent decomposes and the resulting gas expands from within, thus forming a hollow sphere of controllable thickness. The thus produced hollow spheres (20 to 10.sup.3 .mu.m) have a variety of application, and are particularly useful in the fabrication of targets for laser implosion such as neutron sources, laser fusion physics studies, and laser initiated fusion power plants.

  6. Automated apparatus for producing gradient gels

    DOEpatents

    Anderson, Norman L.

    1986-01-01

    Apparatus for producing a gradient gel which serves as a standard medium for a two-dimensional analysis of proteins, the gel having a density gradient along its height formed by a variation in gel composition, with the apparatus including first and second pumping means each including a plurality of pumps on a common shaft and driven by a stepping motor capable of providing small incremental changes in pump outputs for the gel ingredients, the motors being controlled, by digital signals from a digital computer, a hollow form or cassette for receiving the gel composition, means for transferring the gel composition including a filler tube extending near the bottom of the cassette, adjustable horizontal and vertical arms for automatically removing and relocating the filler tube in the next cassette, and a digital computer programmed to automatically control the stepping motors, arm movements, and associated sensing operations involving the filling operation.

  7. Automated apparatus for producing gradient gels

    DOEpatents

    Anderson, N.L.

    1983-11-10

    Apparatus for producing a gradient gel which serves as a standard medium for a two-dimensional analysis of proteins, the gel having a density gradient along its height formed by a variation in gel composition, with the apparatus including first and second pumping means each including a plurality of pumps on a common shaft and driven by a stepping motor capable of providing small incremental changes in pump outputs for the gel ingredients, the motors being controlled, by digital signals from a digital computer, a hollow form or cassette for receiving the gel composition, means for transferring the gel composition including a filler tube extending near the bottom of the cassette, adjustable horizontal and vertical arms for automatically removing and relocating the filler tube in the next cassette, and a digital computer programmed to automatically control the stepping motors, arm movements, and associated sensing operations involving the filling operation.

  8. METHOD OF PRODUCING NEUTRONS

    DOEpatents

    Imhoff, D.H.; Harker, W.H.

    1964-02-01

    A method for producing neutrons is described in which there is employed a confinement zone defined between longitudinally spaced localized gradient regions of an elongated magnetic field. Changed particles and neutralizing electrons, more specifically deuterons and tritons and neutralizng electrons, are injected into the confinement field from ion sources located outside the field. The rotational energy of the parrticles is increased at the gradients by imposing an oscillating transverse electrical field thereacross. The imposition of such oscillating transverse electrical fields improves the reflection capability of such gradient fielda so that the reactive particles are retained more effectively within the zone. With the attainment of appropriate densities of plasma particles and provided that such particles are at a sufficiently high temperature, neutron-producing reactions ensue and large quantities of neutrons emerge from the containment zone. (AEC)

  9. Process for producing silicon

    DOEpatents

    Olson, Jerry M.; Carleton, Karen L.

    1984-01-01

    A process for producing silicon includes forming an alloy of copper and silicon and positioning the alloy in a dried, molten salt electrolyte to form a solid anode structure therein. An electrically conductive cathode is placed in the electrolyte for plating silicon thereon. The electrolyte is then purified to remove dissolved oxides. Finally, an electrical potential is applied between the anode and cathode in an amount sufficient to form substantially pure silicon on the cathode in the form of substantially dense, coherent deposits.

  10. Method of producing imines

    DOEpatents

    Sithambaram, Shanthakumar; Son, Young-Chan; Suib, Steven L.

    2008-04-08

    A method for forming an imine comprises reacting a first reactant comprising a hydroxyl functionality, a carbonyl functionality, or both a hydroxyl functionality and a carbonyl functionality with a second reactant having an amine functionality in the presence of ordered porous manganese-based octahedral molecular sieves and an oxygen containing gas at a temperature and for a time sufficient for the imine to be produced.

  11. Electrode compositions

    DOEpatents

    Block, J.; Fan, X.

    1998-10-27

    An electrode composition is described for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C{sub 8}-C{sub 15} alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5--4.5 volts.

  12. Electrode compositions

    DOEpatents

    Block, Jacob; Fan, Xiyun

    1998-01-01

    An electrode composition for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C.sub.8 -C.sub.15 alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5-4.5 volts.

  13. Partial interlaminar separation system for composites

    NASA Technical Reports Server (NTRS)

    Elber, W. (Inventor)

    1980-01-01

    This inventor relates to an interlaminar separation system for composites wherein a thin layer of a perforated foil film is interposed between adjacent laminae of a composite formed from prepreg tapes to thereby permit laminate adherence through the perforations and produce a composite structure having improved physical property characteristics.

  14. Glass produced by underground nuclear explosions. [Rainier

    SciTech Connect

    Schwartz, L.; Piwinskii, A.; Ryerson, F.; Tewes, H.; Beiriger, W.

    1983-01-01

    Detonation of an underground nuclear explosive produces a strong shock wave which propagates spherically outward, vaporizing the explosive and nearby rock and melting, the surrounding rock. The vaporized material expands adiabatically, forming a cavity. As the energy is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is quenched by fractured rock fragments falling from above as the cavity collapses. Measurements indicate that about 740 tonnes of rock and/or soil are melted for every kiloton (10/sup 12/ calories) of explosive energy, or about 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with explosive debris. The appearance ranges from white pumice to dense, dark lava. The bulk composition and color vary with the amount of explosive iron incorporated into the glass. The refractory explosion products are mixed with the solidified melt, although the degree of mixing is variable. Electron microprobe studies of glasses produced by Rainier in welded tuff have produced the following results: glasses are dehydrated relative to the host media, glasses are extremely heterogeneous on a 20 ..mu..m scale, a ubiquitous feature is the presence of dark marble-cake regions in the glass, which were locally enriched in iron and may be related to the debris, optically amorphous regions provide evidence of shock melting, only limited major element redistribution and homogenization occur within the cavity.

  15. Third Intermetallic Matrix Composites Symposium, volume 350

    SciTech Connect

    Graves, J.A.; Bowman, R.R.; Lewandowski, J.J.

    1994-04-01

    Partial contents include: issues in potential IMC application for aerospace structures; powder metallurgy processing of intermetallic matrix composites; microstructure and properties of intermetallic matrix composites produced by reaction synthesis; combustion synthesis of niobium aluminide matrix composites; ambient temperature synthesis of bulk intermetallics; wear behavior of SHS intermetallic matrix composites; fracture characteristics of metal-intermetallic laminates produced by SHS reactions; and vapor phase synthesis of Ti aluminides and the interfacial bonding effect on the mechanical property of micro-composites reinforced by pyrolized SiC fibers.

  16. 7 CFR 1250.305 - Egg producer or producer.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Egg producer or producer. 1250.305 Section 1250.305... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE EGG RESEARCH AND PROMOTION Egg Research and Promotion Order Definitions § 1250.305 Egg producer or producer. Egg producer or...

  17. 7 CFR 1250.305 - Egg producer or producer.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Egg producer or producer. 1250.305 Section 1250.305... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE EGG RESEARCH AND PROMOTION Egg Research and Promotion Order Definitions § 1250.305 Egg producer or producer. Egg producer or...

  18. 7 CFR 1250.305 - Egg producer or producer.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Egg producer or producer. 1250.305 Section 1250.305... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE EGG RESEARCH AND PROMOTION Egg Research and Promotion Order Definitions § 1250.305 Egg producer or producer. Egg producer or...

  19. 7 CFR 1250.305 - Egg producer or producer.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Egg producer or producer. 1250.305 Section 1250.305... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE EGG RESEARCH AND PROMOTION Egg Research and Promotion Order Definitions § 1250.305 Egg producer or producer. Egg producer or...

  20. 7 CFR 1250.305 - Egg producer or producer.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Egg producer or producer. 1250.305 Section 1250.305... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE EGG RESEARCH AND PROMOTION Egg Research and Promotion Order Definitions § 1250.305 Egg producer or producer. Egg producer or...

  1. ION PRODUCING MECHANISM

    DOEpatents

    Lawrence, E.O.

    1958-09-16

    Improvements are presented in calutron devices and, more specifically, dealswith an improved mounting arrangement fer the ion source of the calutron. An important feature of the invention resides in a pluraiity of insulators so mounted as to be accessible from the exterior of the calutron tank and supporting at their inner ends the ion source. These insutators are arranged in mutually parallel relation and also parallel to the flux of the nmgnetic field, whereby the strain of the supporting elements is reduced to a minimum. In addition the support assembly is secured to a removable wall portion of the task to facilitate withdrawal and examination of the ion producing mechanism.

  2. ION PRODUCING MECHANISM

    DOEpatents

    Backus, J.G.

    1958-09-01

    This patent relates to improvements in calutron devices and particularly describes a novel ion source. The unique feature of this source lies in the shaping of the ionizing electron stream to conform to the arc plasma boundary at the exit slit of the ionization chamber, thereby increasing the ion density produced at the plasma boundary. The particular structure consists of an electron source disposed at onc end of an elongated ionization chambcr and a coilimating electrode positioned to trim the electron stream to a crescent shape before entering the ionization chamber.

  3. Producing Hydrogen With Sunlight

    NASA Technical Reports Server (NTRS)

    Biddle, J. R.; Peterson, D. B.; Fujita, T.

    1987-01-01

    Costs high but reduced by further research. Producing hydrogen fuel on large scale from water by solar energy practical if plant costs reduced, according to study. Sunlight attractive energy source because it is free and because photon energy converts directly to chemical energy when it breaks water molecules into diatomic hydrogen and oxygen. Conversion process low in efficiency and photochemical reactor must be spread over large area, requiring large investment in plant. Economic analysis pertains to generic photochemical processes. Does not delve into details of photochemical reactor design because detailed reactor designs do not exist at this early stage of development.

  4. Chemical composition of Mars

    NASA Technical Reports Server (NTRS)

    Morgan, J. W.; Anders, E.

    1979-01-01

    The chemical composition of Mars is estimated from the cosmochemical model of Ganapathy and Anders (1974) with additional petrological and geophysical constraints. The model assumes that planets and chondrites underwent the same fractionation processes in the solar nebula, and constraints are imposed by the abundance of the heat-producing elements, U, Th and K, the volatile-rich component and the high density of the mantle. Global abundances of 83 elements are presented, and it is noted that the mantle is an iron-rich garnet wehrlite, nearly identical to the bulk moon composition of Morgan at al. (1978) and that the core is sulfur poor (3.5% S). The comparison of model compositions for the earth, Venus, Mars, the moon and a eucrite parent body suggests that volatile depletion correlates mainly with size rather than with radial distance from the sun.

  5. Ceramic Composite Thin Films

    NASA Technical Reports Server (NTRS)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  6. Isolation of unique butyrate-producing bacteria from swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butyrate-producing bacteria in humans contribute to a healthy gastrointestinal tract and are known to be species from clostridial clusters IV, IX, XIVa, and XVI - with the community dominated by clusters XIVa and IV. However, the composition of the butyrate-producing bacterial community in swine is...

  7. Comparing Composites.

    ERIC Educational Resources Information Center

    Mathras, Michael S.

    1993-01-01

    Presents an activity that models the work of chemical engineers. Students design, fabricate, and perform mechanical tests on plaster matrix composites and compare the strength to mass ratios of several products. (PR)

  8. Fuel composition

    SciTech Connect

    Johnson, T.H.

    1990-06-26

    This patent describes a motor fuel composition. It comprises: a mixture of hydrocarbons in the gasoline boiling range containing a deposit preventing or reducing effective amount of poly(olefin)-N-substituted- carbamate.

  9. Process for producing ethanol

    SciTech Connect

    Lantero, O.J.; Fish, J.J.

    1993-07-27

    A process is described for producing ethanol from raw materials containing a high dry solid mash level having fermentable sugars or constituents which can be converted into sugars, comprising the steps of: (a) liquefaction of the raw materials in the presence of an alpha amylase to obtain liquefied mash; (b) saccharification of the liquefied mash in the presence of a glucoamylase to obtain hydrolysed starch and sugars; (c) fermentation of the hydrolysed starch and sugars by yeast to obtain ethanol; and (d) recovering the obtained ethanol, wherein an acid fungal protease is introduced to the liquefied mash during the saccharification and/or to the hydrolysed starch and sugars during the fermentation, thereby increasing the rate of production of ethanol as compared to a substantially similar process conducted without the introduction of the protease.

  10. Consuming Research, Producing Policy?

    PubMed Central

    Evans, Robert G.; Stoddart, Greg L.

    2003-01-01

    The authors’ 1990 article “Producing Health, Consuming Health Care” presented a conceptual framework for synthesizing a rapidly growing body of findings on the nonmedical determinants of health. The article received a very positive response, and here the authors reflect on what lessons might be learned from that response about the style or content of effective interdisciplinary communication. Much substantive knowledge has been accumulated since 1990, and a number of different frameworks have been developed before and since. The authors situate theirs within this literature and consider how they might have modified it if they “knew then what they know now.” They ask what impact this article, and the much broader stream of research on the determinants of health, has had on public policy? PMID:12604475

  11. APPARATUS FOR PRODUCING SHADOWGRAPHS

    DOEpatents

    Wilson, R.R.

    1959-08-11

    An apparatus is presented for obtaining shadowgraphs or radiographs of an object exposed to x rays or the like. The device includes the combination of a cloud chamber having the interior illuminated and a portion thereof transparent to light rays and x'rays, a controlled source of x rays spaced therefrom, photographic recording disposed laterally of the linear path intermediate the source and the chamber portion in oblique angularity in aspect to the path. The object to be studied is disposed intermediate the x-ray source and chamber in the linear path to provide an x-ray transmission barrier therebetween. The shadowgraph is produced in the cloud chamber in response to initiation of the x- ray source and recorded photographically.

  12. Wet oxidation for enhanced oil recovery with produced water recycle

    SciTech Connect

    Chowdhury, A.K.; Pradt, L.A.

    1983-01-01

    Wet oxidation has been shown to be effective in enabling recycling of untreated produced water while generating 100% quality steam/CO/sub 2/ mixtures for enhanced oil recovery. Continuous pilot plant tests with several different fuels and produced water compositions showed no influence of the feed water composition on oxidation rates. Produced water of any quality, including high chlorides, can be used. Low grade fuels such as Syncrude coke are effectively oxidized with no atmospheric pollution emissions; no SOx or NOx is formed in the process. The wet oxidation process can be operated so as to generate only damp, dewatered solid wastes, thereby eliminating the need for disposal of liquid effluents.

  13. Hydride compositions

    DOEpatents

    Lee, Myung W.

    1995-01-01

    A composition for use in storing hydrogen, and a method for making the composition. The composition comprises a mixture of two or more hydrides, each hydride having a different series of hydrogen sorption isotherms that contribute to the overall isotherms of the mixture. The hydrides are chosen so that the isotherms of the mixture have regions wherein the hydrogen equilibrium pressure increases with increasing hydrogen, preferably linearly. The isotherms of the mixture can be adjusted by selecting hydrides with different isotherms and by varying the amounts of the individual hydrides, or both. Preferably, the mixture is made up of hydrides that have isotherms with substantially flat plateaus and in nearly equimolar amounts. The composition is activated by degassing, exposing to hydrogen and then heating at a temperature below the softening temperature of any of the. constituents so that their chemical and structural integrity is preserved. When the composition is used to store hydrogen, its hydrogen content can be found simply by measuring P.sub.H.sbsb.2 and determining H/M from the isothermic function of the composition.

  14. Hydride compositions

    DOEpatents

    Lee, Myung, W.

    1994-01-01

    Disclosed are a composition for use in storing hydrogen and a method for making the composition. The composition comprises a mixture of two or more hydrides, each hydride having a different series of hydrogen sorption isotherms that contribute to the overall isotherms of the mixture. The hydrides are chosen so that the isotherms of the mixture have regions wherein the H equilibrium pressure increases with increasing hydrogen, preferably linearly. The isotherms of the mixture can be adjusted by selecting hydrides with different isotherms and by varying the amounts of the individual hydrides, or both. Preferably, the mixture is made up of hydrides that have isotherms with substantially flat plateaus and in nearly equimolar amounts. The composition is activated by degassing, exposing to H, and then heating below the softening temperature of any of the constituents. When the composition is used to store hydrogen, its hydrogen content can be found simply by measuring P{sub H}{sub 2} and determining H/M from the isothermic function of the composition.

  15. Process for thermochemically producing hydrogen

    DOEpatents

    Bamberger, Carlos E.; Richardson, Donald M.

    1976-01-01

    Hydrogen is produced by the reaction of water with chromium sesquioxide and strontium oxide. The hydrogen producing reaction is combined with other reactions to produce a closed chemical cycle for the thermal decomposition of water.

  16. Terahertz plasmonic composites.

    PubMed

    Nemat-Nasser, Syrus C; Amirkhizi, Alireza V; Padilla, Willie J; Basov, Dimitri N; Nemat-Nasser, Sia; Bruzewicz, Derek; Whitesides, George

    2007-03-01

    The dielectric response of a polymer matrix composite can be substantially modified and tuned within a broad frequency band by integrating within the material an artificial plasmon medium composed of periodically distributed, very thin, electrically conducting wires. In the microwave regime, such plasmon/polymer composites have been studied analytically, computationally, and experimentally. This work reports the design, fabrication, and characterization of similar composites for operation at terahertz frequencies. Such composites require significant reduction in the thickness and spacing of the wires. We used numerical modeling to design artificial effective plasmonic media with turn-on frequencies in the terahertz range. Prototype samples were produced by lithographically embedding very thin gold strips into a PDMS [poly(dimethylsiloxane)] matrix. These samples were characterized with a Fourier-transform infrared interferometer using the frequency-dependent transmission and Kramers-Kronig relations to determine the electromagnetic properties. We report the characterization results for a sample, demonstrating excellent agreement between theory, computer design, and experiment. To our knowledge this is the first demonstration of the possibility of creating composites with tuned dielectric response at terahertz frequencies. PMID:17500816

  17. Terahertz plasmonic composites

    NASA Astrophysics Data System (ADS)

    Nemat-Nasser, Syrus C.; Amirkhizi, Alireza V.; Padilla, Willie J.; Basov, Dimitri N.; Nemat-Nasser, Sia; Bruzewicz, Derek; Whitesides, George

    2007-03-01

    The dielectric response of a polymer matrix composite can be substantially modified and tuned within a broad frequency band by integrating within the material an artificial plasmon medium composed of periodically distributed, very thin, electrically conducting wires. In the microwave regime, such plasmon/polymer composites have been studied analytically, computationally, and experimentally. This work reports the design, fabrication, and characterization of similar composites for operation at terahertz frequencies. Such composites require significant reduction in the thickness and spacing of the wires. We used numerical modeling to design artificial effective plasmonic media with turn-on frequencies in the terahertz range. Prototype samples were produced by lithographically embedding very thin gold strips into a PDMS [poly(dimethylsiloxane)] matrix. These samples were characterized with a Fourier-transform infrared interferometer using the frequency-dependent transmission and Kramers-Kronig relations to determine the electromagnetic properties. We report the characterization results for a sample, demonstrating excellent agreement between theory, computer design, and experiment. To our knowledge this is the first demonstration of the possibility of creating composites with tuned dielectric response at terahertz frequencies.

  18. Giant magnetostrictive composites

    NASA Astrophysics Data System (ADS)

    Duenas, Terrisa Ann

    The limitation of magnetostrictive composites has been in their low magnetostrictive response when compared to their monolithic counterparts. In this dissertation research is presented describing the methods and analysis used to create a giant magnetostrictive composite (GMC) producing giant strains at low fields, exhibiting magnetization ``jumping'' and the ΔE effect. This composite combines the giant magnetostrictive material, Terfenol-D (Tb0.3Dy0.7Fe2) in particle form, with a nonmetallic binder and is capable of producing strains (at room temperature) exceeding 1000 ppm at a nominal field of 1.5 kOe mechanically unloaded and 1200 ppm at 8 MPa preload (2.5 kOe). Several studies leading to the high response of this composite are presented. A connectivity study shows that a [1-3] connected composite produces 50% more strain than a [0-3] composite. A resin study indicates that the lower the viscosity of the resin, the greater the magnetostrictive response; this is attributed to the removal of voids during degassing. A void study correlates the increase in voids to the decrease in strain response. A model is used to correlate analysis with experimental results within 10% accuracy and shows that an optimal volume fraction exists based on the properties of the binder. Using a Polyscience Spurr low- viscosity (60 cps) binder this volume fraction is nominally 20%; this optimum is attributed to the balance of epoxy contracting on the particle (built-in preload) and the actuation delivered by the magnetostrictive material. In addition to the connectivity, resin, void, and volume-fraction study, particle size and gradation studies are presented. Widely dispersed (<106, <212, <300 μm), narrowly dispersed (<45, (90-106), (275-300) μm), and an optimized bimodal (18.7% of (45-90) μm with 81.3% of (250-300) μm) particle distributions are studied. Results show that the larger the particle size, the higher the magnetostrictive response; this is attributed to the reduction of

  19. Field-structured composite studies.

    SciTech Connect

    Martin, James Ellis; Williamson, Rodney L.

    2004-04-01

    Field-structured composites (FSCs) were produced by hosting micron-sized gold-coated nickel particles in a pre-polymer and allowing the mixture to cure in a magnetic field environment. The feasibility of controlling a composite's electrical conductivity using feedback control applied to the field coils was investigated. It was discovered that conductivity in FSCs is primarily determined by stresses in the polymer host matrix due to cure shrinkage. Thus, in cases where the structuring field was uniform and unidirectional so as to produce chainlike structures in the composite, no electrical conductivity was measured until well after the structuring field was turned off at the gel point. In situations where complex, rotating fields were used to generate complex, three-dimensional structures in a composite, very small, but measurable, conductivity was observed prior to the gel point. Responsive, sensitive prototype chemical sensors were developed based on this technology with initial tests showing very promising results.

  20. Cyclotron produced radiopharmaceuticals

    NASA Astrophysics Data System (ADS)

    Kopička, K.; Fišer, M.; Hradilek, P.; Hanč, P.; Lebeda, O.

    2003-01-01

    Some of the cyclotron-produced radionuclides may serve as important materials for the production of radiopharmaceuticals. This lecture deals with basic information relating to various aspects of these compounds. In comparison with radionuclides/compounds used for non-medical purposes, radiopharmaceuticals are subject to a broader scale of regulations, both from the safety and efficacy point of view; besides that, there are both radioactive and medical aspects that must be taken into account for any radiopharmaceutical. According to the regulations and in compliance with general rules of work with radioactivity, radiopharmaceuticals should only be prepared/manufactured under special conditions, using special areas and special equipment and applying special procedures (e.g. sterilisation, disinfection, aseptic work). Also, there are special procedures for cleaning and maintenance. Sometimes the requirements for the product safety clash with those for the safety of the personnel; several examples of solutions pertaining to these cases are given in the lecture. Also, the specific role of cyclotron radiopharmaceuticals is discussed.

  1. Resin systems for producing polymer concrete

    SciTech Connect

    Kukacka, L.E.

    1988-09-01

    When plastics are combined with mixtures of inorganic materials, high-strength, durable, fast-setting composites are produced. These materials are used in structural engineering and other applications, and as a result of the many commercial successes that have been achieved, considerable research and development work is in progress throughout the world. One family of polymer-based composites receiving considerable attention is called polymer concrete. Work in this area is directed toward developing new high-strength durable materials by combining cement and concrete technology with that of polymer chemistry. The purpose of this paper is to discuss the types of resins that can be used to form polymer concretes. Resin selection is normally based upon the desired properties for the composite and cost. However, the physical and chemical properties of the resins before and during curing are also important, particularly for field-applied materials. Currently, for normal temperature (0/degree/ to 30/degree/C) applications, epoxy resins, vinyl monomers such as polyester-styrene, methylmethacrylate, furfuryl alcohol, furan derivatives, urethane, and styrene, are being used. Styrene-trimethylolpropane trimethacrylate (TMPTMA) mixtures and styrene-acrylamide-TMPTMA mixtures yield composites with excellent hydrothermal stability at temperatures up to 150/degree/ and 250/degree/C, respectively, and organosiloxane resins have been successfully tested at 300/degree/C. Of equal importance is the selection of the composition of the inorganic phase of the composite, since chemical interactions between the two phases can significantly enhance the final properties. Further work to elucidate the mechanisms of these interactions is needed. 6 refs.

  2. Preparation of a concentrated organophyllosilicate and nanocomposite composition

    DOEpatents

    Chaiko, David J.; Niyogi, Suhas G.

    2007-01-16

    The present invention provide methods for producing a low moisture organophyllosilicate composition using monomers, oligomers, or polymers to displace water associated with the organophyllosilicates in an aqueous organophyllosilicate slurry or filter cake. The invention additionally provides methods for producing organophyllosilicate nanocomposites from the concentrated organophyllosilicate compositions by dispersing the compositions in a polymer matrix.

  3. Dense, finely, grained composite materials

    DOEpatents

    Dunmead, Stephen D.; Holt, Joseph B.; Kingman, Donald D.; Munir, Zuhair A.

    1990-01-01

    Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

  4. Method for preparing ceramic composite

    DOEpatents

    Alexander, Kathleen B.; Tiegs, Terry N.; Becher, Paul F.; Waters, Shirley B.

    1996-01-01

    A process for preparing ceramic composite comprising blending TiC particulates, Al.sub.2 O.sub.3 particulates and nickle aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m.sup.1/2, a hardness equal to or greater than 18 GPa.

  5. Method for preparing ceramic composite

    DOEpatents

    Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

    1996-01-09

    A process is disclosed for preparing ceramic composite comprising blending TiC particulates, Al{sub 2}O{sub 3} particulates and nickel aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m{sup 1/2}, a hardness equal to or greater than 18 GPa. 5 figs.

  6. Quasicrystalline particulate reinforced aluminum composite

    SciTech Connect

    Anderson, I.E.; Biner, S.B.; Sordelet, D.J.; Unal, O.

    1997-07-01

    Particulate reinforced aluminum and aluminum alloy composites are rapidly emerging as new commercial materials for aerospace, automotive, electronic packaging and other high performance applications. However, their low processing ductility and difficulty in recyclability have been the key concern. In this study, two composite systems having the same aluminum alloy matrix, one reinforced with quasicrystals and the other reinforced with the conventional SiC reinforcements were produced with identical processing routes. Their processing characteristics and tensile mechanical properties were compared.

  7. Thermite Reaction to Produce Artificial Reefs

    NASA Astrophysics Data System (ADS)

    Trevino, Alexandro; Martirosyan, Karen; Kline, Richard

    The degradation of coral reefs is an ecological issue that has prompted new collaboration by different scientific communities that would assist in the regeneration of the reefs. Unfortunately, these processes can be inefficient and extremely expensive prompting a new scientific approach by using solid-state combustion synthesis to regenerate the reefs. In this report we aimed to consolidate a multi-composite material to produce artificial reefs by initiating thermite reaction based on aluminum and polytetrafluoroethylene (PTFE) with natural reefs. By Thermodynamic analysis and experimentation it was established that a range between .03-.07 number of moles of PTFE was sufficient to reach an adiabatic temperature of over 1900 K, a sustained reaction and a physically stable product was achieved. Reefs are primarily composed of carbonates but their exact chemical composition can vary. X-ray diffraction analysis was used to determine the chemical composition of the reef and revealed presence of oxides, carbonates, silicates. The dominant chemical compounds that were identified are, SiO2 -17%, MgSiO3-14.5%, CaCO3- 11.4%, Ca(Si3O4). Using our thermite reaction we aimed to achieve optimal physical, chemical, and biological properties and maintain cost efficiency of the multi-composite material.

  8. Method for producing capsular polysaccharides

    NASA Technical Reports Server (NTRS)

    Kern, Roger G. (Inventor); Petersen, Gene R. (Inventor); Richards, Gil F. (Inventor)

    1994-01-01

    Structurally altered capsular polysaccharides are produced by mutant bacteria. These polysaccharides are isolated by selecting a wild type bacterial strain and a phage producing degradative enzymes that have substrate specificity for the capsular polysaccharides produced by the wild type bacteria. Phage-resistant mutants producing capsular polysaccharides are selected and the structurally altered capsular polysaccharide is isolated therefrom.

  9. Composite material

    DOEpatents

    Hutchens, Stacy A.; Woodward, Jonathan; Evans, Barbara R.; O'Neill, Hugh M.

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  10. Surfactant compositions

    SciTech Connect

    Novakovic, M.; Abend, P.G.

    1987-09-29

    A surfactant composition is described for subsequent addition to a soap slurring comprising an acyloxy alkane sulfonate salt. The sulfonate salt is present in an amount by weight of about 44 percent of about 56 percent. The polyol is present in an amount by weight of about 2 percent to about 6 percent, and water is present in an amount by weight of 26 to 36 percent. The composition constituting a solid reversible solution at ambient temperature and having a solids content of about 58 to 72 percent, whereby subsequent addition of the surfactant composition to a soap slurry results in formation of a soap/detergent bar having a smooth texture, uniform wear properties and a lack of grittiness.

  11. Ultrasonic hammer produces hot spots in solids

    NASA Astrophysics Data System (ADS)

    You, Sizhu; Chen, Ming-Wei; Dlott, Dana D.; Suslick, Kenneth S.

    2015-04-01

    Mechanical action can produce dramatic physical and mechanochemical effects when the energy is spatially or temporally concentrated. An important example of such phenomena in solids is the mechanical initiation of explosions, which has long been speculated to result from ‘hot spot’ generation at localized microstructures in the energetic material. Direct experimental evidence of such hot spots, however, is exceptionally limited; mechanisms for their generation are poorly understood and methods to control their locations remain elusive. Here we report the generation of intense, localized microscale hot spots in solid composites during mild ultrasonic irradiation, directly visualized by a thermal imaging microscope. These ultrasonic hot spots, with heating rates reaching ~22,000 K s-1, nucleate exclusively at interfacial delamination sites in composite solids. Introducing specific delamination sites by surface modification of embedded components provides precise and reliable control of hot spot locations and permits microcontrol of the initiation of reactions in energetic materials including fuel/oxidizer explosives.

  12. Physical composition

    NASA Astrophysics Data System (ADS)

    Healey, Richard

    2013-02-01

    Atomistic metaphysics motivated an explanatory strategy which science has pursued with great success since the scientific revolution. By decomposing matter into its atomic and subatomic parts physics gave us powerful explanations and accurate predictions as well as providing a unifying framework for the rest of science. The success of the decompositional strategy has encouraged a widespread conviction that the physical world forms a compositional hierarchy that physics and other sciences are progressively articulating. But this conviction does not stand up to a closer examination of how physics has treated composition, as a variety of case studies will show.

  13. Composite Riflescope

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Bushnell Division of Bausch & Lomb's Armor-Sight riflescope combines the company's world-renowned optics with a graphite composite (Graphlon VI) developed for space applications. The riflescope is 10 percent lighter than aluminum scopes, and, because its thermal expansion coefficient is near zero, optical distortion from heat and cold extremes is eliminated. It is fogproof and waterproof; advanced multicoated optics provide maximum light transmission to brighten target ranges. Bushnell was assisted by NIAC/USC in searching for technical information on graphic composites and in overcoming difficulties with bonding and porosity.

  14. Composite Cores

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Spang & Company's new configuration of converter transformer cores is a composite of gapped and ungapped cores assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped core with the lower magnetizing requirement of the ungapped core. The uncut core functions under normal operating conditions and the cut core takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. Cores also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.

  15. Resin/graphite fiber composites

    NASA Technical Reports Server (NTRS)

    Cavano, P. J.; Jones, R. J.; Vaughan, R. W.

    1972-01-01

    High temperature resin matrices suitable for use in advanced graphite fiber composites for jet engine applications were evaluated. A series of planned, sequential screening experiments with resin systems in composite form were performed to reduce the number of candidates to a single A-type polyimide resin that repetitively produced void-free, high strength and modulus composites acceptable for use in the 550 F range for 1000 hours. An optimized processing procedure was established for this system. Extensive mechanical property studies characterized this single system, at room temperature, 500 F, 550 F and 600 F, for various exposure times.

  16. Alumina-based ceramic composite

    DOEpatents

    Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

    1996-07-23

    An improved ceramic composite comprising oxide ceramic particulates, nonoxide ceramic particulates selected from the group consisting of carbides, borides, nitrides of silicon and transition metals and mixtures thereof, and a ductile binder selected from the group consisting of metallic, intermetallic alloys and mixtures thereof is described. The ceramic composite is made by blending powders of the ceramic particulates and the ductile to form a mixture and consolidating the mixture of under conditions of temperature and pressure sufficient to produce a densified ceramic composite. 5 figs.

  17. Methods for producing complex films, and films produced thereby

    DOEpatents

    Duty, Chad E.; Bennett, Charlee J. C.; Moon, Ji -Won; Phelps, Tommy J.; Blue, Craig A.; Dai, Quanqin; Hu, Michael Z.; Ivanov, Ilia N.; Jellison, Jr., Gerald E.; Love, Lonnie J.; Ott, Ronald D.; Parish, Chad M.; Walker, Steven

    2015-11-24

    A method for producing a film, the method comprising melting a layer of precursor particles on a substrate until at least a portion of the melted particles are planarized and merged to produce the film. The invention is also directed to a method for producing a photovoltaic film, the method comprising depositing particles having a photovoltaic or other property onto a substrate, and affixing the particles to the substrate, wherein the particles may or may not be subsequently melted. Also described herein are films produced by these methods, methods for producing a patterned film on a substrate, and methods for producing a multilayer structure.

  18. Producing Runaway Stars

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-07-01

    How are the hypervelocity stars weve observed in our galaxy produced? A recent study suggests that these escapees could be accelerated by a massive black hole in the center of the Large Magellanic Cloud.A Black Hole SlingshotSince their discovery in 2005, weve observed dozens of candidate hypervelocity stars stars whose velocity in the rest frame of our galaxy exceeds the local escape velocity of the Milky Way. These stars present a huge puzzle: how did they attain these enormous velocities?One potential explanation is known as the Hills mechanism. In this process, a stellar binary is disrupted by a close encounter with a massive black hole (like those thought to reside at the center of every galaxy). One member of the binary is flung out of the system as a result of the close encounter, potentially reaching very large velocities.A star-forming region known as LHA 120-N 11, located within the LMC. Some binary star systems within the LMC might experience close encounters with a possible massive black hole at the LMCs center. [ESA/NASA/Hubble]Blame the LMC?Usually, discussions of the Hills mechanism assume that Sagittarius A*, the supermassive black hole at the center of the Milky Way, is the object guilty of accelerating the hypervelocity stars weve observed. But what if the culprit isnt Sgr A*, but a massive black hole at the center of the Large Magellanic Cloud (LMC), one of the Milky Ways satellite galaxies?Though we dont yet have evidence of a massive black hole at the center of the LMC, the dwarf galaxy is large enough to potentially host one as large as 100,000 solar masses. Assuming that it does, two scientists at the University of Cambridge, Douglas Boubert and Wyn Evans, have now modeled how this black hole might tear apart binary star systems and fling hypervelocity stars around the Milky Way.Models for AccelerationBoubert and Evans determined that the LMCs hypothetical black hole could easily eject stars at ~100 km/s, which is the escape velocity of the

  19. COMPOSITE ELEMENT

    DOEpatents

    Schaner, B.E.; Wolfe, R.A.

    1962-12-18

    Composite fuel eiements of the sandwich type are reported. The invention resides in the use of a layer of graphite on the interfaces of the flssile material and the cladding to prevent interdiffusion of the fissile material and the ciadding material. (AEC)

  20. Music Composition

    ERIC Educational Resources Information Center

    Helfer, Jason A.

    2015-01-01

    Historically, music programs in K-12 schools have emphasized performance opportunities for children and young people. Until the release of the 1994 National Standards in Music, targeted instruction in composition was frequently overlooked due to the emphasis on performance as well as the expectations of what a school music program ought to produce…

  1. Phosphorescent compositions, methods of making the compositions, and methods of using the compositions

    DOEpatents

    Jia, Weiyi; Wang, Xiaojun; Jia, George D.; Lewis, Linda; Yen, Laurel C.

    2014-06-24

    Compositions, methods of making compositions, materials including compositions, crayons including compositions, paint including compositions, ink including compositions, waxes including compositions, polymers including compositions, vesicles including the compositions, methods of making each, and the like are disclosed.

  2. Phosphorescent compositions, methods of making the compositions, and methods of using the compositions

    DOEpatents

    Jia, Weiyi; Wang, Xiaojun; Yen, William; Yen, Laurel C.; Jia, George D.

    2012-12-04

    Compositions, methods of making compositions, materials including compositions, crayons including compositions, paint including compositions, ink including compositions, waxes including compositions, polymers including compositions, vesicles including the compositions, methods of making each, and the like are disclosed.

  3. Technology for producing carbon field emitters

    SciTech Connect

    Khatapova, R.M.; Demskaya, L.L.; Romanova, V.K.

    1985-12-01

    This paper describes methods for producing field emitters from carbon filaments. Coating of Ni and two-layer coatings of Ni-Mo with a thickness of 10-40 um are applied to the carbon filaments by electrochemical deposition so that they can be spot welded to a metal holder. A technology for attaching carbon filaments with a refractory adhesive composition is also described. Field emitters with point radius of curvature of 0.2-0.4 um are made from three types of carbon filament.

  4. Nitrogen fertility and irrigation effects on cottonseed composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cottonseed products have become a valuable secondary revenue source for cotton (Gossypium hirsutum L.) producers, but how production practices impact cottonseed composition is not clear. This research evaluated how cottonseed composition was altered by varying irrigation and nitrogen fertilization ...

  5. Superconductor Composite

    DOEpatents

    Dorris, Stephen E.; Burlone, Dominick A.; Morgan; Carol W.

    1999-02-02

    A superconducting conductor fabricated from a plurality of wires, e.g., fine silver wires, coated with a superconducting powder. A process of applying superconducting powders to such wires, to the resulting coated wires and superconductors produced therefrom.

  6. Radioisotopes produced by neutron irradiation of food.

    PubMed

    Albright, S; Seviour, R

    2016-04-01

    The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of (24)Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that (24)Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in the previous literature. PMID:26749562

  7. Uncharged positive electrode composition

    DOEpatents

    Kaun, Thomas D.; Vissers, Donald R.; Shimotake, Hiroshi

    1977-03-08

    An uncharged positive-electrode composition contains particulate lithium sulfide, another alkali metal or alkaline earth metal compound other than sulfide, e.g., lithium carbide, and a transition metal powder. The composition along with a binder, such as electrolytic salt or a thermosetting resin is applied onto an electrically conductive substrate to form a plaque. The plaque is assembled as a positive electrode within an electrochemical cell opposite to a negative electrode containing a material such as aluminum or silicon for alloying with lithium. During charging, lithium alloy is formed within the negative electrode and transition metal sulfide such as iron sulfide is produced within the positive electrode. Excess negative electrode capacity over that from the transition metal sulfide is provided due to the electrochemical reaction of the other than sulfide alkali metal or alkaline earth metal compound.

  8. Multi-material Preforming of Structural Composites

    SciTech Connect

    Norris, Robert E.; Eberle, Cliff C.; Pastore, Christopher M.; Sudbury, Thomas Z.; Xiong, Fue; Hartman, David

    2015-05-01

    Fiber-reinforced composites offer significant weight reduction potential, with glass fiber composites already widely adopted. Carbon fiber composites deliver the greatest performance benefits, but their high cost has inhibited widespread adoption. This project demonstrates that hybrid carbon-glass solutions can realize most of the benefits of carbon fiber composites at much lower cost. ORNL and Owens Corning Reinforcements along with program participants at the ORISE collaborated to demonstrate methods for produce hybrid composites along with techniques to predict performance and economic tradeoffs. These predictions were then verified in testing coupons and more complex demonstration articles.

  9. Electrodeposition of nickel composite coatings

    NASA Astrophysics Data System (ADS)

    Borkar, Tushar

    Pulse electrodeposition (PC) and pulse reverse electrodeposition (PRC) bring a new era in improving the surface properties of metals. These processes are associated with many advantages, such as reduction in porosity, low level of inclusions, and higher deposition rates compared to direct current (DC) electrodeposition process. There is much more flexibility in varying three basic parameters which are, pulse current density, on time, and off time in pulse electrodeposition resulting in unique composition and microstructure of coating being deposited. In this work, nickel matrix composite coatings were synthesized by co-depositing nano particles (Al2O3, SiC, and ZrO2) from Watts bath. To get detailed insight into effect of processing parameters on the microstructure, mechanical, and tribological properties of the composite coatings, the coatings were also fabricated using DC, PC, and PRC techniques. Also, the effect of bath loading on the level of reinforcement in the coating was investigated for Ni-Al2O 3 composite coatings. Furthermore an attempt was made to produce Ni-CNT coatings by pulse electrodeposition method. Pure nickel coatings were also prepared for comparison. Composite coatings deposited using PC and PRC techniques exhibited significant improvement in microhardness and wear resistance. The presence of nanoparticles in the composite coating seems to prohibit the columnar growth of the nickel grains resulting in random/weak texture and smaller thickness of the composite coatings. Ni-Al2O3 composite coatings show maximum hardness and wear resistance compared to Ni-SiC and Ni-ZrO 2 composite coatings. As Al2O3 content in electroplating bath increases, Microhardness and wear resistance of composite coatings increases but thickness of the coatings decreases due to nanoparticles obstructing grain growth. The Ni-CNT composite coatings exhibited significantly improved microhardness compared to pure nickel coatings.

  10. Continuous Fiber Ceramic Composites (CFCC)

    SciTech Connect

    R. A. Wagner

    2002-12-18

    This report summarizes work to develop CFCC's for various applications in the Industries of the Future (IOF) and power generation areas. Performance requirements range from relatively modest for hot gas filters to severe for turbine combustor liners and infrared burners. The McDermott Technology Inc. (MTI) CFCC program focused on oxide/oxide composite systems because they are known to be stable in the application environments of interest. The work is broadly focused on dense and porous composite systems depending on the specific application. Dense composites were targeted at corrosion resistant components, molten aluminum handling components and gas turbine combustor liners. The development work on dense composites led to significant advances in fiber coatings for oxide fibers and matrix densification. Additionally, a one-step fabrication process was developed to produce low cost composite components. The program also supported key developments in advanced oxide fibers that resulted in an improved version of Nextel 610 fiber (commercially available as Nextel 650) and significant progress in the development of a YAG/alumina fiber. Porous composite development focused on the vacuum winding process used to produce hot gas filters and infrared burner components.

  11. Hyperhalogens and highly electronegative compositions

    DOEpatents

    Jena, Puru; Gantefoer, Gerd

    2016-08-16

    Hyperhalogens, a new class of highly electronegative species, are now invented. A hyperhalogen is a superhalogen-containing composition in which the electron affinity (EA) of the hyperhalogen is even larger than that of the superhalogens they are composed of. Novel production methods are provided in which highly electronegative species are produced by surrounding a central metal atom by superhalogen moieties.

  12. Torrefied biomass-polypropylene composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Torrefied almond shells and wood chips were incorporated into polypropylene as fillers to produce torrefied biomass-polymer composites. Response surface methodology was used to examine the effects of filler concentration, filler size, and lignin factor (relative lignin to cellulose concentration) on...

  13. Methods for producing silicon carbide architectural preforms

    NASA Technical Reports Server (NTRS)

    DiCarlo, James A. (Inventor); Yun, Hee (Inventor)

    2010-01-01

    Methods are disclosed for producing architectural preforms and high-temperature composite structures containing high-strength ceramic fibers with reduced preforming stresses within each fiber, with an in-situ grown coating on each fiber surface, with reduced boron within the bulk of each fiber, and with improved tensile creep and rupture resistance properties for each fiber. The methods include the steps of preparing an original sample of a preform formed from a pre-selected high-strength silicon carbide ceramic fiber type, placing the original sample in a processing furnace under a pre-selected preforming stress state and thermally treating the sample in the processing furnace at a pre-selected processing temperature and hold time in a processing gas having a pre-selected composition, pressure, and flow rate. For the high-temperature composite structures, the method includes additional steps of depositing a thin interphase coating on the surface of each fiber and forming a ceramic or carbon-based matrix within the sample.

  14. Alloy and method of producing the same

    DOEpatents

    Hufnagel, Todd C.; Ott, Ryan T.; Fan, Cang; Kecskes, Laszlo

    2005-07-19

    In accordance with a preferred embodiment of the invention, an alloy or other composite material is provided formed of a bulk metallic glass matrix with a microstructure of crystalline metal particles. The alloy preferably has a composition of (X.sub.a Ni.sub.b Cu.sub.c).sub.100-d-c Y.sub.d Al.sub.c, wherein the sum of a, b and c equals 100, wherein 40.ltoreq.a.ltoreq.80, 0.ltoreq.b.ltoreq.35, 0.ltoreq.c.ltoreq.40, 4.ltoreq.d.ltoreq.30, and 0.ltoreq.e.ltoreq.20, and wherein preferably X is composed of an early transition metal and preferably Y is composed of a refractory body-centered cubic early transition metal. A preferred embodiment of the invention also provides a method of producing an alloy composed of two or more phases at ambient temperature. The method includes the steps of providing a metastable crystalline phase composed of at least two elements, heating the metastable crystalline phase together with at least one additional element to form a liquid, casting the liquid, and cooling the liquid to form the alloy. In accordance with a preferred embodiment of the invention, the composition and cooling rate of the liquid can be controlled to determine the volume fraction of the crystalline phase and determine the size of the crystalline particles, respectively.

  15. Explosive bonding of metal-matrix composites

    NASA Technical Reports Server (NTRS)

    Reece, O. Y.

    1969-01-01

    Explosive bonding process produces sheet composites of aluminum alloy reinforced by high-strength stainless steel wires. The bonds are excellent metallurgically, no external heat is required, various metals can be bonded, and the process is inexpensive.

  16. Rapid Production of Composite Prototype Hardware

    NASA Technical Reports Server (NTRS)

    DeLay, T. K.

    2000-01-01

    The objective of this research was to provide a mechanism to cost-effectively produce composite hardware prototypes. The task was to take a hands-on approach to developing new technologies that could benefit multiple future programs.

  17. An Efficient Composition for Bengal Lights.

    ERIC Educational Resources Information Center

    Comet, M.; Schreyeck, L.; Fuzellier, H.

    2002-01-01

    Reports the discovery of an efficient base composition for making bengal lights that is obtained with potassium chlorate and thiourea. Combining this mixture with appropriate flame coloring can produce several impressive bengal lights. (DDR)

  18. Does subduction zone magmatism produce average continental crust

    NASA Technical Reports Server (NTRS)

    Ellam, R. M.; Hawkesworth, C. J.

    1988-01-01

    The question of whether present day subduction zone magmatism produces material of average continental crust composition, which perhaps most would agree is andesitic, is addressed. It was argued that modern andesitic to dacitic rocks in Andean-type settings are produced by plagioclase fractionation of mantle derived basalts, leaving a complementary residue with low Rb/Sr and a positive Eu anomaly. This residue must be removed, for example by delamination, if the average crust produced in these settings is andesitic. The author argued against this, pointing out the absence of evidence for such a signature in the mantle. Either the average crust is not andesitic, a conclusion the author was not entirely comfortable with, or other crust forming processes must be sought. One possibility is that during the Archean, direct slab melting of basaltic or eclogitic oceanic crust produced felsic melts, which together with about 65 percent mafic material, yielded an average crust of andesitic composition.

  19. Combustion method for producing fullerenes

    DOEpatents

    Howard, J.B.; McKinnon, J.T.

    1993-12-28

    A method for synthesizing fullerenes in flames is provided. Fullerenes are prepared by burning carbon-containing compounds in a flame and collecting the condensable. The condensable contain the desired fullerenes. Fullerene yields can be optimized and fullerene composition can be selectively varied. Fullerene yields and compositions are determined by selectively controlling flame conditions and parameters such as C/O ratio, pressure, temperature, residence time, diluent concentration and gas velocity. 4 figures.

  20. Combustion method for producing fullerenes

    DOEpatents

    Howard, Jack B.; McKinnon, J. Thomas

    1993-01-01

    A method for synthesizing fullerenes in flames is provided. Fullerenes are prepared by burning carbon-containing compounds in a flame and collecting the condensibles. The condensibles contain the desired fullerenes. Fullerene yields can be optimized and fullerene composition can be selectively varied. Fullerene yields and compositions are determined by selectively controlling flame conditions and parameters such as C/O ratio, pressure, temperature, residence time, diluent concentration and gas velocity.

  1. Diamond-silicon carbide composite and method

    DOEpatents

    Zhao, Yusheng

    2011-06-14

    Uniformly dense, diamond-silicon carbide composites having high hardness, high fracture toughness, and high thermal stability are prepared by consolidating a powder mixture of diamond and amorphous silicon. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPam.sup.1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness.

  2. Light sensitive achiral polar polymeric composites

    NASA Astrophysics Data System (ADS)

    González-Henríquez, C. M.; Soto-Bustamante, E. A.; Vergara-Toloza, R. O.; Haase, W.

    2011-07-01

    The occurrence of antiferroelectric phenomenon in achiral composites composed of azo-benzene containing liquid crystals was observed. Some of the composites evidenced typical antiferroelectric polarization hysteresis loop in the mesophase, showing bilayer smectic C 2 mesophases with some interdigitation grade at the layer interface in a broad temperature range. Surprisingly composites of similar structure developed pyroelectricity but not switchable states. This new class of antiferroelectric materials is also capable of producing E-Z photoisomerization making them good candidates for energy harvesting.

  3. Gas composition shifts in Devonian shales

    SciTech Connect

    Schettler, P.D.; Parmely, C.R. )

    1989-08-01

    Analysis of the gas composition of Devonian shale wells indicates that the composition of produced gas shifts during the production history of the well. Possible mechanisms to explain this behavior are examined in light of field and laboratory data. Application of diffusion theory is made to explain adsorption-like behavior exhibited by some shales.

  4. Diamond-silicon carbide composite

    DOEpatents

    Qian, Jiang; Zhao, Yusheng

    2006-06-13

    Fully dense, diamond-silicon carbide composites are prepared from ball-milled microcrystalline diamond/amorphous silicon powder mixture. The ball-milled powder is sintered (P=5–8 GPa, T=1400K–2300K) to form composites having high fracture toughness. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPa.dot.m1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness. X-ray diffraction patterns and Raman spectra indicate that amorphous silicon is partially transformed into nanocrystalline silicon at 5 GPa/873K, and nanocrystalline silicon carbide forms at higher temperatures.

  5. Damage of hybrid composite laminates

    NASA Astrophysics Data System (ADS)

    Haery, Haleh A.; Kim, Ho Sung

    2013-08-01

    Hybrid laminates consisting of woven glass fabric/epoxy composite plies and woven carbon fabric/epoxy composite plies are studied for fatigue damage and residual strength. A theoretical framework based on the systems approach is proposed as a guide to deal with the complexity involving uncertainties and a large number of variables in the hybrid composite system. A relative damage sensitivity factor expression was developed for quantitative comparisons between non-hybrid and hybrid composites. Hypotheses derived from the theoretical framework were tested and verified. The first hypothesis was that the difference between two different sets of properties produces shear stress in interface between carbon fibre reinforced plastics (CRP) and glass fibre reinforced plastics (GRP), and eventually become a source for CRP/GRP interfacial delamination or longitudinal cracking. The second hypothesis was that inter-fibre bundle delamination occurs more severely to CRP sub-system than GRP sub-system.

  6. Phosphazene polymer containing composites and method for making phosphazene polymer containing composites

    SciTech Connect

    Allen, C.A.; Grey, A.E.; McCaffrey, R.R.; Simpson, B.M.; Stone, M.L.

    1990-12-31

    The object of the invention is to provide a composite material comprised of phosphazene polymer. A feature of phosphazene-containing composites is their superior stiffness, thermal stability, and hardness which is lacking in more typical composite constituents. An advantage of using phosphazene composites is a wider range of applications, including uses in harsh environments. Another object of the present invention provides a method for producing phosphazene-containing composite materials through a pultrusion process. In brief, these and other objects are achieved by a composite produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite. 2 figs., 6 tabs.

  7. Method to produce large, uniform hollow spherical shells

    DOEpatents

    Hendricks, Charles D.

    1985-01-01

    Large, uniform hollow spherical shells are produced by forming uniform size drops of heat decomposable or vaporizable material, evaporating the drops to form dried particles, coating the dried particles with a layer of shell forming material, and heating the composite particles to melt the outer layer and decompose or vaporize the inner particle to form an expanding inner gas bubble which expands the outer layer. By cycling the temperature and pressure on the hollow shells, spherical shells with uniform walls are produced.

  8. Method of producing submicron size particles and product produced thereby

    DOEpatents

    Bourne, R.S.; Eichman, C.C.; Welbon, W.W.

    1988-05-11

    Submicron size particles are produced by using a sputtering process to deposit particles into a liquid. The liquid is processed to recover the particles therefrom, and the particles have sizes in the range of twenty to two hundred Angstroms. Either metallic or non-metallic particles can be produced, and the metallic particles can be used in ''metallic inks.'' 4 figs.

  9. Fiber reinforced PMR polyimide composites

    NASA Technical Reports Server (NTRS)

    Cavano, P. J.; Winters, W. E.

    1978-01-01

    Commercially obtained PMR-15 polyimide prepregs with S-glass and graphite fiber reinforcements were evaluated along with in-house prepared glass and graphite cloth PMR 2 materials. A novel autoclave approach was conceived and used to demonstrate that both the PMR systems respond to 1.4 MPa (200 psi) autoclave pressures to produce void free composites equivalent to die molded laminates. Isothermal gravimetric analysis and subsequent mechanical property tests indicated that the PMR 2 system was significantly superior in thermo-oxidative stability, and that S-glass reinforcements may contribute to the accelerated degradation of composites at 316 C (600 F) when compared to graphite fiber reinforced composites. Fully reversed bending fatigue experiments were conducted with a type of fixture unused for organic matrix composites. These studies indicated that the graphite fiber composites were clearly superior in fatigue resistance to the glass fiber reinforced material and that PMR matrix composite systems yield performance of the same order as composite materials employing other families of matrices.

  10. Concrete compositions and methods

    SciTech Connect

    Chen, Irvin; Lee, Patricia Tung; Patterson, Joshua

    2015-06-23

    Provided herein are compositions, methods, and systems for cementitious compositions containing calcium carbonate compositions and aggregate. The compositions find use in a variety of applications, including use in a variety of building materials and building applications.

  11. ) Hybrid Composite

    NASA Astrophysics Data System (ADS)

    Show, Bijay Kumar; Mondal, Dipak Kumar; Maity, Joydeep

    2014-12-01

    In this research work, the dry sliding wear behavior of 6351 Al-(4 vol.% SiC + 4 vol.% Al2O3) hybrid composite was investigated at low sliding speed (1 m/s) against a hardened EN 31 disk at different loads. In general, the wear mechanism involved adhesion (along with associated subsurface cracking and delamination) and microcutting abrasion at lower load. While at higher load, abrasive wear involving microcutting and microploughing along with adherent oxide formation was observed. The overall wear rate increased with increasing normal load. The massive particle clusters as well as individual reinforcement particles were found to stand tall to resist abrasive wear. Besides, at higher load, the generation of adherent nodular tribo-oxide through nucleation and epitaxial growth on existing Al2O3 particles lowered down the wear rate. Accordingly, at any normal load, 6351 Al-(4 vol.% SiC + 4 vol.% Al2O3) hybrid composite exhibited superior wear resistance (lower overall wear rate) than the reported wear resistance of monolithic 6351 Al alloy.

  12. The unnatural composite Higgs

    NASA Astrophysics Data System (ADS)

    Barnard, James; Gherghetta, Tony; Ray, Tirtha Sankar; Spray, Andrew

    2015-01-01

    Composite Higgs models can trivially satisfy precision-electroweak and flavour constraints by simply having a large spontaneous symmetry breaking scale, f ≳ 10 TeV. This produces a `split' spectrum, where the strong sector resonances have masses greater than 10 TeV and are separated from the pseudo Nambu-Goldstone bosons, which remain near the electroweak scale. Even though a tuning of order 10-4 is required to obtain the observed Higgs boson mass, the big hierarchy problem remains mostly solved. Intriguingly, models with a fully-composite right-handed top quark also exhibit improved gauge coupling unification. By restricting ourselves to models which preserve these features we find that the symmetry breaking scale cannot be arbitrarily raised, leading to an upper bound f ≲ 100-1000 TeV. This implies that the resonances may be accessible at future colliders, or indirectly via rare-decay experiments. Dark matter is identified with a pseudo Nambu-Goldstone boson, and we show that the smallest coset space containing a stable, scalar singlet and an unbroken SU(5) symmetry is SU(7) /SU(6) × U(1). The colour-triplet pseudo Nambu-Goldstone boson also contained in this coset space is metastable due to a residual symmetry. It can decay via a displaced vertex when produced at colliders, leading to a distinctive signal of unnaturalness.

  13. Produce handling and processing practices.

    PubMed Central

    Beuchat, L. R.; Ryu, J. H.

    1997-01-01

    In the past decade, outbreaks of human illness associated with the consumption of raw vegetables and fruits (or unpasteurized products produced from them) have increased in the United States. Changes in agronomic, harvesting, distribution, processing, and consumption patterns and practices have undoubtedly contributed to this increase. Pathogens such as Listeria monocytogenes, Clostridium botulinum, and Bacillus cereus are naturally present in some soil, and their presence on fresh produce is not rare. Salmonella, Escherichia coli O157:H7, Campylobacter jejuni, Vibrio cholerae, parasites, and viruses are more likely to contaminate fresh produce through vehicles such as raw or improperly composted manure, irrigation water containing untreated sewage, or contaminated wash water. Contact with mammals, reptiles, fowl, insects, and unpasteurized products of animal origin offers another avenue through which pathogens can access produce. Surfaces, including human hands, which come in contact with whole or cut produce represent potential points of contamination throughout the total system of growing, harvesting, packing, processing, shipping, and preparing produce for consumption. Treatment of produce with chlorinated water reduces populations of pathogenic and other microorganisms on fresh produce but cannot eliminate them. Reduction of risk for human illness associated with raw produce can be better achieved through controlling points of potential contamination in the field; during harvesting; during processing or distribution; or in retail markets, food-service facilities, or the home. PMID:9366597

  14. Producing and optimizing novel materials and structures

    NASA Astrophysics Data System (ADS)

    Ashrafi, Mahdi

    2011-12-01

    A series of detailed experimental and finite element investigations were carried out to study the response of selected objects which are currently utilized for load carrying. These investigations were later applied to optimize the mechanical performance of the studied structures and materials. First, a number of experiments and detailed finite element simulations were carried out to study the response and failure of single lap joints with non-flat interface under uniaxial tension. The adherents were made from fiber reinforced epoxy composite and the custom-made mold allowed the fibers to follow the profile of the bonded joint interface. The experiments showed that the interface shape has significant effect on the mechanical behavior and strength of the bonded joints. Finite element simulations were performed to estimate the distribution of shear and peeling stresses along the bonded joints and the results were linked to the experimental investigations. Additional parametric calculations were also carried out to highlight the role of interface shape on the distribution of stresses, and inherently the overall strength and behavior of the bonded joints. In addition, the role of a central void on the distribution of the stresses in a bonded joint with flat and non-flat sinusoidal interfaces was investigated. The second topic concerns Wood Plastic Composites (WPC) which are widely used in the industry due to its durability, low cost, and anti-moisture properties in comparison with the natural wood. In this research, we have produced flout shaped WPC samples using African black wood powder and Phenolic resin in a hot compression molding set-up. Initial WPC composites were produced by systematically changing the wood volume fraction. Based on these results the optimum temperature, pressure and wood volume fraction for developing WPC in a form of a flute is developed. A series of experimental procedures were performed to improve mechanical properties of WPC samples by

  15. Composing, Songwriting, and Producing: Informing Popular Music Pedagogy

    ERIC Educational Resources Information Center

    Tobias, Evan S.

    2013-01-01

    In forwarding comprehensive popular music pedagogies, music educators might acknowledge and address expanded notions of composition in popular music that include processes of recording, engineering, mixing, and producing along with the technologies, techniques, and ways of being musical that encompass these processes. This article advances a…

  16. 27 CFR 19.67 - Spirits produced in industrial processes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... produced as a by-product in connection with chemical or other processes) are distillers and are required to... nonpotable chemical mixtures containing spirits, including any provision relating to qualification, if such...; (ii) Chemical composition and source of the nonpotable mixture; (iii) Approximate percentages...

  17. Possibility of producing multilayer ingots by electroslag remelting

    NASA Astrophysics Data System (ADS)

    Chumanov, I. V.; Porsev, M. A.

    2010-12-01

    A new method is proposed for the production of multilayer ingots by electroslag remelting of a composite electrode consisting of different steel grades. This method differs from the well-known technology in electrode rotation, which makes it possible to substantially decrease the transition zone length. A scheme is suggested to produce a thick bimetal plate.

  18. Emerging perspectives on the natural microbiome of fresh produce vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants harbor a diverse microbiome existing as bacterial populations on the leaf surface (the phyllosphere) and within plant tissues (endophytes). The composition of this microbiome has been largely unexplored in fresh produce vegetables, where studies have tended to focus on pathogen detection and...

  19. Guide to Producing Print Materials.

    ERIC Educational Resources Information Center

    Far West Lab. for Educational Research and Development, San Francisco, CA.

    This is a simple how-to-do it manual intended to help projects that wish to produce print materials. It highlights the stages involved in producing print materials, giving an overview of the steps required and offering hints on different approaches to the various processes. The manual begins with the comprehensive layout (dummy) stage and proceeds…

  20. Microbial safety of fresh produce

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The book entitled “Microbial Safety of Fresh Produce” with 23 chapters is divided into following six sections: Microbial contamination of fresh produce, Pre-harvest strategies, post-harvest interventions, Produce safety during processing and handling, Public, legal, and economic Perspectives, and Re...

  1. Method of producing molybdenum-99

    DOEpatents

    Pitcher, Eric John

    2013-05-28

    Method of producing molybdenum-99, comprising accelerating ions by means of an accelerator; directing the ions onto a metal target so as to generate neutrons having an energy of greater than 10 MeV; directing the neutrons through a converter material comprising techentium-99 to produce a mixture comprising molybdenum-99; and, chemically extracting the molybdenum-99 from the mixture.

  2. Method for producing a borohydride

    DOEpatents

    Kong, Peter C.

    2010-06-22

    A method for producing a borohydride is described that includes the steps of providing a source of borate; providing a material that chemically reduces the source of the borate to produce a borohydride; and reacting the source of the borate and the material by supplying heat at a temperature that substantially effects the production of the borohydride.

  3. Iron Aluminide Composites

    SciTech Connect

    Schneibel, J.H.

    1998-11-20

    Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB{sub 2}, and ZrB{sub 2}. In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructure, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength at elevated temperatures (1073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a mile of mixtures. Interestingly, sufficiently thin (< 1 {micro}m) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminizes, environmental embrittlement is dramatically reduced in iron aluminide composites.

  4. Composite Tank

    NASA Technical Reports Server (NTRS)

    DeLay, Thomas K. (Inventor)

    2000-01-01

    A composite tank for containing liquid oxygen and the method of making the same Wherein a water-soluble mandrel having ing the desired tank configuration and a cylindrical protuberance on at least one end is fitted with an inner boss conformance, to the configuration of the mandrel and in outer boss conforming to the configuration of the inner boss, the bosses each having a tubular portion for receiving the protuberance on the mandrel and a spherical portion. The mandrel and the bosses are first coated with a nickel coating. The mandrel is then wrapped with graphite fibers wetted with an epoxy resin and this resin is cured. A layer of insulating foam is then applied to the tank and cured. The insulating foam is machined to a desired concentration and a layer of aramid fibers wetted with a second epoxy resin is wrapped around the tank. The second resin is cured and the water soluble mandrel is washed from inside the tank.

  5. Composite foams

    DOEpatents

    Williams, Jr., Joel M.; Nyitray, Alice M.; Wilkerson, Mark H.

    1990-01-01

    Composite foams are provided comprising a first rigid, microcellular, open-celled organic polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 1 micron to about 30 microns, said first foam containing a second polymer having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 or a second polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 0.01 microns to about 1.0 micron within the open cells of said first foam.

  6. Composite foams

    DOEpatents

    Williams, Jr., Joel M.; Nyitray, Alice M.; Wilkerson, Mark H.

    1991-01-01

    Composite foams are provided comprising a first rigid, microcellular, open-celled organic polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 1 micron to about 30 microns, said first foam containing a second polymer having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 or a second polymer foam having a density of from about 0.015 g/cm.sup.3 to about 0.20 g/cm.sup.3 and a pore size of from about 0.01 microns to about 1.0 micron within the open cells of said first foam.

  7. Computer Music Synthesis and Composition

    NASA Astrophysics Data System (ADS)

    Ayers, Lydia

    What is computer music composition? Composers are using the computer for everything from MIDI instruments communicating with computer sequencers, pitch trackers analyzing the sounds of acoustic instruments and converting them to pitch information, live performers with recorded music, performers with interactive computer programs, computer music produced by dancers using sensors, automatic music composition with the computer programs composing the music, composing with sounds or parts of sounds rather than notes, how to structure the use of time, composing with timbres, or the colors of sounds, and timbre morphing, such as a gong morphing to a voice, composing with textures and texture morphing, such as fluttertonguing morphing to pitch, granular synthesis, trills and convolution.

  8. Composites structures for bone tissue reconstruction

    NASA Astrophysics Data System (ADS)

    Neto, W.; Santos, João.; Avérous, L.; Schlatter, G.; Bretas, Rosario.

    2015-05-01

    The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth.

  9. THE BALLISTICS OF A RIBBON COMPOSITE

    SciTech Connect

    Larcombe, J.; Morley, M.; Earp, S.; Proud, W. G.; Fray, A. J.; French, M. A.

    2009-12-28

    The impact behaviour of composites is of great importance in the field of aerospace and vehicle protection. The combination of formability, lightness and strength make composite systems attractive compared to equivalent monolithic systems. However, their use as optical components has been hampered by their lack of transparency. Transparency is strongly affected by refractive index differences in the materials that form the composite. In this study a number of ribbon-based composites were produced. The impact velocity, sample deformation during the impact process and residual impactor velocity were measured. This allowed comparison between the materials ballistic efficiency. The materials are then compared to other transparent systems.

  10. Composites structures for bone tissue reconstruction

    SciTech Connect

    Neto, W.; Santos, João; Avérous, L.; Schlatter, G.; Bretas, Rosario

    2015-05-22

    The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth.

  11. Morphology and microstructure of composite materials

    NASA Technical Reports Server (NTRS)

    Tiwari, S. N.; Srinivansan, K.

    1991-01-01

    Lightweight continuous carbon fiber based polymeric composites are currently enjoying increasing acceptance as structural materials capable of replacing metals and alloys in load bearing applications. As with most new materials, these composites are undergoing trials with several competing processing techniques aimed at cost effectively producing void free consolidations with good mechanical properties. As metallic materials have been in use for several centuries, a considerable database exists on their morphology - microstructure; and the interrelationships between structure and properties have been well documented. Numerous studies on composites have established the crucial relationship between microstructure - morphology and properties. The various microstructural and morphological features of composite materials, particularly those accompanying different processing routes, are documented.

  12. Method of producing polyalkylated oligoalkylenepolyamines

    DOEpatents

    Elangovan, Arumugasamy

    2014-02-25

    A method of preparing polyalkylated oligoalkylenepolyamines is provided. The method includes contacting oligoalkylenepolyamine with a reagent composition comprising (a) alkyl bromide and/or alkyl chloride; (b) a basic agent; and (c) iodide salt. The alkylation reaction may be carried out in a polar, aprotic organic solvent.

  13. Cellulase producing microorganism ATCC 55702

    DOEpatents

    Dees, H. Craig

    1997-01-01

    Bacteria which produce large amounts of cellulase--containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualifies for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

  14. Microorganisms for producing organic acids

    SciTech Connect

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  15. Methods of producing cesium-131

    DOEpatents

    Meikrantz, David H; Snyder, John R

    2012-09-18

    Methods of producing cesium-131. The method comprises dissolving at least one non-irradiated barium source in water or a nitric acid solution to produce a barium target solution. The barium target solution is irradiated with neutron radiation to produce cesium-131, which is removed from the barium target solution. The cesium-131 is complexed with a calixarene compound to separate the cesium-131 from the barium target solution. A liquid:liquid extraction device or extraction column is used to separate the cesium-131 from the barium target solution.

  16. Cellulase producing microorganism ATCC 55702

    DOEpatents

    Dees, H.C.

    1997-12-30

    Bacteria which produce large amounts of cellulase--containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualifies for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

  17. Performance profiles of major energy producers

    NASA Astrophysics Data System (ADS)

    1980-12-01

    Data for 26 major energy producing companies (coal, oil, gas, nuclear) for 1977 and 1978 are presented. Data were collected using the Financial Reporting System (FRS) reporting Form EIA-28 which collects disaggregated financial data on revenues and expenses, assets and liabilities, and sources and uses of funds. The overall corporate financial performance of 26 FRS companies are compared with the other major industrial companies. Differences in relative commitment and profitability associated with alternative lines of corporate activity are examined. The size composition and international character of FRS companies are examined. Oil and gas resource development efforts in 1978 are traced. Data on resource development expenditures are complemented by information on reserve holdings, changes in reserves, and characteristics of exploration and development efforts. Foreign activity is compared with domestic.

  18. Do oblique impacts produce Martian meteorites

    NASA Astrophysics Data System (ADS)

    Nyquist, L. E.

    1983-11-01

    It is pointed out that several achondritic meteorites, classified as shergottites, nakhlites, and chassignites, have a number of unusual characteristics. Following the suggestion of Wood and Ashwal (1981) these meteorites are collectively referred to as SNC meteorites. The major element compositions of the SNC meteorites are, in general, distinct from those of other meteorites and lunar samples, and similar to certain terrestrial rocks. The geochemical and geochronological characteristics of the SNC meteorites strongly imply that their parent body was on the order of lunar size or larger and geologically active. Serious attention must be given to the hypothesis of a Martian origin of the SNC meteorites and to dynamic processes capable of delivering Martian meteorites to earth. In connection with the present investigation, it is suggested that oblique impacts of large meteoroids can produce ejecta which is entrained with the ricocheting projectile and accelerated to velocities in excess of Martian escape velocity.

  19. Characterization of cellulose and other exopolysaccharides produced from Gluconacetobacter strains.

    PubMed

    Fang, Lin; Catchmark, Jeffrey M

    2015-01-22

    This study characterized the cellulosic and non-cellulosic exopolysaccharides (EPS) produced by four Gluconacetobacter strains. The yields of bacterial cellulose and water-soluble polysaccharides were dependent on both carbon source and Gluconacetobacter strain. The carbon substrate also affected the composition of the free EPS. When galactose served as an exclusive carbon source, Gluconacetobacter xylinus (G. xylinus) ATCC 53524 and ATCC 700178 produced a distinct alkaline stable crystalline product, which influenced the crystallization of cellulose. Gluconacetobacter hansenii (G. hansenii) ATCC 23769 and ATCC 53582, however, did not exhibit any significant change in cellulose crystal properties when galactose was used as the carbon source. Microscopic observation further confirmed significant incorporation of EPS into the cellulose composites. The cellulosic network produced from galactose medium showed distinctive morphological and structural features compared to that from glucose medium. PMID:25439946

  20. Novel alkyd-type coating resins produced using cationic polymerization

    SciTech Connect

    Chisholm, Bret J.; Kalita, Harjyoti; Alam, Samim; Jayasooriyamu, Anurad; Fernando, Shashi; Samanata, Satyabrata; Bahr, James; Selvakumar, Sermadurai; Sibi, Mukund; Vold, Jessica; Ulven, Chad

    2015-05-06

    Novel, partially bio-based poly(vinyl ether) copolymers derived from soybean oil and cyclohexyl vinyl ether (CHVE) were produced by cationic polymerization and investigated for application as alkyd-type surface coatings. Compared to conventional alkyd resins, which are produced by high temperature melt condensation polymerization, the poly(v9nyl ether)s provide several advantages. These advantages include milder, more energy efficient polymer synthesis, elimination of issues associated with gelation during polymer synthesis, production of polymers with well-defined composition and relatively narrow molecular weight distribution, and elimination of film formation and physical property issues associated with entrained monomers, dimers, trimers, etc. The results of the studied showed that the thermal, mechanical, and physical properties of the coatings produced from these novel polymers varied considerably as a function of polymer composition and cure temperature. Overall, the results suggest a good potential for these novel copolymers to be used for coatings cured by autoxidation.

  1. Composition and methods for improved fuel production

    SciTech Connect

    Steele, Philip H.; Tanneru, Sathishkumar; Gajjela, Sanjeev K.

    2015-12-29

    Certain embodiments of the present invention are configured to produce boiler and transportation fuels. A first phase of the method may include oxidation and/or hyper-acidification of bio-oil to produce an intermediate product. A second phase of the method may include catalytic deoxygenation, esterification, or olefination/esterification of the intermediate product under pressurized syngas. The composition of the resulting product--e.g., a boiler fuel--produced by these methods may be used directly or further upgraded to a transportation fuel. Certain embodiments of the present invention also include catalytic compositions configured for use in the method embodiments.

  2. Hollow Spheres in Composite Materials and Metallic Hollow Sphere Composites (MHSC)

    NASA Astrophysics Data System (ADS)

    Baumeister, Erika; Molitor, Martin

    The newly developed metallic hollow spheres are used in combination with a polymeric matrix for producing metallic hollow-sphere-composites (MSHC), which have been developed for mechanical engineering applications in the “InnoZellMet” project.

  3. Method of making a partial interlaminar separation composite system

    NASA Technical Reports Server (NTRS)

    Elber, W. (Inventor)

    1981-01-01

    An interlaminar separation system for composites is disclosed a thin layer of a perforated foil film is interposed between adjacent laminae of a composite formed from prepreg tapes. Laminae adherence takes place through the perforations and a composite structure with improved physical property characteristics is produced.

  4. Jet Shockwaves Produce Gamma Rays

    NASA Video Gallery

    Theorists believe that GRB jets produce gamma rays by two processes involving shock waves. Shells of material within the jet move at different speeds and collide, generating internal shock waves th...

  5. Methods of producing transportation fuel

    DOEpatents

    Nair, Vijay; Roes, Augustinus Wilhelmus Maria; Cherrillo, Ralph Anthony; Bauldreay, Joanna M.

    2011-12-27

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for producing transportation fuel is described herein. The method for producing transportation fuel may include providing formation fluid having a boiling range distribution between -5.degree. C. and 350.degree. C. from a subsurface in situ heat treatment process to a subsurface treatment facility. A liquid stream may be separated from the formation fluid. The separated liquid stream may be hydrotreated and then distilled to produce a distilled stream having a boiling range distribution between 150.degree. C. and 350.degree. C. The distilled liquid stream may be combined with one or more additives to produce transportation fuel.

  6. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    DOEpatents

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2015-07-21

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  7. Al Composites

    NASA Astrophysics Data System (ADS)

    Chandanayaka, Tharaka; Azarmi, Fardad

    2014-05-01

    In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 μm were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

  8. Analysis of Graphite-Reinforced Cementitious Composites

    NASA Technical Reports Server (NTRS)

    Vaughan, R. E.

    2002-01-01

    Strategically embedding graphite meshes in a compliant cementitious matrix produces a composite material with relatively high tension and compressive properties as compared to steel-reinforced structures fabricated from a standard concrete mix. Although these composite systems are somewhat similar, the methods used to analyze steel-reinforced composites often fail to characterize the behavior of their more advanced graphite-reinforced counterparts. This Technical Memorandum describes some of the analytical methods being developed to determine the deflections and stresses in graphite-reinforced cementitious composites. It is initially demonstrated that the standard transform section method fails to provide accurate results when the elastic moduli ratio exceeds 20. An alternate approach is formulated by using the rule of mixtures to determine a set of effective material properties for the composite. Tensile tests are conducted on composite samples to verify this approach. When the effective material properties are used to characterize the deflections of composite beams subjected to pure bending, an excellent agreement is obtained. Laminated composite plate theory is investigated as a means for analyzing even more complex composites, consisting of multiple graphite layers oriented in different directions. In this case, composite beams are analyzed using the laminated composite plate theory with material properties established from tensile tests. Then, finite element modeling is used to verify the results. Considering the complexity of the samples, a very good agreement is obtained.

  9. Insensitive explosive composition and method of fracturing rock using an extrudable form of the composition

    DOEpatents

    Davis, Lloyd L

    2013-11-05

    Insensitive explosive compositions were prepared by reacting di-isocyanate and/or poly-isocyanate monomers with an explosive diamine monomer. Prior to a final cure, the compositions are extrudable. The di-isocyanate monomers tend to produce tough, rubbery materials while polyfunctional monomers (i.e. having more than two isocyanate groups) tend to form rigid products. The extrudable form of the composition may be used in a variety of applications including rock fracturing.

  10. Insensitive explosive composition and method of fracturing rock using an extrudable form of the composition

    DOEpatents

    Davis, Lloyd L.

    2015-07-28

    Insensitive explosive compositions were prepared by reacting di-isocyanate and/or poly-isocyanate monomers with an explosive diamine monomer. Prior to a final cure, the compositions are extrudable. The di-isocyanate monomers tend to produce tough, rubbery materials while polyfunctional monomers (i.e. having more than two isocyanate groups) tend to form rigid products. The extrudable form of the composition may be used in a variety of applications including rock fracturing.

  11. Fatigue of composites

    NASA Technical Reports Server (NTRS)

    Salkind, M. J.

    1972-01-01

    The failure mechanisms in the fatigue of composite materials are analyzed in terms of the requirements for designing fatigue-critical composite structures. Fiber reinforced polymers, fiber reinforced metals, fatigue of composite structures, and composite design considerations are discussed. It is concluded that composite materials offer the engineer the opportunity for tailoring stiffness in different directions for designing dynamic components.

  12. Development of piezoelectric composites for transducers

    NASA Astrophysics Data System (ADS)

    Safari, A.

    1994-07-01

    For the past decade and a half, many different types of piezoelectric ceramic-polymer composites have been developed intended for transducer applications. These diphasic composites are prepared from non-active polymer, such as epoxy, and piezoelectric ceramic, such as PZT, in the form of filler powders, elongated fibers, multilayer and more complex three-dimensional structures. For the last four years, most of the efforts have been given to producing large area and fine scale PZT fiber composites. In this paper, processing of piezoelectric ceramic-polymer composites with various connectivity patterns are reviewed. Development of fine scale piezoelectric composites by lost mold, injection molding and the relic method are described. Research activities of different groups for preparing large area piezocomposites for hydrophone and actuator applications are briefly reviewed. Initial development of electrostrictive ceramics and composites are also

  13. Intercalated hybrid graphite fiber composite

    NASA Technical Reports Server (NTRS)

    Gaier, James R. (Inventor)

    1993-01-01

    The invention is directed to a highly conductive lightweight hybrid material and methods of producing the same. The hybrid composite is obtained by weaving strands of a high strength carbon or graphite fiber into a fabric-like structure, depositing a layer of carbon onto the structure, heat treating the structure to graphitize the carbon layer, and intercalating the graphitic carbon layer structure. A laminate composite material useful for protection against lightning strikes comprises at least one layer of the hybrid material over at least one layer of high strength carbon or graphite fibers. The composite material of the present invention is compatible with matrix compounds, has a coefficient of thermal expansion which is the same as underlying fiber layers, and is resistant to galvanic corrosion in addition to being highly conductive. These materials are useful in the aerospace industry, in particular as lightning strike protection for airplanes.

  14. Nanostructured composite reinforced material

    DOEpatents

    Seals, Roland D.; Ripley, Edward B.; Ludtka, Gerard M.

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  15. Producing liquid fuels from biomass

    NASA Astrophysics Data System (ADS)

    Solantausta, Yrjo; Gust, Steven

    The aim of this survey was to compare, on techno-economic criteria, alternatives of producing liquid fuels from indigenous raw materials in Finland. Another aim was to compare methods under development and prepare a proposal for steering research related to this field. Process concepts were prepared for a number of alternatives, as well as analogous balances and production and investment cost assessments for these balances. Carbon dioxide emissions of the alternatives and the price of CO2 reduction were also studied. All the alternatives for producing liquid fuels from indigenous raw materials are utmost unprofitable. There are great differences between the alternatives. While the production cost of ethanol is 6 to 9 times higher than the market value of the product, the equivalent ratio for substitute fuel oil produced from peat by pyrolysis is 3 to 4. However, it should be borne in mind that the technical uncertainties related to the alternatives are of different magnitude. Production of ethanol from barley is of commercial technology, while biomass pyrolysis is still under development. If the aim is to reach smaller carbon dioxide emissions by using liquid biofuels, the most favorable alternative is pyrolysis oil produced from wood. Fuels produced from cultivated biomass are more expensive ways of reducing CO2 emissions. Their potential of reducing CO2 emissions in Finland is insignificant. Integration of liquid fuel production to some other production line is more profitable.

  16. Postharvest treatments of fresh produce.

    PubMed

    Mahajan, P V; Caleb, O J; Singh, Z; Watkins, C B; Geyer, M

    2014-06-13

    Postharvest technologies have allowed horticultural industries to meet the global demands of local and large-scale production and intercontinental distribution of fresh produce that have high nutritional and sensory quality. Harvested products are metabolically active, undergoing ripening and senescence processes that must be controlled to prolong postharvest quality. Inadequate management of these processes can result in major losses in nutritional and quality attributes, outbreaks of foodborne pathogens and financial loss for all players along the supply chain, from growers to consumers. Optimal postharvest treatments for fresh produce seek to slow down physiological processes of senescence and maturation, reduce/inhibit development of physiological disorders and minimize the risk of microbial growth and contamination. In addition to basic postharvest technologies of temperature management, an array of others have been developed including various physical (heat, irradiation and edible coatings), chemical (antimicrobials, antioxidants and anti-browning) and gaseous treatments. This article examines the current status on postharvest treatments of fresh produce and emerging technologies, such as plasma and ozone, that can be used to maintain quality, reduce losses and waste of fresh produce. It also highlights further research needed to increase our understanding of the dynamic response of fresh produce to various postharvest treatments. PMID:24797137

  17. Postharvest treatments of fresh produce

    PubMed Central

    Mahajan, P. V.; Caleb, O. J.; Singh, Z.; Watkins, C. B.; Geyer, M.

    2014-01-01

    Postharvest technologies have allowed horticultural industries to meet the global demands of local and large-scale production and intercontinental distribution of fresh produce that have high nutritional and sensory quality. Harvested products are metabolically active, undergoing ripening and senescence processes that must be controlled to prolong postharvest quality. Inadequate management of these processes can result in major losses in nutritional and quality attributes, outbreaks of foodborne pathogens and financial loss for all players along the supply chain, from growers to consumers. Optimal postharvest treatments for fresh produce seek to slow down physiological processes of senescence and maturation, reduce/inhibit development of physiological disorders and minimize the risk of microbial growth and contamination. In addition to basic postharvest technologies of temperature management, an array of others have been developed including various physical (heat, irradiation and edible coatings), chemical (antimicrobials, antioxidants and anti-browning) and gaseous treatments. This article examines the current status on postharvest treatments of fresh produce and emerging technologies, such as plasma and ozone, that can be used to maintain quality, reduce losses and waste of fresh produce. It also highlights further research needed to increase our understanding of the dynamic response of fresh produce to various postharvest treatments. PMID:24797137

  18. Asymmetric Dielectric Elastomer Composite Material

    NASA Technical Reports Server (NTRS)

    Stewart, Brian K. (Inventor)

    2014-01-01

    Embodiments of the invention provide a dielectric elastomer composite material comprising a plurality of elastomer-coated electrodes arranged in an assembly. Embodiments of the invention provide improved force output over prior DEs by producing thinner spacing between electrode surfaces. This is accomplished by coating electrodes directly with uncured elastomer in liquid form and then assembling a finished component (which may be termed an actuator) from coated electrode components.

  19. Lightweight composite reflector panels

    NASA Technical Reports Server (NTRS)

    Freeland, R. E.; Mcelroy, P. M.

    1988-01-01

    The Hexel Corp. has produced additional composite panels, based on JPL designs, that: (1) have increased the panel size from 0.15 to 0.40 meters, (2) have improved the as-manufactured surface precision 3.0 to approx. 1.0 micron RMS, (3) have utilized different numbers of face sheet plys, (4) have improved face sheet fiber orientation, (5) have variations of aluminum honeycomb core cell size, (6) have combined graphite/epoxy (Gr/Ep) face sheets with E-glass honeycomb cores, and (7) have used standard aluminum core with face sheets composed of combinations of glass, Kevlar, and carbon fibers. Additionally, JPL has identified candidate alternate materials for the facesheets and core, modified the baseline polymer panel matrix material, and developed new concepts for panel composite cores. Dornier designed and fabricated three 0.6 meter Gr/Ep panels, that were evaluated by JPL. Results of both the Hexel and Dornier panel work were used to characterize the state-of-the-art for Gr/Ep mirrors.

  20. Lunar atmospheric composition experiment

    NASA Technical Reports Server (NTRS)

    Hoffman, J. H.

    1975-01-01

    Apollo 17 carried a miniature mass spectrometer, called the Lunar Atmospheric Composition Experiment (LACE), to the moon as part of the Apollo Lunar Surface Experiments Package (ALSEP) to study the composition and variations in the lunar atmosphere. The instrument was successfully deployed in the Taurus-Littrow Valley with its entrance aperture oriented upward to intercept and measure the downward flux of gases at the lunar surface. During the ten lunations that the LACE operated, it produced a large base of data on the lunar atmosphere, mainly collected at night time. It was found that thermal escape is the most rapid loss mechanism for hydrogen and helium. For heavier gases, photoionization followed by acceleration through the solar wind electric field accounted for most of the loss. The dominant gases on the moosn were argon and helium, and models formed for their distribution are described in detail. It is concluded that most of the helium in the lunar atmosphere is of solar wind origin, and that there also exist very small amounts of methane, ammonia, and carbon dioxide.

  1. Composite oxygen transport membrane

    SciTech Connect

    Christie, Gervase Maxwell; Lane, Jonathan A.

    2014-08-05

    A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

  2. Composite powder particles

    NASA Technical Reports Server (NTRS)

    Parker, Donald S. (Inventor); MacDowell, Louis G. (Inventor)

    2009-01-01

    A liquid coating composition including a coating vehicle and composite powder particles disposed within the coating vehicle. Each composite powder particle may include a magnesium component, a zinc component, and an indium component.

  3. Method for producing nanostructured metal-oxides

    DOEpatents

    Tillotson, Thomas M.; Simpson, Randall L.; Hrubesh, Lawrence W.; Gash, Alexander

    2006-01-17

    A synthetic route for producing nanostructure metal-oxide-based materials using sol-gel processing. This procedure employs the use of stable and inexpensive hydrated-metal inorganic salts and environmentally friendly solvents such as water and ethanol. The synthesis involves the dissolution of the metal salt in a solvent followed by the addition of a proton scavenger, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively. Using this method synthesis of metal-oxide nanostructured materials have been carried out using inorganic salts, such as of Fe.sup.3+, Cr.sup.3+, Al.sup.3+, Ga.sup.3+, In.sup.3+, Hf.sup.4+, Sn.sup.4+, Zr.sup.4+, Nb.sup.5+, W.sup.6+, Pr.sup.3+, Er.sup.3+, Nd.sup.3+, Ce.sup.3+, U.sup.3+ and Y.sup.3+. The process is general and nanostructured metal-oxides from the following elements of the periodic table can be made: Groups 2 through 13, part of Group 14 (germanium, tin, lead), part of Group 15 (antimony, bismuth), part of Group 16 (polonium), and the lanthanides and actinides. The sol-gel processing allows for the addition of insoluble materials (e.g., metals or polymers) to the viscous sol, just before gelation, to produce a uniformly distributed nanocomposites upon gelation. As an example, energetic nanocomposites of Fe.sub.xO.sub.y gel with distributed Al metal are readily made. The compositions are stable, safe, and can be readily ignited to thermitic reaction.

  4. Continious production of exfoliated graphite composite compositions and flow field plates

    DOEpatents

    Shi, Jinjun; Zhamu, Aruna; Jang, Bor Z.

    2010-07-20

    A process of continuously producing a more isotropic, electrically conductive composite composition is provided. The process comprises: (a) continuously supplying a compressible mixture comprising exfoliated graphite worms and a binder or matrix material, wherein the binder or matrix material is in an amount of between 3% and 60% by weight based on the total weight of the mixture; (b) continuously compressing the compressible mixture at a pressure within the range of from about 5 psi or 0.035 MPa to about 50,000 psi or 350 MPa in at least a first direction into a cohered graphite composite compact; and (c) continuously compressing the composite compact in a second direction, different from the first direction, to form the composite composition in a sheet or plate form. The process leads to composite plates with exceptionally high thickness-direction electrical conductivity.

  5. Emissions from Produced Water Treatment Ponds, Uintah Basin, Utah, USA

    NASA Astrophysics Data System (ADS)

    Mansfield, M. L.; Lyman, S. N.; Tran, H.; O'Neil, T.; Anderson, R.

    2015-12-01

    An aqueous phase, known as "produced water," usually accompanies the hydrocarbon fluid phases that are extracted from Earth's crust during oil and natural gas extraction. Produced water contains dissolved and suspended organics and other contaminants and hence cannot be discharged directly into the hydrosphere. One common disposal method is to discharge produced water into open-pit evaporation ponds. Spent hydraulic fracturing fluids are also often discharged into the same ponds. It is obvious to anyone with a healthy olfactory system that such ponds emit volatile organics to the atmosphere, but very little work has been done to characterize such emissions. Because oil, gas, and water phases are often in contact in geologic formations, we can expect that more highly soluble compounds (e.g., salts, alcohols, carbonyls, carboxyls, BTEX, etc.) partition preferentially into produced water. However, as the water in the ponds age, many physical, chemical, and biological processes alter the composition of the water, and therefore the composition and strength of volatile organic emissions. For example, some ponds are aerated to hasten evaporation, which also promotes oxidation of organics dissolved in the water. Some ponds are treated with microbes to promote bio-oxidation. In other words, emissions from ponds are expected to be a complex function of the composition of the water as it first enters the pond, and also of the age of the water and of its treatment history. We have conducted many measurements of emissions from produced water ponds in the Uintah Basin of eastern Utah, both by flux chamber and by evacuated canister sampling with inverse modeling. These measurements include fluxes of CO2, CH4, methanol, and many other volatile organic gases. We have also measured chemical compositions and microbial content of water in the ponds. Results of these measurements will be reported.

  6. Producing miniature threads. Final report

    SciTech Connect

    Gillespie, L.K.; Robb, J.M.

    1981-11-01

    Miniature precision actuators, timers, and switches typically utilize miniature threads to provide convenient assembly, disassembly and adjustment. Thread rolling provides high-quality external threads with greater strength and lower cost than other thread-producing techniques. Tap breakage is a significant problem when 0.5 and 0.6 Unified National Miniature (UNM) threads must be produced in hard materials such as SAE K95100 high-permeability magnetic steel. Aluminum parts can be tapped with no difficulty in these sizes. Stainless steel 0.5 UNM screws break at loads of 21 lb (53 N). Thread failure occurs at thread heights of 62% full thread or lower.

  7. Shiga Toxin Producing Escherichia coli.

    PubMed

    Bryan, Allen; Youngster, Ilan; McAdam, Alexander J

    2015-06-01

    Shiga toxin-producing Escherichia coli (STEC) is among the common causes of foodborne gastroenteritis. STEC is defined by the production of specific toxins, but within this pathotype there is a diverse group of organisms. This diversity has important consequences for understanding the pathogenesis of the organism, as well as for selecting the optimum strategy for diagnostic testing in the clinical laboratory. This review includes discussions of the mechanisms of pathogenesis, the range of manifestations of infection, and the several different methods of laboratory detection of Shiga toxin-producing E coli. PMID:26004641

  8. Apparatus for producing laser targets

    DOEpatents

    Jarboe, T.R.; Baker, W.R.

    1975-09-23

    This patent relates to an apparatus and method for producing deuterium targets or pellets of 25u to 75u diameter. The pellets are sliced from a continuously spun solid deuterium thread at a rate of up to 10 pellets/second. The pellets after being sliced from the continuous thread of deuterium are collimated and directed to a point of use, such as a laser activated combustion or explosion chamber wherein the pellets are imploded by laser energy or laser produced target plasmas for neutral beam injection. (auth)

  9. Method for producing laser targets

    DOEpatents

    Jarboe, Thomas R.; Baker, William R.

    1977-01-01

    An apparatus and method for producing deuterium targets or pellets of 25.mu. to 75.mu. diameter. The pellets are sliced from a continuously spun solid deuterium thread at a rate of up to 10 pellets/second. The pellets after being sliced from the continuous thread of deuterium are collimated and directed to a point of use, such as a laser activated combustion or explosion chamber wherein the pellets are imploded by laser energy or laser produced target plasmas for neutral beam injection.

  10. Producing undistorted acoustic sine waves.

    PubMed

    Boutin, Henri; Smith, John; Wolfe, Joe

    2014-04-01

    A simple digital method is described that can produce an undistorted acoustic sine wave using an amplifier and loudspeaker having considerable intrinsic distortion, a common situation at low frequencies and high power. The method involves, first, using a pure sine wave as the input and measuring the distortion products. An iterative procedure then progressively adds harmonics with appropriate amplitude and phase to cancel any distortion products. The method is illustrated by producing a pure 52 Hz sine wave at 107 dB sound pressure level with harmonic distortion reduced over the audible range to >65 dB below the fundamental. PMID:25234964

  11. Composition of natural gas and crude oil produced from 14 wells in the Lower Silurian "Clinton" Sandstone and Medina Group Sandstones, northeastern Ohio and northwestern Pennsylvania: Chapter G.6 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Burruss, Robert A.; Ryder, Robert T.

    2014-01-01

    The geochemical processes that control the distribution of hydrocarbons in the regional accumulation of natural gas and crude oil in reservoirs of Early Silurian age in the central Appalachian basin are not well understood. Gas and oil samples from 14 wells along a down-dip transect through the accumulation in northeastern Ohio and northwestern Pennsylvania were analyzed for molecular and stable isotopic compositions to look for evidence of hydrocarbon source, thermal maturation, migration, and alteration parameters. The correlation of carbon and hydrogen stable isotopic composition of methane with thermal maturation indicates that the deepest gases are more thermally mature than independent estimates of thermal maturity of the reservoir horizon based on the conodont alteration index. This correlation indicates that the natural gas charge in the deepest parts of the regional accumulation sampled in this study originated in deeper parts of the Appalachian basin and migrated into place. Other processes, including mixing and late-stage alteration of hydrocarbons, may also impact the observed compositions of natural gases and crude oils.

  12. Food Irradiation for Produce Safety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A research priority for the produce industry is the development of an effective, safe and commercially applicable kill step. Irradiation is a nonthermal process that has been shown to inactivate human pathogens from fruits and vegetables. Irradiation treatment at 1.0 kGy can reduce the surface popul...

  13. Institutional Producers of Physics Research.

    ERIC Educational Resources Information Center

    Cooper, Marianne; Watterson, Hermine M.

    In order to identify producers of physics research and to determine their relative productivity, institutional affiliations of authors as given in nine physics journals were studied. Organizations were classified and analyzed by type and geographical location, and productivity established. Findings indicate that organizations differ in their rate…

  14. The Top STEM Degree Producers

    ERIC Educational Resources Information Center

    Diverse: Issues in Higher Education, 2012

    2012-01-01

    This article presents a list of the top Science, Technology, Engineering, and Mathematics (STEM) degree producers in the U.S. This list is broken down into seven categories: (1) Total Minority Research/Scholarship and Other Doctoral: Mathematics and Statistics; (2) Total Minority Bachelors: Biological and Biomedical Sciences; (3) Total Minority…

  15. The Top Theological Degree Producers

    ERIC Educational Resources Information Center

    Diverse: Issues in Higher Education, 2012

    2012-01-01

    Each year, "Diverse: Issues in Higher Education" publishes a list of the Top 100 producers of associate, bachelor's and graduate degrees awarded to minority students based on research conducted by Dr. Victor M. H. Borden, professor of educational leadership and policy studies at Indiana University Bloomington. This year, for the first time, it has…

  16. Process for producing chalcogenide semiconductors

    DOEpatents

    Noufi, R.; Chen, Y.W.

    1985-04-30

    A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

  17. Process for producing chalcogenide semiconductors

    DOEpatents

    Noufi, Rommel; Chen, Yih-Wen

    1987-01-01

    A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

  18. Marine bacteria which produce tetrodotoxin.

    PubMed Central

    Simidu, U; Noguchi, T; Hwang, D F; Shida, Y; Hashimoto, K

    1987-01-01

    A number of type strains of marine bacteria, including members of the family Vibrionaceae, were cultured and examined for tetrodotoxin productivity by high-performance liquid chromatography and gas chromatography-mass spectrometry. Most of the Vibrionaceae strains produced tetrodotoxin, anhydrotetrodotoxin, or both. PMID:3310884

  19. METHOD FOR PRODUCING DIBORON TETRACHLORIDE

    DOEpatents

    Frazer, J.W.; Holzmann, R.T.

    1961-08-01

    A method of producing diboron tetrachloride from boron trichloride is described. Gaseous boron trichloride is passed through a cavity resonating at a microwave frequency whereby a portion of the boron trichloride is converted into diboron tetrachloride. The diboron tetrachloride may then be separated from the boron trichloride by conventional means. (AEC)

  20. Student Produced Advanced Mathematical Software.

    ERIC Educational Resources Information Center

    Hogben, Leslie

    The intent of this project was to develop a course for mathematics graduate students at Iowa State University. They would design and write computer programs for use by undergraduate mathematics students, and then offer the course and actually produce the software. Phase plane graphics for ordinary differential equations was selected as the topic.…

  1. Producing Talent and Variety Shows.

    ERIC Educational Resources Information Center

    Szabo, Chuck

    1995-01-01

    Identifies key aspects of producing talent shows and outlines helpful hints for avoiding pitfalls and ensuring a smooth production. Presents suggestions concerning publicity, scheduling, and support personnel. Describes types of acts along with special needs and problems specific to each act. Includes a list of resources. (MJP)

  2. Chemical recycling of scrap composites

    NASA Technical Reports Server (NTRS)

    Allred, Ronald E.; Salas, Richard M.

    1994-01-01

    There are no well-developed technologies for recycling composite materials other than grinding to produce fillers. New approaches are needed to reclaim these valuable resources. Chemical or tertiary recycling, conversion of polymers into low molecular weight hydrocarbons for reuse as chemicals or fuels, is emerging as the most practical means for obtaining value from waste plastics and composites. Adherent Technologies is exploring a low-temperature catalytic process for recycling plastics and composites. Laboratory results show that all types of plastics, thermosets as well as thermoplastics, can be converted in high yields to valuable hydrocarbon products. This novel catalytic process runs at 200 C, conversion times are rapid, the process is closed and, thus, nonpolluting, and no highly toxic gas or liquid products have been observed so no negative environmental impact will result from its implementation. Tests on reclamation of composite materials show that epoxy, imide, and engineering thermoplastic matrices can be converted to low molecular weight hydrocarbons leaving behind the reinforcing fibers for reuse as composite reinforcements in secondary, lower-performance applications. Chemical recycling is also a means to dispose of sensitive or classified organic materials without incineration and provides a means to eliminate or reduce mixed hazardous wastes containing organic materials.

  3. Carbon-fiber composite molecular sieves for gas separation

    SciTech Connect

    Jagtoyen, M.; Derbyshire, F.; Kimber, G.; Fei, Y.Q.

    1995-08-01

    The progress of research in the development of novel, rigid, monolithic adsorbent carbon fiber composites is described. Carbon fiber composites are produced at ORNL and activated at the CAER using steam or CO{sub 2} under different conditions, with the aims of producing a uniform degree of activation through the material, and of closely controlling pore structure and adsorptive properties The principal focus of the work to date has been to produce materials with narrow porosity for use in gas separations.

  4. Composite millicharged dark matter

    NASA Astrophysics Data System (ADS)

    Kouvaris, Chris

    2013-07-01

    We study a composite millicharged dark matter model. The dark matter is in the form of pionlike objects emerging from a higher scale QCD-like theory. We present two distinct possibilities with interesting phenomenological consequences based on the choice of the parameters. In the first one, the dark matter is produced nonthermally, and it could potentially account for the 130 GeV Fermi photon line via decays of the “dark pions.” We estimate the self-interaction cross section, which might play an important role both in changing the dark matter halo profile at the center of the galaxy and in making the dark matter warmer. In the second version the dark matter is produced via the freeze-in mechanism. Finally we impose all possible astrophysical, cosmological and experimental constraints. We study in detail generic constraints on millicharged dark matter that can arise from anomalous isotope searches of different elements and we show why constraints based on direct searches from underground detectors are not generally valid.

  5. A smoke producing rocket motor for atmospheric wind profiling

    SciTech Connect

    Grubelich, M.C. ); Rowland, J. . Applied Physics Lab.)

    1991-01-01

    A composite propellant was developed to produce a dense plume from a rocket motor. The development of this propellant combined the smoke producing capabilities of a smoke generator with a rocket motor, thereby integrating the separate systems into one unit. A rocket motor was designed for use with this propellant to produce a high density particulate plume. This plume could then be used to determine the wind profile in the atmosphere by using a light detection and ranging system. Additionally, this smoke producing propellant could be used for rapid screening or identification. The burn rate characteristics of the propellant were measured and static firings of rocket motors were conducted to determine the performance of the propellant. The results of these tests will be presented as well as theoretical performance predictions of a flight vehicle.

  6. A smoke producing rocket motor for atmospheric wind profiling

    SciTech Connect

    Grubelich, M.C.; Rowland, J.

    1991-12-31

    A composite propellant was developed to produce a dense plume from a rocket motor. The development of this propellant combined the smoke producing capabilities of a smoke generator with a rocket motor, thereby integrating the separate systems into one unit. A rocket motor was designed for use with this propellant to produce a high density particulate plume. This plume could then be used to determine the wind profile in the atmosphere by using a light detection and ranging system. Additionally, this smoke producing propellant could be used for rapid screening or identification. The burn rate characteristics of the propellant were measured and static firings of rocket motors were conducted to determine the performance of the propellant. The results of these tests will be presented as well as theoretical performance predictions of a flight vehicle.

  7. Working Toward Nanotube Composites

    NASA Technical Reports Server (NTRS)

    Arepalli, Sivaram; Nikolaev, Pavel; Gorelik, Olga; Hadjiev, Victor G.; Scott, Carl D.; Files, Bradley S.

    2001-01-01

    One of the most attractive applications of single-wall carbon nanotubes (SWNT) is found in the area of structural materials. Nanotubes have a unique combination of high strength, modulus, and elongation to failure, and therefore have potential to significantly enhance the mechanical properties of today's composites. This is especially attractive for the aerospace industry looking for any chance to save weight. This is why NASA has chosen to tackle this difficult application of SWNT. Nanotube properties differ significantly from that of conventional carbon fibers, and a whole new set of problems, including adhesion and dispersion in the adhesive polymer matrix, must be resolved in order to engineer superior composite materials. From recent work on a variety of applications it is obvious that the wide range of research in nanotubes will lead to advances in physics, chemistry, and engineering. However, the possibility of ultralightweight structures is what causes dreamers to really get excited. One of the important issues in composite engineering is aspect ratio of the fibers, since it affects load transfer in composites. Nanotube length was a gray area for years, since they are formed in bundles, making it impossible to monitor individual nanotube length. Even though bundles are observed to be tens and hundreds of microns long, they can be built of relatively short tubes weakly bound by Van der Waals forces. Nanotube length can be affected by subsequent purification and ultrasound processing, which has been necessary in order to disperse nanotubes and introduce them into a polymer matrix. Some calculations show that nanotubes with 10(exp 5) aspect ratio may be necessary to achieve good load transfer. We show here that nanotubes produced in our laser system are as much as tens of microns long and get cut into lengths of hundreds of nanometers during ultrasound processing. Nanotube length was measured by AFM on pristine nanotube specimens as well, as after sonication

  8. Influence of Binder in Iron Matrix Composites

    SciTech Connect

    Shamsuddin, S.; Jamaludin, S. B.; Hussain, Z.; Ahmad, Z. A.

    2010-03-11

    The ability to use iron and its alloys as the matrix material in composite systems is of great importance because it is the most widely used metallic material with a variety of commercially available steel grades [1]. The aim of this study is to investigate the influence of binder in particulate iron based metal matrix composites. There are four types of binder that were used in this study; Stearic Acid, Gummi Arabisch, Polyvinyl alcohol 15000 MW and Polyvinyl alcohol 22000 MW. Six different weight percentage of each binder was prepared to produce the composite materials using powder metallurgy (P/M) route; consists of dry mixing, uniaxially compacting at 750 MPa and vacuum sintering at 1100 deg. C for two hours. Their characterization included a study of density, porosity, hardness and microstructure. Results indicate that MMC was affected by the binder and stearic acid as a binder produced better properties of the composite.

  9. Method for producing electricity using a platinum-ruthenium-palladium catalyst in a fuel cell

    DOEpatents

    Gorer, Alexander

    2004-01-27

    A method for producing electricity using a fuel cell that utilizes a ternary alloy composition as a fuel cell catalyst, the ternary alloy composition containing platinum, ruthenium and palladium. The alloy shows increased activity as compared to well-known catalysts.

  10. [Characteristics of domestically produced siloxane elastomer for making elastic gingival prosthetic device].

    PubMed

    Riakhovskiĭ, A N; Poiurovskaia, I Ia; Kirillova, E V

    2006-01-01

    Gingival prosthetics effectively eliminates esthetic and phonetic disturbances in cases of pronounced gingival recession. Technology for making elastic gingival prosthetic devices of domestically produced siloxane elastomer composition with microwave siloxane vulcanization is described as well as the technique for making combined gingival prosthetics of siloxane composition and colorless plastic. PMID:16482030

  11. Methods for producing monodispersed particles of barium titanate

    DOEpatents

    Hu, Zhong-Cheng

    2001-01-01

    The present invention is a low-temperature controlled method for producing high-quality, ultrafine monodispersed nanocrystalline microsphere powders of barium titanate and other pure or composite oxide materials having particles ranging from nanosized to micronsized particles. The method of the subject invention comprises a two-stage process. The first stage produces high quality monodispersed hydrous titania microsphere particles prepared by homogeneous precipitation via dielectric tuning in alcohol-water mixed solutions of inorganic salts. Titanium tetrachloride is used as an inorganic salt precursor material. The second stage converts the pure hydrous titania microsphere particles into crystalline barium titanate microsphere powders via low-temperature, hydrothermal reactions.

  12. Method and apparatus for producing small hollow spheres

    DOEpatents

    Hendricks, Charles D.

    1979-01-01

    Method and apparatus for producing small hollow spheres of glass, metal or plastic, wherein the sphere material is mixed with or contains as part of the composition a blowing agent which decomposes at high temperature (T.gtoreq.600.degree. C.). As the temperature is quickly raised, the blowing agent decomposes and the resulting gas expands from within, thus forming a hollow sphere of controllable thickness. The thus produced hollow spheres (20 to 10.sup.3 .mu.m) have a variety of application, and are particularly useful in the fabrication of targets for laser implosion such as neutron sources, laser fusion physics studies, and laser initiated fusion power plants.

  13. Hydroxyapatite Coatings Produced by Surface-Induced Mineralizaiton

    SciTech Connect

    Campbell, Allison A.; Deatherage, Brooke L.; Li, Xiaohong S.; Nelson, Bradley J.; Bottoni, Craig R.; Dejong, E. Schuyler

    2002-01-03

    The surface-induced mineralization (SIM) process is based on the observation that, in nature, organisms use biopolymers to produce ceramic composites such as teeth, bones, and shells. The SIM process involves modification of a surface to introduce surface functionalization followed by immersion in aqueous supersaturated calcium phosphate solutions. This room temperature process has advantages over conventional methods of calcium phosphate deposition in that uniform coatings are produced onto complex-shaped and/or microporous samples. Additionally, because it is a room temperature process, biological agents can be incorporated.

  14. Bimodal magmatism produced by progressively inhibited crustal assimilation.

    PubMed

    Meade, F C; Troll, V R; Ellam, R M; Freda, C; Font, L; Donaldson, C H; Klonowska, I

    2014-01-01

    The origin of bimodal (mafic-felsic) rock suites is a fundamental question in volcanology. Here we use major and trace elements, high-resolution Sr, Nd and Pb isotope analyses, experimental petrology and thermodynamic modelling to investigate bimodal magmatism at the iconic Carlingford Igneous Centre, Ireland. We show that early microgranites are the result of extensive assimilation of trace element-enriched partial melts of local metasiltstones into mafic parent magmas. Melting experiments reveal the crust is very fusible, but thermodynamic modelling indicates repeated heating events rapidly lower its melt-production capacity. Granite generation ceased once enriched partial melts could no longer form and subsequent magmatism incorporated less fertile restite compositions only, producing mafic intrusions and a pronounced compositional gap. Considering the frequency of bimodal magma suites in the North Atlantic Igneous Province, and the ubiquity of suitable crustal compositions, we propose 'progressively inhibited crustal assimilation' (PICA) as a major cause of bimodality in continental volcanism. PMID:24947142

  15. Bimodal magmatism produced by progressively inhibited crustal assimilation

    NASA Astrophysics Data System (ADS)

    Meade, F. C.; Troll, V. R.; Ellam, R. M.; Freda, C.; Font, L.; Donaldson, C. H.; Klonowska, I.

    2014-06-01

    The origin of bimodal (mafic-felsic) rock suites is a fundamental question in volcanology. Here we use major and trace elements, high-resolution Sr, Nd and Pb isotope analyses, experimental petrology and thermodynamic modelling to investigate bimodal magmatism at the iconic Carlingford Igneous Centre, Ireland. We show that early microgranites are the result of extensive assimilation of trace element-enriched partial melts of local metasiltstones into mafic parent magmas. Melting experiments reveal the crust is very fusible, but thermodynamic modelling indicates repeated heating events rapidly lower its melt-production capacity. Granite generation ceased once enriched partial melts could no longer form and subsequent magmatism incorporated less fertile restite compositions only, producing mafic intrusions and a pronounced compositional gap. Considering the frequency of bimodal magma suites in the North Atlantic Igneous Province, and the ubiquity of suitable crustal compositions, we propose ‘progressively inhibited crustal assimilation’ (PICA) as a major cause of bimodality in continental volcanism.

  16. PROCESS FOR PRODUCING URANIUM HALIDES

    DOEpatents

    Murphree, E.V.

    1957-10-29

    A process amd associated apparatus for producing UF/sub 4/ from U/sub 3/ O/sub 8/ by a fluidized'' technique are reported. The U/sub 3/O/sub 8/ is first reduced to UO/sub 2/ by reaction with hydrogen, and the lower oxide of uranium is then reacted with gaseous HF to produce UF/sub 4/. In each case the reactant gas is used, alone or in combination with inert gases, to fluidize'' the finely divided reactant solid. The complete setup of the plant equipment including bins, reactor and the associated piping and valving, is described. An auxiliary fluorination reactor allows for the direct production of UF/sub 6/ from UF/sub 4/ and fluorine gas, or if desired, UF/sub 4/ may be collected as the product.

  17. PROCESS FOR PRODUCING URANIUM TETRAFLUORIDE

    DOEpatents

    Harvey, B.G.

    1954-09-14

    >This patent relates to improvements in the method for producing uranium tetrafluoride by treating an aqueous solutlon of a uranyl salt at an elevated temperature with a reducing agent effective in acld solutlon in the presence of hydrofluoric acid. Uranium tetrafluoride produced this way frequentiy contains impurities in the raw material serving as the source of uranium. Uranium tetrafluoride much less contaminated with impurities than when prepared by the above method can be prepared from materials containing such impurities by first adding a small proportion of reducing agent so as to cause a small fraction, for example 1 to 5% of the uranium tetrafluoride to be precipitated, rejecting such precipitate, and then precipitating and recovering the remainder of the uranium tetrafluoride.

  18. Process for producing advanced ceramics

    DOEpatents

    Kwong, Kyei-Sing

    1996-01-01

    A process for the synthesis of homogeneous advanced ceramics such as SiC+AlN, SiAlON, SiC+Al.sub.2 O.sub.3, and Si.sub.3 N.sub.4 +AlN from natural clays such as kaolin, halloysite and montmorillonite by an intercalation and heat treatment method. Included are the steps of refining clays, intercalating organic compounds into the layered structure of clays, drying the intercalated mixture, firing the treated atmospheres and grinding the loosely agglomerated structure. Advanced ceramics produced by this procedure have the advantages of homogeneity, cost effectiveness, simplicity of manufacture, ease of grind and a short process time. Advanced ceramics produced by this process can be used for refractory, wear part and structure ceramics.

  19. Method for producing carbon nanotubes

    DOEpatents

    Phillips, Jonathan; Perry, William L.; Chen, Chun-Ku

    2006-02-14

    Method for producing carbon nanotubes. Carbon nanotubes were prepared using a low power, atmospheric pressure, microwave-generated plasma torch system. After generating carbon monoxide microwave plasma, a flow of carbon monoxide was directed first through a bed of metal particles/glass beads and then along the outer surface of a ceramic tube located in the plasma. As a flow of argon was introduced into the plasma through the ceramic tube, ropes of entangled carbon nanotubes, attached to the surface of the tube, were produced. Of these, longer ropes formed on the surface portion of the tube located in the center of the plasma. Transmission electron micrographs of individual nanotubes revealed that many were single-walled.

  20. Does Oenococcus oeni produce histamine?

    PubMed

    Garcia-Moruno, Emilia; Muñoz, Rosario

    2012-07-01

    The presence of histamine in wine and other fermented foods may pose a toxicological risk for consumers. Production of histamine by Oenococcus oeni, which is the main agent of malolactic fermentation in wine and thus very important for the wine industry, has been extensively analyzed with contradictory results. If histamine production by O. oeni strains is a widespread trait, enological practices will be affected and the use of non-producing commercial O. oeni starters should be strongly recommended to avoid histamine production during winemaking. However, a review of published data showed that most evidence strongly supports the view that O. oeni is not responsible for histamine production in wine. We therefore propose the adoption of common analytical methods and the introduction of publicly-available validated histamine-producing O. oeni reference strains as a common positive control in assays to resolve this important issue. PMID:22652194