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Sample records for heat-resistant materials ii

  1. Plasma treatment of heat-resistant materials

    NASA Astrophysics Data System (ADS)

    Vlasov, V. A.; Kosmachev, P. V.; Skripnikova, N. K.; Bezukhov, K. A.

    2015-11-01

    Refractory lining of thermal generating units is exposed to chemical, thermal, and mechanical attacks. The degree of fracture of heat-resistant materials depends on the chemical medium composition, the process temperature and the material porosity. As is known, a shortterm exposure of the surface to low-temperature plasma (LTP) makes possible to create specific coatings that can improve the properties of workpieces. The aim of this work is to produce the protective coating on heat-resistant chamotte products using the LTP technique. Experiments have shown that plasma treatment of chamotte products modifies the surface, and a glass-ceramic coating enriched in mullite is formed providing the improvement of heat resistance. For increasing heat resistance of chamotte refractories, pastes comprising mixtures of Bacor, alumina oxide, and chamot were applied to their surfaces in different ratios. It is proved that the appropriate coating cannot be created if only one of heat-resistant components is used. The required coatings that can be used and recommended for practical applications are obtained only with the introduction of powder chamot. The paste composition of 50% chamot, 25% Bacor, and 25% alumina oxide exposed to plasma treatment, has demonstrated the most uniform surface fusion.

  2. Reaction synthesis of heat-resistant materials

    SciTech Connect

    Deevi, S.C.; Sikka, V.K.

    1995-12-31

    Exothermicity associated with the synthesis of aluminides can be utilized to obtain aluminides of transition metals. Combustion synthesis, extrusion, and hot pressing were utilized to obtain dense intermetallics and their composites. Composites were analyzed by X- ray diffraction and microscopy techniques, and tensile properties were measured on button-head and sheet specimens of intermetallics and their composites. Mechanical properties of intermetallics obtained by reaction synthesis and densification compare well with conventionally processed materials. Reaction-synthesis principles were also extended to weld overlays. Possible approaches to obtaining dense products by reaction synthesis and densification are summarized in a schematic illustration. 19 refs., 14 figs., 3 tabs.

  3. Heat resistant alloys as interconnect materials of reduced temperature SOFCs

    NASA Astrophysics Data System (ADS)

    Jian, Li; Jian, Pu; Guangyuan, Xie; Shunxu, Wang; Jianzhong, Xiao

    Heat-resistant alloys, Haynes 230 and SS310, were exposed to air and humidified H 2 at 750 °C for up to 1000 h, respectively, simulating the environments in reduced temperature solid oxide fuel cells (SOFCs). The oxidized samples were characterized by using SEM, EDS and X-ray diffraction to obtain the morphology, thickness, composition and crystal structure of the oxide scales. A mechanism for the formation of metallic Ni-rich nodules on top of the oxide scale in Haynes 230 sample oxidized in humidified H 2 was established. Thermodynamic analysis confirmed that MnCr 2O 4 is the favored spinel phase, together with Cr 2O 3, in the oxide scales.

  4. The Further Development of Heat-Resistant Materials for Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Bollenrath, Franz

    1946-01-01

    The present report deals with the problems involved in the greater utilization and development of aircraft engine materials, and specifically; piston materials, cylinder heads, exhaust valves, and exhaust gas turbine blading. The blades of the exhaust gas turbine are likely to be the highest stressed components of modern power plants from a thermal-mechanical and chemical standpoint, even though the requirements on exhaust valves of engines with gasoline injection are in general no less stringent. For the fire plate in Diesel engines the specifications for mechanical strength and design are not so stringent, and the question of heat resistance, which under these circumstances is easier obtainable, predominates.

  5. Calculation and experimental study on high-speed impact of heat-resistant coating materials with a meteoric particle

    NASA Astrophysics Data System (ADS)

    Glazunov, Anatoly; Ishchenko, Aleksandr; Afanas'eva, Svetlana; Belov, Nikolai; Burkin, Viktor; Rogaev, Konstantin; Yugov, Nikolai

    2016-01-01

    The given article presents the conducted calculation and experimental study on destruction of heat-resistant coating material of an aircraft in the process of high-speed interaction of the steel spherical projectile. The projectile is imitating a meteoric particle. The study was conducted in the wide range of velocities. The mathematical behavioral model of heat-resistant coating under high-speed impact was developed. The interaction of ameteoric particle with an element of the protective structure has especially individual character and depends on impact velocity and angle, materials of the interacting solids.

  6. Insulation Performance of Heat-Resistant Material for High-Speed Aircraft Under Thermal Environments

    NASA Astrophysics Data System (ADS)

    Wu, Dafang; Wang, Yuewu; Gao, Zhentong; Yang, Jialing

    2015-09-01

    Lightweight insulation materials are widely used to thermally protect high-speed aircraft, such as missiles. Thermal conductivity is an important parameter used to evaluate the efficiency of a material's thermal insulation performance. Since thermal conductivities provided from material handbooks or manufacturers are discrete data for different temperature ranges, there is a deviation between those and actual parameters in terms of continuous nonlinear variations. Therefore, this study measures the thermal conductivities of lightweight thermal insulation materials at high temperatures, and the relationship between the thermal conductivity and temperature is obtained. A finite element model of the thermal insulation materials is also established and applied to numerically calculate the thermal insulation properties for high-temperature ceramic fiber insulation materials using the experimentally obtained nonlinear relationship between thermal conductivity and temperature. Additionally, a transient aerodynamic heating experiment simulation system is used to thermally test the same materials; the calculated and experimental results for the same materials are compared, which exhibit good consistency that demonstrates that accurate results can be obtained from the numerical computation using the relationship established from the experimentally measured conductivity and temperature.

  7. Heat resistant materials and their feasibility issues for a space nuclear transportation system

    SciTech Connect

    Olsen, C.S.

    1991-01-01

    A number of nuclear propulsion concepts based on solid-core nuclear propulsion are being evaluated for a nuclear propulsion transportation system to support the Space Exploration Initiative (SEI) involving the reestablishment of a manned lunar base and the subsequent exploration of Mars. These systems will require high-temperature materials to meet the operating conditions with appropriate reliability and safety built into these systems through the selection and testing of appropriate materials. The application of materials for nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP) systems and the feasibility issues identified for their use will be discussed. Some mechanical property measurements have been obtained, and compatibility tests were conducted to help identify feasibility issues. 3 refs., 1 fig., 4 tabs.

  8. Operating experience with the heat-resistant material 15 NiCuMoNb 5 in conventional power plants

    SciTech Connect

    Adamsky, F.J.; Teichmann, H.; Tolksdorf, E.

    1998-07-01

    The forerunners of the material 15 NiCuMoNb 5 (WB 36), known as CuNi steels for boiler drums, allowed operating pressures to exceed 100 bar for the first time in the 30s, thereby creating the basis for power station to achieve high performance and efficiency levels. Even present day steel developments for the thick walled components used in nuclear technology have almost reached the level of this steel with regard to the high temperature limit of elasticity as a design value up to temperatures of 400 C, but have not exceeded it. In the mid-60s, extensive investigations were carried out into these materials following a few spectacular cases of serious damage, basically manifesting themselves in two ways: as cracks in the area of the downpipe bores and brittle fractures revealed by pressure testing. The cracks were recognized as stress/strain-induced corrosion and this was counteracted internally by improving the quality of the water, particularly with regard to its oxygen content. The inadequate toughness characteristics, responsible for the fractures occurring during the pressure test, were improved by specific alloying measures and in particular by reducing the sulphur content. Particular attention was paid to welding work. Reporting on operating experience means reporting the results of investigations into damage to components made from heat-resistant materials and providing a critical evaluation. A few examples are summarized below for this purpose. Some are current examples and others go back a few years, but are still the subject of discussion in the sector because of the fundamental knowledge to be gained from them.

  9. Effects of alpha-tocopherol addition to polymeric coatings on the UV and heat resistance of a fibrous collagen material--chrome-free leather

    Technology Transfer Automated Retrieval System (TEKTRAN)

    UV and heat resistance are very important qualities of leather because most leather products are constantly exposed to outdoor environments. In recent years, we have focused on using environmentally friendly antioxidants that will improve the UV and heat resistance of chrome-free leather. Tocopher...

  10. Heat resistant protective hand covering

    NASA Technical Reports Server (NTRS)

    Tschirch, R. P.; Sidman, K. R.; Arons, I. J. (Inventor)

    1984-01-01

    A heat-resistant aromatic polyamide fiber is described. The outer surface of the shell is coated with a fire-resistant elastomer and liner. Generally conforming and secured to the shell and disposed inwardly of the shell, the liner is made of a felt fabric of temperature-resistant aromatic polymide fiber.

  11. Heat resistant process gas line

    SciTech Connect

    Venable, C.R. Jr.

    1987-05-12

    A method is described of forming a heat resistant gas transfer line comprising a tubular metal outer shell, a tubular inner liner formed of prefired refractory rings joined together by shiplap joints having expansion gaps, and an intermediate liner comprising bubble alumina concrete filing the annular space between the inner liner and the outer shell. The method comprises placing on the inside lower surface of the outershell bubble alumina concrete forms capable of supporting the refractory rings in the desired location within the outer shell, securing decomposable rings to the refractory rings in the area where the shiplap joints are to be so that a suitable expansion gap will be provided in the shiplap joints when the combustible rings are destroyed.

  12. Heat resistant protective hand covering

    NASA Technical Reports Server (NTRS)

    Sidman, K. R.; Arons, I. J. (Inventor)

    1984-01-01

    The heat resistant, protective glove is made up of first and second shell sections which define a palm side and a backside, respectively. The first shell section is made of a twill wave fabric of a temperature-resistant aromatic polyamide fiber. The second shell section is made of a knitted fabric of a temperature-resistant aromatic polyamide fiber. The first and second shell sections are secured to one another, e.g., by sewing, to provide the desired glove configuration and an opening for insertion of the wearer's hand. The protective glove also includes a first liner section which is secured to and overlies the inner surface of the first shell section and is made of a felt fabric of a temperature-resistant aromatic polyamide fiber and has a flame resistant, elastomenic coating on the surface facing and overlying the inner surface of the first shell section.

  13. Testing Method for Heat Resistance Under Temperature Gradient

    NASA Astrophysics Data System (ADS)

    Takagi, K.; Kawasaki, A.; Itoh, Y.; Harada, Y.; Ono, F.

    2007-12-01

    “Testing Method for Heat Resistance under Temperature Gradient” is a Japanese Industrial Standard (JIS) newly established by the Minister of Economy, Trade and Industry, after deliberations by the Japanese Industrial Standards Committee, in accordance with the Industrial Standardization Law. This standard specified the testing method for heat resistance under temperature gradient of materials and coated members of equipment exposed to high temperature, such as aircraft engines, gas turbines, and so on. This paper introduces the principle and overview of the established standard. In addition, taking the heat cycle test using the burner rig for instance, we specifically illustrate the acquirable data and their analysis in the standard. Monitoring of the effective thermal conductivity and acoustic emission particularly enables to the non-destructive evaluation of failure cycle.

  14. Method for producing heat-resistant semi-inorganic compounds

    NASA Technical Reports Server (NTRS)

    Yajima, S.; Okamura, K.; Shishido, T.; Hasegawa, Y.

    1983-01-01

    The method for producing a heat resistant, semi-inorganic compound is discussed. Five examples in which various alcohols, phenols, and aromatic carbonic acids are used to test heat resistance and solubility are provided.

  15. Evaluation of Heat Checking and Washout of Heat Resistant Superalloys and Coatings for Die inserts

    SciTech Connect

    David Schwam; John F. Wallace; Yulong Zhu; Edward Courtright; Harold Adkins

    2005-01-30

    This project had two main objectives: (1) To design, fabricate and run a full size test for evaluating soldering and washout in die insert materials. This test utilizes the unique capabilities of the 350 Ton Squeeze Casting machine available in the Case Meal Casting Laboratory. Apply the test to evaluate resistance of die materials and coating, including heat resistant alloys to soldering and washout damage. (2) To evaluate materials and coatings, including heat resistant superalloys, for use as inserts in die casting of aluminum alloys.

  16. Heat resistance poly(vinyl alcohol) hydrogel

    NASA Astrophysics Data System (ADS)

    Yoshii, F.; Makuuchi, K.; Darwis, D.; Iriawan, T.; Razzak, M. T.; Rosiak, Janusz M.

    1995-08-01

    Six methods were used to evaluate the heat resistance of poly(vinyl alcohol) (PVA) hydrogel prepared by a combination of electron beam irradiation and acetalization of PVA. The physical properties of the hydrogel depended on the degree of acetilization which was affected by content of water in PVA sheet of acetalization in formaldehyde solution at 60°C. It was found that the optimum water content was 20-30%. The acetalized PVA sheet gave maximum tensile strength in electron beams irradiation at 100 kGy. The tensile strength of the hydrogel film increased to 20 MPa from 14 MPa by the irradiation. Heat resistance of the hydrogel was evaluated by measuring the mechanical properties after sterilization in a steam autoclave at 121°C for 90 min. The tensile strength decreased to 10 MPa whereas the elongation at break increased to 300%. The tackiness of the hydrogel was improved by radiation grafting of acrylic acid. Wholesomeness of the hydrogel as a wound dressing was evaluated by attaching to a burn or wound of the back skin of marmots. Advantages of the hydrogel over a gauze dressing were homogeneous adhesion to the affected parts, easy removal without damage to renewed skin and slightly faster rate of reconstruction of the injured skin.

  17. Spore heat resistance and specific mineralization.

    PubMed Central

    Bender, G R; Marquis, R E

    1985-01-01

    Spores of Bacillus megaterium ATCC 19213, Bacillus subtilis niger and Bacillus stearothermophilus ATCC 7953 were converted to fully demineralized, but viable, H forms by controlled acid titration. H forms were more heat sensitive than were native forms, but z values were greater for killing of H spores than those for native spores. Therefore, the differences in heat sensitivity between native and H forms decreased with increasing killing temperature. The increase in heat sensitivity associated with demineralization did not appear to be due to damage to cortex lytic enzymes of the germination system because it could not be moderated by decoating heated H spores and plating them on medium with added lysozyme. H spores could be remineralized by means of back titration with appropriate base solutions. The remineralized spores, except for the Na form, were then more heat resistant than were H spores. Ca and Mn were more effective in restoring resistance than were Mg and K. Generally, the remineralized forms (except for the Na form) had z values greater than those of the native forms but still less than those of the H forms. At lower killing temperatures, the reinstatement of resistance could be related to the extent of remineralization. However, at higher killing temperatures, only a fraction of the mineral was effective in restoring resistance, and higher levels of remineralization did not result in greater resistance. Mineralization is clearly an important factor in spore heat resistance, but the relationship between resistance and mineralization is complex and dependent on killing temperature. PMID:3937495

  18. Genetic determinants of heat resistance in Escherichia coli

    PubMed Central

    Mercer, Ryan G.; Zheng, Jinshui; Garcia-Hernandez, Rigoberto; Ruan, Lifang; Gänzle, Michael G.; McMullen, Lynn M.

    2015-01-01

    Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR). This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli. PMID:26441869

  19. Frictional and heat resistance characteristics of coconut husk particle filled automotive brake pad

    NASA Astrophysics Data System (ADS)

    Bahari, Shahril Anuar; Chik, Mohd Syahrizul; Kassim, Masitah Abu; Som Said, Che Mohamad; Misnon, Mohd Iqbal; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    The objective of this study was to determine the friction and heat resistance characteristics of automotive brake pad composed with different sizes and percentages of coconut husk particle. The materials used were phenolic resin (phenol formaldehyde) as binder, copper, graphite and brass as friction producer/modifiers, magnesium oxide as abrasive material, steel and barium sulfate as reinforcement while coconut husk particle as filler. To obtain particle, the coconut husk was ground and dried to 3% moisture content. Then the coconut husk particle was screened using 80 mesh (to obtain coarse dust) and 100 mesh (to obtain fine dust). Different percentages of particle, such as 10 and 30% were used in the mixture of brake pad materials. Then the mixture was hot-pressed to produce brake pad. Chase machine was used to determine the friction coefficient in friction resistance testing, while thermogravimetric analyzer (TGA) machine was used to determine the heat decomposition values in heat resistance testing. Results showed that brake pad with 100 mesh and 10% composition of coconut husk particle showed the highest friction coefficient. For heat resistance, brake pad with 100 mesh and 30% composition of coconut husk dust showed the highest decomposition temperature, due to the high percentage of coconut husk particle in the composition, thus increased the thermal stability. As a comparison, brake pad composed with coconut husk particle showed better heat resistance results than commercial brake pad.

  20. Some Properties of Heat-Resistant and Heat-Sensitive Strains of Clostridium perfringens I. Heat Resistance and Toxigenicity1

    PubMed Central

    Weiss, Karl F.; Strong, Dorothy H.

    1967-01-01

    Heat resistance at 100 C (D-values), sporulating ratios, toxigenicity for mice, and lecithinase activity (as micrograms per milliliter of enzyme, ascertained by the lecithovitellin reaction) were determined for four strains of Clostridium perfringens. A definite inverse relationship between thermal resistance and toxigenicity was found. The D-values ranged from 17.6 for the most heat-resistant strain to 0.3 for the strain possessing the least heat resistance, with corresponding lecithinase activities from 25 to 133 μg/ml of enzyme. The sporulating ratios did not differ greatly between the strains. The heat stability of the toxin was greater at 100 C than at 75 C. There was a noticeable difference between the heat stabilities of the toxin in the culture fluids of the heat-sensitive and heat-resistant strains at pH 7.0 when the toxic filtrates were held at 100 C. At a holding temperature of 75 C, a similar but lesser difference was observed at pH 5.5. Heat resistance and lecithinase activity did not change when a substrain of the least heat-resistant parent strain was obtained through heat selection by a single transfer, or when the most heat-resistant strain was transferred serially 12 times. PMID:4289809

  1. BOOK REVIEW: Heterogeneous Materials I and Heterogeneous Materials II

    NASA Astrophysics Data System (ADS)

    Knowles, K. M.

    2004-02-01

    In these two volumes the author provides a comprehensive survey of the various mathematically-based models used in the research literature to predict the mechanical, thermal and electrical properties of hetereogeneous materials, i.e., materials containing two or more phases such as fibre-reinforced polymers, cast iron and porous ceramic kiln furniture. Volume I covers linear properties such as linear dielectric constant, effective electrical conductivity and elastic moduli, while Volume II covers nonlinear properties, fracture and atomistic and multiscale modelling. Where appropriate, particular attention is paid to the use of fractal geometry and percolation theory in describing the structure and properties of these materials. The books are advanced level texts reflecting the research interests of the author which will be of significant interest to research scientists working at the forefront of the areas covered by the books. Others working more generally in the field\

  2. Heat-Resistant Crack-Free Superhydrophobic Polydivinylbenzene Colloidal Films.

    PubMed

    Wang, Zefeng; Ye, Weiwei; Luo, Xinran; Wang, Zhonggang

    2016-03-29

    Highly cross-linked poly(divinylbenzene) (PDVB) spherical colloidal particles with nano-, submicron-, and micron-sizes of 157.2 nm, 602.1 nm, and 5.1 μm were synthesized through emulsion and dispersion polymerization methods. The influences of particle size on the surface morphology, roughness, superhydrophobicity, and critical cracking thickness of colloidal films were studied in detail. The results show that PDVB colloidal films possess large water contact angle (CA) over 151°, belonging to superhydrophobic materials. Moreover, it is interesting to observe that the highly cross-linked network structure leads to PDVB film's excellent heat-resistance. The CA and rough surface morphology remain nearly unchanged after thermal-treatment of films at 150 °C for 24 h. In addition, no cracks were observed in films with thicknesses up to 8.1 μm, exceeding most of polymer and inorganic particle films reported in the literature. The simple and scalable preparation method, low-cost, superhydrophobicity, and excellent thermal stability endow the PDVB colloidal films with promising applications in advanced coating fields, especially when employed in the high-temperature service environment. PMID:26986041

  3. Significant effect of Ca2+ on improving the heat resistance of lactic acid bacteria.

    PubMed

    Huang, Song; Chen, Xiao Dong

    2013-07-01

    The heat resistance of lactic acid bacteria (LAB) has been extensively investigated due to its highly practical significance. Reconstituted skim milk (RSM) has been found to be one of the most effective protectant wall materials for microencapsulating microorganisms during convective drying, such as spray drying. In addition to proteins and carbohydrate, RSM is rich in calcium. It is not clear which component is critical in the RSM protection mechanism. This study investigated the independent effect of calcium. Ca(2+) was added to lactose solution to examine its influence on the heat resistance of Lactobacillus rhamnosus ZY, Lactobacillus casei Zhang, Lactobacillus plantarum P8 and Streptococcus thermophilus ND03. The results showed that certain Ca(2+) concentrations enhanced the heat resistance of the LAB strains to different extents, that is produced higher survival and shorter regrowth lag times of the bacterial cells. In some cases, the improvements were dramatic. More scientifically insightful and more intensive instrumental study of the Ca(2+) behavior around and in the cells should be carried out in the near future. In the meantime, this work may lead to the development of more cost-effective wall materials with Ca(2+) added as a prime factor. PMID:23617813

  4. Bonding Heat-Resistant Fabric to Tile

    NASA Technical Reports Server (NTRS)

    Holt, J. W.; Smiser, L. W.

    1985-01-01

    Acid etching, densification, and silica cement ensure strong bond. Key step in preparation for bonding to glazed tile is etching quartz fabric and tile with acid. This increases adhesion of silica cement used to form bond. Procedures use high-temperature materials exclusively and therefore suitable for securing flexible seals and heat barriers around doors and viewing ports in furnaces and kilns.

  5. Bacterial spore heat resistance correlated with water content, wet density, and protoplast/sporoplast volume ratio.

    PubMed Central

    Beaman, T C; Greenamyre, J T; Corner, T R; Pankratz, H S; Gerhardt, P

    1982-01-01

    Five types of dormant Bacillus spores, between and within species, were selected representing a 600-fold range in moist-heat resistance determined as a D100 value. The wet and dry density and the solids and water content of the entire spore and isolated integument of each type were determined directly from gram masses of material, with correction for interstitial water. The ratio between the volume occupied by the protoplast (the structures bounded by the inner pericytoplasm membrane) and the volume occupied by the sporoplast (the structures bounded by the outer pericortex membrane) was calculated from measurements made on electron micrographs of medially thin-sectioned spores. Among the various spore types, an exponential increase in the heat resistance correlated directly with the wet density and inversely with the water content and with the protoplast/sporoplast volume ratio. Altogether with results supported a hypothesis that the extent of heat resistance is based in whole or in part on the extent of dehydration and diminution of the protoplast in the dormant spore, without implications about physiological mechanisms for attaining this state. Images PMID:6802802

  6. Sporulation, Heat Resistance, and Biological Properties of Clostridium perfringens

    PubMed Central

    Nishida, S.; Seo, N.; Nakagawa, M.

    1969-01-01

    A sporulation medium for 134 Clostridium perfringens strains, including types A, B, C, D, E, and F, was devised according to Grelet's observation that sporulation occurred when cultural environment became limited in any nutritional requirement indispensable for the growth of the organism. Sporulation took place most prominently when 10% cooked-meat broth (pH 7.2) containing 3% Proteose Peptone and 1% glucose was used for the preculture and 2% Poli Peptone medium (pH 7.8) was used for the subculture medium. Sometimes, terminal spores could be observed. A correlation between sporulation and heat resistance was examined by use of C. perfringens strains isolated from samples heated at different temperatures. Almost all strains isolated from unheated samples and from those heated at lower temperatures gave rise to spores in our sporulation medium, but the spores were weakly heat-resistant, whereas strains isolated from samples heated at 100 C for 60 min were highly heat-resistant but sporulated poorly. A majority of these heat-resistant strains were non-gelatinolytic and definitely salicin-fermenting. Images PMID:4304763

  7. Protoplast dehydration correlated with heat resistance of bacterial spores.

    PubMed Central

    Nakashio, S; Gerhardt, P

    1985-01-01

    Water content of the protoplast in situ within the fully hydrated dormant bacterial spore was quantified by use of a spore in which the complex of coat and outer (pericortex) membrane was genetically defective or chemically removed, as evidenced by susceptibility of the cortex to lysozyme and by permeability of the periprotoplast integument to glucose. Water content was determined by equilibrium permeability measurement with 3H-labeled water (confirmed by gravimetric measurement) for the entire spore, with 14C-labeled glucose for the integument outside the inner (pericytoplasm) membrane, and by the difference for the protoplast. The method was applied to lysozyme-sensitive spores of Bacillus stearothermophilus, B. subtilis, B. cereus, B. thuringiensis, and B. megaterium (four types). Comparable lysozyme-resistant spores, in which the outer membrane functioned as the primary permeability barrier to glucose, were employed as controls. Heat resistances were expressed as D100 values. Protoplast water content of the lysozyme-sensitive spore types correlated with heat resistance exponentially in two distinct clusters, with the four B. megaterium types in one alignment, and with the four other species types in another. Protoplast water contents of the B. megaterium spore types were sufficiently low (26 to 29%, based on wet protoplast weight) to account almost entirely for their lesser heat resistance. Corresponding values of the other species types were similar or higher (30 to 55%), indicating that these spores depended on factors additional to protoplast dehydration for their much greater heat resistance. PMID:3988704

  8. Leather Coated with Mixtures of Humectant and Antioxidants to Improve UV and Heat Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ultraviolet (UV) and heat resistance are very important qualities for leather products. We recently developed an environmentally friendly finishing process for improving the UV- and heat resistance of automobile upholstery leather. We previously reported and demonstrated some promising results fro...

  9. Hot deformation of heat-resistant superalloys -- An overview

    SciTech Connect

    Chaudhury, P.K.; Zhao, D.; Thirukkonda, M.; Guillard, S.

    1995-12-31

    The hot deformation behavior was investigated for four heat-resistant Ni-, Fe-, and Co-base superalloys: Haynes 188, 230, 556, and HR-160. Compression tests were conducted over a wide range of processing conditions. The flow behavior and deformed microstructures were characterized, while recrystallized grain size and percentage of recrystallization were measured for deformed specimens under selected conditions. From the experimental data, constitutive equations and microstructure maps were constructed. During the high temperature deformation, a number of mutually interacting metallurgical processes, such as dynamic recrystallization and precipitation, occurred. Their influence on hot formability and deformed microstructure have been represented by deformation microstructure maps that can serve as a guideline for hot deformation process design and subsequent heat treatment after hot forming. The workability and deformation behaviors of the heat-resistant alloys are also compared in The light of alloy development to ensure the fabricability of newly developed alloys.

  10. Production of Heat Resistant Composite based on Siloxane Elastomer and Multiwall Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Bessonov, I. V.; Karelina, N. V.; Kopitsyna, M. N.; Morozov, A. S.; Reznik, S. V.; Skidchenko, V. Yu.

    2016-02-01

    Development of a new generation of composite with unique thermal properties is an important task in the fields of science and technology where material is operated at high temperatures and exposure to a short-wave radiation. Recent studies show that carbon nanomaterials (fullerenes and carbon nanotubes) could improve the thermal, radiation and thermal-oxidative stability of the polymer matrix. In this article the development of a new heat resistant composite based on elastomer and carbon nanotubes (CNT) was performed and physicochemical properties of final product were evaluated.

  11. Development of heat resistant polyphenol compounds applied to the spin-on carbon hardmask

    NASA Astrophysics Data System (ADS)

    Makinoshima, Takashi; Satou, Takashi; Horiuchi, Junya; Okada, Kana; Shimizu, Yoko; Echigo, Masatoshi

    2016-03-01

    In this paper, we report the development of a new polyphenol, NF7177, applied to the Spin-On Carbon Hardmask and the thermosetting properties. The new polyphenol derivatives were easily synthesized by the condensation of aldehydes and dihydroxybiphenyl compounds. We found new polyphenol NF7177 was showed the good applicability to the raw material for the Spin-On Carbon Hardmask [1]. It was indicated that the heat resistance of NF7177 was due to cross-linking based on dehydration reaction. Furthermore the thermosetting properties seem to be depend on the number and position of OH group.

  12. Curriculum Materials in Consumer Education. Volume II.

    ERIC Educational Resources Information Center

    Brown, Marjorie M.; Strom, Sharon M.

    This volume explores the problem of taking an intelligent approach to advertising. Curriculum materials are provided for three conceptual levels of this problem and include objectives, directed activities, suggestions for feedback to students, a list of materials required for teaching each stage, and teacher references. Support materials include…

  13. ECON 12: Student Materials. Units I and II.

    ERIC Educational Resources Information Center

    Wiggins, Suzanne

    These are the student materials for the experimental 12th grade economics course outlined and described in ECON 12: Teacher's Materials (see SO 000 029). The materials for the seven lessons of Unit I, "What is Economics," and the eight lessons of Unit II, "U. S. Price System," include content outlines, worksheets, graphs, some programs, and…

  14. Heat-resistant thermosetting resins and maleimido prepolymers based on a novel tetrakisaminophenoxycyclotriphosphazene

    SciTech Connect

    Kumar, D.; Gupta, A.D.; Khullar, M.

    1993-12-31

    A novel monomer, 2,2,4,4-tetrakis(4`-aminophenoxy)-6,6-diphenylcyclotriphosphazene (IV), useful for producing a variety of heat- and fire-resistant polymers, has been synthesized in good yield. Its synthesis involve Friedel-Frafts reaction of hexachlorocyclotriphosphazene (I) with benzene followed by the reaction of 2,2,4,4-tetrachloro-6,6-diphenylcyclotriphosphazene (II) with potassium 4-nitrophenoxide. The reduction of the obtained 2,2,4,4-tetrakis(4`-nitrophenoxy)-6, 6-diphenylcyclotriphosphazene (III) with molecular hydrogen in presence of PtO{sub 2} gave the tetrakisamine (IV). Heat-resistant thermosetting resins (X) and (XI) were synthesized by the reaction of tetrakisamine (IV) with maleic anhydride followed by insitu cyclodehydration and polymerization of the prepolymers (VIII) and (IX) at 235{+-}5{degrees}C for 1.5 and 290{degrees}C for 0.5 h. The TGA analysis of the developed cyclotriphosphazene containing cyclomatrix resins showed their thermal-stability up to 350{degrees}C and char yield of 71% in nitrogen at 800{degrees}C and 65% in air at 700{degrees}C. The structure of the synthesized monomer and intermediates were characterized by FT-IR, {sup 1}H-NMR, {sup 31}P-NMR, mass spectroscopy, DSC and elemental analysis. These resins are potential candidates for the development of heat-resistant composites, laminates, and adhesives in space, aerospace, and electronic industry.

  15. Selecting Instructional Materials: Part II. Matching Materials to Needs.

    ERIC Educational Resources Information Center

    Talmage, Harriet

    1981-01-01

    Presents a three-phase process for selecting instructional materials: (1) screening materials; (2) matching screened materials to identified district characteristics and needs; and (3) decision-making. Part I of this three-part article appeared in "Curriculum Review," January 1981, pp9-14. (SJL)

  16. RTNS-II fusion materials irradiation facility

    SciTech Connect

    Heikkinen, D.W.; Tuckerman, D.B.; Davis, J.C.; Massoletti, D.J.; Short, D.W.

    1986-01-01

    The Rotating Target Neutron Source (RTNS-II) facility provides an intense source of 14-MeV neutrons for the fusion energy programs of Japan and the United States. Each of the two identical accelerator-based neutron sources is capable of providing source strengths in excess of 3 x 10/sup 13/ n/s using deuteron beam currents up to 150 mA. The present status of the facility, as well as the various upgrade options, will be described in detail.

  17. Instructional Units for Industrial Materials, Vol. II.

    ERIC Educational Resources Information Center

    San Jose State Coll., CA.

    This second volume contains the remainder of the experiments and instructional material developed at the NDEA Institute. Included are seven units on polymers, three units on electronics, three units on graphic arts, 10 units on fuels and lubricants, and one unit on textiles. A list of reviewed films and source availability is appended. Volume I is…

  18. Self-healing of creep damage in heat resisting steels

    NASA Astrophysics Data System (ADS)

    Shinya, Norio; Kyono, Junro

    2002-07-01

    In heat resisting steels, micro holes, called creep cavities, are formed at grain boundaries by long term use at high temperatures. These creep cavities grow along grain boundaries, form grain boundary cracks by linking up each other anc cause low ductility and premature fracture as shown in Fig. 1. Therefore long term creep rupture strength and ductilities chiefly depend upon the behavior of nucleation and growth of creep cavities. If the growth of creep cavities could be suppressed, creep rupture strength and ductilities should be improved remarkably. Present work is intended to propose a self-healing process for the cavitation, and improve the creep rupture properties by the self-healing. It is thought that chemical compound of BN precipitates at inside surface of creep cavity by addition of B and N to heat resisting steels. As the BN is very stable at high temperatures, the precipitation of BN at creep cavity surface is expected to suppress the creep cavity growth and bring about the healing effect on the cavitation.

  19. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods

    NASA Astrophysics Data System (ADS)

    Kou, Xiao-Xi; Li, Rui; Hou, Li-Xia; Huang, Zhi; Ling, Bo; Wang, Shao-Jin

    2016-07-01

    Knowledge of bacteria’s heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria’s heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample’s thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS’s performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria’s thermo-tolerances.

  20. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods

    PubMed Central

    Kou, Xiao-xi; Li, Rui; Hou, Li-xia; Huang, Zhi; Ling, Bo; Wang, Shao-jin

    2016-01-01

    Knowledge of bacteria’s heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria’s heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample’s thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS’s performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria’s thermo-tolerances. PMID:27465120

  1. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods.

    PubMed

    Kou, Xiao-Xi; Li, Rui; Hou, Li-Xia; Huang, Zhi; Ling, Bo; Wang, Shao-Jin

    2016-01-01

    Knowledge of bacteria's heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria's heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample's thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS's performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria's thermo-tolerances. PMID:27465120

  2. Heat-Resistant Co-W Catalytic Metals for Multilayer Graphene Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Ueno, Kazuyoshi; Karasawa, Yusuke; Kuwahara, Satoru; Baba, Shotaro; Hanai, Hitoshi; Yamazaki, Yuichi; Sakuma, Naoshi; Kajita, Akihiro; Sakai, Tadashi

    2013-04-01

    Multilayer graphene (MLG) is expected to be a low-resistance and high-reliability interconnect material replacing copper (Cu) in nanoscale interconnects. Chemical vapor deposition (CVD) on catalytic metals is expected as a practical method for MLG deposition. To obtain high-quality MLG films without catalyst agglomeration by CVD, heat-resistant Co-W catalytic metals were investigated. The agglomeration of the Co-W catalytic metals was suppressed by increasing the W composition; however, MLG deposition was suppressed at the same time. The effects of W addition on the MLG growth were discussed from the viewpoints of the crystallographic change of the Co-W catalysts and chemical reactions. It was found that the Co grain size was reduced and the fcc Co formation was suppressed by W addition. In addition, graphite formation was supposed to be suppressed by W addition owing to the formation of phases other than fcc Co according to the Co-W-C phase diagram. With the optimum W concentration, MLG crystallinity was improved by high-temperature CVD using the heat-resistant Co-W catalytic metals (0.7 at. %) without agglomeration, compared with that in the case of using pure-Co catalysts.

  3. Solubility of Structurally Complicated Materials: II. Bone

    NASA Astrophysics Data System (ADS)

    Horvath, Ari L.

    2006-12-01

    Bone is a structurally complex material, formed of both organic and inorganic chemicals. The organic compounds constitute mostly collagen and other proteins. The inorganic or bone mineral components constitute predominantly calcium, phosphate, carbonate, and a host of minor ingredients. The mineralized bone is composed of crystals which are closely associated with a protein of which collagen is an acidic polysaccharide material. This association is very close and the protein integrates into the crystalline structure. The mineralization involves the deposition of relatively insoluble crystals on an organic framework. The solubility process takes place when the outermost ions in the crystal lattice breakaway from the surface and become separated from the crystal. This is characteristic for ions dissolving in water or aqueous solutions at the specified temperature. The magnitude of solubility is temperature and pH dependent. Bone is sparingly soluble in most solvents. Enamel is less soluble than bone and fluoroapatite is the least soluble of all apatites in acid buffers. Collagen is less soluble in neutral salt solution than in dilute acid solutions at ambient temperatures. The solubility of collagens in solvents gradually decreases with increasing age of the bone samples.

  4. Heat-resistant agglutinin 1 is an accessory enteroaggregative Escherichia coli colonization factor.

    PubMed

    Bhargava, Samhita; Johnson, Brandon B; Hwang, Jennifer; Harris, Tamia A; George, Anu S; Muir, Amanda; Dorff, Justin; Okeke, Iruka N

    2009-08-01

    Enteroaggregative Escherichia coli (EAEC) is an important cause of acute and persistent diarrhea. The defining stacked brick adherence pattern of Peruvian EAEC isolate 042 has previously been attributed to aggregative adherence fimbriae II (AAF/II), which confer aggregative adherence on laboratory E. coli strains. EAEC strains also show exceptional autoaggregation and biofilm formation, other phenotypes that have hitherto been ascribed to AAF/II. We report that EAEC 042 carries the heat-resistant agglutinin (hra1) gene, also known as hek, which encodes an outer membrane protein. Like AAF/II, the cloned EAEC 042 hra1 gene product is sufficient to confer autoaggregation, biofilm formation, and aggregative adherence on nonadherent and nonpathogenic laboratory E. coli strains. However, an 042 hra1 deletion mutant is not deficient in these phenotypes compared to the wild type. EAEC strain 042 produces a classic honeycomb or stacked brick pattern of adherence to epithelial cells. Unlike wild-type 042, the hra1 mutant typically does not form a tidy stacked brick pattern on HEp-2 cells in culture, which is definitive for EAEC. Moreover, the hra1 mutant is significantly impaired in the Caenorhabditis elegans slow kill colonization model. Our data suggest that the exceptional colonization of strain 042 is due to multiple factors and that Hra1 is an accessory EAEC colonization factor. PMID:19482929

  5. Integrated Thermal Protection Systems and Heat Resistant Structures

    NASA Technical Reports Server (NTRS)

    Pichon, Thierry; Lacoste, Marc; Glass, David E.

    2006-01-01

    In the early stages of NASA's Exploration Initiative, Snecma Propulsion Solide was funded under the Exploration Systems Research & Technology program to develop integrated thermal protection systems and heat resistant structures for reentry vehicles. Due to changes within NASA's Exploration Initiative, this task was cancelled early. This presentation provides an overview of the work that was accomplished prior to cancellation. The Snecma team chose an Apollo-type capsule as the reference vehicle for the work. They began with the design of a ceramic aft heatshield (CAS) utilizing C/SiC panels as the capsule heatshield, a C/SiC deployable decelerator and several ablators. They additionally developed a health monitoring system, high temperature structures testing, and the insulation characterization. Though the task was pre-maturely cancelled, a significant quantity of work was accomplished.

  6. Photovoltaic module encapsulation design and materials selection. Volume II

    SciTech Connect

    Cuddihy, E.

    1984-06-01

    This is Volume II of Photovoltaic Module Encapsulation Design and Materials Selection: a periodically updated handbook of encapsulation technology, developed with the support of the Flat-Plate Solar Array Project (FSA), managed for the Department of Energy (DOE) by the Jet Propulsion Laboratory. Volume II describes FSA encapsulation technology developed between June 1, 1982, and January 1, 1984. Emphasis during this period shifted from materials development to demonstration of reliability and durability in an outdoor environment; the updated information in this volume reflects the developing technology base related to both reliability and encapsulation process improvements.

  7. Polymeric Coatings Containing Antioxidants to Improve UV- and Heat Resistance of Chrome-Free Leather

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For automotive upholstery leather, UV and heat resistance are very important qualities, particularly for non-chrome-tanned (chrome-free) leather. One of our research endeavors has focused on an environmentally friendly finishing process that will improve the UV and heat resistance of automobile uph...

  8. Characterizing He II flow through porous materials using counterflow data

    NASA Technical Reports Server (NTRS)

    Maddocks, J. R.; Van Sciver, S. W.

    1991-01-01

    An empirical extension of the two-fluid model is used to characterize He II flow through porous materials. It is shown that four empirical parameters are necessary to describe the pressure and temperature differences induced by He II flow through a porous sample. The three parameters required to determine pressure differences are measured in counterflow and found to compare favorably with those for isothermal flow. The fourth parameter, the Gorter-Mellink constant, differs substantially from smooth tube values. It is concluded that parameter values determined from counterflow can be used to predict pressure and temperature differences in a variety of flows to an accuracy of about +/- 20 percent.

  9. Viability and heat resistance of murine norovirus on bread.

    PubMed

    Takahashi, Michiko; Takahashi, Hajime; Kuda, Takashi; Kimura, Bon

    2016-01-01

    Contaminated bread was the cause of a large-scale outbreak of norovirus disease in Japan in 2014. Contamination of seafood and uncooked food products by norovirus has been reported several times in the past; however the outbreak resulting from the contamination of bread products was unusual. A few reports on the presence of norovirus on bread products are available; however there have been no studies on the viability and heat resistance of norovirus on breads, which were investigated in this study. ce:italic>/ce:italic> strain 1 (MNV-1), a surrogate for human norovirus, was inoculated directly on 3 types of bread, but the infectivity of MNV-1 on bread samples was almost unchanged after 5days at 20°C. MNV-1 was inoculated on white bread that was subsequently heated in a toaster for a maximum of 2min. The results showed that MNV-1 remained viable if the heating period was insufficient to inactivate. In addition, bread dough contaminated with MNV-1 was baked in the oven. Our results indicated that MNV-1 may remain viable on breads if the heating duration or temperature is insufficient. PMID:26485672

  10. Heat Resistance of Salmonella: the Uniqueness of Salmonella senftenberg 775W

    PubMed Central

    Ng, Henry; Bayne, Henry G.; Garibaldi, John A.

    1969-01-01

    Of approximately 300 cultures of Salmonella, representing 75 different serotypes, none was found to be as heat-resistant as S. senftenberg 775W. However, S. blockley 2004 was 5 times more heat-resistant and S. senftenberg 775W was 30 times more heat-resistant than S. typhimurium Tm-1, the reference strain in this study. All other strains of Salmonella tested, including 19 strains of S. senftenberg and 7 strains of S. blockley, had decimal reduction times at 57 C of about 1 min, equivalent to that of the reference organism, Tm-1. As observed in other bacterial species, strain 775W is more heat-sensitive in the log phase than in the stationary phase of growth. Cells from cultures grown at 44 C were more heat-resistant than those grown at either 35 or 15 C; the medium of growth, whether minimal or complex, made no appreciable difference in heat resistance. Cells from cultures limited by a carbon source were killed at a much slower rate than those limited by a nitrogen source and exhibited a 1-hr lag at 55 C before a significant rate of kill was attained. For any given set of growth conditions, strain 775W was always more heat-resistant than another strain of S. senftenberg, 197B, which has normal heat resistance. PMID:5774764

  11. RTNS-II - a fusion materials research tool

    NASA Astrophysics Data System (ADS)

    Logan, C. M.; Heikkinen, D. W.

    1982-09-01

    Rotating Target Neutron Source-II (RTNS-II) is a national facility for fusion materials research. It contains two 14 MeV neutron sources. Deuterons are accelerated to ˜ 400 keV and transported to a rotating titanium tritide target. Present source strength is greater than 1 × 10 13 n/s and source diameter is 1 cm fwhm. An air-levitated vacuum seal permits rotation of the target at 5000 rpm with negligible impact on accelerator vacuum system gas load. Targets are cooled by chilled water flowing through internal channels in a copper alloy substrate. Substrates are produced by solid-state diffusion bonding of two sheets, one containing etched cooling channels. An electroforming process is being developed which will reduce substrate cost and improve reliability. Titanium tritide coating thickness is ˜ 10 μm giving an initial tritium inventory for the present 23 cm diameter targets of 3.7 × 10 7 MBq. Operating interval between target changes is typically about 80 h. Thirteen laboratories and universities have participated in the experimental program at RTNS-II. Most measurements have been directed at understanding defect production and low-dose damage microstructure. The principal diagnostic tools have been cryogenic resistivity measurements, mechanical properties assessment and transmission electron microscopy. Some engineering tests have been conducted in support of near-term magnetic confinement experiments and of reactor materials which will see small lifetime doses.

  12. II-VI Materials-Based High Performance Intersubband Devices

    NASA Astrophysics Data System (ADS)

    Ravikumar, Arvind Pawan

    Mid-infrared (mid-IR) light is of vital technological importance because of its application in trace-gas absorption spectroscopy, imaging, free-space communication or infrared countermeasures. Thus the ability to generate and detect mid-IR light at low cost and preferably, at room temperature is of utmost importance. High performance quantum cascade (QC) lasers - mid-IR light sources based on optical transitions in thin quantum wells, and intersubband infrared detectors - namely the quantum well infrared photodetectors (QWIPs) and quantum cascade detectors (QCDs), have rapidly advanced, due to excellent material quality of III-V materials. In spite of this tremendous success, there lie challenges such as lack of efficient short-wavelength emitters or broadband detectors - challenges that arise from intrinsic materials properties. As a central theme in this thesis, we look at a new class of materials, the II-VI based ZnCdSe/ZnCdMgSe system, to close technological gaps and develop high performance infrared light sources and detectors in the entire mid-IR regime. To that end, we first demonstrate the flexibility that the combination of II-VI materials and band structure engineering allows by developing various QWIPs, QCDs and QC emitters at different wavelengths, not easily achieved by other materials. The performance of these first-of-their-kind detectors is already comparable to existing commercial solutions. To fully realize the potential of this new material system, we also developed a room-temperature broadband infrared detector detecting between 3 and 6 mum with record responsivity. With this technology, it is now possible to monolithically integrate high performance mid-IR lasers and detectors for on-chip applications. One of the challenges with all intersubband detectors is that they do not absorb normally incident light, like most conventional detectors. In order to make intersubband detectors attractive to commercial exploration, we develop a novel method to

  13. Effect of ultrasonic waves on the heat resistance of Bacillus cereus and Bacillus licheniformis spores.

    PubMed

    Burgos, J; Ordóñez, J A; Sala, F

    1972-09-01

    Heat resistance of Bacillus cereus and Bacillus licheniformis spores in quarter-strength Ringer solution decreases markedly after ultrasonic treatments which are unable to kill a significant proportion of the spore population. This effect does not seem to be caused by a loss of Ca(2+) or dipicolinic acid. The use of ultrasonics to eliminate vegetative cells or to break aggregates in Bacillus spore suspensions to be used subsequently in heat resistance experiments appears to be unadvisable. PMID:4627969

  14. A study of the dry heat resistance of naturally occurring organisms widely dispersed on a surface

    NASA Technical Reports Server (NTRS)

    Garst, D. M.; Lindell, K. F.

    1971-01-01

    Although Bacillus subtilis var. niger is the standard test organism for NASA planetary quarantine sterilization studies, it was found that some naturally occurring soil organisms are more heat resistant. The separation of these organisms from soil particles is described. Experiments are discussed which were designed to show that the heat resistance is a natural characteristic of the organisms, rather than a condition induced by the clumping effect of agglomerated particles and organisms.

  15. The effect of creep on magnetic domain structure of heat resistant steels

    NASA Astrophysics Data System (ADS)

    Zhang, S. Z.; Tu, S. T.

    2013-04-01

    The magnetic domain and magnetic properties of heat resistant steels including 10CrMo910, P91 and 23CrMoNiWV88 are investigated in the present work. The magnetic properties characterized by magnetic hysteresis loop of the three materials under 500-600°C are measured by vibrating sample magnetometer (VSM). The magnetic domain structure of as-received and crept specimens is observed by magnetic force microscope (MFM). The magnetic domain of ferrite phase change from initial stripe pattern to maze pattern during creep. The black and white fringes and stripe-like pattern have also been found in the P91 and 23CrMoNiWV88 specimens, respectively. The experimental results reveal that the magnetic domain structure is strongly influenced by microstructures with different distributions of the carbides. It is shown that the coercivity and remanence of each material although has a remarkable decrease at 500-600°C especially for P91 almost 64% decrease, it's still the same magnitude as the one at room temperature. All the short-term crept specimens with different creep damage have a linear increase in coercivity and remanence comparing to the as-received 10CrMo910 specimens. These results indicate that it should be possible to develop an in-situ monitoring technology for creep damage based on magnetism measurement.

  16. Microstructural characterization of dissimilar welds between alloy 800 and HP heat-resistant steel

    SciTech Connect

    Dehmolaei, R.; Shamanian, M. Kermanpur, A.

    2008-10-15

    In this study, dissimilar welds between HP heat-resistant steel and Incoloy 800 were made with four different filler materials including: 309 stainless steel and nickel-based Inconel 82, 182 and 617. The microstructure of the base metals, weld metals and their interfaces were characterized by utilizing optical and scanning electron microscopy. Grain boundaries migration in the weld metals was studied. It was found that the migration of grain boundaries in the Inconel 82 weld metal was very extensive. Precipitates of TiC and M{sub 23}C{sub 6} (M = Cr and Mo) in the Inconel 617 weld metal are identified. The necessary conditions for the formation of cracks close to the fusion line of the 309-HP joints are described. Furthermore unmixed zone near the fusion line between HP steel base metal and Inconel 82 weld metal is discussed. An epitaxial growth is characterized at the fusion line of the 309-Alloy 800 and Inconel 617-Alloy 800 joints.

  17. A View of Compatible Heat-Resistant Alloy and Coating Systems at High-Temperatures

    SciTech Connect

    Narita, Toshio

    2009-09-14

    Conventional and advanced coatings were reviewed, and it was pointed out that the coated Ni-base superalloys decreased their creep rupture life significantly at higher temperatures, and the advanced high strength superalloy became more remarkably. Concept of diffusion barrier coating system (DBC system) and their formation process was introduced, and the results obtained for several heat-resistant alloys, stainless steel (SUS310S), Ni-Mo base alloy (Hastelloy-X), and 4{sup th} generation single crystal superalloy (TMS-138) were given. It was noted that creep-rupture life of the SUS310S and Hastelloy-X with the DBC system became longer than those of the bare alloys with or without conventional {beta}-NiAl coatings. This is due to slow creep-deformation of the Re-base alloy layer as the diffusion barrier. A novel concept based on combination of superalloys and coatings was proposed, by taking both the materials science and corrosion science into consideration.

  18. A View of Compatible Heat-Resistant Alloy and Coating Systems at High-Temperatures

    NASA Astrophysics Data System (ADS)

    Narita, Toshio

    2009-09-01

    Conventional and advanced coatings were reviewed, and it was pointed out that the coated Ni-base superalloys decreased their creep rupture life significantly at higher temperatures, and the advanced high strength superalloy became more remarkably. Concept of diffusion barrier coating system (DBC system) and their formation process was introduced, and the results obtained for several heat-resistant alloys, stainless steel (SUS310S), Ni-Mo base alloy (Hastelloy-X), and 4th generation single crystal superalloy (TMS-138) were given. It was noted that creep-rupture life of the SUS310S and Hastelloy-X with the DBC system became longer than those of the bare alloys with or without conventional β-NiAl coatings. This is due to slow creep-deformation of the Re-base alloy layer as the diffusion barrier. A novel concept based on combination of superalloys and coatings was proposed, by taking both the materials science and corrosion science into consideration.

  19. Heat-resistant protein expression during germination of maize seeds under water stress.

    PubMed

    Abreu, V M; Silva Neta, I C; Von Pinho, E V R; Naves, G M F; Guimarães, R M; Santos, H O; Von Pinho, R G

    2016-01-01

    Low water availability is one of the factors that limit agricultural crop development, and hence the development of genotypes with increased water stress tolerance is a challenge in plant breeding programs. Heat-resistant proteins have been widely studied, and are reported to participate in various developmental processes and to accumulate in response to stress. This study aimed to evaluate heat-resistant protein expression under water stress conditions during the germination of maize seed inbreed lines differing in their water stress tolerance. Maize seed lines 91 and 64 were soaked in 0, -0.3, -0.6, and -0.9 MPa water potential for 0, 6, 12, 18, and 24 h. Line 91 is considered more water stress-tolerant than line 64. The analysis of heat-resistant protein expression was made by gel electrophoresis and spectrophotometry. In general, higher expression of heat-resistant proteins was observed in seeds from line 64 subjected to shorter soaking periods and lower water potentials. However, in the water stress-tolerant line 91, a higher expression was observed in seeds that were subjected to -0.3 and -0.6 MPa water potentials. In the absence of water stress, heat-resistant protein expression was reduced with increasing soaking period. Thus, there was a difference in heat-resistant protein expression among the seed lines differing in water stress tolerance. Increased heat-resistant protein expression was observed in seeds from line 91 when subjected to water stress conditions for longer soaking periods. PMID:27525950

  20. Characterizing He II flow through porous materials using counterflow data

    NASA Technical Reports Server (NTRS)

    Maddocks, J. R., Jr.; Vansciver, Steven W.

    1990-01-01

    Proposed space applications, such as the cooling of infrared and x ray telescopes, have generated substantial interest in the behavior of He II flowing in porous materials. For design purposes, classical porous media correlations and room temperature data are often used to obtain order of magnitude estimates of expected pressure drops, while the attendant temperature differences are either ignored or estimated using smooth tube correlations. A more accurate alternative to this procedure is suggested by an empirical extension of the two fluid model. It is shown that four empirical parameters are necessary to describe the pressure and temperature differences induced by He II flow through a porous sample. The three parameters required to determine pressure differences are measured in counterflow and found to compare favorably with those for isothermal flow. The fourth parameter, the Gorter-Mellink constant, differs substantially from smooth tube values. It is concluded that parameter values determined from counterflow can be used to predict pressure and temperature differences in a variety of flows to an accuracy of about + or - 20 pct.

  1. Structure degradation of 25Cr35Ni heat-resistant tube associated with surface coking and internal carburization

    SciTech Connect

    Wu, X.Q.; Yang, Y.S.; Zhan, Q.; Hu, Z.Q.

    1998-10-01

    Microstructures of 25Cr35Ni heat-resistant cracking tube after service were investigated and degradation mechanism of tube material was discussed. Results reveal that three distinguished zones, that is, internal oxide, carbide free, and internally carburized zones, will gradually develop in the inner wall of a cracking tube during service. Carbide free and internally carburized zones are formed primarily in relation to the periodic spalling and regeneration of surface oxide scale, and diffusion velocity of carbon and carbide forming elements in matrix and the solubility limit of carbon in alloy. The formation and growth of filament coke can aggravate structure degradation of the inner wall of the cracking tube, while deposition of lamellar and spheroidal coke may slow structure degradation to some extent. Surface coking and decoking cycles strongly aggravate the structure degradation of tube material and damage the service life of the cracking tube.

  2. First Results of Saturation Curve Measurements of Heat-Resistant Steel Using GEANT4 and MCNP5 Codes

    NASA Astrophysics Data System (ADS)

    Hoang, Duc-Tam; Tran, Thien-Thanh; Le, Bao-Tran; Tran, Kim-Tuyet; Huynh, Dinh-Chuong; Vo, Hoang-Nguyen; Chau, Van-Tao

    A gamma backscattering technique is applied to calculate the saturation curve and the effective mass attenuation coefficient of material. A NaI(Tl) detector collimated by collimator of large diameter is modeled by Monte Carlo technique using both MCNP5 and GEANT4 codes. The result shows a good agreement in response function of the scattering spectra for the two codes. Based on such spectra, the saturation curve of heat-resistant steel is determined. The results represent a strong confirmation that it is appropriate to use the detector collimator of large diameter to obtain the scattering spectra and this work is also the basis of experimental set-up for determining the thickness of material.

  3. 46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Class II non-vital systems-materials and pressure design. 128.220 Section 128.220 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and...

  4. 46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II non-vital systems—materials and pressure design. (a) Except as provided by §§ 128.230, 128.240, and... 46 Shipping 4 2011-10-01 2011-10-01 false Class II non-vital systems-materials and pressure...

  5. Heat-resistant fungi of importance to the food and beverage industry.

    PubMed

    Tournas, V

    1994-01-01

    Spoilage of pasteurized and canned fruit and fruit products caused by heat-resistant molds have been reported repeatedly in recent years. Species most commonly implicated in fruit and fruit product disintegration are Byssochlamys fulva, Byssochlamys nivea, Neosartorya fischeri, Talaromyces flavus, and Eupenicillium brefeldianum. These organisms are saprophytic rather than parasitic and usually contaminate fruits on or near the ground. They can survive heat treatments used for fruit processing and can grow and spoil the products during storage at room temperature, which results in great economic losses. Mold heat resistance is attributed to the formation of sexual spores, ascospores. Ascospores have a wide range of heat resistance, depending on species, strain, age of organism, heating medium, pH, presence of sugars, fats, and acids in heating medium, growth conditions, etc. The mechanism(s) of thermoresistance are not clear; probably some very stable compound(s) critical to germination and outgrowth are present in the heat-resistant ascospores. Besides spoilage, the heat-resistant molds produce a number of toxic secondary metabolites, such as byssotoxin A; byssochlamic acid; the carcinogen, patulin, the tremorgenic substances, fumitremorgin A and C, and verruculogen; fischerin, which caused fatal peritonitis in mice; and eupenifeldin, a compound possessing cytotoxicity as well as in vivo antitumor activity. Growth of heat-resistant fungi can be controlled by lowering the water activity, adding sulfur dioxide, sorbate, or benzoate; washing of fruits in hypochlorite solution before heat treatment reduces the number of ascospores and makes the heat destruction more successful. More research is needed to elucidate the mechanism(s) of thermoresistance and develop new methods for the complete inactivation of resistant ascospores. PMID:7857517

  6. American Material Culture: Investigating a World War II Trash Dump

    SciTech Connect

    Julie Braun

    2005-10-01

    The Idaho National Laboratory: An Historical Trash Trove Historians and archaeologists love trash, the older the better. Sometimes these researchers find their passion in unexpected places. In this presentation, the treasures found in a large historic dump that lies relatively untouched in the middle of the Idaho National Laboratory (INL) will be described. The U.S. military used the central portion of the INL as one of only six naval proving grounds during World War II. They dumped trash in dry irrigation canals during and after their wartime activities and shortly before the federal government designated this arid and desolate place as the nation’s nuclear reactor testing station in 1949. When read critically and combined with memories and photographs, the 60-year old trash provides a glimpse into 1940s’ culture and the everyday lives of ordinary people who lived and worked during this time on Idaho’s desert. Thanks to priceless stories, hours of research, and the ability to read the language of historic artifacts, the dump was turned from just another trash heap into a treasure trove of 1940s memorabilia. Such studies of American material culture serve to fire our imaginations, enrich our understanding of past practices, and humanize history. Historical archaeology provides opportunities to integrate inanimate objects with animated narrative and, the more recent the artifacts, the more human the stories they can tell.

  7. 46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class II... a corrosion-resistant material and, if ferrous, be hot-dip galvanized or be at least of...

  8. The Use of Mixed Tocopherols to Improve UV and Heat Resistance of Leather

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most leather products are constantly exposed to outdoor environments, therefore UV and heat resistance are very important qualities, particularly for non-chrome-tanned (chrome-free) leather. In recent years, we have addressed this problem and focused on an environmentally friendly finishing process...

  9. Investigation of heat-resistant layered coating of Al-Cr-Ni

    NASA Astrophysics Data System (ADS)

    Shmorgun, V. G.; Trykov, Y. P.; Bogdanov, A. I.; Taube, A. O.

    2016-02-01

    The paper shows the transformation of the structure and phase composition of the layered coating system Al-Cr-Ni, obtained by the heat treatment of multilayered composite H20N80+AD1, welded by explosion, in the time range 1-300 hours. The cyclic heat resistance of the coating at 1150 ° C is studied.

  10. Heat resistance of Alicyclobacillus acidocaldarius in water, various buffers, and orange juice.

    PubMed

    Palop, A; Alvarez, I; Raso, J; Condón, S

    2000-10-01

    The effect of the pH or the composition of the heating medium and of the sporulation temperature on the heat resistance of spores of a thermoacidophilic spore-forming microorganism isolated from a dairy beverage containing orange fruit concentrate was investigated. The species was identified as Alicyclobacillus acidocaldarius. The spores showed the same heat resistance in citrate-phosphate buffers of pH 4 and 7, in distilled water, and in orange juice at any of the temperatures tested (D120 degrees C = 0.1 min and z = 7 degrees C). A raise in 20 degrees C in the sporulation temperature (from 45 to 65 degrees C) increased the heat resistance eightfold (from D110 degrees C = 0.48 min when sporulated at 45 degrees C to 3.9 min when sporulated at 65 degrees C). The z-values remained constant for all sporulation temperatures. The spores of this strain of A. acidocaldarius were very heat resistant and could easily survive any heat treatment currently applied to pasteurize fruit juices. PMID:11041137

  11. Quantifying variety-specific heat resistance and the potential for adaptation to climate change.

    PubMed

    Tack, Jesse; Barkley, Andrew; Rife, Trevor W; Poland, Jesse A; Nalley, Lawton Lanier

    2016-08-01

    The impact of climate change on crop yields has become widely measured; however, the linkages for winter wheat are less studied due to dramatic weather changes during the long growing season that are difficult to model. Recent research suggests significant reductions under warming. A potential adaptation strategy involves the development of heat resistant varieties by breeders, combined with alternative variety selection by producers. However, the impact of heat on specific wheat varieties remains relatively unstudied due to limited data and the complex genetic basis of heat tolerance. Here, we provide a novel econometric approach that combines field-trial data with a genetic cluster mapping to group wheat varieties and estimate a separate extreme heat impact (temperatures over 34 °C) across 24 clusters spanning 197 varieties. We find a wide range of heterogeneous heat resistance and a trade-off between average yield and resistance. Results suggest that recently released varieties are less heat resistant than older varieties, a pattern that also holds for on-farm varieties. Currently released - but not yet adopted - varieties do not offer improved resistance relative to varieties currently grown on farm. Our findings suggest that warming impacts could be significantly reduced through advances in wheat breeding and/or adoption decisions by producers. However, current adaptation-through-adoption potential is limited under a 1 °C warming scenario as increased heat resistance cannot be achieved without a reduction in average yields. PMID:26577840

  12. Heat resistance of Yersinia enterocolitica grown at different temperatures and heated in different media.

    PubMed

    Pagán, R; Mañas, P; Raso, J; Trepat, F J

    1999-03-01

    In the range of 4-20 degrees C, growth temperature did not influence the heat resistance at 54-66 degrees C for Yersinia enterocolitica at pH 7 in citrate phosphate buffer. However, when cells were grown at 37 degrees C. the D62 increased from 0.044 to 0.17 min. This increase was constant at all heating temperatures tested (z = 5.7-5.8). Growth temperature did not influence the proportion of heat-damaged cells after a heat treatment, as measured by their response to a 2% of sodium chloride added to the recovery medium. The sensitivity of heat treated cells to nisin or lysozyme depended on growth temperature: Whereas the number of cells grown at 4 degrees C surviving heat treatment was the same regardless of the presence of 100 IU/ml of nisin or 100 microg/ml of lysozyme in the recovery medium, that of cells grown at 37 degrees C was, in these media, lower. The pH of maximum heat resistance in citrate phosphate buffer was pH 7 for cells grown at 37 degrees C, but pH 5 for those grown at 4 degrees C. In both suspensions the magnitude of the effect of pH on heat resistance was constant at all heating temperatures. For cells grown at 4 degrees C the heat resistance at 54-66 degrees C, in skimmed milk or pH 7 buffer, was the same. For cells grown at 37 degrees C this also applied for heat treatment at 66 degrees C but at 56 degrees C the heat resistance in skimmed milk was higher. PMID:10357274

  13. Recalling Prerequisite Material in a Calculus II Course to Improve Student Success

    ERIC Educational Resources Information Center

    Mokry, Jeanette

    2016-01-01

    This article discusses preparation assignments used in a Calculus II course that cover material from prerequisite courses. Prior to learning new material, students work on problems outside of class involving concepts from algebra, trigonometry, and Calculus I. These problems are directly built upon in order to answer Calculus II questions,…

  14. Integrated Thermal Protection Systems and Heat Resistant Structures

    NASA Technical Reports Server (NTRS)

    Pichon, Thierry; Lacoste, Marc; Barreteau, R.; Glass, David E.

    2006-01-01

    In the early stages of NASA's Exploration Initiative, Snecma Propulsion Solide was funded under the Exploration Systems Research & Technology program to develop a CMC heatshield, a deployable decelerator, and an ablative heat shield for reentry vehicles. Due to changes within NASA's Exploration Initiative, this task was cancelled in early FY06. This paper will give an overview of the work that was accomplished prior to cancellation. The Snecma team consisted of MT Aerospace, Germany, and Materials Research & Design (MR&D), NASA Langley, NASA Dryden, and NASA Ames in the United States. An Apollo-type capsule was chosen as the reference vehicle for the work. NASA Langley generated the trajectory and aerothermal loads. Snecma and MT Aerospace began the design of a ceramic aft heatshield (CAS) utilizing C/SiC panels as the capsule heatshield. MR&D led the design of a C/SiC deployable decelerator, NASA Ames led the characterization of several ablators, NASA Dryden led the development of a heath management system and the high temperature structures testing, and NASA Langley led the insulation characterization. Though the task was pre-maturely cancelled, a significant quantity of work was accomplished.

  15. Cu(II) and Zn(II) adsorption capacity of three different clay liner materials.

    PubMed

    Musso, T B; Parolo, M E; Pettinari, G; Francisca, F M

    2014-12-15

    Sorption of Cu(II) and Zn(II) on three natural clays meeting the international requirements for use as liners was evaluated by means of batch tests. The purpose of this research was to determine the retention capacities of the clays for metal cations commonly present in urban solid waste leachates. The pH and ionic strength conditions were set at values frequently found in real leachates. The changes observed in the XRD patterns and FTIR spectra upon adsorption can be considered an evidence of clay-metal electrostatic interaction. The Langmuir model was found to best describe the sorption processes, offering maximum sorption capacities from 8.16 to 56.89 mg/g for Cu(II) and from 49.59 to 103.83 mg/g for Zn(II). All samples remove more Zn(II) than Cu(II), which may be related to the different geometry of the hydrated Cu(II) cation. The total amount of metal sorption was strongly influenced by the total specific surface area, the presence of carbonates and the smectite content of the clays. In addition to their known quality as physical barriers, the adsorbed amounts obtained indicate the suitability of the tested clays to contribute to the retardation of Cu(II) and Zn(II) transport through clay liners. PMID:25156265

  16. Heat-resistance of Hamigera avellanea and Thermoascus crustaceus isolated from pasteurized acid products.

    PubMed

    Scaramuzza, Nicoletta; Berni, Elettra

    2014-01-01

    Products containing sugar or fruit derivatives are usually subjected to a pasteurization process that can anyway be ineffective to kill ascospores from heat-resistant molds. Although the most occurring and economically relevant heat-resistant species belong to Byssochlamys, Neosartorya, Talaromyces, and Eupenicillium genera, an increasing number of uncommon heat-resistant isolates have been recently detected as spoiling microorganisms in such products. Since Hamigera spp. and Thermoascus spp. were those more frequently isolated at SSICA, heat resistance of Hamigera avellanea and Thermoascus crustaceus strains from pasteurized acid products was studied in apple juice, in blueberry and grape juice and in a buffered glucose solution. Data obtained from thermal death curves and statistical elaboration of raw data showed that D values of H. avellanea may vary between 11.11 and 66.67 min at 87°C, between 4.67 and 13.51 at 90°C, and between 0.43 and 1.52 min at 95°C. Similarly, D values of T. crustaceus may vary between 18.52 and 90.91 min at 90°C, between 2.79 and 19.23 at 93°C, and between 1.11 and 2.53 min at 95°C. For both strains studied, the z-values calculated from the decimal reduction time curves did not prove to be significantly influenced by the heating medium, that being 4.35°C, 5.39°C or 5.27°C for H. avellanea and 4.42°C, 3.69°C or 3.37°C for T. crustaceus, respectively in apple juice, in blueberry and grape juice or in the buffered glucose solution. Considering the pasteurization treatments industrially applied to fruit-based foods, the variation of thermal parameters does not seem to be a possible way to avoid product spoilage by these two species and only good practices applied to reduce the original load of heat-resistant fungi can help producers to prevent losses in contaminated finished products, as usually happens for other heat resistant molds. PMID:24239977

  17. 46 CFR 128.210 - Class II vital systems-materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Class II vital systems-materials. 128.210 Section 128.210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.210 Class II vital systems—materials. Except as provided by §§ 128.230...

  18. MRP II (material requirements planning): one year later.

    PubMed

    Tull, W L; Norman, R L

    1994-08-01

    This article addresses the continued need for the behavior change process that must be managed long after materiel requirements planning (MRP II) implementation. Mason & Hanger, Pantex Plant is the final assembly and dismantlement facility for all United States nuclear weapons. On October 1, 1990, Mason & Hanger implemented a full production cutover to MRP II. One year later, following class A certification, the MRP II implementation team is still actively managing the change process through education and training programs and overall continuous improvement initiatives. Actual behavior change problems are identified together with the proven solutions implemented in a government-owned, contractor-operated facility environment. Performance measurements ranging from senior management planning to shop floor accomplishments and cost variance reports are shown as normal management tools used to identify target improvement areas. PMID:10135462

  19. Enhanced microwave absorbing properties and heat resistance of carbonyl iron by electroless plating Co

    NASA Astrophysics Data System (ADS)

    Wang, Hongyu; Zhu, Dongmei; Zhou, Wancheng; Luo, Fa

    2015-11-01

    Co coated carbonyl iron particles (Co (CI)) are fabricated through electroless plating method, and the electromagnetic microwave absorbing properties are investigated in the frequencies during 8.2-12.4 GHz. The complex permittivity of CI particles after electroless plating Co is higher than that of raw CI particles due to improvment of the polarization process. Furthermore, according to the XRD and TG results, the Co layer can enhance the heat resistance of CI particles. The bandwidth below -10 dB can reach 3.9 GHz for the Co(CI) absorbent. The results indicate that the electroless plating Co not only enhances the absorbing properties but also improves the heat resistance of CI.

  20. Advances in Materials Science for Environmental and Energy Technologies II

    SciTech Connect

    Matyas, Dr Josef; Ohji, Tatsuki; Liu, Xingbo; Paranthaman, Mariappan Parans; Devanathan, Ram; Fox, Kevin; Singh, Mrityunjay; Wong-ng, Winnie

    2013-01-01

    The Materials Science and Technology 2012 Conference and Exhibition (MS&T'12) was held October 7-11, 2012, in Pittsburgh, Pennsylvania. One of the major themes of the conference was Environmental and Energy Issues. Papers from five of the symposia held under that theme are invluded in this volume. These symposia included Materials Issues in Nuclear Waste Management for the 21st Century; Green Technologies for Materials Manufacturing and Processing IV; Energy Storage: Materials, Systems and Applications; Energy Conversion-Photovoltaic, Concentraing Solar Power and Thermoelectric; and Materials Development for Nuclear Applications and Extreme Environments.

  1. Incidence and Diversity of Potentially Highly Heat-Resistant Spores Isolated at Dairy Farms

    PubMed Central

    Scheldeman, Patsy; Pil, Annelies; Herman, Lieve; De Vos, Paul; Heyndrickx, Marc

    2005-01-01

    The presence of highly heat-resistant spores of Bacillus sporothermodurans in ultrahigh-temperature or sterilized consumer milk has emerged as an important item in the dairy industry. Their presence is considered undesirable since they hamper the achievement of commercial sterility requirements. By using a selective 30-min heat treatment at 100°C, 17 Belgian dairy farms were screened to evaluate the presence, sources, and nature of potentially highly heat-resistant spores in raw milk. High numbers of these spores were detected in the filter cloth of the milking equipment and in green crop and fodder samples. About 700 strains were isolated after the selective heating, of which 635 could be screened by fatty acid methyl ester analysis. Representative strains were subjected to amplified ribosomal DNA restriction analysis, 16S rRNA gene sequencing, percent G+C content, and DNA-DNA reassociations for further identification. The strain collection showed a remarkable diversity, with representatives of seven aerobic spore-forming genera. Bacillus licheniformis and Bacillus pallidus were the most predominant species overall. Twenty-three percent of the 603 spore-forming isolates proved to belong to 18 separate novel species. These findings suggest that the selective heating revealed a pool of unknown organisms with a higher heat-resistant character. This study showed that high spore counts can occur at the dairy farm and that feed and milking equipment can act as reservoirs or entry points for potentially highly heat-resistant spores into raw milk. Lowering this spore load by good hygienic measures could probably further reduce the contamination level of raw milk, in this way minimizing the aerobic spore-forming bacteria that could lead to spoilage of milk and dairy products. Assessment and characterization of this particular flora are of great importance to allow the dairy or food industry to adequately deal with newly arising microbiological problems. PMID:15746351

  2. The IBM Mag Card II Typewriter: Self-Instructional Materials.

    ERIC Educational Resources Information Center

    Moyer, Ruth A.

    Designed for use in Trident Technical College's Secretarial Science Instructional Lab, this learning module provides self-instructional lessons and self-tests to teach students to operate the IBM Mag Card II Typewriter. Each module focuses on one or more features of the machine, providing learning objectives, illustrations, detailed explanations…

  3. Simple bond-order-type interatomic potential for an intermixed Fe-Cr-C system of metallic and covalent bondings in heat-resistant ferritic steels

    SciTech Connect

    Kumagai, Tomohisa Nakamura, Kaoru; Yamada, Susumu; Ohnuma, Toshiharu

    2014-12-28

    It is known that M{sub 23}C{sub 6}(M = Cr/Fe) behavior in heat-resistant ferritic steels affects the strength of the material at high temperature. The ability to garner direct information regarding the atomic motion using classical molecular dynamics simulations is useful for investigating the M{sub 23}C{sub 6} behavior in heat-resistant ferritic steels. For such classical molecular dynamics calculations, a suitable interatomic potential is needed. To satisfy this requirement, an empirical bond-order-type interatomic potential for Fe-Cr-C systems was developed because the three main elements to simulate the M{sub 23}C{sub 6} behavior in heat-resistant ferritic steels are Fe, Cr, and C. The angular-dependent term, which applies only in non-metallic systems, was determined based on the similarity between a Finnis-Sinclair-type embedded-atom-method interatomic potential and a Tersoff-type bond-order potential. The potential parameters were determined such that the material properties of Fe-Cr-C systems were reproduced. These properties include the energy and lattice constants of 89 crystal structures; the elastic constants of four realistic precipitates; the bulk moduli of B1, B2, and B3 crystals; the surface energies of B1 and B2 crystals; and the defect-formation energies and atomic configurations of 66 Fe-Cr-C complexes. Most of these material properties were found to be reproduced by our proposed empirical bond-order potentials. The formation energies and lattice constants of randomly mixed Fe-Cr alloys calculated using the interatomic potentials were comparable to those obtained through experiments and first-principles calculations. Furthermore, the energies and structures of interfaces between Cr carbide and α-Fe as predicted through first-principles calculations were well reproduced using these interatomic potentials.

  4. SIGNAL MEDIATORS AT INDUCTION OF HEAT RESISTANCE OF WHEAT PLANTLETS BY SHORT-TERM HEATING.

    PubMed

    Karpets, Yu V; Kolupaev, Yu E; Yastreb, T O

    2015-01-01

    The effects of functional interplay of calcium ions, reactive oxygen species (ROS) and nitric oxide (NO) in the cells of wheat plantlets roots (Triticum aestivum L.) at the induction of their heat resistance by a short-term influence of hyperthermia (heating at the temperature of 42 degrees C during 1 minute) have been investigated. The transitional increase of NO and H2O2 content, invoked by heating, was suppressed by the treatment of plantlets with the antagonists of calcium EGTA (chelator of exocellular calcium), lanthanum chloride (blocker of calcium channels of various types) and neomycin (inhibitor of phosphatidylinositol-dependent phospholipase C). The rise of hydrogen peroxide content, caused by hardening, was partially suppressed by the action of inhibitors of nitrate reductase (sodium wolframate) and NO-synthase (N(G)-nitro-L-arginine methyl ester--L-NAME), and the increasing of nitric oxide content was suppressed by the treatment of plants with the antioxidant ionol and with the scavenger of hydrogen peroxide (dimethylthiourea). These compounds and antagonists of calcium also partially removed the effect of the rise of plantlets' heat resistance, invoked by hardening heating. The conclusion on calcium's role in the activation of enzymatic systems, generating reactive oxygen species and nitric oxide, and on the functional interplay of these signal mediators at the induction of heat resistance of plantlets by hardening heating is made. PMID:27025064

  5. Porphyrin photosensitivity in cell lines expressing a heat-resistant phenotype

    NASA Astrophysics Data System (ADS)

    Gomer, Charles J.; Rucker, Natalie; Wong, Sam

    1990-07-01

    In-vitro sensitivity to porphyrin mediated photodynamic therapy (PDT) has been examined in cell lines resistant to hyperthermia. Parental (HA-i) and heat resistant (3012) Chinese hamster fibroblasts as well as parental (RIF-i) and temperature resistant (TR-4, TR-5 and TR-iO) mouse radiation-induced fibrosarcoma cells were evaluated for thermal and PDT sensitivity. Quantitative survival curves were generated and porphyrin uptake properties were obtained for all cell lines. Significant resistance to hyperthermia (450C for varying exposure periods) was documented for the 3012 and TR cell strains when compared to 'the parent lines. However, normal and heat resistant clones exhibited comparable levels of porphyrin uptake and photosensitivity. Our results indicate that cross resistance between hyperthermia and PDT is not observed and that members of the 70 kD heat shock protein family (which are elevated in the thermal resistant cells and may be associated with the heat resistant phenotype) do not play a significant role in modulating PDT sensitivity. Mechanisms of in-vitro cytotoxicity appear to be different for PDT and hyperthermia even though possible subcellular targets (such as the plasma membrane) and types of damage (protein denaturation) may be similar for the two modalities.

  6. Heat resistance of Listeria monocytogenes in vacuum packaged pasteurized fish fillets.

    PubMed

    Ben Embarek, P K; Huss, H H

    1993-11-01

    The heat resistance of two strains of Listeria monocytogenes in sous-vide cooked fillets of cod and salmon was investigated. Fish sticks of 5 g were inoculated, vacuum-packed and heated at different combinations of time and temperature (58-80 degrees C). Time-temperature combinations allowing survival and time-temperature combinations at which the bacteria were destroyed, were used to determine D- and z-values. D-values were in the range of what has been published for other food products. D60-values were between 1.95 and 4.48 min depending on the strain and the fish. Both strains were one-four-times more heat resistant in salmon than in cod, showing the importance of the heating menstruum. This difference may be due to the higher fat content in salmon as compared to cod. Z-values were calculated to be 5.65 and 6.4 degrees C, respectively, for the two strains. The suitability of methods for heat resistance experiments and the survival of L. monocytogenes in sous-vide cooked fish fillets are discussed. PMID:8268058

  7. Heat Resistant Characteristics of Major Royal Jelly Protein 1 (MRJP1) Oligomer

    PubMed Central

    Moriyama, Takanori; Ito, Aimi; Omote, Sumire; Miura, Yuri; Tsumoto, Hiroki

    2015-01-01

    Soluble royal jelly protein is a candidate factor responsible for mammiferous cell proliferation. Major royal jelly protein 1 (MRJP1), which consists of oligomeric and monomeric forms, is an abundant proliferative protein in royal jelly. We previously reported that MRJP1 oligomer has biochemical heat resistance. Therefore, in the present study, we investigated the effects of several heat treatments (56, 65 and 96°C) on the proliferative activity of MRJP1 oligomer. Heat resistance studies showed that the oligomer molecular forms were slightly maintained until 56℃, but the molecular forms were converted to macromolecular heat-aggregated MRJP1 oligomer at 65℃ and 96℃. But, the growth activity of MRJP1 oligomer treated with 96°C was slightly attenuated when compared to unheated MRJP1 oligomer. On the other hand, the cell proliferation activity was preserved until 96℃ by the cell culture analysis of Jurkat cells. In contrast, those of IEC-6 cells were not preserved even at 56°C. The present observations suggest that the bioactive heat-resistance properties were different by the origin of the cells. The cell proliferation analysis showed that MRJP1 oligomer, but not MRJP2 and MRJP3, significantly increased cell numbers, suggesting that MRJP1 oligomer is the predominant proliferation factor for mammiferous cells. PMID:26020775

  8. 46 CFR 128.210 - Class II vital systems-materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....210 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.210 Class II vital systems—materials... Commanding Officer, Marine Safety Center, if shown to provide a level of safety equivalent to materials...

  9. Dependence of heat resistance of Drosophila on ambient temperature and relationship of this property to mutation process

    SciTech Connect

    Tikhomirova, M.M.; Belyatskaya, O.Ya.

    1986-04-01

    It has been demonstrated that thermosensitvity of the gametes in Drosophila line T correlates with the heat resistance of the flies. This property of the gametes is determined during ontogenesis, depending on the temperature during development and not by genotypic preadaptation as such, i.e., affinity of the females to the heat resistance line T. The ability of females to acquire heat resistance during the adult phase (in the first three days after emergence), i.e., by acclimatization to a temperature different from the temperature during development does not change the response of the gametes to extreme temperature which had developed during ontogenesis under a particular temperature.

  10. Plumbing Specialist II & III, 3-22. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    These military-developed curriculum materials consist of a course description, course chart, plan of instruction, lesson plans, study guides, and workbooks for use in training plumbing specialists II and III. Covered in the course blocks are building waste systems and exterior and interior supply systems. Course block II, on building waste…

  11. TORO II simulations of induction heating in ferromagnetic materials

    SciTech Connect

    Adkins, D.R.; Gartling, D.K.; Kelley, J.B.; Kahle, P.M.

    1997-09-01

    TORO II is a finite element computer program that is used in the simulation of electric and magnetic fields. This code, which was developed at Sandia National Laboratories, has been coupled with a finite element thermal code, COYOTE II, to predict temperature profiles in inductively heated parts. The development of an effective technique to account for the nonlinear behavior of the magnetic permeability in ferromagnetic parts is one of the more difficult aspects of solving induction heating problems. In the TORO II code, nonlinear, spatially varying magnetic permeability is approximated by an effective permeability on an element-by-element basis that effectively provides the same energy deposition that is produced when the true permeability is used. This approximation has been found to give an accurate estimate of the volumetric heating distribution in the part, and predicted temperature distributions have been experimentally verified using a medium carbon steel and a 10kW industrial induction heating unit. Work on the model was funded through a Cooperative Research and Development Agreement (CRADA) between the Department of Energy and General Motors` Delphi Saginaw Steering Systems.

  12. Section II Part D and adoption of foreign materials

    SciTech Connect

    Gold, M.

    1995-12-01

    This paper describes the background, development, and structure of Section 2, Part D, of the ASME Boiler and Pressure Vessel Code. Section 2 deals with materials, and Part D, in particular, contains tables of design values of materials for use in conjunction with the construction sections of the Code: Sections 1, 3, and 8. The arrangement of Section 2, Part D, will be described with particular emphasis on how the allowable stress and design stress intensity tables are organized. Additionally, changes to Section 2, Part D that have been authorized, and are presently being implemented, will be discussed. These include the new policy decision to permit incorporation of materials from organizations other than ASTM and AWS, and particularly from International organizations; the adoption of a new Appendix to Section 2, Part D, addressing metallurgical phenomena that are important to the selection and application of materials in Code construction; and the decision to develop a new Appendix to address dual marking and material substitution.

  13. Changes In Mechanical Properties Of Heat Resisting Alloy For A Satellite Propulsion System After A Nitriding Process

    NASA Astrophysics Data System (ADS)

    Kagawa, Hideshi; Fujii, Go; Kajiwara, Kenichi; Kuroda, Daisuke; Suzuki, Takuya; Yamabe-Mitarai, Yoko; Murakami, Hideyuki; Ono, Yoshinori

    2012-07-01

    Haynes25 (L-605) is a common heat resistant alloy used in mono-propellant structures and screen materials for catalyst beds. The lifetime requirements for thrusters have expanded dramatically after studies conducted in the 1970s on mono-propellant materials used to extend the service life. The material design had long remained unchanged, and the L-605 was still used as thruster material due to its good heritage. However, some important incidents involving degradation were found during the test-unit break-up inspection following the thruster life tests. The Japanese research team focused on the L-605 degradations found on the catalyst bed screen mesh used for mono-propellant thruster and analysed the surface of the wire material and the cross- section of the wire screen mesh used in the life tests. The investigation showed that the degradation was caused by nitriding L-605 component elements. The team suggested that the brittle fracture was attributable to tungsten (W) carbides, which formed primarily in the grain boundaries, and chromium (Cr) nitride, which formed mainly in the parts in contact with the hot firing gas. The team also suggested the installation of a platinum coating on the material surface as a countermeasure L-605 nitric degradation. Inconel 625 is now selected as a mono-propellant structure material due to its marginal raw material characters and cost. The team believes that Inconel 625 does not form W carbides since it contains no tungsten component, but does contain Cr and Fe, which form nitrides easily. Therefore, the team agreed that for the Inconel 625, there was a need to evaluate changes in the microstructure and mechanical properties following exposure to hot nitrogen gases. This paper will describe these changes of Inconel 625.

  14. The effect of lime-dried sewage sludge on the heat-resistance of eco-cement.

    PubMed

    Li, Wen-Quan; Liu, Wei; Cao, Hai-Hua; Xu, Jing-Cheng; Liu, Jia; Li, Guang-Ming; Huang, Juwen

    2016-01-01

    The treatment and disposal of sewage sludge is a growing problem for sewage treatment plants. One method of disposal is to use sewage sludge as partial replacement for raw material in cement manufacture. Although this process has been well researched, little attention has been given to the thermal properties of cement that has had sewage sludge incorporated in the manufacturing process. This study investigated the fire endurance of eco-cement to which lime-dried sludge (LDS) had been added. LDS was added in proportions of 0%, 3%, 6%, 9%, and 12% (by weight) to the raw material. The eco-cement was exposed to 200, 400, or 600 °C for 3 h. The residual strength and the microstructural properties of eco-cement were then studied. Results showed that the eco-cement samples suffered less damage than conventional cement at 600 °C. The microstructural studies showed that LDS incorporation could reduce Ca(OH)(2) content. It was concluded that LDS has the potential to improve the heat resistance of eco-cement products. PMID:27386999

  15. Optimization and characterization of poly(phthalazinone ether ketone) (PPEK) heat-resistant porous fiberous mat by electrospinning

    NASA Astrophysics Data System (ADS)

    Shi, R.; Bin, Y. Z.; Yang, W. X.; Wang, D.; Wang, J. Y.; Jian, X. G.

    2016-08-01

    Poly(phthalazinone ether ketone) (PPEK) is noted for its outstanding heat-resistance property and mechanical strength. A one-step electrospinning method was conducted to produce PPEK micro-nano porous fibrous mat. We gave emphasis study on the spinnability, optimized conditions, fibers' morphology, surface science and fracture mechanism. The uniform electrospun fibrous mat resulted from PPEK/chloroform binary system indicated that PPEK would be a prospective material to be applied in electrospinning. Addition of a small amount of non-solvent (ethanol) turned out to be advantageous to the reduction of fiber diameter and the alleviation of choking during spinning process. Organic salt (benzyltrimethylammonium chloride) was employed to increase the conductivity of solution for the formation of thin fiber. After trials, PPEK/chloroform/ethanol system with salt and PPEK/NMP system were taken as two optimized systems. These two systems showed different pore fraction in N2 adsorption test, and displayed different mechanical behaviors in uniaxial tension test. The fibrous mat from PPEK/chloroform/ethanol system showed a feature of ductile fracture with relatively low fracture strength but long fracture deformation, while the fibrous mat from PPEK/NMP system showed a feature of brittle fracture with small deformation but quite large fracture strength of ca. 6 MPa. Finally thermogravimetric analysis indicated that the resultant PPEK fibrous mat did not decompose until the temperature reached 478 °C, which qualified the resultant fibrous mat as a promising material used under high-temperature condition.

  16. Synthesis and processing of intelligent cost-effective structures phase II (SPICES II): smart materials aircraft applications evaluation

    NASA Astrophysics Data System (ADS)

    Dunne, James P.; Jacobs, Steven W.; Baumann, Erwin W.

    1998-06-01

    The second phase of the synthesis and processing of intelligent cost effective structures (SPICES II) program sought to identify high payoff areas for both naval and aerospace military systems and to evaluate military systems and to evaluate the benefits of smart materials incorporation based on their ability to redefine the mission scenario of the candidate platforms in their respective theaters of operation. The SPICES II consortium, consisting of The Boeing Company, Electric Boat Corporation, United Technologies Research Center, and Pennsylvania State University, surveyed the state-of-the-art in smart structures and evaluated potential applications to military aircraft, marine and propulsion systems components and missions. Eleven baseline platforms comprising a wide variety of missions were chosen for evaluation. Each platform was examined in its field of operation for areas which can be improved using smart materials insertion. Over 250 smart materials applications were proposed to enhance the platforms. The applications were examined and, when possible, quantitatively analyzed for their effect on mission performance. The applications were then ranked for payoff, risk, and time frame for development and demonstration. Details of the efforts made in the SPICES II program pertaining to smart structure applications on military and transport aircraft will be presented. A brief discussion of the core technologies will be followed by presentation of the criteria used in ranking each application. Thereafter, a selection of the higher ranking proposed concepts are presented in detail.

  17. 46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Class II non-vital systems-materials and pressure design. 128.220 Section 128.220 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Materials and Pressure Design § 128.220 Class...

  18. 10 CFR 76.115 - Special nuclear material of moderate strategic significance-Category II.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Special nuclear material of moderate strategic significance-Category II. 76.115 Section 76.115 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safeguards and Security § 76.115 Special nuclear material of...

  19. 10 CFR 76.115 - Special nuclear material of moderate strategic significance-Category II.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Special nuclear material of moderate strategic significance-Category II. 76.115 Section 76.115 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safeguards and Security § 76.115 Special nuclear material of...

  20. Boron and Zirconium from Crucible Refractories in a Complex Heat-Resistant Alloy

    NASA Technical Reports Server (NTRS)

    Decker, R F; Rowe, John P; Freeman, J W

    1958-01-01

    In a laboratory study of the factors involved in the influence of induction vacuum melting on 55ni-20cr-15co-4mo-3ti-3al heat resistant alloy, it was found that the major factor was the type of ceramic used as the crucible. The study concluded that trace amounts of boron or zirconium derived from reaction of the melt with the crucible refactories improved creep-rupture properties at 1,600 degrees F. Boron was most effective and, in addition, markedly improved hot-workability.

  1. Structural and mechanical properties of heat-resistant granular nickel alloys

    SciTech Connect

    Eremenko, V.I.; Anoshkin, N.F.; Fatkullin, O.Kh.

    1992-05-01

    In order to realize the advantage afforded by granular metallurgy, it is necessary to know the laws of structure formation at every stage of the fabrication of semifinished products for heat-resistant nickel alloys. In this regard the structural features connected with the manufacture of granules by rapid cooling of a melt should be taken into account, as well as those related to the specific technological processes used in reworking (hot isostatic pressing - HIP) and heat treatment. 3 refs., 7 figs., 2 tabs.

  2. Effect of pH on Thermoanaerobacterium thermosaccharolyticum DSM 571 growth, spore heat resistance and recovery.

    PubMed

    Mtimet, Narjes; Guégan, Stéphanie; Durand, Lucile; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier

    2016-05-01

    Thermophilic spore-forming bacteria are potential contaminants in several industrial sectors involving high temperatures (40-65 °C) in the manufacturing process. Among those thermophilic spore-forming bacteria, Thermoanaerobacterium thermosaccharolyticum, called "the swelling canned food spoiler", has generated interest over the last decade in the food sector. The aim of this study was to investigate and to model pH effect on growth, heat resistance and recovery abilities after a heat-treatment of T. thermosaccharolyticum DSM 571. Growth and sporulation were conducted on reinforced clostridium media and liver broth respectively. The highest spore heat resistances and the greatest recovery ability after a heat-treatment were obtained at pH condition allowing maximal growth rate. Growth and sporulation boundaries were estimated, then models using growth limits as main parameters were extended to describe and quantify the effect of pH on recovery of injured spores after a heat-treatment. So, cardinal values were used as a single set of parameters to describe growth, sporulation and recovery abilities. Besides, this work suggests that T. thermosaccharolyticum preserve its ability for germination and outgrowth after a heat-treatment at a low pH where other high resistant spore-forming bacteria like Geobacillus stearothermophilus are unable to grow. PMID:26742617

  3. Heat-resistant organic molecular layer as a joint interface for metal reduction on plastics surfaces

    NASA Astrophysics Data System (ADS)

    Sang, Jing; Aisawa, Sumio; Hirahara, Hidetoshi; Kudo, Takahiro; Mori, Kunio

    2016-04-01

    Heat-resistant organic molecular layers have been fabricated by triazine-based silane coupling agent for metal reduction on plastic surfaces using adsorption method. These molecular layers were used as an interfacial layer between polyamide (PA6) and metal solution to reduce Ag+ ion to Ag0. The interfacial behaviors of triazine molecular layer at the interfaces between PA6 and Ag solution were investigated using quartz crystal microbalance (QCM). The kinetics of molecular adsorption on PA6 was investigated by using triazine-based silane coupling agent solutions at different pH and concentration. X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and local nano thermal analysis were employed to characterize the surfaces and interfaces. The nano thermal analysis results show that molecular layers of triazine-based silane coupling agent greatly improved heat resistance of PA6 resin from 170 °C up to 230 °C. This research developed an in-depth insight for molecular behaviors of triazine-based silane coupling agent at the PA6 and Ag solution interfaces and should be of significant value for interfacial research between plastics and metal solution in plating industry.

  4. Control of Byssochlamys and Related Heat-resistant Fungi in Grape Products

    PubMed Central

    King, A. Douglas; Michener, H. David; Ito, Keith A.

    1969-01-01

    Heat-resistant strains of Byssochlamys fulva, B. nivea, and other heat-resistant fungi were isolated from vineyard soil, grapes, grape-processing lines, and waste pomace. They are known to remain in grape juice occasionally and to grow in grape juice products. Ascospores of these fungi have a D value (decimal reduction time) of about 10 min at 190 F (88 C), but in the presence of 90 μliters of SO2 per liter (normally added to the juice) the D value was cut in half. Filtration through a commercial diatomaceous filter aid (also a common processing step) entrapped all but about 0.001% of experimentally added spores. Thus, heat in the presence of SO2 and filtration together can reduce the population of these spores by several orders of magnitude. Growth was also prevented by benzoate or sorbate in low concentrations. Oxygen must be reduced to extremely low levels before lack of oxygen limits growth. Images PMID:16349856

  5. Developmental acclimation to low or high humidity conditions affect starvation and heat resistance of Drosophila melanogaster.

    PubMed

    Parkash, Ravi; Ranga, Poonam; Aggarwal, Dau Dayal

    2014-09-01

    Several Drosophila species originating from tropical humid localities are more resistant to starvation and heat stress than populations from high latitudes but mechanistic bases of such physiological changes are largely unknown. In order to test whether humidity levels affect starvation and heat resistance, we investigated developmental acclimation effects of low to high humidity conditions on the storage and utilization of energy resources, body mass, starvation survival, heat knockdown and heat survival of D. melanogaster. Isofemale lines reared under higher humidity (85% RH) stored significantly higher level of lipids and showed greater starvation survival hours but smaller in body size. In contrast, lines reared at low humidity evidenced reduced levels of body lipids and starvation resistance. Starvation resistance and lipid storage level were higher in females than males. However, the rate of utilization of lipids under starvation stress was lower for lines reared under higher humidity. Adult flies of lines reared at 65% RH and acclimated under high or low humidity condition for 200 hours also showed changes in resistance to starvation and heat but such effects were significantly lower as compared with developmental acclimation. Isofemale lines reared under higher humidity showed greater heat knockdown time and heat-shock survival. These laboratory observations on developmental and adult acclimation effects of low versus high humidity conditions have helped in explaining seasonal changes in resistance to starvation and heat of the wild-caught flies of D. melanogaster. Thus, we may suggest that wet versus drier conditions significantly affect starvation and heat resistance of D. melanogaster. PMID:24845200

  6. Effect of heating rate on highly heat-resistant spore-forming microorganisms.

    PubMed

    Gómez-Jódar, Isabel; Ros-Chumillas, María; Palop, Alfredo

    2016-03-01

    Highly heat-resistant spore-forming Bacillus cause nonsterility problems in canned food and reduce the shelf life of many processed foods. The aim of this research was to evaluate the thermal inactivation of Bacillus sporothermodurans IIC65, Bacillus subtilis IC9, and Geobacillus stearothermophilus T26 under isothermal and nonisothermal conditions. The data obtained showed that B. sporothermodurans and B. subtilis were more heat resistant than G. stearothermophilus. The survival curves of B. sporothermodurans and B. subtilis showed shoulders, while the survival curves of G. stearothermophilus showed tails. Under nonisothermal treatment, at heating rates of 1 and 20 ℃/min, time needed to completely inactivate G. stearothermophilus was shorter than that required for B. sporothermodurans and B. subtilis. In complex heat treatments (heating-holding-cooling), the survival curves of B. sporothermodurans and B. subtilis showed the same activation shoulders than those obtained under isothermal treatments and the activation shoulders were again absent in the case of G. stearothermophilus. Predictions fitted quite well the data obtained for B. sporothermodurans. In contrast, the data for B. subtilis showed half a log cycle more survival than expected and in the case of G. stearothermophilus, the survival curve obtained showed much higher inactivation than expected. PMID:25852134

  7. Mode II Interlaminar Fracture Toughness and Fatigue Characterization of a Graphite Epoxy Composite Material

    NASA Technical Reports Server (NTRS)

    O'Brien, T. Kevin; Johnston, William M.; Toland, Gregory J.

    2010-01-01

    Mode II interlaminar fracture toughness and delamination onset and growth characterization data were generated for IM7/8552 graphite epoxy composite materials from two suppliers for use in fracture mechanics analyses. Both the fracture toughness testing and the fatigue testing were conducted using the End-notched Flexure (ENF) test. The ENF test for mode II fracture toughness is currently under review by ASTM as a potential standard test method. This current draft ASTM protocol was used as a guide to conduct the tests on the IM7/8552 material. This report summarizes the test approach, methods, procedures and results of this characterization effort.

  8. Selection and Evaluation of Heat-Resistant Alloys for Planar SOFC Interconnect Applications

    SciTech Connect

    Yang, Z Gary; Weil, K. Scott; Paxton, Dean M.; Stevenson, Jeffry W.

    2002-11-21

    Over the past several years, the steady reduction in SOFC operating temperatures to the intermediate range of 700~850oC [1] has made it feasible for lanthanum chromite to be supplanted by metals or alloys as the interconnect materials. Compared to doped lanthanum chromite, metals or alloys offer significantly lower raw material and fabrication costs. However, to be a durable and reliable, a metal or alloy has to satisfy several functional requirements specific to the interconnect under SOFC operating conditions. Specifically, the interconnect metal or alloy should possess the following properties: (i) Good surface stability (resistance to oxidation, hot corrosion, and carburization) in both cathodic (air) and anodic (fuel) atmospheres; (ii) Thermal expansion matching to the ceramic PEN (positive cathode-electrolyte-negative anode) and seal materials (as least for a rigid seal design); (iii) High electrical conductivity through both the bulk material and in-situ formed oxide scales; (iv) Bulk and interfacial thermal mechanical reliability and durability at the operating temperature; (v) Compatibility with other materials in contact with interconnects such as seals and electrical contact materials.

  9. Combined Effect of Co and W on Deformation Resistance of 12Cr Heat-Resistant Steel for USC Steam Turbines

    NASA Astrophysics Data System (ADS)

    Cui, Huiran; Sun, Feng; Chen, Ke; Wu, Jiansheng

    2011-12-01

    12Cr heat-resistant steels with different concentrations of Co and W, with Mo equivalent (Mo + 1/2W) fixed at 1.6 wt.%, were prepared by arc-melting and hot rolling processes. Mechanical properties were evaluated by tensile tests conducted at a low strain rate 2 × 10-5 s-1 at 575, 600, and 625 °C. Microstructure of the steels was investigated via optical microscopy (OM) and electron transmission microscopy (TEM). The results show that when the content of W is fixed, the steel with 3.1 wt.% Co and the steel with 3.8 wt.% Co are found to obtain the best deformation resistance values at 575, 600, and at 625 °C; when the Co content is fixed, the steel with 1.5 wt.% W shows better performance. The highest ultimate tensile strength (UTS) and yield stress (YS) were achieved for the steel when its W content is at 1.5 wt.% and Co content is at 3.1 wt.% or 3.8 wt.%. Deformation resistance is related to the initial dislocation density in the steels, which increases with increasing Co content and decreases with increasing W content. It is verified that the deformation mechanism of the tested steels during high-temperature tensile tests at a low strain rate is that of the recovery-controlled dislocation creep. Furthermore, the thermodynamic calculation result is in agreement with the experimental result, demonstrating that 0.85Mo-1.5W-3.8Co steel has the best deformation resistance at 625 °C. Therefore, 0.85Mo-1.5W-3.1Co steel is recommended as a potential candidate material for 600 °C class steam turbines, and 0.85Mo-1.5W-3.8Co steel is also a potential material for 625 °C class Ultra supercritical (USC) steam turbines.

  10. Teaching General and Systemic Pathology in a New Veterinary School. II. Materials and Costs

    ERIC Educational Resources Information Center

    Crowell, W. A.; And Others

    1976-01-01

    The amounts, types and costs of materials used to initiate a Year II (sophomore) pathology course in the L.S.U. School of Veterinary Medicine were tabulated. Use of the autotutorial method resulted in slightly greater costs than the traditional method, but this was offset by general satisfaction with it. (Author/LBH)

  11. 10 CFR 76.115 - Special nuclear material of moderate strategic significance-Category II.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Special nuclear material of moderate strategic significance-Category II. 76.115 Section 76.115 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION... designated by the U.S. Department of Energy (DOE) as Unclassified Controlled Nuclear Information must...

  12. 10 CFR 76.115 - Special nuclear material of moderate strategic significance-Category II.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Special nuclear material of moderate strategic significance-Category II. 76.115 Section 76.115 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION... designated by the U.S. Department of Energy (DOE) as Unclassified Controlled Nuclear Information must...

  13. Strand II: Sociological Health Problems. Prototype Curriculum Materials for the Elementary and Secondary Grades.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    These publications contain three of the topics for Strand II, Sociological Health Problems, which have been prepared as part of the kindergarten through twelve health syllabus revision project. The material included is intended for use in grades four through twelve. The topics covered are alcohol education, drugs and narcotics, and smoking. The…

  14. 10 CFR 76.115 - Special nuclear material of moderate strategic significance-Category II.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Special nuclear material of moderate strategic significance-Category II. 76.115 Section 76.115 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION... designated by the U.S. Department of Energy (DOE) as Unclassified Controlled Nuclear Information must...

  15. Liposome technology. Volume II: Incorporation of drugs, proteins and genetic material

    SciTech Connect

    Gregoriadis, G.

    1984-01-01

    These three volumes cover liposome technology in pharmacology and medicine. Contributors emphasize methodology used in their own laboratories, and include a brief introduction, coverage of relevant literature, applications and critical evaluations for the methods they describe. Volume II presents procedures for the entrapment of a number of drugs, including genetic material, into selected types of liposomes.

  16. Fire- and heat-resistant laminating resins based on maleimido-substituted aromatic cyclotriphosphazenes

    NASA Technical Reports Server (NTRS)

    Kumar, D.; Fohlen, G. M.; Parker, J. A.

    1983-01-01

    A novel class of flame- and heat-resistant polymers has been synthesized by the thermal polymerization of maleimido-substituted aromatic cyclotriphosphazenes. The polymer obtained from tris-(aminophenoxy)tris(maleimidophenoxy)cyclotriphosphazene has good thermal stability and is noteworthy for its high char yield, viz., 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates prepared with this polymer did not burn in pure oxygen, even at 300 C, and were tested for mechanical properties. Hexakis(4-maleimidophenoxy)cyclotriphosphazene and some fluorine-containing monomers have also been synthesized. The structures of these cyclic phosphazene precursors and polymers were characterized by FT IR spectrophotometry, H-1 NMR, F-19 NMR, and P-31 solid-state magic angle spinning NMR spectroscopy, and mass spectrometry. The curing behavior of the polymer precursors and the thermal stabilities of the polymers were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA).

  17. Scorpion Venom Heat-Resistant Peptide Protects Transgenic Caenorhabditis elegans from β-Amyloid Toxicity

    PubMed Central

    Zhang, Xiao-Gang; Wang, Xi; Zhou, Ting-Ting; Wu, Xue-Fei; Peng, Yan; Zhang, Wan-Qin; Li, Shao; Zhao, Jie

    2016-01-01

    Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Our previous studies found SVHRP could enhance neurogenesis and inhibit microglia-mediated neuroinflammation in vivo. Here, we use the transgenic CL4176, CL2006, and CL2355 strains of Caenorhabditis elegans which express the human Aβ1-42 to investigate the effects and the possible mechanisms of SVHRP mediated protection against Aβ toxicity in vivo. The results showed that SVHRP-fed worms displayed remarkably decreased paralysis, less abundant toxic Aβ oligomers, reduced Aβ plaque deposition with respect to untreated animals. SVHRP also suppressed neuronal Aβ expression-induced defects in chemotaxis behavior and attenuated levels of ROS in the transgenic C. elegans. Taken together, these results suggest SVHRP could protect against Aβ-induced toxicity in C. elegans. Further studies need to be conducted in murine models and humans to analyze the effectiveness of the peptide. PMID:27507947

  18. Dry-heat resistance of selected psychrophiles. [Viking lander in spacecraft sterilization

    NASA Technical Reports Server (NTRS)

    Winans, L.; Pflug, I. J.; Foster, T. L.

    1977-01-01

    The dry-heat resistance characteristics of spores of psychrophilic organisms isolated from soil samples from the Viking spacecraft assembly areas at Cape Kennedy Space Flight Center, Cape Canaveral, Fla., were studied. Spore suspensions were produced, and dry-heat D values were determined for the microorganisms that demonstrated growth or survival under a simulated Martian environment. The dry-heat tests were carried out by using the planchet-boat-hot plate system at 110 and 125 C with an ambient relative humidity of 50% at 22 C. The spores evaluated had a relatively low resistance to dry heat. D (110 C) values ranged from 7.5 to 122 min, whereas the D (125 C) values ranged from less than 1.0 to 9.8 min.

  19. Thermal, epithermal and thermalized neutron attenuation properties of ilmenite-serpentine heat resistant concrete shield

    NASA Astrophysics Data System (ADS)

    Kany, A. M. I.; El-Gohary, M. I.; Kamal, S. M.

    1994-07-01

    Experimental measurements were carried out to study the attenuation properties of low-energy neutrons transmitted through unheated and preheated barries of heavy-weight, highly hydrated and heat-resistant concrete shields. The concrete shields under investigation have been prepared from naturally occurring ilmenite and serpentine Egyptian ores. A collimated beam obtained from an Am-Be source was used as a source of neutrons, while the measurements of total thermal, epithermal, and thermalized neutron fluxes were performed using a BF-3 detector, multichannel analyzer and Cd filter. Results show that the ilmenite-serpentine concrete proved to be a better thermal, epithermal and thermalized neutron attenuator than the ordinary concrete especially at a high temperature of concrete exposure.

  20. Multiplexed Optical Transmission System For Automobiles Using Polymer Fiber With High Heat Resistance

    NASA Astrophysics Data System (ADS)

    Sasayama, Takao; Asano, Hideki; Taketani, Noriaki

    1989-02-01

    A multiplexed optical transmission system for automobiles utilizing newly developed polymer fiber has been proposed. The system is composed with a star-shaped optical network, in which the ootical signals can be transmitted bi-directionally through polymer optical fiber and optical branches with the central and local controllers. The polymer fiber has been developed for this purpose in order to overcome the conventional problems which prevented its wide use for a long time. The new polymer fiber is fabricated with a thereto-setting resin for core which is pushed out from heating furnace after the process of polymerization. The fiber shows the desirable characteristics for this application, that is, the heat resistance is as high as 200°C, and the transmission loss is as low as 0.5003/m at 660 nm wavelength.

  1. Effects of Animal Alimentary Passage on the Heat Resistance of Clostridium perfringens1

    PubMed Central

    Canada, James C.; Strong, Dorothy H.

    1965-01-01

    The resistance to heat, as measured by D values and phantom thermal death time curves, was observed to increase for one of three strains of Clostridium perfringens type A subsequent to animal passage. Animal passage was accomplished by the force-feeding of germ-free mice with bacterial suspensions of the organism, followed by the force-feeding of additional gnotobiotic mice with the contaminated feces. For the one strain in which an increase in heat resistance was noted, the result could not be attributed to mouse feces per se, since the presence of sterile germ-free mouse feces in a suspending medium did not protect C. perfringens spores from elevated temperature destruction. PMID:4286397

  2. Improved Temperature-Gradient Incubator and the Maximal Growth Temperature and Heat Resistance of Salmonella

    PubMed Central

    Elliott, R. Paul; Heiniger, Patricia K.

    1965-01-01

    An improved all-metal temperature-gradient incubator produces its gradient by means of a bar permanently installed in a near-vertical position with its lower end in a cool constant-temperature water bath and with thermostatically controlled heaters near its top. Bolts hold the incubator in contact with the temperature-gradient bar, and polyurethane foam insulates the entire assemblage during use. Maximal growth temperatures of 34 representative strains of Salmonella were found to be between 43.2 and 46.2 C. In an agar medium with an initial level of 106 cells per milliliter, no strain survived 50 C for 48 hr. S. senftenberg 775W showed no greater heat resistance at or near 48 C than did other species or other S. senftenberg strains. However, it was considerably more resistant than other strains at 55 C. Images Fig. 2 PMID:14264850

  3. Scorpion Venom Heat-Resistant Peptide Protects Transgenic Caenorhabditis elegans from β-Amyloid Toxicity.

    PubMed

    Zhang, Xiao-Gang; Wang, Xi; Zhou, Ting-Ting; Wu, Xue-Fei; Peng, Yan; Zhang, Wan-Qin; Li, Shao; Zhao, Jie

    2016-01-01

    Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Our previous studies found SVHRP could enhance neurogenesis and inhibit microglia-mediated neuroinflammation in vivo. Here, we use the transgenic CL4176, CL2006, and CL2355 strains of Caenorhabditis elegans which express the human Aβ1-42 to investigate the effects and the possible mechanisms of SVHRP mediated protection against Aβ toxicity in vivo. The results showed that SVHRP-fed worms displayed remarkably decreased paralysis, less abundant toxic Aβ oligomers, reduced Aβ plaque deposition with respect to untreated animals. SVHRP also suppressed neuronal Aβ expression-induced defects in chemotaxis behavior and attenuated levels of ROS in the transgenic C. elegans. Taken together, these results suggest SVHRP could protect against Aβ-induced toxicity in C. elegans. Further studies need to be conducted in murine models and humans to analyze the effectiveness of the peptide. PMID:27507947

  4. Experience of application of a heat-resistant coating to protect billets in heating for metal forming

    NASA Astrophysics Data System (ADS)

    Radyuk, A. G.; Titlyanov, A. E.; Glukhov, L. M.

    2015-12-01

    The purpose of the work is to search for heat-resistant coatings for titanium and steel billets upon heating for metal forming. A water-based heat-resistant coating, which has an operating temperature of 1200°C and a binder consisting of an acrylic emulsion with additions of colloidal graphite, bentonite, and an aluminum powder, is studied. This coating favors a decrease in the thickness of the defective surface layer that forms when titanium and steel billets are heated for metal forming.

  5. Heat resistance of dermatophyte's conidiospores from athletes kits stored in Nigerian University Sport's Center.

    PubMed

    Essien, J P; Jonah, I; Umoh, A A; Eduok, S I; Akpan, E J; Umoiyoho, A

    2009-03-01

    The incidence and heat resistance of conidiospores produced by dermatophytes isolated from athlete's kits (canvasses, stockings and spike shoes) stored in Nigerian University Sport's Centre were investigated. Epidermophyton floccosum, Microsporum oudouinii, Microsporum canis, Trichophyton concentricum, Trichophyton mentagrophytes and Trichophyton rubrum were isolated and their incidence on the athlete's kits varied with the species and type of kits. Among the isolates T. mentagrophytes, T. rubrum and E. floccosum with 25%, 23% and 20% prevalence rates respectively, were the most common isolates, and are often associated with tinea pedis (athletes foot). Canvasses with the highest incidence of dermatophytes (25 out of 34 fungal isolates) were the most contaminated kits and could serve as effective articles for the transmission of tinea pedis among athletes in Nigeria. The common etiological agents screened, produced asexual spores (conidiospores) that exhibited high resistance to heat treatment at 80 degrees C. Of the three isolates, E. floccosum, with a decimal reduction time (D-value) of D80 = 4.4 min was the most resistant followed by T. mentagrophytes with D80 = 4.0 min and then T. rubrum with D80 = 3.2 min. The spores elimination pattern indicates that increasing the heating duration would decrease the decimal reduction time and possibly denature the fungal propagules but may damage the skin during treatment with hot water compresses. The findings have shown that the use of hot water compresses is palliative but heat treatment especially vapour-heat treatment offers adequate preventive measures if applied for periodic treatment of contaminated kits. However, determining the correct condition for effective decontamination will require detailed understanding of the heat resistance of fungal spores. Otherwise treatment of kits with detergent and chaotropic agent such as urea and guanidinium salt is preferred to heat treatment. PMID:19388558

  6. Synthesis of amino functionalized magnetic graphenes composite material and its application to remove Cr(VI), Pb(II), Hg(II), Cd(II) and Ni(II) from contaminated water.

    PubMed

    Guo, Xiaoyao; Du, Bin; Wei, Qin; Yang, Jian; Hu, Lihua; Yan, Liangguo; Xu, Weiying

    2014-08-15

    In the present study, a kind of graphenes magnetic material (Fe3O4-GS) was prepared by compositing graphene sheet with ferroferric oxide, and shown to be effective for removing Cr(VI), Pb(II), Hg(II), Cd(II) and Ni(II) ions from aqueous solution. The synthesized sorbent was characterized by SEM, TEM, FTIR, XRD, XPS and BET, respectively. The pHZPC value of the sorbent was estimated to be 3.5 by alkaline-titration methods. Fe3O4-GS can be simply recovered from water with magnetic separation at low magnetic field within one minute. The sorption capacities of the metals were 17.29, 27.95, 23.03, 27.83 and 22.07 mg g(-1) for Cr(VI), Pb(II), Hg(II), Cd(II) and Ni(II), respectively. Kinetic data showed good correlation with pseudo-second-order equation and the Freundlich model was found to fit for the isotherm data of all the heavy metal ions. It was found that the metals sorption was accomplished mainly via chelation or ion exchange. The results of thermodynamic studies illustrate that the adsorption process was endothermic and spontaneous in nature. PMID:25016452

  7. Porous membrane with high curvature, three-dimensional heat-resistance skeleton: a new and practical separator candidate for high safety lithium ion battery.

    PubMed

    Shi, Junli; Xia, Yonggao; Yuan, Zhizhang; Hu, Huasheng; Li, Xianfeng; Zhang, Huamin; Liu, Zhaoping

    2015-01-01

    Separators with high reliability and security are in urgent demand for the advancement of high performance lithium ion batteries. Here, we present a new and practical porous membrane with three-dimension (3D) heat-resistant skeleton and high curvature pore structure as a promising separator candidate to facilitate advances in battery safety and performances beyond those obtained from the conventional separators. The unique material properties combining with the well-developed structural characteristics enable the 3D porous skeleton to own several favorable properties, including superior thermal stability, good wettability with liquid electrolyte, high ion conductivity and internal short-circuit protection function, etc. which give rise to acceptable battery performances. Considering the simply and cost-effective preparation process, the porous membrane is deemed to be an interesting direction for the future lithium ion battery separator. PMID:25653104

  8. Porous membrane with high curvature, three-dimensional heat-resistance skeleton: a new and practical separator candidate for high safety lithium ion battery

    PubMed Central

    Shi, Junli; Xia, Yonggao; Yuan, Zhizhang; Hu, Huasheng; Li, Xianfeng; Zhang, Huamin; Liu, Zhaoping

    2015-01-01

    Separators with high reliability and security are in urgent demand for the advancement of high performance lithium ion batteries. Here, we present a new and practical porous membrane with three-dimension (3D) heat-resistant skeleton and high curvature pore structure as a promising separator candidate to facilitate advances in battery safety and performances beyond those obtained from the conventional separators. The unique material properties combining with the well-developed structural characteristics enable the 3D porous skeleton to own several favorable properties, including superior thermal stability, good wettability with liquid electrolyte, high ion conductivity and internal short-circuit protection function, etc. which give rise to acceptable battery performances. Considering the simply and cost-effective preparation process, the porous membrane is deemed to be an interesting direction for the future lithium ion battery separator. PMID:25653104

  9. Development of Simultaneous Corrosion Barrier and Optimized Microstructure in FeCrAl Heat-Resistant Alloy for Energy Applications. Part 1: The Protective Scale

    NASA Astrophysics Data System (ADS)

    Pimentel, G.; Aranda, M. M.; Chao, J.; González-Carrasco, J. L.; Capdevila, C.

    2015-09-01

    Coarse-grained Fe-based oxide dispersion-strengthened (ODS) steels are a class of advanced materials for combined cycle gas turbine systems to deal with operating temperatures and pressures of around 1100°C and 15-30 bar in aggressive environments, which would increase biomass energy conversion efficiencies up to 45% and above. This two-part paper reports the possibility of the development of simultaneous corrosion barrier and optimized microstructure in a FeCrAl heat-resistant alloy for energy applications. The first part reports the mechanism of generating a dense, self-healing α-alumina layer by thermal oxidation, during a heat treatment that leads to a coarse-grained microstructure with a potential value for high-temperature creep resistance in a FeCrAl ODS ferritic alloy, which will be described in more detail in the second part.

  10. The SpmA/B and DacF proteins of Clostridium perfringens play important roles in spore heat resistance.

    PubMed

    Orsburn, Benjamin; Sucre, Katie; Popham, David L; Melville, Stephen B

    2009-02-01

    Strains of Clostridium perfringens that cause acute food poisoning have been shown to produce spores that are significantly more heat resistant than those of other strains. Previous studies demonstrated that the spore core density and the ratio of spore cortex peptidoglycan relative to the germ cell wall were factors that correlated with the heat resistance of a C. perfringens spore. To further evaluate these relationships, mutant strains of C. perfringens SM101 were constructed with null mutations in dacF, encoding a D,D-carboxypeptidase, and in the spmA-spmB operon, which is involved in spore core dehydration. The dacF mutant was shown to produce less spore cortex peptidoglycan and had a corresponding decrease in spore heat resistance. The spmA-spmB strain produced highly unstable spores with significantly lower core densities and increased heat sensitivity, which were easily destroyed during treatments affecting the spore coat layers. These results support the previous assertion that a threshold core density as well as a high ratio of cortex peptidoglycan relative to the germ cell wall contribute to the formation of a more heat-resistant spore in this species. PMID:19189487

  11. Physiological quality and gene expression related to heat-resistant proteins at different stages of development of maize seeds.

    PubMed

    Andrade, T; Von Pinho, E V R; Von Pinho, R G; Oliveira, G E; Andrade, V; Fernandes, J S

    2013-01-01

    We quantified and characterized the expression of heat-resistant proteins during seed development of maize lines with distinct levels of tolerance to high drying temperature. A corn field was planted for multiplication of seeds of different lines, two tolerant and two non-tolerant to high drying temperatures. Harvest of the seeds was carried out at various stages of development and they were then subjected to tests of moisture content, germination, first count of germination, accelerated aging, and cold test. The seeds were stored in a freezer for later analysis of expression of heat-resistant proteins by means of real-time PCR, electrophoresis, and spectrophotometry. We observed that heat-resistant proteins are expressed in a differential manner in seeds from different lines and at different stages of development. The expression of heat-resistant proteins was earlier in lines tolerant to high drying temperatures. Greater germination and vigor values was found for seeds collected at the last stage of development. PMID:24085427

  12. New hybrid materials as Zn(II) sorbents in water samples

    SciTech Connect

    Perez-Quintanilla, Damian

    2010-09-15

    Mesoporous silicas have been chemically modified with 5-mercapto-1-methyltetrazole (MTTZ) obtaining hybrid materials denominated MTTZ-MSU-2 and MTTZ-HMS. These materials were employed as Zn(II) sorbents from aqueous media at room temperature. The effect of several variables (stirring time, pH, presence of other metals) has been studied using batch and column techniques. Flame atomic absorption spectrometry (FAAS) was used to determinate Zn(II) concentration in the filtrate or in the eluted solution after the adsorption process. The results indicate that under pH 8, the maximum adsorption value was 0.94 {+-} 0.01 and 0.72 {+-} 0.01 mmol Zn(II)/g for MTTZ-MSU-2 and MTTZ-HMS, respectively. In tap water samples, a preconcentration factor of 200 was obtained. On the basis of these results, it can be concluded that it is possible to modify chemically MSU-2 and HMS with 5-mercapto-1-methyltetrazole and to use the resulting modified mesoporous silica as an effective adsorbent for Zn(II) in aqueous media.

  13. The Heat Resistance of Microbial Cells Represented by D Values Can be Estimated by the Transition Temperature and the Coefficient of Linear Expansion.

    PubMed

    Nakanishi, Koichi; Kogure, Akinori; Deuchi, Keiji; Kuwana, Ritsuko; Takamatsu, Hiromu; Ito, Kiyoshi

    2015-01-01

    We previously developed a method for evaluating the heat resistance of microorganisms by measuring the transition temperature at which the coefficient of linear expansion of a cell changes. Here, we performed heat resistance measurements using a scanning probe microscope with a nano thermal analysis system. The microorganisms studied included six strains of the genus Bacillus or related genera, one strain each of the thermophilic obligate anaerobic bacterial genera Thermoanaerobacter and Moorella, two strains of heat-resistant mold, two strains of non-sporulating bacteria, and one strain of yeast. Both vegetative cells and spores were evaluated. The transition temperature at which the coefficient of linear expansion due to heating changed from a positive value to a negative value correlated strongly with the heat resistance of the microorganism as estimated from the D value. The microorganisms with greater heat resistance exhibited higher transition temperatures. There was also a strong negative correlation between the coefficient of linear expansion and heat resistance in bacteria and yeast, such that microorganisms with greater heat resistance showed lower coefficients of linear expansion. These findings suggest that our method could be useful for evaluating the heat resistance of microorganisms. PMID:26699861

  14. Draft Genome Sequences of Two Heat-Resistant Mutant Strains (A52 and B41) of the Photosynthetic Hydrogen-Producing Bacterium Rhodobacter capsulatus

    PubMed Central

    Gokce, Abdulmecit; Cakar, Zeynep Petek; Yucel, Meral; Ozcan, Orhan; Sencan, Sevde; Sertdemir, Ibrahim; Erguner, Bekir; Yuceturk, Betul; Sarac, Aydan; Yuksel, Bayram

    2016-01-01

    The draft genome sequences of two heat-resistant mutant strains, A52 and B41, derived from Rhodobacter capsulatus DSM 1710, and with different hydrogen production levels, are reported here. These sequences may help understand the molecular basis of heat resistance and hydrogen production in R. capsulatus. PMID:27284151

  15. Draft Genome Sequences of Two Heat-Resistant Mutant Strains (A52 and B41) of the Photosynthetic Hydrogen-Producing Bacterium Rhodobacter capsulatus.

    PubMed

    Gokce, Abdulmecit; Cakar, Zeynep Petek; Yucel, Meral; Ozcan, Orhan; Sencan, Sevde; Sertdemir, Ibrahim; Erguner, Bekir; Yuceturk, Betul; Sarac, Aydan; Yuksel, Bayram; Ozturk, Yavuz

    2016-01-01

    The draft genome sequences of two heat-resistant mutant strains, A52 and B41, derived from Rhodobacter capsulatus DSM 1710, and with different hydrogen production levels, are reported here. These sequences may help understand the molecular basis of heat resistance and hydrogen production in R. capsulatus. PMID:27284151

  16. Effects of pulp capping materials on fracture resistance of Class II composite restorations

    PubMed Central

    Kucukyilmaz, Ebru; Yasa, Bilal; Akcay, Merve; Savas, Selcuk; Kavrik, Fevzi

    2015-01-01

    Objective: The aim of this study was to investigate the effect of cavity design and the type of pulp capping materials on the fracture resistance of Class II composite restorations. Materials and Methods: Sixty freshly extracted, sound molar teeth were selected for the study. A dovetail cavity on the mesio-occlusal and a slot cavity on disto-occlusal surfaces of each tooth were prepared, and the teeth were divided 4 groups which one of them as a control group. The pulp capping materials (TheraCal LC, Calcimol LC, Dycal) applied on pulpo-axial wall of each cavity, and the restoration was completed with composite resin. The teeth were subjected to a compressive load in a universal mechanical testing machine. The surfaces of the tooth and restoration were examined under a stereomicroscope. The data were analyzed using factorial analysis of variance and Tukey's test. Results: For pulp capping materials, the highest fracture load (931.15 ± 203.81 N) and the lowest fracture load (832.28 ± 245.75 N) were calculated for Control and Dycal group, respectively. However, there were no statistically significant differences among all groups (P > 0.05). The fracture load of the dovetail groups was significantly higher than those of the slot cavity groups (P < 0.05). Conclusion: Dovetail cavity design shows better fracture resistance in Class II composite restorations, independent of used or not used pulp capping materials. PMID:26038653

  17. Structural transformations in heat-resistant protective coatings on nickel alloys

    SciTech Connect

    Veksler, Yu.G.; Lesnikov, V.P.; Paleeva, S.Ya.; Lesnikova, E.G.; Myal'nitsa, G.F.

    1987-09-01

    In this work a comprehensive metallophysical study was carried out for two aluminosilicide slip coatings of the systems Al-Si and Al-Nb-Si and an electron-beam Co-Cr-Al-Y coating on alloy EP-539 (17...19% Cr, 4...6% Co, 2.5...4% W, 4.5...6.5% Mo, 2...3% Ti, 3...4% Al, 1.4...2% Nb, balance Ni) after high-temperature testing. The protective properties of the coatings were evaluated from the results of laboratory tests for heat resistance at 1000/sup 0/C in the combustion products of diesel fuel with added sulfur at 970, 1000, and 1060/sup 0/C for 100 h and after full-scale tests for 150, 250, 400, and 700 h. Metallographic, hardness, x-ray, and micro x-ray studies of the coating were carried out. Layer-by-layer phase composition and the lattice spacing of the main phases were determined. X-ray analysis was carried out in an a DRON-1 diffractometer in copper K/sub ..-->../-radiation, and x-ray microanalysis was carried out in a MS-46 Cameca microanalyzer

  18. Manufacture of a heat-resistant alloy with modified specifications for HTGR structural applications

    SciTech Connect

    Sahira, K.; Kondo, T.; Takeiri, T.

    1984-07-01

    A method of manufacturing a nuclear grade nickel-base heat-resistant alloy in application to heliumcooled reactor primary circuit components has been developed. The Hastelloy-XR alloy, a version of Hastelloy-X, was made available by combining the basic studies of the oxidation behavior of Hastelloy-X and the improvement of manufacturing techniques. In the primary and remelting steps, the choice of appropriate processes was made by performing numerical analyses of the statistical deviation of both chemical composition and the products' mechanical properties. The feasibility of making larger electroslag remelting ingots with reasonable control of macrosegregation was examined by the calculation of a molten metal pool shape during melting. The hot workability of Hastelloy-XR was confirmed to be equivalent to that of Hastelloy-X and the importance of controlling the thermal and mechanical processes more closely was stressed in obtaining a higher level of quality assurance for the nuclear applications. The possibility of enhancing the high-temperature mechanical performance of Hastelloy-XR was suggested based on the preliminary test results with the heats manufactured with controlled boron content.

  19. Characterization and radiation response of a heat-resistant variant of V79 cells

    SciTech Connect

    Campbell, S.D.; Kruuv, J.; Lepock, J.R.

    1983-01-01

    A thermoresistant variant of the established cell line V79-S171-W1 was isolated after treatment with nitrosoguanidine and repeated heat treatments at 42.6 to 43 degrees C, and showed an enhanced ability to survive at 42.6, 43.5, and 44.5 degrees C. The rates of inactivation of the normal and heat-resistant lines differed by approximately a factor of 2 over this temperature range. This level of thermoresistance was stable for the first 80 doublings, but was lost by 120 doublings. This may have been due to a reversion to the normal V79 line since there was no continuous selection pressure and the thermoresistant variant, which was designated at HR7, had a longer average doubling time. Transient thermotolerance was induced in both the V79 and HR7 cells by a 10-min exposure to 44.5 degrees C. After 3 hr incubation at 37 degrees C, both cell lines had an identical sensitivity to further exposure to 44.5 degrees C. Thus the long-term thermoresistance of the HR7 cells may be due to a permanent induction of a low level of thermotolerance. The (ionizing) radiation survival curves and the ability to repair sublethal radiation damage were identical for the thermoresistant variant and the parent cell line.

  20. Response of Two Heat Shock Genes to Selection for Knockdown Heat Resistance in Drosophila Melanogaster

    PubMed Central

    McColl, G.; Hoffmann, A. A.; McKechnie, S. W.

    1996-01-01

    To identify genes involved in stress resistance and heat hardening, replicate lines of Drosophila melanogaster were selected for increased resistance to knockdown by a 39° heat stress. Two selective regimes were used, one with and one without prior hardening. Mean knockdown times were increased from ~5 min to >20 min after 18 generations. Initial realized heritabilities were as high as 10% for lines selected without hardening, and crosses between lines indicated simple additive gene effects for the selected phenotypes. To survey allelic variation and correlated selection responses in two candidate stress genes, hsr-omega and hsp68, we applied denaturing gradient gel electrophoresis to amplified DNA sequences from small regions of these genes. After eight generations of selection, allele frequencies at both loci showed correlated responses for selection following hardening, but not without hardening. The hardening process itself was associated with a hsp68 frequency change in the opposite direction to that associated with selection that followed hardening. These stress loci are closely linked on chromosome III, and the hardening selection established a disequilibrium, suggesting an epistatic effect on resistance. The data indicate that molecular variation in both hsr-omega and hsp68 contribute to natural heritable variation for hardened heat resistance. PMID:8844150

  1. Mechanically alloyed Ni-base alloys for heat-resistant applications

    SciTech Connect

    Wilson, R.K.; Fischer, J.J.

    1995-12-31

    INCONEL alloys MA 754 and MA 758 are nickel-base oxide dispersion-strengthened (ODS) alloys made by mechanical alloying (MA). Commercial use of Ma Ni-base alloys to date has been predominantly in aerospace applications of alloy MA 754 as turbine engine vanes. Both alloys are suitable for industrial heat treating components and other heat resistant alloy applications. Field trials and commercial experience in such applications of MA alloys are being gained while high temperature property characterization and new product form development continue. Hot isostatic pressing (HIP) is the standard consolidation method for billets from which large bar and plate are produced for industrial applications of MA. This paper describes production of standard mill shapes from HIP billets, and it presents information on current and potential uses of MA alloys in applications such as: skid rails for use in high temperature walking beam furnaces, heat treating furnace components, components for handling molten glass, and furnace tubes. The paper includes comparison of the properties obtained in alloy MA 754 (20% Cr) and alloy MA 758 (30% Cr).

  2. Dimensional and material characteristics of direct deposited tool steel by CO II laser

    NASA Astrophysics Data System (ADS)

    Choi, J.

    2006-01-01

    Laser aided direct metalimaterial deposition (DMD) process builds metallic parts layer-by-layer directly from the CAD representation. In general, the process uses powdered metaUmaterials fed into a melt pool, creating fully dense parts. Success of this technology in the die and tool industry depends on the parts quality to be achieved. To obtain designed geometric dimensions and material properties, delicate control of the parameters such as laser power, spot diameter, traverse speed and powder mass flow rate is critical. In this paper, the dimensional and material characteristics of directed deposited H13 tool steel by CO II laser are investigated for the DMD process with a feedback height control system. The relationships between DMD process variables and the product characteristics are analyzed using statistical techniques. The performance of the DMD process is examined with the material characteristics of hardness, porosity, microstructure, and composition.

  3. The Energy Materials in-Situ Laboratory Berlin (EMIL) at BESSY II

    NASA Astrophysics Data System (ADS)

    Follath, R.; Hävecker, M.; Reichardt, G.; Lips, K.; Bahrdt, J.; Schäfers, F.; Schmid, P.

    2013-03-01

    The Helmholtz Center Berlin (HZB) and the Max-Planck Society (MPG) strengthen their research in renewable energies with the implementation of the joint Energy Material in-Situ Lab Berlin (EMIL) at the third generation light source BESSY II. The new facility is dedicated to the in-situ and in-system x-ray analysis of materials and devices for photovoltaic applications, (photo-) catalytic processes, energie conversion and storage. To obtain a comprehensive understanding of the involved materials, spectroscopic methods with x-rays from the soft- up to the hard x-ray regime reveal an almost complete picture of their chemical and electronic properties. The contribution presents the layout of the x-ray beamlines and their performance in terms of photon flux, energy resolution and spot sizes.

  4. Study of the influence of sporulation conditions on heat resistance of Geobacillus stearothermophilus used in the development of biological indicators for steam sterilization.

    PubMed

    Guizelini, Belquis P; Vandenberghe, Luciana P S; Sella, Sandra Regina B R; Soccol, Carlos Ricardo

    2012-12-01

    Biological indicators are important tools in infection control via sterilization process monitoring. The use of a standardized spore crop with a well-defined heat resistance will guarantee the quality of a biological indicator. Ambient factors during sporulation can affect spore characteristics and properties, including heat resistance. The aim of this study is to evaluate the main sporulation factors responsible for heat resistance in Geobacillus stearothermophilus, a useful biological indicator for steam sterilization. A sequence of a three-step optimization of variables (initial pH, nutrient concentration, tryptone, peptone, beef extract, yeast extract, manganese sulfate, magnesium sulfate, calcium chloride and potassium phosphate) was carried out to screen those that have a significant influence on heat resistance of produced spores. The variable exerting greatest influence on G. stearothermophilus heat resistance during sporulation was found to be the initial pH. Lower nutrient concentration and alkaline pH around 8.5 tended to enhance decimal reduction time at 121 °C (D(121°C)). A central composite design enabled a fourfold enhancement in heat resistance, and the model obtained accurately describes positive pH and negative manganese sulfate concentration influence on spore heat resistance. PMID:22872104

  5. Chelating agent free-solid phase extraction (CAF-SPE) of Co(II), Cu(II) and Cd(II) by new nano hybrid material (ZrO2/B2O3).

    PubMed

    Yalçinkaya, Ozcan; Kalfa, Orhan Murat; Türker, Ali Rehber

    2011-11-15

    New nano hybrid material (ZrO(2)/B(2)O(3)) was synthesized and applied as a sorbent for the separation and/or preconcentration of Co(II), Cu(II) and Cd(II) in water and tea leaves prior to their determination by flame atomic absorption spectrometry. Synthesized nano material was characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction. The optimum conditions for the quantitative recovery of the analytes, including pH, eluent type and volume, flow rate of sample solution were examined. The effect of interfering ions was also investigated. Under the optimum conditions, adsorption isotherms and adsorption capacities have been examined. The recoveries of Co(II), Cu(II) and Cd(II) were 96 ± 3%, 95 ± 3%, 98 ± 4% at 95% confidence level, respectively. The analytical detection limits for Co(II), Cu(II), and Cd(II) were 3.8, 3.3, and 3.1 μg L(-1), respectively. The reusability and adsorption capacities (32.2 mg g(-1) for Co, 46.5 mg g(-1) for Cu and 109.9 mg g(-1) for Cd) of the sorbent were found as satisfactory. The accuracy of the method was confirmed by analyzing certified reference material (GBW-07605 Tea leaves) and spiked real samples. The method was applied for the determination of analytes in tap water and tea leaves. PMID:21889841

  6. Self-association motifs in the enteroaggregative Escherichia coli heat-resistant agglutinin 1.

    PubMed

    Glaubman, Jessica; Hofmann, Jennifer; Bonney, Megan E; Park, Sumin; Thomas, Jessica M; Kokona, Bashkim; Ramos Falcón, Laura I; Chung, Yoonjie K; Fairman, Robert; Okeke, Iruka N

    2016-07-01

    The heat-resistant agglutinin 1 (Hra1) is an integral outer membrane protein found in strains of Escherichia coli that are exceptional colonizers. Hra1 from enteroaggregative E. coli strain 042 is sufficient to confer adherence to human epithelial cells and to cause bacterial autoaggregation. Hra1 is closely related to the Tia invasin, which also confers adherence, but not autoaggregation. Here, we have demonstrated that Hra1 mediates autoaggregation by self-association and we hypothesize that at least some surface-exposed amino acid sequences that are present in Hra1, but absent in Tia, represent autoaggregation motifs. We inserted FLAG tags along the length of Hra1 and used immune-dot blots to verify that four in silico-predicted outer loops were indeed surface exposed. In Hra1 we swapped nine candidate motifs in three of these loops, ranging from one to ten amino acids in length, to the corresponding sequences in Tia. Three of the motifs were required for Hra1-mediated autoaggregation. The database was searched for other surface proteins containing these motifs; the GGXWRDDXK motif was also present in a surface-exposed region of Rck, a Salmonella enterica serotype Typhimurium complement resistance protein. Cloning and site-specific mutagenesis demonstrated that Rck can confer weak, GGXWRDDXK-dependent autoaggregation by self-association. Hra1 and Rck appear to form heterologous associations and GGXWRDDXK is required on both molecules for Hra1-Rck association. However, a GGYWRDDLKE peptide was not sufficient to interfere with Hra1-mediated autoaggregation. In the present study, three autoaggregation motifs in an integral outer membrane protein have been identified and it was demonstrated that at least one of them works in the context of a different cell surface. PMID:27166217

  7. Efficacy of Traditional Almond Decontamination Treatments and Electron Beam Irradiation against Heat-Resistant Salmonella Strains.

    PubMed

    Cuervo, Mary P; Lucia, Lisa M; Castillo, Alejandro

    2016-03-01

    Two outbreaks of salmonellosis were linked to the consumption of raw almonds from California in 2001 and 2004. As a result, federal regulations were developed, which mandate that all almonds grown in California must be treated with a process that results in a 4-log reduction of Salmonella. Because most of the technologies approved to treat almonds rely on the application of heat to control Salmonella, an evaluation of alternative technologies for inactivating heat-resistant Salmonella Enteritidis PT30 and Salmonella Senftenberg 775W was needed. In this study, almonds were inoculated with Salmonella Enteritidis PT30 and Salmonella Senftenberg 775W and then treated with an electron beam (e-beam) or by blanching or oil roasting. The irradiation D10-values for Salmonella Enteritidis PT30 and Salmonella Senftenberg 775W treated with e-beam were 0.90 and 0.72 kGy, respectively. For heat treatments, thermal D10-values for Salmonella Enteritidis PT30 and Salmonella Senftenberg 775W strains were 15.6 and 12.4 s, respectively, when subjected to blanching at 88°C and 13.2 and 10.9 s, respectively, when roasted in oil at 127 ± 2°C. No significant differences in irradiation and thermal treatment results were observed between Salmonella Enteritidis PT30 and Salmonella Senftenberg 775W (P > 0.05), indicating that e-beam irradiation may be a feasible technology for reducing Salmonella in almonds. However, the sensory changes resulting from irradiating at the doses used in this study must be evaluated before e-beam irradiation can be used as a nonthermal alternative for decontamination of almonds. PMID:26939646

  8. Characteristics of heat resistant alloys Ti10Nb45Al and Ti18Nb48Al

    SciTech Connect

    Weijun Zhang; Guoliang Chen; Yandong Wang; Zuqing Sun )

    1993-05-01

    Based on a systematic study of the ternary Ti-Nb-Al system, two attractive heat resistant alloys, Ti10Nb45Al and Ti18Nb48Al, were developed, and the characteristics of these alloys were discussed: (1) After annealing at 1,200 C for 240 h and furnace cooling to room temperature, the Ti10Nb45Al alloy exhibits an [alpha][sub 2] + [gamma] lamellar microstructure, and the Ti18Nb48Al alloy shows a plate-like structure consisting of [alpha][sub 2], [gamma] and [gamma][sub 1] phases. (2) The specific strengths of Ti10Nb45Al and Ti18Nb48Al are much higher than TiAl and superalloys in the temperature range of 800 [approximately] 1,100 C. The compressive yield strengths of these alloys are on the order of 700 MPa at 800 C and 350 MPa at 1,100 C. The density of these alloys is about 4.3 g/cm[sup 3]. (3) The annealed Ti10Nb45Al and Ti18Nb48Al exhibit some ductility at room temperature, with the compressive elongation on the order of 12% and the fracture toughness as high as 16 MPa[radical]m. The ductile-brittle transformation temperatures for Ti10Nb45Al and Ti18Nb48Al are 650 C and 750 C, respectively. (4) The parabolic constant K[sub p] for oxidation of Ti10Nb45Al and Ti18Nb48Al are 0.88 and 0.29 mg[sup 2]cm[sup [minus]4]h[sup [minus]1] respectively, which are two orders of magnitude lower than that of TiAl and Ti[sub 3]Al alloys.

  9. Novel Solar Energy Conversion Materials by Design of Mn(II) Oxides

    SciTech Connect

    Lany, S.; Peng, H.; Ndione, P.; Zakutayev, A.; Ginley, D. S.

    2013-01-01

    Solar energy conversion materials need to fulfill simultaneously a number of requirements in regard of their band-structure, optical properties, carrier transport, and doping. Despite their desirable chemical properties, e.g., for photo-electrocatalysis, transition-metal oxides usually do not have desirable semiconducting properties. Instead, oxides with open cation d-shells are typically Mott or charge-transfer insulators with notoriously poor transport properties, resulting from large effective electron/hole masses or from carrier self-trapping. Based on the notion that the electronic structure features (p-d interaction) supporting the p-type conductivity in d10 oxides like Cu2O and CuAlO2 occurs in a similar fashion also in the d5 (high-spin) oxides, we recently studied theoretically the band-structure and transport properties of the prototypical binary d5 oxides MnO and Fe2O3 [PRB 85, 201202(R)]. We found that MnO tends to self-trap holes by forming Mn+III, whereas Fe2O3 self-traps electrons by forming Fe+II. However, the self-trapping of holes is suppressed by when Mn is tetrahedrally coordinated, which suggests specific routes to design novel solar conversion materials by considering ternary Mn(II) oxides or oxide alloys. We are presenting theory, synthesis, and initial characterization for these novel energy materials.

  10. Identification and characterization of a heat-resistant protease from Serratia liquefaciens isolated from Brazilian cold raw milk.

    PubMed

    Machado, Solimar Gonçalves; Heyndrickx, Marc; De Block, Jan; Devreese, Bart; Vandenberghe, Isabel; Vanetti, Maria Cristina Dantas; Van Coillie, Els

    2016-04-01

    The cold storage of raw milk before heat treatment in dairy industry promotes the growth of psychrotrophic microorganisms, which are known for their ability to produce heat-resistant proteolytic enzymes. Although Pseudomonas is described as the main causative genus for high proteolytic spoilage potential in dairy products, Serratia liquefaciens secretes proteases and may be found in raw milk samples as well. However, at the present there is no information about the proteolytic spoilage potential of S. liquefaciens in milk after heat-treatment. The main aim of this research was to assess the proteolytic spoilage potential of S. liquefaciens isolated from Brazilian raw milk and to characterize the involved protease. S. liquefaciens was shown to secrete one heat-resistant spoilage metalloprotease of, approximately, 52 kDa encoded by the ser2 gene. The heat-resistance of Ser2 was similar to the aprX encoded metalloprotease produced by Pseudomonas. Although the ser2 gene was detected in all S. liquefaciens isolates tested in this study, the proteolytic activity of the isolates in milk was highly heterogeneous. Since nucleotide and deduced amino acid sequences of ser2 of all tested isolates are identical, this heterogeneity may be attributed to differences in enzyme expression levels or post-translational modifications. PMID:26874224

  11. On the heat flux vector for flowing granular materials--part II: derivation and special cases

    SciTech Connect

    Massoudi, Mehrdad

    2006-09-10

    Heat transfer plays a major role in the processing of many particulate materials. The heat flux vector is commonly modelled by the Fourier's law of heat conduction and for complex materials such as non-linear fluids, porous media, or granular materials, the coefficient of thermal conductivity is generalized by assuming that it would depend on a host of material and kinematical parameters such as temperature, shear rate, porosity or concentration, etc. In Part I, we will give a brief review of the basic equations of thermodynamics and heat transfer to indicate the importance of the modelling of the heat flux vector. We will also discuss the concept of effective thermal conductivity (ETC) in granular and porous media. In Part II, we propose and subsequently derive a properly frame-invariant constitutive relationship for the heat flux vector for a (single phase) flowing granular medium. Standard methods in continuum mechanics such as representation theorems and homogenization techniques are used. It is shown that the heat flux vector in addition to being proportional to the temperature gradient (the Fourier's law), could also depend on the gradient of density (or volume fraction), and D (the symmetric part of the velocity gradient) in an appropriate manner. The emphasis in this paper is on the idea that for complex non-linear materials it is the heat flux vector which should be studied; obtaining or proposing generalized form of the thermal conductivity is not always appropriate or sufficient.

  12. Modifications in membrane fatty acid composition of Salmonella typhimurium in response to growth conditions and their effect on heat resistance.

    PubMed

    Alvarez-Ordóñez, Avelino; Fernández, Ana; López, Mercedes; Arenas, Ricardo; Bernardo, Ana

    2008-04-30

    The effects of growth temperature (in the range 10-45 degrees C) and acidification up to pH 4.5 of the culture medium (Brain Heart Infusion, BHI) with different organic acids (acetic, citric and lactic) and hydrochloric acid on membrane fatty acid composition and heat resistance of Salmonella typhimurium CECT 443 were studied. The heat resistance was maximal in cells grown at 45 degrees C (cells grown in non-acidified BHI showed a D58-value of 0.90 min) and decreased with decreasing growth temperature up to 10 degrees C (D58-value of 0.09 min). The growth of cells in acidified media caused an increase in their heat resistance. In general, acid adapted cells showed D-values of between 1.5 and 2 times higher than the corresponding for non-acid adapted control cells. This cross-protection response, which has important implications in food processing, was not dependent on the pH value and the acid used to acidify the growth medium. A membrane adaptation corresponding to an increase in the unsaturated to saturated fatty acids ratio (UFA/SFA) and membrane fluidity was observed at low growth temperature. Moreover, the acidification of the growth medium caused a decrease in UFA/SFA ratio and in the C18:1 relative concentration, and an increase in cyclopropane fatty acids (CFA) content mainly due to the increase in cyc19 relative concentration. Thus, acid adapted cells showed CFA levels 1.5 times higher than non-acid adapted control cells. A significant proportion of unsaturated fatty acids were converted to their cyclopropane derivatives during acid adaptation. These changes in membrane fatty acid composition result in cells with decreased membrane fluidity. A clear relation between membrane fatty acid composition and heat resistance was observed. In general, D-values were maximum for cells with low UFA/SFA ratio, and, consequently, with low membrane fluidity. Moreover, CFA formation played a major role in protecting acid adapted cells from heat inactivation. However

  13. The EBR-II materials-surveillance program. 5: Results of SURV-5.

    SciTech Connect

    Ruther, W.E.; Staffon, J.D.; Carlson, B.G.; Allen, T.R.

    1998-01-01

    In March of 1965, a set of surveillance (SURV) samples was placed in the EBR-II reactor to determine the effect of irradiation, thermal aging, and sodium corrosion on reactor materials. Eight subassemblies were placed into row 12 positions of EBR-II to determine the effect of irradiation at 370 C. Two subassemblies were placed into the primary sodium basket to determine the effect of thermal aging at 370 C. One half of all samples were exposed to primary system sodium while one half were sealed in capsules with a helium atmosphere. Fifteen different structural materials were tested in the SURV program. In this work, the properties of these materials irradiated at 370 C to a total fluence of 3.2 {times} 10{sup 22} n/cm{sup 2} were determined. These materials are the fifth set of irradiated subassemblies to be examined as part of the SURV program (SURV-5). The properties analyzed were weight, density, microstructure, hardness, tensile and yield strength, and fracture resistance. Of all the alloys examined in SURV-5, only Berylco-25 showed any significant weight loss. Stainless steel (both 304 and 347) had the largest density decrease, although the density decrease from irradiation for all alloys was less than 0.4 percent. The microstructure of both Berylco-25 and the aluminum-bronze alloy was altered significantly. Iron- and nickel-base alloys showed little change in microstructure. Austenitic steels (304 and 347) harden with irradiation. The hardness of Inconel X750 did not change significantly with irradiation. The ultimate tensile strength of Inconel X750, 304 stainless steel, 420 stainless steel and welded 304 changed little due to a fluence increase from 2.2 {times} 10{sup 22} n/cm{sup 2} (the maximum fluence of the SURV-4 samples) to 3.2 {times} 10{sup 22} n/cm{sup 2}.

  14. Communications for Lifelong Success I and II (Tech Prep English I and II). Pilot Test Materials for Pendleton High School, Pendleton, South Carolina. Draft.

    ERIC Educational Resources Information Center

    Turlington, Anita; And Others

    These instructional materials include six supplementary units for Tech Prep English I (grade 9) and six assignments for Tech Prep English II (grade 10). The Tech Prep English I units have these components: unit objectives, introduction, and follow-up exercises. Topics include goal setting, problem solving and decision making, listening and reading…

  15. Materials information for science and technology (MIST): Project overview: Phases I and II and general considerations

    SciTech Connect

    Grattidge, W.; Westbrook, J.; McCarthy, J.; Northrup, C. Jr.; Rumble, J. Jr.

    1986-01-01

    This report documents the initial phases of the Materials Information for Science and Technology (MIST) project jointly supported by the Department of Energy and the National Bureau of Standards. The purpose of MIST is to demonstrate the power and utility of computer access to materials property data. The initial goals include: to exercise the concept of a computer network of materials databases and to build a demonstration of such a system suitable for use as the core of operational systems in the future. Phases I and II are described in detail herein. In addition, a discussion is given of the expected usage of the system. The primary MIST prototype project is running on an IBM 3084 under STS at the Stanford University's Information Technology Services (ITS). Users can access the Stanford system via ARPANET, TELENET, and TYMNET, as well as via commercial telephone lines. For fastest response time and use of the full screen PRISM interface, direct connection using a 2400 baud modem with the MNP error-correcting protocol over standard telephone lines gives the best results - though slower speed connections and a line-oriented interface are also available. This report gives detailed plans regarding the properties to be enterend and the materials to be entered into the system.

  16. Biological indicators for low temperature steam formaldehyde sterilization: effect of defined media on sporulation, germination index and moist heat resistance at 110 degrees C of Bacillus strains.

    PubMed

    Hoxey, E V; Soper, C J; Davies, D J

    1985-02-01

    Choice of a biological indicator depends upon selecting a strain with the optimum balance of desirable properties. Screening 20 strains of Bacillus spp. for sporulation on three defined media has shown the wide variation that occurs in requirements for sporulation and properties of the resultant spores. Comparison of germination index and moist heat resistance of resultant spores suggest that a combination of high germination index, high heat resistance and linear inactivation may not be possible. PMID:3980302

  17. Alkali metal protective garment and composite material

    SciTech Connect

    Ballif, J.L.; Yuan, W.W.

    1980-09-16

    A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium are described. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

  18. Alkali metal protective garment and composite material

    SciTech Connect

    Ballif, III, John L.; Yuan, Wei W.

    1980-01-01

    A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

  19. Modeling of chemical interactions of fuel rod materials at high temperatures II. Investigation of downward relocation of molten materials

    NASA Astrophysics Data System (ADS)

    Veshchunov, M. S.; Palagin, A. V.

    1998-01-01

    In Part II of the modeling of chemical interactions of fuel rod materials at high temperatures, qualitative results on the nature of Zr-rich melt oxidation and interactions with fuel rods allow further interpretation of the post-test examinations of structures (debris) formed in the CORA tests under more complicated conditions, namely during downward relocation of the melt. In this situation, the molten mass extensively oxidizes and simultaneously dissolves UO 2 pellets and ZrO 2 scales of the cladding. The analysis of these simultaneous physico-chemical processes on the basis of the kinetic oxidation/dissolution model developed in Part I of the paper, allows a new interpretation and explanation of the CORA tests results concerning relocation dynamics of the major part of the melt (slow relocation of melt in the form of massive slug rather than quick relocations of droplets and rivulets), formation of local blockages (debris) in the interrod space and accumulation of the melt in the core region in the form of molten pool.

  20. An Overview of 2014 SBIR Phase I and Phase II Materials Structures for Extreme Environments

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung D.; Steele, Gynelle C.; Morris, Jessica R.

    2015-01-01

    NASA's Small Business Innovation Research (SBIR) program focuses on technological innovation by investing in development of innovative concepts and technologies to help NASA mission directorates address critical research needs for Agency programs. This report highlights nine of the innovative SBIR 2014 Phase I and Phase II projects that emphasize one of NASA Glenn Research Center's six core competencies-Materials and Structures for Extreme Environments. The technologies cover a wide spectrum of applications such as high temperature environmental barrier coating systems, deployable space structures, solid oxide fuel cells, and self-lubricating hard coatings for extreme temperatures. Each featured technology describes an innovation, technical objective, and highlights NASA commercial and industrial applications. This report provides an opportunity for NASA engineers, researchers, and program managers to learn how NASA SBIR technologies could help their programs and projects, and lead to collaborations and partnerships between the small SBIR companies and NASA that would benefit both.

  1. HARWI-II, The New High-Energy Beamline for Materials Science at HASYLAB/DESY

    SciTech Connect

    Beckmann, Felix; Lippmann, Thomas; Metge, Joachim; Dose, Thomas; Donath, Tilman; Schreyer, Andreas; Tischer, Markus; Liss, Klaus Dieter

    2004-05-12

    The GKSS Forschungszentrum Geesthacht, Germany, will setup a new high-energy beamline specialized for texture, strain and imaging measurements for materials science at the Hamburger Synchrotronstrahlungslabor HASYLAB of the Deutsches Elektronen-Synchrotron DESY. Four different experiments will be installed at the new wiggler HARWI-II. The high pressure cell will be run by the GFZ Potsdam, Germany, the high-energy diffractometer together with a microtomography camera will be run by the GKSS. A further station will allow space for the diffraction enhanced imaging setup. The optics will provide for a small white beam (0.5 mm x 0.5 mm) and a large monochromatic X-ray beam (50 mm x 10 mm) with an energy range of 20 to 250 keV.

  2. Light-curing considerations for resin-based composite materials: a review. Part II.

    PubMed

    Malhotra, Neeraj; Mala, Kundabala

    2010-10-01

    As discussed in Part I, the type of curing light and curing mode impact the polymerization kinetics of resin-based composite (RBC) materials. Major changes in light-curing units and curing modes have occurred. The type of curing light and mode employed affects the polymerization shrinkage and associated stresses, microhardness, depth of cure, degree of conversion, and color change of RBCs. These factors also may influence the microleakage in an RBC restoration. Apart from the type of unit and mode used, the polymerization of RBCs is also affected by how a light-curing unit is used and handled, as well as the aspects associated with RBCs and the environment. Part II discusses the various clinical issues that should be considered while curing RBC restorations in order to achieve the best possible outcome. PMID:20960988

  3. Multiple Conformations of the Loop Region Confers Heat-Resistance on SsArd1, a Thermophilic NatA.

    PubMed

    Chang, Yu-Yung; Hsu, Chun-Hua

    2016-02-01

    Structural comparison indicates that the loop region between β3 and β4 of SsArd1 is extended relative to the corresponding region in mesophilic Nats, and forms a plastic hydrogen-bond network mainly at two serine residues. Strikingly, two single-point mutants showed ∼3 °C decrease in melting temperature, and two other variants showed ∼7 °C decrease; this correlated with significantly reduced enzymatic activity. To our knowledge, this is the first discovery of a loop region capable of remarkably improving protein thermostability. This provides a novel route to engineer heat-resistant proteins. PMID:26593285

  4. Hydramite II screening tests of potential bremsstrahlung converter debris shield materials

    SciTech Connect

    Reedy, E.D. Jr.; Hedemann, M.A.; Stark, M.A.

    1986-03-01

    Results of a brief test series aimed at screening a number of potential bremsstrahlung converter debris shield materials are reported. These tests were run on Sandia National Laboratories' Hydramite II accelerator using a diode configuration which produces a pinched electron beam. The materials tested include: (1) laminated Kevlar 49/polyester and E-glass/polyester composites, (2) a low density laminated Kevlar 49 composite, and (3) two types of through-the-thickness reinforced Kevlar 49 composites. As expected, tests using laminated Kevlar 49/polyester shields showed that shield permanent set (i.e., permanent deflection) increased with increasing tantalum conversion foil thickness and decreased with increasing shield thickness. The through-the-thickness reinforced composites developed localized, but severe, back surface damage. The laminated composites displayed little back surface damage, although extensive internal matrix cracking and ply delaminations were generated. Roughly the same degree of permanent set was produced in shields made from the low density Kevlar 49 composite and the Kevlar 49/polyester. The E-glass reinforced shields exhibited relatively low levels of permanent set.

  5. Heat resistance of Salmonella enterica is increased by pre-adaptation to peanut oil or sub-lethal heat exposure.

    PubMed

    Fong, Karen; Wang, Siyun

    2016-09-01

    Cross-protection represents a considerable challenge in the food industry where hurdled interventions are often employed to reduce Salmonella contamination. The heat resistance of Salmonella strains from five serotypes (i.e., Typhimurium, Enteritidis, Tennessee, Thompson and Hartford) at 70 °C was determined by measurement of viable cell populations before and after adaptation to two common stresses employed in low-water activity food processing, desiccation and sub-lethal heat treatment. Survival of Salmonella at 70 °C significantly increased (p < 0.05) following the six-day incubation in peanut oil (aw 0.52 ± 0.00) and/or the exposure to a sub-lethal heat treatment at 45 °C for 3 min. Quantitative PCR revealed upregulation of two desiccation stress-related genes, fadA and otsB, following the peanut oil incubation, whereas heat treatment induced upregulation of a heat-resistance gene, dnaK. Invasion gene invA and alternative sigma factor rpoE were downregulated following either of the treatments. Interestingly, different Salmonella strains yielded different transcriptional profiles. The strain-specific resistance phenotypes and transcriptional profiles provided further insights into the mechanisms employed to tolerate desiccation and heat stresses in the food industry. PMID:27217370

  6. Effect of NaCl on heat resistance, antibiotic susceptibility, and Caco-2 cell invasion of Salmonella.

    PubMed

    Yoon, Hyunjoo; Park, Beom-Young; Oh, Mi-Hwa; Choi, Kyoung-Hee; Yoon, Yohan

    2013-01-01

    This study evaluated the effects of NaCl on heat resistance, antibiotic susceptibility, and Caco-2 cell invasion of Salmonella. Salmonella typhimurium NCCP10812 and Salmonella enteritidis NCCP12243 were exposed to 0, 2, and 4% NaCl and to sequential increase of NaCl concentrations from 0 to 4% NaCl for 24 h at 35°C. The strains were then investigated for heat resistance (60°C), antibiotic susceptibility to eight antibiotics, and Caco-2 cell invasion efficiency. S. typhimurium NCCP10812 showed increased thermal resistance (P < 0.05) after exposure to single NaCl concentrations. A sequential increase of NaCl concentration decreased (P < 0.05) the antibiotic sensitivities of S. typhimurium NCCP10812 to chloramphenicol, gentamicin, and oxytetracycline. NaCl exposure also increased (P < 0.05) Caco-2 cell invasion efficiency of S. enteritidis NCCP12243. These results indicate that NaCl in food may cause increased thermal resistance, cell invasion efficiency, and antibiotic resistance of Salmonella. PMID:23936782

  7. Modelling the influence of the sporulation temperature upon the bacterial spore heat resistance, application to heating process calculation.

    PubMed

    Leguérinel, I; Couvert, O; Mafart, P

    2007-02-28

    Environmental conditions of sporulation influence bacterial heat resistance. For different Bacillus species a linear Bigelow type relationship between the logarithm of D values determined at constant heating temperature and the temperature of sporulation was observed. The absence of interaction between sporulation and heating temperatures allows the combination of this new relationship with the classical Bigelow model. The parameters zT and zT(spo) of this global model were fitted to different sets of data regarding different Bacillus species: B. cereus, B. subtilis, B. licheniformis, B. coagulans and B. stearothermophilus. The origin of raw products or food process conditions before a heat treatment can lead to warm temperature conditions of sporulation and to a dramatic increase of the heat resistance of the generated spores. In this case, provided that the temperature of sporulation can be assessed, this model can be easily implemented to rectify F values on account of possible increase of thermal resistance of spores and to ensure the sterilisation efficacy. PMID:17184868

  8. Luminescent Nafion membranes dyed with ruthenium(II) complexes as sensing materials for dissolved oxygen

    SciTech Connect

    Garcia-Fresnadillo, D.; Orellana, G.; Marazuela, M.D.; Moreno-Bondi, M.C.

    1999-09-14

    The absorption spectroscopy, photophysics, and dioxygen quenching of [RuL{sub 3}]{sup 2+} luminescent probes, where L stands for 2,2{prime}-bipyridine, 1,10-phenanthroline, 5-octadecanamide-1,10-phenanthroline, and 4,7-diphenyl-1,10-phenanthroline (dip), electrostatically loaded onto Nafion ionomer membrane have been investigated in air and in organic solvents and water, with the aim of developing rugged materials for optical sensing of molecular oxygen. The significant differences in size and hydrophobicity of the Ru(II) dyes have been used to probe their location within the perfluorinated ionomer pore network, as well as to gain insight into the oxygen accessibility to its microcrystalline and interfacial domains. While the absorption maximums of the probes (444--458nm) remain relative unchanged, their emission wavelengths (578--622 nm) are extremely sensitive to the degree of Nafion swelling by the solvent. This feature has been characterized by measuring the density (1.19--2.04 g cm{sup {minus}3}) of the solvent-saturated ionomer and the mass and volume fractions of solvents (0.0--0.7) uptake by the original acidic Nafion and Li{sup +}-, Na{sup +}-, or K{sup +}-exchanged films. The excited-state lifetimes of the [RuL{sub 3}]{sup 2+} complexes (0.03--4.9{micro}s) reflect important variations of the microenvironment around the luminescent probes, which are rationalized in terms of their location and oxygen accessibility when loaded onto the polysulfonated material. Emission quenching rate constants of 1.7 {+-} 0.3 M{sup {minus}1}s{sup {minus}1} have been measured for the [Ru(dip){sub 3}]{sup 2+}-dyed films dipped in methanol; their oxygen sensitivity turns out to be independent of the Ru(II) loading and counterion of Nafion. Highly oxygen-sensitive luminescent membranes, suitable for continuous monitoring in organic solvents, water, or gas phase, have been prepared by immobilization of [Ru(dip){sub 3}]{sup 2+} indicator in 178-{micro}m thick Nafion, with response

  9. Doorways II: Community Counselor Reference Materials. On School-Related Gender-Based Violence Prevention and Response

    ERIC Educational Resources Information Center

    US Agency for International Development, 2009

    2009-01-01

    The Doorways training program was designed by the U.S. Agency for International Development (USAID)-funded Safe Schools Program (Safe Schools) to enable teachers, community members and students to prevent and respond to school-related gender-based violence (SRGBV). This booklet, "Doorways II: Community Counselor Reference Materials on…

  10. Towards an accurate and computationally-efficient modelling of Fe(II)-based spin crossover materials.

    PubMed

    Vela, Sergi; Fumanal, Maria; Ribas-Arino, Jordi; Robert, Vincent

    2015-07-01

    The DFT + U methodology is regarded as one of the most-promising strategies to treat the solid state of molecular materials, as it may provide good energetic accuracy at a moderate computational cost. However, a careful parametrization of the U-term is mandatory since the results may be dramatically affected by the selected value. Herein, we benchmarked the Hubbard-like U-term for seven Fe(ii)N6-based pseudo-octahedral spin crossover (SCO) compounds, using as a reference an estimation of the electronic enthalpy difference (ΔHelec) extracted from experimental data (T1/2, ΔS and ΔH). The parametrized U-value obtained for each of those seven compounds ranges from 2.37 eV to 2.97 eV, with an average value of U = 2.65 eV. Interestingly, we have found that this average value can be taken as a good starting point since it leads to an unprecedented mean absolute error (MAE) of only 4.3 kJ mol(-1) in the evaluation of ΔHelec for the studied compounds. Moreover, by comparing our results on the solid state and the gas phase of the materials, we quantify the influence of the intermolecular interactions on the relative stability of the HS and LS states, with an average effect of ca. 5 kJ mol(-1), whose sign cannot be generalized. Overall, the findings reported in this manuscript pave the way for future studies devoted to understand the crystalline phase of SCO compounds, or the adsorption of individual molecules on organic or metallic surfaces, in which the rational incorporation of the U-term within DFT + U yields the required energetic accuracy that is dramatically missing when using bare-DFT functionals. PMID:26040609

  11. Predicting critical temperatures of iron(II) spin crossover materials: density functional theory plus U approach.

    PubMed

    Zhang, Yachao

    2014-12-01

    A first-principles study of critical temperatures (T(c)) of spin crossover (SCO) materials requires accurate description of the strongly correlated 3d electrons as well as much computational effort. This task is still a challenge for the widely used local density or generalized gradient approximations (LDA/GGA) and hybrid functionals. One remedy, termed density functional theory plus U (DFT+U) approach, introduces a Hubbard U term to deal with the localized electrons at marginal computational cost, while treats the delocalized electrons with LDA/GGA. Here, we employ the DFT+U approach to investigate the T(c) of a pair of iron(II) SCO molecular crystals (α and β phase), where identical constituent molecules are packed in different ways. We first calculate the adiabatic high spin-low spin energy splitting ΔE(HL) and molecular vibrational frequencies in both spin states, then obtain the temperature dependent enthalpy and entropy changes (ΔH and ΔS), and finally extract T(c) by exploiting the ΔH/T - T and ΔS - T relationships. The results are in agreement with experiment. Analysis of geometries and electronic structures shows that the local ligand field in the α phase is slightly weakened by the H-bondings involving the ligand atoms and the specific crystal packing style. We find that this effect is largely responsible for the difference in T(c) of the two phases. This study shows the applicability of the DFT+U approach for predicting T(c) of SCO materials, and provides a clear insight into the subtle influence of the crystal packing effects on SCO behavior. PMID:25481157

  12. Predicting critical temperatures of iron(II) spin crossover materials: Density functional theory plus U approach

    SciTech Connect

    Zhang, Yachao

    2014-12-07

    A first-principles study of critical temperatures (T{sub c}) of spin crossover (SCO) materials requires accurate description of the strongly correlated 3d electrons as well as much computational effort. This task is still a challenge for the widely used local density or generalized gradient approximations (LDA/GGA) and hybrid functionals. One remedy, termed density functional theory plus U (DFT+U) approach, introduces a Hubbard U term to deal with the localized electrons at marginal computational cost, while treats the delocalized electrons with LDA/GGA. Here, we employ the DFT+U approach to investigate the T{sub c} of a pair of iron(II) SCO molecular crystals (α and β phase), where identical constituent molecules are packed in different ways. We first calculate the adiabatic high spin-low spin energy splitting ΔE{sub HL} and molecular vibrational frequencies in both spin states, then obtain the temperature dependent enthalpy and entropy changes (ΔH and ΔS), and finally extract T{sub c} by exploiting the ΔH/T − T and ΔS − T relationships. The results are in agreement with experiment. Analysis of geometries and electronic structures shows that the local ligand field in the α phase is slightly weakened by the H-bondings involving the ligand atoms and the specific crystal packing style. We find that this effect is largely responsible for the difference in T{sub c} of the two phases. This study shows the applicability of the DFT+U approach for predicting T{sub c} of SCO materials, and provides a clear insight into the subtle influence of the crystal packing effects on SCO behavior.

  13. Examining Mechanisms of Groundwater Hg(II) Treatment by Reactive Materials: An EXAFS Study

    SciTech Connect

    Gibson, Blair D.; Ptacek, Carol J.; Lindsay, Matthew B.J.; Blowes, David W.

    2012-02-07

    Laboratory batch experiments were conducted to examine mechanisms of Hg(II) removal by reactive materials proposed for groundwater treatment. These materials included granular iron filings (GIF), 1:1 (w/w) mixtures of metallurgical granular Fe powder + elemental S (MGI+S) and elemental Cu + elemental S (Cu+S), granular activated carbon (GAC), attapulgite clay (ATP), ATP treated with 2-amino-5-thiol-1,3,4-thiadiazole (ATP-a), and ATP treated with 2,5-dimercapto-1,3,4-thiadiazole (ATP-d). Following treatment of simulated groundwater containing 4 mg L{sup -1} Hg for 8 or 16 days, the solution pH values ranged from 6.8 to 8.8 and Eh values ranged from +400 to -400 mV. Large decreases in aqueous Hg concentrations were observed for ATP-d (>99%), GIF (95%), MGI+S (94%), and Cu+S (90%). Treatment of Hg was less effective using ATP (29%), ATP-a (69%), and GAC (78%). Extended X-ray absorption fine structure (EXAFS) spectra of Hg on GIF, MGI+S, and GAC indicated the presence of an Hg-O bond at 2.04-2.07 {angstrom}, suggesting that Hg was bound to GIF corrosion products or to oxygen complexes associated with water sorbed to activated carbon. In contrast, bond lengths ranging from 2.35 to 2.48 {angstrom} were observed for Hg in Cu+S, ATP-a, and ATP-d treatments, suggesting the formation of Hg-S bonds.

  14. Assessment of Heat Resistance of Bacterial Spores from Food Product Isolates by Fluorescence Monitoring of Dipicolinic Acid Release

    PubMed Central

    Kort, Remco; O'Brien, Andrea C.; van Stokkum, Ivo H. M.; Oomes, Suus J. C. M.; Crielaard, Wim; Hellingwerf, Klaas J.; Brul, Stanley

    2005-01-01

    This study is aimed at the development and application of a convenient and rapid optical assay to monitor the wet-heat resistance of bacterial endospores occurring in food samples. We tested the feasibility of measuring the release of the abundant spore component dipicolinic acid (DPA) as a probe for heat inactivation. Spores were isolated from the laboratory type strain Bacillus subtilis 168 and from two food product isolates, Bacillus subtilis A163 and Bacillus sporothermodurans IC4. Spores from the lab strain appeared much less heat resistant than those from the two food product isolates. The decimal reduction times (D values) for spores from strains 168, A163, and IC4 recovered on Trypticase soy agar were 1.4, 0.7, and 0.3 min at 105°C, 120°C, and 131°C, respectively. The estimated Z values were 6.3°C, 6.1°C, and 9.7°C, respectively. The extent of DPA release from the three spore crops was monitored as a function of incubation time and temperature. DPA concentrations were determined by measuring the emission at 545 nm of the fluorescent terbium-DPA complex in a microtiter plate fluorometer. We defined spore heat resistance as the critical DPA release temperature (Tc), the temperature at which half the DPA content has been released within a fixed incubation time. We found Tc values for spores from Bacillus strains 168, A163, and IC4 of 108°C, 121°C, and 131°C, respectively. On the basis of these observations, we developed a quantitative model that describes the time and temperature dependence of the experimentally determined extent of DPA release and spore inactivation. The model predicts a DPA release rate profile for each inactivated spore. In addition, it uncovers remarkable differences in the values for the temperature dependence parameters for the rate of spore inactivation, DPA release duration, and DPA release delay. PMID:16000762

  15. Field-Selective Anomaly and Chiral Mode Reversal in Type-II Weyl Materials.

    PubMed

    Udagawa, M; Bergholtz, E J

    2016-08-19

    Three-dimensional condensed matter incarnations of Weyl fermions generically have a tilted dispersion-in sharp contrast to their elusive high-energy relatives where a tilt is forbidden by Lorentz invariance, and with the low-energy excitations of two-dimensional graphene sheets where a tilt is forbidden by either crystalline or particle-hole symmetry. Very recently, a number of materials (MoTe_{2}, LaAlGe, and WTe_{2}) have been identified as hosts of so-called type-II Weyl fermions whose dispersion is so strongly tilted that a Fermi surface is formed, whereby the Weyl node becomes a singular point connecting electron and hole pockets. We here predict that these systems have remarkable properties in the presence of magnetic fields. Most saliently, we show that the nature of the chiral anomaly depends crucially on the relative angle between the applied field and the tilt, and that an inversion-asymmetric overtilting creates an imbalance in the number of chiral modes with positive and negative slopes. The field-selective anomaly gives a novel magneto-optical resonance, providing an experimental way to detect concealed Weyl nodes. PMID:27588869

  16. Material properties of femoral cancellous bone in axial loading. Part II: Time dependent properties.

    PubMed

    Zilch, H; Rohlmann, A; Bergmann, G; Kölbel, R

    1980-01-01

    In part I of this communication we reported on some time independent material properties of cancellous bone specimens from different regions of human femora. In part II we will report on our investigations of the time dependent behaviour, i.e. stress relaxation and creep. Cylindrical specimens were obtained from the head and condyles of pairs of cadaveric femora and subjected to axial loading. The data were evaluated statistically. The medianL values for relaxation of cancellous bone were greater in the femoral head than in the condyles, greater proximally than distally and greater medially than laterally in the condyles. The distribution of creep was found to be the reverse. The correlation analysis showed that a linear correlation between compressive strength, apparent density and the time dependent properties cannot be assumed. The time dependent properties reported here would appear to demonstrate the visco-elastic behaviour of cancellous bone. An experimental foundation and explanation is presented for the clinical practice of re-tightening cancellous bone screws one time only. PMID:7458609

  17. I: Hydrodynamic-focusing microreactor II: Mechanically interlocked molecules for functional materials

    NASA Astrophysics Data System (ADS)

    Coti, Karla Karina

    I: Microreactors, a class of microfluidics, offer numerous benefits -- such as small sample requirement, short analysis times and automations -- and have been used to study reactions of chemical and biological reagents. In order to understand the relationship between fast mixing, product regioselectivity, as well as the ability to separate, in time and space, the nanoparticle (NP) formation stages, a microreactor capable of fast and controllable mixing was developed (Chapter 1) based on multi-lamination and hydrodynamic-focusing. By taking advantage of the fast and controllable mixing properties of this novel microreactor one can control the time when chemical reactions commence inside the microchannels. These properties of the microreactor can be exploited to improve the product regioselectivity of a diazo-coupling reaction to attain a product distribution of monoazo to diazo product of ˜1:99, a selectivity unprecedented in both conventional, macroscopic reactors and other microfluidic systems. Additionally, the ability to separate different stages during the NP formation process inside the microreactor, allowed us to study the aggregation of polypyrrole NPs. II: Supramolecular actuators and molecular interlocked molecules, such as catenanes and rotaxanes, have attracted considerable attention because of their sophisticated topology and their application in functional molecular devices. The blending of supramolecular and mechanostereochemistry with mesoporous silica NPs has proven to be a powerful combination, leading to the development of a new class of materials -- mechanized silica nanoparticles ( Chapter 2). These new hybrid materials are designed to release their content in response to an external stimuli and their development is being driven by the need to improve current drug delivery technologies. In an effort to explore how the stimuli-controlled mechanical movement of switchable, bistable [2]rotaxanes -- based on a cyclobis(paraquat-p-phenylene) ring

  18. Preparation and characterization of Fe-Al intermetallic layer on the surface of T91 heat-resistant steel

    NASA Astrophysics Data System (ADS)

    Shi, Zimu; Cao, Jianbo; Han, Fusheng

    2014-04-01

    A Fe-Al intermetallic layer was formed on the surface of T91 heat-resistant steel by a molten aluminum hot-dipping and heat diffusion treatment. It is shown that the layer was composed of Al, FeAl3 and Fe2Al5 phases in the as-dipped state while only Fe3Al phase retained after the heat treatment. The intermetallic layer exhibited typical columnar grain structure after the heat treatment, and the thickness of aluminizing layer was increased from 55 μm at 760 °C to around 100 μm at 1050 °C heat treatment. Such a phase composition and grain morphology are favorable for the oxidation and corrosion resistance of T91 steel.

  19. Intergranular Cracking Susceptibility of 2.25Cr Heat-Resistant Steels Depending on Alloying Elements and Impurities

    NASA Astrophysics Data System (ADS)

    Sung, Hyun Je; Heo, Nam Hoe; Kim, Sung-Joon

    2016-05-01

    The intergranular cracking susceptibility of 2.25Cr heat-resistant steels increases with increasing bulk phosphorus content. This is due to the increase in phosphorus segregation concentration of prior austenite grain boundaries (PAGBs) and the prior austenite grain boundary/carbide interfaces (GCIs) with increasing bulk phosphorus content. Moreover, the susceptibility is higher in tungsten-added steels than the molybdenum-added steel. This is attributed to the higher driving force for carbide formation of tungsten which causes more active carbide formation in the tungsten-added steel, the consequent absence of the repulsive segregation between carbon and phosphorus, and the final higher phosphorus segregation concentration at the PAGBs and the GCIs. Additionally, the absence of sulfur segregation at the PAGBs and the GCIs of the molybdenum-added steel, which arises from the repulsive segregation between carbon and sulfur, acts as an additional factor which lowers the intergranular cracking susceptibility.

  20. Microstructure and mechanical properties of heat-resistant 12% Cr ferritic-martensitic steel EK-181 after thermomechanical treatment

    NASA Astrophysics Data System (ADS)

    Polekhina, N. A.; Litovchenko, I. Yu.; Tyumentsev, A. N.; Astafurova, E. G.; Chernov, V. M.; Leontyeva-Smirnova, M. V.

    2015-10-01

    The effect of high-temperature thermomechanical treatment (TMT) with the deformation in the austenitic region on the features of microstructure, phase transformations and mechanical properties of low-activation 12% Cr ferritic-martensitic steel EK-181 is investigated. It is established, that directly after thermomechanical treatment (without tempering) the sizes and density of V(CN) particles are comparable with those after a traditional heat treatment (air quenching and tempering at 720°C, 3 h), where these particles are formed only during tempering. It causes the increasing of the yield strength of the steel up to ≈1450 MPa at room temperature and up to ≈430 MPa at the test temperature T = 650°C. The potential of microstructure modification by this treatment aimed at improving heat resistance of steel is discussed.

  1. Effect of thymol in heating and recovery media on the isothermal and non-isothermal heat resistance of Bacillus spores.

    PubMed

    Esteban, Maria-Dolores; Conesa, Raquel; Huertas, Juan-Pablo; Palop, Alfredo

    2015-06-01

    Members of the genus Bacillus include important food-borne pathogen and spoilage microorganisms for food industry. Essential oils are natural products extracted from herbs and spices, which can be used as natural preservatives in many foods because of their antibacterial, antifungal, antioxidant and anti-carcinogenic properties. The aim of this research was to explore the effect of the addition of different concentrations of thymol to the heating and recovery media on the thermal resistance of spores of Bacillus cereus, Bacillus licheniformis and Bacillus subtilis at different temperatures. While the heat resistance was hardly reduced when thymol was present in the heating medium, the effect in the recovery medium was greater, reducing the D100 °C values down to one third for B. subtilis and B. cereus when 0.5 mM thymol was added. This effect was dose dependent and was also observed at other heating temperatures. PMID:25790989

  2. New Methods of Simulation of Mn(II) EPR Spectra: Single Crystals, Polycrystalline and Amorphous (Biological) Materials

    NASA Astrophysics Data System (ADS)

    Misra, Sushil K.

    Biological systems exhibit properties of amorphous materials. The Mn(II) ion in amorphous materials is characterized by distributions of spin-Hamiltonian parameters around mean values. It has a certain advantage over other ions, being one of the most abundant elements on the earth. The extent to which living organisms utilize manganese varies from one organism to the other. There is a fairly high concentration of the Mn(II) ion in green plants, which use it in the O2 evolution reaction of photosynthesis (Sauer, 1980). Structure-reactivity relationships in Mn(II)-O2 complexes are given in a review article by Coleman and Taylor (1980). Manganese is a trace requirement in animal nutrition; highly elevated levels of manganese in the diet can be toxic, probably because of an interference with iron homeostasis (Underwood, 1971). On the other hand, animals raised with a dietary deficiency of manganese exhibit severe abnormalities in connective tissue; these problems have been attributed to the obligatory role of Mn(II) in mucopolysaccharide metabolism (Leach, 1971). Mn(II) has been detected unequivocally in living organisms.

  3. Possibility of enhancement of the high-temperature strength and the heat resistance of a nickel aluminide-based structural intermetallic alloy

    NASA Astrophysics Data System (ADS)

    Bazyleva, O. A.; Shestakov, A. V.; Arginbaeva, E. G.; Turenko, E. Yu.

    2016-01-01

    The assimilation of a number of rare-earth metals (REM = praseodymium, neodymium, erbium) in a cast high-temperature nickel aluminide-based intermetallic alloy and the effect of REM alloying of the alloy on the critical temperatures, the high-temperature strength, and the heat resistance (time to failure) of the structural alloy are studied. It is shown that the heat resistance and the time to failure of the alloy at 1200°C can be increased by microalloying of the intermetallic alloy with REM.

  4. Sol-gel encapsulation of binary Zn(II) compounds in silica nanoparticles. Structure-activity correlations in hybrid materials targeting Zn(II) antibacterial use.

    PubMed

    Halevas, E; Nday, C M; Kaprara, E; Psycharis, V; Raptopoulou, C P; Jackson, G E; Litsardakis, G; Salifoglou, A

    2015-10-01

    In the emerging issue of enhanced multi-resistant properties in infectious pathogens, new nanomaterials with optimally efficient antibacterial activity and lower toxicity than other species attract considerable research interest. In an effort to develop such efficient antibacterials, we a) synthesized acid-catalyzed silica-gel matrices, b) evaluated the suitability of these matrices as potential carrier materials for controlled release of ZnSO4 and a new Zn(II) binary complex with a suitably designed well-defined Schiff base, and c) investigated structural and textural properties of the nanomaterials. Physicochemical characterization of the (empty-loaded) silica-nanoparticles led to an optimized material configuration linked to the delivery of the encapsulated antibacterial zinc load. Entrapment and drug release studies showed the competence of hybrid nanoparticles with respect to the a) zinc loading capacity, b) congruence with zinc physicochemical attributes, and c) release profile of their zinc load. The material antimicrobial properties were demonstrated against Gram-positive (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus) and negative (Escherichia coli, Pseudomonas aeruginosa, Xanthomonas campestris) bacteria using modified agar diffusion methods. ZnSO4 showed less extensive antimicrobial behavior compared to Zn(II)-Schiff, implying that the Zn(II)-bound ligand enhances zinc antimicrobial properties. All zinc-loaded nanoparticles were less antimicrobially active than zinc compounds alone, as encapsulation controls their release, thereby attenuating their antimicrobial activity. To this end, as the amount of loaded zinc increases, the antimicrobial behavior of the nano-agent improves. Collectively, for the first time, sol-gel zinc-loaded silica-nanoparticles were shown to exhibit well-defined antimicrobial activity, justifying due attention to further development of antibacterial nanotechnology. PMID:26198972

  5. Using coal fly ash as a support for Mn(II), Co(II) and Ni(II) and utilizing the materials as novel oxidation catalysts for 4-chlorophenol mineralization.

    PubMed

    Deka, Bharati; Bhattacharyya, K G

    2015-03-01

    In this work, Mn(II), Co(II) and Ni(II) were incorporated into waste coal fly ash used as a catalyst support by refluxing with the appropriate aqueous salt solution. The materials were calcined at 773-873 K for 5 h and the amount of divalent cations entering into the fly ash was determined by AAS measurements. Further characterization included estimation of oxides by XRF, structural properties by XRD, topographical features by SEM, surface functional groups by FT-IR, surface area and pore dimensions by BET N2-adsorption isotherms. The efficiency of the materials as environmental oxidation catalysts were tested with respect to destruction of 4-chlorophenol (4-CP) in water in the presence of hydrogen peroxide. Considered as one of the most persistent, toxic and largely applied organic compound, 4-CP enters water from the effluents of petrochemical, plastic, pesticide, kraft mill and other organochemical industries and research centers. Wet oxidation of 4-CP was tested by varying the mole ratio of 4-CP and H2O2, catalyst load, temperature, reaction time, 4-CP concentration and pH. Oxidation of 4-CP (5 × 10(-3) M or 643 mg L(-1)) was 51.1% for Mn(II)-fly ash, 58.3% for Co(II)-fly ash and 61.0% for Ni(II)-fly ash after 180 min at 323 K with 4-CP: H2O2 mole ratio of 1:1. COD load of the reaction mixture (4-CP: 5 × 10(-3) M, H2O2: 5 × 10(-3) M, catalyst load: 1.0 g L(-1), temperature 323 K, reaction time 0-240 min) decreased from 1480 to 620, 380, and 140 mg L(-1) respectively after oxidation with Mn(II)-fly ash, Co(II)-fly ash and Ni(II)-fly ash (overall COD reduction was 58.0, 74.3 and 90.5% respectively). The oxidation followed second order kinetics with the average rate coefficient of 7.9, 1.3 and 1.2 L mol(-1) min(-1) for Mn(II)-, Co(II)- and Ni(II)-fly ash. Increase in H2O2: 4-CP mole ratio from 1:1 to 20:1 (reaction time 300 min, catalyst load 1.0 g L(-1)) enhanced destruction from 52.1 to 95.6% for Mn(II)-fly ash, 58.3-95.6% for Co(II)-fly ash and from 60.4 to

  6. CONTINUOUS MULTILIGAND DISTRIBUTION MODEL USED TO PREDICT THE STABILITY CONSTANT OF CU(II) METAL COMPLEXATION WITH HUMIC MATERIAL FROM FLUORESCENCE QUENCHING DATA

    EPA Science Inventory

    We report the use of a pH-dependent continuous multiligand distribution model to determine the stability constant between Cu(II) and dissolved humic material. luorescence quenching of the humic material by Cu(II) is used to produce spectral titration curves. he values form the ti...

  7. Ultrastrong Polyoxyzole Nanofiber Membranes for Dendrite-Proof and Heat-Resistant Battery Separators.

    PubMed

    Hao, Xiaoming; Zhu, Jian; Jiang, Xiong; Wu, Haitao; Qiao, Jinshuo; Sun, Wang; Wang, Zhenhua; Sun, Kening

    2016-05-11

    Polymeric nanomaterials emerge as key building blocks for engineering materials in a variety of applications. In particular, the high modulus polymeric nanofibers are suitable to prepare flexible yet strong membrane separators to prevent the growth and penetration of lithium dendrites for safe and reliable high energy lithium metal-based batteries. High ionic conductance, scalability, and low cost are other required attributes of the separator important for practical implementations. Available materials so far are difficult to comply with such stringent criteria. Here, we demonstrate a high-yield exfoliation of ultrastrong poly(p-phenylene benzobisoxazole) nanofibers from the Zylon microfibers. A highly scalable blade casting process is used to assemble these nanofibers into nanoporous membranes. These membranes possess ultimate strengths of 525 MPa, Young's moduli of 20 GPa, thermal stability up to 600 °C, and impressively low ionic resistance, enabling their use as dendrite-suppressing membrane separators in electrochemical cells. With such high-performance separators, reliable lithium-metal based batteries operated at 150 °C are also demonstrated. Those polyoxyzole nanofibers would enrich the existing library of strong nanomaterials and serve as a promising material for large-scale and cost-effective safe energy storage. PMID:27105287

  8. Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma evokes distinct changes in morphology and integrity of spores.

    PubMed

    van Bokhorst-van de Veen, Hermien; Xie, Houyu; Esveld, Erik; Abee, Tjakko; Mastwijk, Hennie; Nierop Groot, Masja

    2015-02-01

    Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for validation of chemical sterilization and thermal processes, respectively. The different spores showed variation in their degree of inactivation by applied heat, hypochlorite, hydrogen peroxide, and UV treatments, whereas similar inactivation results were obtained with the different spores treated with nitrogen CAP. G. stearothermophilus spores displayed high resistance to heat, hypochlorite, hydrogen peroxide, while for UV treatment B. atrophaeus spores are most tolerant. Scanning electron microscopy analysis revealed distinct morphological changes for nitrogen CAP-treated B. cereus spores including etching effects and the appearance of rough spore surfaces, whereas morphology of spores treated with heat or disinfectants showed no such changes. Moreover, microscopy analysis revealed CAP-exposed B. cereus spores to turn phase grey conceivably because of water influx indicating damage of the spores, a phenomenon that was not observed for non-treated spores. In addition, data are supplied that exclude UV radiation as determinant of antimicrobial activity of nitrogen CAP. Overall, this study shows that nitrogen CAP treatment has a biocidal effect on selected Bacillus and Geobacillus spores associated with alterations in spore surface morphology and loss of spore integrity. PMID:25481059

  9. Dry-heat Resistance of Bacillus Subtilis Var. Niger Spores on Mated Surfaces

    NASA Technical Reports Server (NTRS)

    Simko, G. J.; Devlin, J. D.; Wardle, M. D.

    1971-01-01

    Bacillus subtilis var. niger spores were placed on the surfaces of test coupons manufactured from typical spacecraft materials including stainless steel, magnesium, titanium, and aluminum. These coupons were then juxtaposed at the inoculated surfaces and subjected to test pressures of 0, 1000, 5000, and 10,000 psi. Tests were conducted in ambient, nitrogen, and helium atmospheres. While under the test pressure condition, the spores were exposed to 125 C for intervals of 5, 10, 20, 50, or 80 min. Survivor data were subjected to a linear regression analysis that calculated decimal reduction times.

  10. Fire and heat resistant laminating resins based on maleimido substituted aromatic cyclotriphosphazene polymer

    NASA Technical Reports Server (NTRS)

    Kumar, Devendra (Inventor); Fohlen, George M. (Inventor); Parker, John A. (Inventor)

    1987-01-01

    4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g., hexakis amino or trisaminophenoxy trisphenoxy cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

  11. Design and characterization of a composite material based on Sr(II)-loaded clay nanotubes included within a biopolymer matrix.

    PubMed

    Del Buffa, Stefano; Bonini, Massimo; Ridi, Francesca; Severi, Mirko; Losi, Paola; Volpi, Silvia; Al Kayal, Tamer; Soldani, Giorgio; Baglioni, Piero

    2015-06-15

    This paper reports on the preparation, characterization, and cytotoxicity of a hybrid nanocomposite material made of Sr(II)-loaded Halloysite nanotubes included within a biopolymer (3-polyhydroxybutyrate-co-3-hydroxyvalerate) matrix. The Sr(II)-loaded inorganic scaffold is intended to provide mechanical resistance, multi-scale porosity, and to favor the in-situ regeneration of bone tissue thanks to its biocompatibility and bioactivity. The interaction of the hybrid system with the physiological environment is mediated by the biopolymer coating, which acts as a binder, as well as a diffusional barrier to the Sr(II) release. The degradation of the polymer progressively leads to the exposure of the Sr(II)-loaded Halloysite scaffold, tuning its interaction with osteogenic cells. The in vitro biocompatibility of the composite was demonstrated by cytotoxicity tests on L929 fibroblast cells. The results indicate that this composite material could be of interest for multiple strategies in the field of bone tissue engineering. PMID:25778738

  12. Predictive model for the reduction of heat resistance of Listeria monocytogenes in ground beef by the combined effect of sodium chloride and apple polyphenols

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the combined effect of three internal temperatures (57.5, 60, and 62.5C) and different concentrations (0 to 3.0 wt/wt %) of sodium chloride (NaCl) and apple polyphenols (APP), individually and in combination, on the heat-resistance of a five-strain cocktail of Listeria monocytogenes ...

  13. A low dose pre-irradiation induces radio- and heat-resistance via HDM2 and NO radicals, and is associated with p53 functioning

    NASA Astrophysics Data System (ADS)

    Takahashi, A.; Ohnishi, T.

    2009-04-01

    The aim of this work was to clarify the effect of low dose pre-irradiation on radio- and heat-sensitivity. Wild-type (wt) p53 and mutated (m) p53 cells derived from the human lung cancer H1299 cell line were used. The parental H1299 cell line is p53-null. Cellular sensitivities were determined with a colony-forming assay. When wtp53 cells were exposed to a low dose X-irradiation, induction of radio- and heat-resistance was observed only in the absence of RITA (an inhibitor of p53-HDM2 interactions), aminoguanidine (an iNOS inhibitor) and c-PTIO (an NO radical scavenger). In contrast, the induced radio- and heat-resistance was not observed under similar conditions in mp53 cells. Moreover, heat-resistance as well as radio-resistance developed when wtp53 cells were treated with ISDN (an NO generating agent) alone. These findings suggest that NO radicals are an initiator of radio- and heat-resistance, and function through the activation of HDM2 and the depression of p53 accumulation.

  14. [Induction of heat resistance in wheat coleoptiles by salicylic and succinic acids: connection of the effect with the generation and neutralization of active oxygen forms].

    PubMed

    Kolupaev, Iu E; Iastreb, T O; Shvidenko, N V; Karpets, Iu V

    2012-01-01

    The influence of salicylic (SaA) and succinic (SuA) acids on the generation of active oxygen forms (AOFs) and the heat resistance of wheat (Triticum aestivum L.) coleoptiles has been studied. The treatment of coleoptiles with 10 microM SaA or SuA results in the accumulation of hydrogen peroxide and enhanced formation of a superoxide anion radical. This effect is partially suppressed by both alpha-naphthol (the NADPH oxidase inhibitor) and salicylhydroxamic acid (peroxidase inhibitor). SaA and SuA cause an increase in the activity of antioxidant enzymes, such as superoxide dismutase, catalase, and soluble peroxidase, and improve the heat resistance ofcoleoptiles. Antioxidant ionol and compounds, which inhibit the NADPH oxidase and peroxidase, significantly reduce the positive influence of SaA and SuA on the heat resistance of wheat coleoptiles. AOFs are considered to be intermediates for heat resistance induction in coleoptiles, treated with SaA and SuA; enhanced AOF generation can be caused by an increased activity of the NADPH oxidase and peroxidase. PMID:23101394

  15. Color-tunable heat-resistant polyaryletherketones co-coordinated with various rare earth ions

    NASA Astrophysics Data System (ADS)

    Liu, Dan; Shi, Qirong; Wang, Zhonggang

    2012-09-01

    Europium (Eu3+) and terbium (Tb3+) ions coordinated with 1,10-phenantroline (Phen), N,N-dimethylformamide (DMF) and carboxyl-containing polyaryletherketone (PEK) represent new luminescent materials (PEK-Eux3+Tb1-x3+-Phens, x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1). The results of FTIR, elemental analysis and XRD confirm that the coordination reaction indeed occurs and the rare earth ions are homogeneously dispersed in the PEK matrix. The polyarylethertone rare earth complexes exhibit high glass transition temperature and good thermal stability because of their wholly aromatic structures. The luminescence measurements indicate that the relative emission intensities of Tb3+ to Eu3+ ions depend on their ratio in the system, and the color of PEK-Eux3+Tb1-x3+-Phens under UV excitation can be tuned by changing the x value. The materials thus prepared show promising potential in the full color large area display field.

  16. Band Offsets of III-V and II-VI Materials Studied by Temperature-Dependent Internal Photoemission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Perera, A. G. U.; Lao, Y. F.; Wijewarnasuriya, P. S.; Krishna, S. S.

    2016-06-01

    The band offset at the interface of a heterojunction is one of the most important parameters determining the characteristics of devices constructed from heterojunction. Accurate knowledge of band offsets and their temperature dependence will allow one to simulate and predict the device performances. We present a temperature-dependent internal-photoemission spectroscopy (TDIPS) for studying the band offsets. Applications of the TDIPS into III-V and II-VI materials are discussed.

  17. Kinetics of isochronal austenization in modified high Cr ferritic heat-resistant steel

    NASA Astrophysics Data System (ADS)

    Liu, Chenxi; Liu, Yongchang; Zhang, Dantian; Yan, Zesheng

    2011-12-01

    Employment of high Cr ferritic steels as a main structural material is considered as a way to achieve economical competitiveness of main steam pipe and nuclear reactors in power plants. Differential dilatometry and microstructure observation were employed to investigate the isochronal austenitic transformation of the modified high Cr ferritic steel. The kinetics of the isochronal austenitic transformation were described by a phase-transformation model involving site saturation (pre-existing nuclei), diffusion-controlled growth, and incorporating an impingement correction. The experimental results and kinetic analysis indicate that an increase of the heating rate promotes the diffusion-controlled austenitic transformation. The dissolving degree of precipitates during the austenization process affects the activation energy for diffusion and the undissolved precipitates lead to an increase of the onset temperature of the subsequent martensite transformation upon cooling.

  18. Heat treating of a lamellar eutectic alloy (gamma/gamma prime + delta). [heat resistant alloys

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.; Dreshfield, R. L.

    1976-01-01

    Eutectic superalloys are being developed at several laboratories for application as aircraft gas turbine airfoils. One such alloy was subjected to several heat treatments to determine if its mechanical properties could be improved. It was found that by partially dissolving the alloy at 1210 C and then aging at 900 C the tensile strength can be increased about 12 percent at temperatures up to 900 C. At 1040 C no change in tensile strength was observed. Times to rupture were measured between 760 and 1040 C and were essentially the same or greater than for as-grown material. Tensile and rupture ductility of the alloy are reduced by heat treatment. Photographs of the microstructure are shown.

  19. Novel heat-resistance UV curable waterborne polyurethane coatings modified by melamine

    NASA Astrophysics Data System (ADS)

    Fang, Z. H.; Duan, H. Y.; Zhang, Z. H.; Wang, J.; Li, D. Q.; Huang, Y. X.; Shang, J. J.; Liu, Z. Y.

    2011-03-01

    Novel UV curable waterborne polyurethane coatings (UVWPU) modified by melamine was prepared using isophorone diisocyanate (IPDI), polyethylene glycol (PEG), α,α-dimethylol propionic acid (DMPA), hydroxyethyl acrylate (HEA) as main materials. Copolymer structure was verified using Fourier transform infrared spectroscopy (FT-IR). Performance of the coatings was evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), and mechanical tests such as pencil hardness and resistance to water. The results showed that the modified UVWPU film had the good thermal resistance, water resistance and mechanical properties. The optimum melamine dosage was 4.70 wt.%, the glass transition temperature ( Tg) of the modified film increased by 20.4 °C and 5% weight-loss temperature (253 °C) increased by 105 °C. No change color, crinkle, desquamate, dehisce and frothy were found after the modified film dried at 130 °C for 2 h.

  20. Coatings of active and heat-resistant cobalt-aluminium xerogel catalysts.

    PubMed

    Schubert, Miriam; Schubert, Lennart; Thomé, Andreas; Kiewidt, Lars; Rosebrock, Christopher; Thöming, Jorg; Roessner, Frank; Bäumer, Marcus

    2016-09-01

    The application of catalytically coated metallic foams in catalytic processes has a high potential for exothermic catalytic reactions such as CO2 methanation or Fischer-Tropsch synthesis due to good heat conductivity, improved turbulent flow properties and high catalyst efficiencies. But the preparation of homogenous catalyst coats without pore blocking is challenging with conventional wash coating techniques. Here, we report on a stable and additive free colloidal CoAlOOH suspension (sol) for the preparation of catalytically active Co/Al2O3 xerogel catalysts and coatings. Powders with 18wt% Co3O4 prepared from this additive free synthesis route show a catalytic activity in Fischer-Tropsch synthesis and CO2 methanation which is similar to a catalyst prepared by incipient wetness impregnation (IWI) after activating the material under flowing hydrogen at 430°C. Yet, the xerogel catalyst exhibits a much higher thermal stability as compared to the IWI catalyst, as demonstrated in catalytic tests after different heat agings between 430°C and 580°C. It was also found that the addition of polyethylene glycol (PEG) to the sol influences the catalytic properties of the formed xerogels negatively. Only non-reducible cobalt spinels were formed from a CoAlOOH sol with 20wt% PEG. Metallic foams with pores sizes between 450 and 1200μm were coated with the additive free CoAlOOH sol, which resulted in homogenous xerogel layers. First catalytic tests of the coated metal foams (1200μm) showed good performance in CO2 methanation. PMID:27240245

  1. A Guide for Selecting Bilingual Bicultural Resource Materials. [Volume II]. Analyses and Annotations of Dutch Bilingual and Bicultural Resource Materials.

    ERIC Educational Resources Information Center

    Watt, Michael; De Jong, Marilyn

    This is the second of three volumes reporting a project to develop an instrument to evaluate instructional materials used in bilingual education, community language education, and bicultural education programs in Australian schools. The project had three purposes: (1) to examine the research literature on the development of models and instruments…

  2. Screening foods for processing-resistant bacterial spores and characterization of a pressure- and heat-resistant Bacillus licheniformis isolate.

    PubMed

    Ahn, Juhee; Balasubramaniam, V M

    2014-06-01

    This study was carried out to isolate pressure- and heat-resistant indicator spores from selected food matrices (black pepper, red pepper, garlic, and potato peel). Food samples were processed under various thermal (90 to 105°C) and pressure (700 MPa) combination conditions, and surviving microorganisms were isolated. An isolate from red pepper powder, Bacillus licheniformis, was highly resistant to pressure-thermal treatments. Spores of the isolate in deionized water were subjected to the combination treatments of pressure (0.1 to 700 MPa) and heat (90 to 121°C). Compared with the thermal treatment, the combined pressure-thermal treatments considerably reduced the numbers of B. licheniformis spores to less than 1.0 log CFU/g at 700 MPa plus 105°C and at 300 to 700 MPa plus 121°C. The inactivation kinetic parameters of the isolated B. licheniformis spores were estimated using linear and nonlinear models. Within the range of the experimental conditions tested, the pressure sensitivity (zP) of the spores decreased with increasing temperature (up to 121°C), and the temperature sensitivity (zT) was maximum at atmospheric pressure (0.1 MPa). These results will be useful for developing a combined pressure-thermal inactivation kinetics database for various bacterial spores. PMID:24853517

  3. Oxidation resistance of eight heat-resistant alloys at 870, 980, 1,095, and 1,150 C

    SciTech Connect

    Rundell, G.; McConnell, J. )

    1991-10-01

    Oxidation testing of heat-resistant alloys is described. The testing procedure utilized weight-gain measurements using one specimen, which was withdrawn and weighted at intervals of 1 week, for 10-18 weeks. The specimen was placed in a porcelain cup during exposure and covered upon cooling to retain spalled oxide. Weight gain was used to determine the kinetics of oxidation and was extrapolated to 3,000 hr. The specimen was withdrawn at the end of the exposure, weighed, cathodically descaled, and reweighed. The ratio of oxygen ions to metal ions was determined for each alloy and test temperature. This ratio approaches the stoichiometric ratio for Fe{sub 3}O{sub 4} or Cr{sub 2}O{sub 3}. The ratio for each test is used to convert weight gain to weight loss. The amount of adherent oxide was determined as well as the total amount of oxide, leading to an expression for oxide adherency. The oxidation resistance of Fe-Cr-Ni alloys increased with increasing Cr and Ni, with Cr being the most critical element. Additions of Si, Al, or Ce were shown to extend the usefulness of Fe-Cr-Ni alloys.

  4. Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery.

    PubMed

    Zhang, Jianjun; Yue, Liping; Kong, Qingshan; Liu, Zhihong; Zhou, Xinhong; Zhang, Chuanjian; Xu, Quan; Zhang, Bo; Ding, Guoliang; Qin, Bingsheng; Duan, Yulong; Wang, Qingfu; Yao, Jianhua; Cui, Guanglei; Chen, Liquan

    2014-01-01

    A sustainable, heat-resistant and flame-retardant cellulose-based composite nonwoven has been successfully fabricated and explored its potential application for promising separator of high-performance lithium ion battery. It was demonstrated that this flame-retardant cellulose-based composite separator possessed good flame retardancy, superior heat tolerance and proper mechanical strength. As compared to the commercialized polypropylene (PP) separator, such composite separator presented improved electrolyte uptake, better interface stability and enhanced ionic conductivity. In addition, the lithium cobalt oxide (LiCoO2)/graphite cell using this composite separator exhibited better rate capability and cycling retention than that for PP separator owing to its facile ion transport and excellent interfacial compatibility. Furthermore, the lithium iron phosphate (LiFePO4)/lithium cell with such composite separator delivered stable cycling performance and thermal dimensional stability even at an elevated temperature of 120°C. All these fascinating characteristics would boost the application of this composite separator for high-performance lithium ion battery. PMID:24488228

  5. Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery

    PubMed Central

    Zhang, Jianjun; Yue, Liping; Kong, Qingshan; Liu, Zhihong; Zhou, Xinhong; Zhang, Chuanjian; Xu, Quan; Zhang, Bo; Ding, Guoliang; Qin, Bingsheng; Duan, Yulong; Wang, Qingfu; Yao, Jianhua; Cui, Guanglei; Chen, Liquan

    2014-01-01

    A sustainable, heat-resistant and flame-retardant cellulose-based composite nonwoven has been successfully fabricated and explored its potential application for promising separator of high-performance lithium ion battery. It was demonstrated that this flame-retardant cellulose-based composite separator possessed good flame retardancy, superior heat tolerance and proper mechanical strength. As compared to the commercialized polypropylene (PP) separator, such composite separator presented improved electrolyte uptake, better interface stability and enhanced ionic conductivity. In addition, the lithium cobalt oxide (LiCoO2)/graphite cell using this composite separator exhibited better rate capability and cycling retention than that for PP separator owing to its facile ion transport and excellent interfacial compatibility. Furthermore, the lithium iron phosphate (LiFePO4)/lithium cell with such composite separator delivered stable cycling performance and thermal dimensional stability even at an elevated temperature of 120°C. All these fascinating characteristics would boost the application of this composite separator for high-performance lithium ion battery. PMID:24488228

  6. Enhanced Heat Resistance of Al-Cu-Mg Alloy by a Combination of Pre-stretching and Underaging

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohu; Liu, Zhiyi; Bai, Song; Lin, Lianghua; Ye, Chengwu; Wang, Heng

    2016-06-01

    Enhanced heat resistance of Al-Cu-Mg alloy by employing a combined effect of pre-stretching and underaging has been characterized by thermal exposure, tensile testing, transmission electron microscopy (TEM) examination, and quantitative analysis. Tensile testing results showed that the samples subjected to both pre-stretching and underaging processing, presented a high tensile strength up to 440 MPa after thermal exposure at 200 °C for 500 h. This suggests that the long-time application temperature of Al-Cu-Mg alloys, which were normally applied at elevated temperature below 150 °C or even below 100 °C, can be raised to 200 °C by employing a combined effect of pre-stretching and underaging. TEM results showed that a fine and a narrow size distribution range of S' phase was formed by the combined processing of pre-stretching and underaging, as compared to that without pre-stretching. Quantitative analysis results indicated that this narrow range of size distribution greatly reduced the growth rate of S' phase during thermal exposure. It is suggested that this effect was ascribed to the Ostwald ripening mechanism.

  7. A novel mechanism of protein thermostability: a unique N-terminal domain confers heat resistance to Fe/Mn-SODs.

    PubMed

    Wang, Wei; Ma, Ting; Zhang, Baoliang; Yao, Nana; Li, Mingchang; Cui, Lianlei; Li, Guoqiang; Ma, Zhenping; Cheng, Jiansong

    2014-01-01

    Superoxide dismutases (SODs), especially thermostable SODs, are widely applied in medical treatments, cosmetics, food, agriculture, and other industries given their excellent antioxidant properties. A novel thermostable cambialistic SOD from Geobacillus thermodenitrificans NG80-2 exhibits maximum activity at 70 °C and high thermostability over a broad range of temperatures (20-80 °C). Unlike other reported SODs, this enzyme contains an extra repeat-containing N-terminal domain (NTD) of 244 residues adjacent to the conserved functional SODA domain. Deletion of the NTD dramatically decreased its optimum active temperature (OAT) to 30 °C and also impaired its thermostability. Conversely, appending the NTD to a mesophilic counterpart from Bacillus subtilis led to a moderately thermophilic enzyme (OAT changed from 30 to 55 °C) with improved heat resistance. Temperature-dependant circular dichroism analysis revealed the enhanced conformational stability of SODs fused with this NTD. Furthermore, the NTD also contributes to the stress resistance of host proteins without altering their metal ion specificity or oligomerisation form except for a slight effect on their pH profile. We therefore demonstrate that the NTD confers outstanding thermostability to the host protein. To our knowledge, this is the first discovery of a peptide capable of remarkably improving protein thermostability and provides a novel strategy for bioengineering thermostable SODs. PMID:25445927

  8. A novel mechanism of protein thermostability: a unique N-terminal domain confers heat resistance to Fe/Mn-SODs

    PubMed Central

    Wang, Wei; Ma, Ting; Zhang, Baoliang; Yao, Nana; Li, Mingchang; Cui, Lianlei; Li, Guoqiang; Ma, Zhenping; Cheng, Jiansong

    2014-01-01

    Superoxide dismutases (SODs), especially thermostable SODs, are widely applied in medical treatments, cosmetics, food, agriculture, and other industries given their excellent antioxidant properties. A novel thermostable cambialistic SOD from Geobacillus thermodenitrificans NG80-2 exhibits maximum activity at 70°C and high thermostability over a broad range of temperatures (20–80°C). Unlike other reported SODs, this enzyme contains an extra repeat-containing N-terminal domain (NTD) of 244 residues adjacent to the conserved functional SODA domain. Deletion of the NTD dramatically decreased its optimum active temperature (OAT) to 30°C and also impaired its thermostability. Conversely, appending the NTD to a mesophilic counterpart from Bacillus subtilis led to a moderately thermophilic enzyme (OAT changed from 30 to 55°C) with improved heat resistance. Temperature-dependant circular dichroism analysis revealed the enhanced conformational stability of SODs fused with this NTD. Furthermore, the NTD also contributes to the stress resistance of host proteins without altering their metal ion specificity or oligomerisation form except for a slight effect on their pH profile. We therefore demonstrate that the NTD confers outstanding thermostability to the host protein. To our knowledge, this is the first discovery of a peptide capable of remarkably improving protein thermostability and provides a novel strategy for bioengineering thermostable SODs. PMID:25445927

  9. Scorpion Venom Heat-Resistant Peptide Attenuates Glial Fibrillary Acidic Protein Expression via c-Jun/AP-1.

    PubMed

    Cao, Zhen; Wu, Xue-Fei; Peng, Yan; Zhang, Rui; Li, Na; Yang, Jin-Yi; Zhang, Shu-Qin; Zhang, Wan-Qin; Zhao, Jie; Li, Shao

    2015-11-01

    Scorpion venom has been used in the Orient to treat central nervous system diseases for many years, and the protein/peptide toxins in Buthus martensii Karsch (BmK) venom are believed to be the effective components. Scorpion venom heat-resistant peptide (SVHRP) is an active component of the scorpion venom extracted from BmK. In a previous study, we found that SVHRP could inhibit the formation of a glial scar, which is characterized by enhanced glial fibrillary acidic protein (GFAP) expression, in the epileptic hippocampus. However, the cellular and molecular mechanisms underlying this process remain to be clarified. The results of the present study indicate that endogenous GFAP expression in primary rat astrocytes was attenuated by SVHRP. We further demonstrate that the suppression of GFAP was primarily mediated by inhibiting both c-Jun expression and its binding with AP-1 DNA binding site and other factors at the GFAP promoter. These results support that SVHRP contributes to reducing GFAP at least in part by decreasing the activity of the transcription factor AP-1. In conclusion, the effects of SVHRP on astrocytes with respect to the c-Jun/AP-1 signaling pathway in vitro provide a practical basis for studying astrocyte activation and inhibition and a scientific basis for further studies of traditional medicine. PMID:26134308

  10. Development and Exchange of Instructional Resources in Water Quality Control Programs, II: Instructional Materials Available.

    ERIC Educational Resources Information Center

    Austin, John H.

    This document is one in a series of reports which reviews instructional materials and equipment for water and wastewater treatment plant personnel. Approximately 900 items are listed in this document along with guidelines for the production of instructional materials. Information is provided regarding the source, type of material, intended…

  11. Removal of Cd (II) from synthetic wastewater by alginate-Ayous wood sawdust (Triplochiton scleroxylon) composite material.

    PubMed

    Njimou, Jacques Romain; Măicăneanu, Andrada; Indolean, Cerasella; Nanseu-Njiki, Charles Péguy; Ngameni, Emmanuel

    2016-06-01

    The biosorption characteristics of Cd (II) ions from synthetic wastewater using raw Ayous wood sawdust (Triplochiton scleroxylon), r-AS, immobilized by sodium alginate were investigated with respect to pH, biomass quantity, contact time, initial concentration of heavy metal, temperature and stirring rate. The experimental data fitted well with the Langmuir isotherm, suggesting that monolayer adsorption of the cadmium ions onto alginate-Ayous sawdust composite (a-ASC). The obtained monolayer adsorption capacity of a-ASC for Cd (II) was 6.21 mg/g. From the Dubinin-Radushkevich isotherm model, a 5.39 kJ/mol value for the mean free energy was calculated, indicating that Cd (II) biosorption could include an important physisorption stage. Thermodynamic calculations showed that the Cd (II) biosorption process was feasible, endothermic and spontaneous in nature under examined conditions. The results indicated that a-ASC could be an alternative material replacing more costly adsorbents used for the removal of heavy metals. PMID:26698559

  12. Accelerated Sorption Diffusion for Cu(II) Retention by Anchorage of Nano-zirconium Dioxide onto Highly charged Polystyrene Material

    PubMed Central

    Zhang, Qingrui; Du, Qing; Jiao, Tifeng; Teng, Jie; Sun, Qina; Peng, Qiuming; Chen, Xinqing; Gao, Faming

    2015-01-01

    The development of nanocomposite with strong adsorption ability exhibits great potential applications for environmental remediation. However, the pore blocking in preparation frequently constrains sorption diffusion, resulting in low utilization efficiency. Here we synthesized a new nano-ZrO2/Polystyrene (NZO-PS) material tailored with a specific fixed SO3-Na group to enhance Cu(II) removal. The NZO-PS exhibits efficient Cu(II) sequestration in a wide pH range (3.0–6.5) and preferential sorption performances. The efficient kinetic behavior and column applicability suggest the blocked pore channel is not a matter when presence of negatively charged moiety, which accelerates Cu(II) sorption diffusion and enrichment toward target active site. Moreover, the exhausted NZO-PS can be readily regenerated through HCl-NaCl binary solution. The preparation route can be extended to synthesize other functional composited materials. Simultaneously, the characteristics of simplicity, high-yield and regeneration provide some promising industrial merits. PMID:26184921

  13. Lightweight inflatable material with low permeability

    NASA Technical Reports Server (NTRS)

    White, E. C.; Matthews, F. R.

    1973-01-01

    Material features combination of Mylar, for strength, and Saran, for impermeable qualities. Second lamination of Mylar prevents blocking, adds strength, and increases barrier rating. Different combinations of laminations produce variety of thicknesses and barrier ratings. Material can be metallized for increased barrier reliability and radar reflectivity, and can be treated with a heat-resistant coating.

  14. INFORMATION: Inspection Report on "Removal of Categories I and II Special Nuclear Material from Sandia National Laboratories-New Mexico"

    SciTech Connect

    2010-01-01

    The Department of Energy's (DOE's) Sandia National Laboratories-New Mexico (Sandia) develops science-based technologies in support of national security in areas such as nuclear weapons, nonproliferation, military technologies, and homeland security. Sandia's primary mission is ensuring that the U.S. nuclear arsenal is safe, secure, and reliable and can fully support the Nation's deterrence policy. Part of this mission includes systems engineering of nuclear weapons; research, design, and development of non-nuclear components; manufacturing of non-nuclear weapons components; the provision of safety, security, and reliability assessments of stockpile weapons; and the conduct of high-explosives research and development and environmental testing. Sandia Corporation, a subsidiary of Lockheed Martin Corporation, operates Sandia for the National Nuclear Security Administration (NNSA). On May 7, 2004, the Secretary announced that the Department would evaluate missions at DOE sites to consolidate Special Nuclear Material (SNM) in the most secure environments possible. The Administrator of the NNSA said that this effort was a key part of an overall plan to transform the nuclear weapons complex into a smaller, safer, more secure, and more efficient national security enterprise. In February 2008, Sandia was the first site to report it had reduced its on-site inventory of nuclear material below 'Categories I and II' levels, which require the highest level of security to protect material such as plutonium and highly enriched uranium. The Office of Inspector General initiated an inspection to determine if Sandia made appropriate adjustments to its security posture in response to the removal of the Categories I and II SNM. We found that Sandia adjusted its security posture in response to the removal of Categories I and II SNM. For example, security posts were closed; unneeded protective force weapons and equipment were excessed from the site; and, Sandia's Site Safeguards and

  15. Copper(I) and copper(II) uranyl heterometallic hybrid materials.

    PubMed

    Weng, Zhehui; Zhang, Zhi-hui; Olds, Travis; Sterniczuk, Marcin; Burns, Peter C

    2014-08-01

    Two copper-uranium heterometallic compounds, [(UO2)3Cu(II)O2(C6NO2)5] (1) and [(UO2)Cu(I)(C6NO2)3] (2), have been synthesized by the reaction of uranyl acetate with copper salts in the presence of isonicotinic acid. Both compounds have been characterized by single-crystal X-ray diffraction, IR, Raman, and UV-vis spectroscopy. In compound 1, interactions between copper and uranium centers occur and result in a three-dimensional pillar layered structure. Compound 1 is also the first example of a heterometallic uranyl organic framework with a trinuclear U3O18 building block. Compound 2 is the first uranyl organic framework that contains monovalent copper, which arises from the reaction of Cu(II) chloride and is assumed to be due to the oxidation of chloride at low pH. PMID:25029287

  16. Novel type-II material system for laser applications in the near-infrared regime

    SciTech Connect

    Berger, C. Möller, C.; Hens, P.; Fuchs, C.; Stolz, W.; Koch, S. W.; Ruiz Perez, A.

    2015-04-15

    The design and experimental realization of a type-II “W”-multiple quantum well heterostructure for emission in the λ > 1.2 μm range is presented. The experimental photoluminescence spectra for different excitation intensities are analyzed using microscopic quantum theory. On the basis of the good theory–experiment agreement, the gain properties of the system are computed using the semiconductor Bloch equations. Gain values comparable to those of type-I systems are obtained.

  17. Phosphorous and aluminum gettering in Silicon-Film{trademark} Product II material

    SciTech Connect

    Cotter, J.E.; Barnett, A.M.; Hall, R.B.

    1995-08-01

    Gettering processes are being developed for the Silicon-Film{trademark} Product II solar cell structure. These processes have been developed specifically for films of silicon grown on dissimilar substrates with barrier layers. Gettering with both phosphorous- and aluminum-based processing sequences has resulted in enhancement of minority carrier diffusion length. Long diffusion lengths have allowed the characterization of light trapping in thin films of silicon grown on barrier-coated substrates.

  18. Information Identification and Organization. Student Study Guide. Module II: Organization and Acquisition of Information and Materials.

    ERIC Educational Resources Information Center

    Bolvin, Boyd M.; West, Sharon

    This second module in a three module program examines the types of materials and services that are available in a community information center or library and the tools or sources for obtaining them. The module covers: ways in which books and other materials are arranged and organized; descriptions of library catalogs and the basic information…

  19. IMPACTS OF MATERIAL SUBSTITUTION IN AUTOMOBILE MANUFACTURE ON RESOURCE RECOVERY. VOLUME II. APPENDICES A-E

    EPA Science Inventory

    Probable changes in the mix of materials used to manufacture automobiles were examined to determine if economic or technical problems in recycling could arise such that the 'abandoned automobile problem' would be resurrected. Future trends in materials composition of the automobi...

  20. Nine Model Programs for Young Children: Appendix of Supplementary Materials. Volume II.

    ERIC Educational Resources Information Center

    Quillian, Benjamin F., Jr.; Rogers, Kathryn S.

    This appendix to the National Program on Early Childhood Education (NPECE) Survey contains materials intended to provide additional information about six of the nine programs described in the survey. The materials include: (1) narrative descriptions of cooking and reading experiences for the Tucson Early Education Model; (2) information on…

  1. Heat resistant polyphosphazene polymers

    NASA Technical Reports Server (NTRS)

    Fewell, L. L.; Allcock, H. R.; Obrien, J. P.; Scopelianos, A. G.

    1981-01-01

    Polymers of carboranyl substituted polyphosphazene are stable at high temperatures and produce insulating char upon pyrolysis. Substituted compounds are prepared by heat polymerizing carboranyl halophosphazene, which is obtained by reacting lithium carborane with, for example, hexachlorocyclotriphosphazene under anhydrous conditions. Chlorine of polymer may be replaced by aryloxy and alkoxy groups.

  2. 30 CFR 57.22222 - Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....22222 Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). Brattice cloth and ventilation tubing shall be approved by MSHA in accordance with 30 CFR part 7, or shall bear a BC or VT... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation materials (I-A, I-B, I-C, II-A,...

  3. The heat-resistant agglutinin family includes a novel adhesin from enteroaggregative Escherichia coli strain 60A.

    PubMed

    Mancini, Justin; Weckselblatt, Brooke; Chung, Yoonjie K; Durante, Julia C; Andelman, Steven; Glaubman, Jessica; Dorff, Justin D; Bhargava, Samhita; Lijek, Rebeccah S; Unger, Katherine P; Okeke, Iruka N

    2011-09-01

    Heat-resistant agglutinin 1 (Hra1) is an accessory colonization factor of enteroaggregative Escherichia coli (EAEC) strain 042. Tia, a close homolog of Hra1, is an invasin and adhesin that has been described in enterotoxigenic E. coli. We devised a PCR-restriction fragment length polymorphism screen for the associated genes and found that they occur among 55 (36.7%) of the enteroaggregative E. coli isolates screened, as well as lower proportions of enterotoxigenic, enteropathogenic, enterohemorrhagic, and commensal E. coli isolates. Overall, 25%, 8%, and 3% of 150 EAEC strains harbored hra1 alone, tia alone, or both genes, respectively. One EAEC isolate, 60A, produced an amplicon with a unique restriction profile, distinct from those of hra1 and tia. We cloned and sequenced the full-length agglutinin gene from strain 60A and have designated it hra2. The hra2 gene was not detected in any of 257 diarrheagenic E. coli isolates in our collection but is present in the genome of Salmonella enterica serovar Heidelberg strain SL476. The cloned hra2 gene from strain 60A, which encodes a predicted amino acid sequence that is 64% identical to that of Hra1 and 68% identical to that of Tia, was sufficient to confer adherence on E. coli K-12. We constructed an hra2 deletion mutant of EAEC strain 60A. The mutant was deficient in adherence but not autoaggregation or invasion, pointing to a functional distinction from the autoagglutinin Hra1 and the Tia invasin. Hra1, Tia, and the novel accessory adhesin Hra2 are members of a family of integral outer membrane proteins that confer different colonization-associated phenotypes. PMID:21764925

  4. Formation Mechanism of Type IV Failure in High Cr Ferritic Heat-Resistant Steel-Welded Joint

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Tsukamoto, S.; Shirane, T.; Abe, F.

    2013-10-01

    The mechanism of type IV failure has been investigated by using a conventional 9Cr ferritic heat-resistant steel Gr.92. In order to clarify the main cause of type IV failure, different heat treatments were performed on the base metal in order to change the prior austenite grain (PAG) size and precipitate distribution after applying the heat-affected zone (HAZ) simulated thermal cycle at the peak temperature of around A c3 ( A c3 HAZ thermal cycle) and postweld heat treatment (PWHT). The microstructural evolution during the A c3 HAZ thermal cycle and PWHT was investigated by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), electron probe microanalysis (EPMA), and transmission electron microscope (TEM). It was found that M23C6 carbides were scarcely precipitated at the newly formed fine PAG, block, and lath boundaries in A c3 HAZ-simulated Gr.92, because the carbide forming elements such as Cr and C were segregated at the former PAG and block boundaries of the base metal. On the other hand, if all the boundaries were covered by sufficient M23C6 carbides by homogenization of the alloying elements prior to applying the HAZ thermal cycle, the creep strength was much improved even if the fine PAG was formed. From these results, it is concluded that fine-grained microstructure cannot account for the occurrence of type IV failure, and it only has a small effect during long-term creep. The most important factor is the precipitate formation behavior at various boundaries. Without sufficient boundary strengthening by precipitates, the microstructure of A c3 HAZ undergoes severe changes even during PWHT and causes premature failure during creep.

  5. Modeling the thermal inactivation kinetics of heat-resistant Salmonella Enteritidis and Oranienburg in 10 percent salted liquid egg yolk.

    PubMed

    Gurtler, Joshua B; Marks, Harry M; Jones, Deana R; Bailey, Rebecca R; Bauer, Nathan E

    2011-06-01

    There is no suitable model for predicting thermal inactivation kinetics of Salmonella spp. for many types of liquid egg products, including salted liquid egg yolk, for use in updating U.S. Department of Agriculture (USDA) pasteurization guidelines. This is because, in part, of the variations in Salmonella strains and the changes in the processing of liquid egg products over the past 40 years. The objectives of the present study were to determine the thermal inactivation kinetics and to create a general thermal inactivation kinetics model that can be used for estimating log reductions of salmonellae in 10% salted liquid egg yolk for temperatures between 62.2 and 69°C. This model can be used by processors to help ensure adequate pasteurization. This was accomplished by studying the inactivation kinetics of a three-strain composite of heat-resistant Salmonella serovars Enteritidis and Oranienburg, inoculated into commercially processed 10% salted liquid egg yolk. The survival curves were convex, with asymptotic D-values. From these curves, a general model was developed to predict log reductions for given times at specified temperatures. For example, at a temperature of 67.3°C (153.1°F) for 3.5 min, our model predicts a 5-log reduction would be obtained, whereas with the current USDA minimum required pasteurization regimen (63.33°C [146°F] for 3.5 min), our model predicts that a reduction of only 2.7 log would be obtained. The results of this study provide information that can be used by processors to aid in producing safe, pasteurized egg yolk products, and for satisfying USDA pasteurization performance standards and developing industry guidance. PMID:21669063

  6. Neuroprotection by scorpion venom heat resistant peptide in 6-hydroxydopamine rat model of early-stage Parkinson's disease.

    PubMed

    Yin, Sheng-Ming; Zhao, Dan; Yu, De-Qin; Li, Sheng-Long; An, Dong; Peng, Yan; Xu, Hong; Sun, Yi-Ping; Wang, Dong-Mei; Zhao, Jie; Zhang, Wan-Qin

    2014-12-25

    Neuroprotective effect of scorpion venom on Parkinson's disease (PD) has already been reported. The present study was aimed to investigate whether scorpion venom heat resistant peptide (SVHRP) could attenuate ultrastructural abnormalities in mitochondria and oxidative stress in midbrain neurons of early-stage PD model. The early-stage PD model was established by injecting 6-hydroxydopamine (6-OHDA) (20 μg/3 μL normal saline with 0.1% ascorbic acid) into the striatum of Sprague Dawley (SD) rats unilaterally. The rats were intraperitoneally administered with SVHRP (0.05 mg/kg per day) or vehicle (saline) for 1 week. Two weeks after 6-OHDA treatment, the rats received behavior tests for validation of model. Three weeks after 6-OHDA injection, the immunoreactivity of dopaminergic neurons were detected by immunohistochemistry staining, and the ultrastructure of neuronal mitochondria in midbrain was observed by electron microscope. In the meantime, the activities of monoamine oxidase-B (MAO-B), superoxide dismutase (SOD) and content of malondialdehyde (MDA) in the mitochondria of the midbrain neurons, as well as the inhibitory ability of hydroxyl free radical and the antioxidant ability in the serum, were measured by corresponding kits. The results showed that 6-OHDA reduced the optical density of dopaminergic neurons, induced damage of mitochondrial ultrastructure of midbrain neurons, decreased SOD activity, increased MAO-B activity and MDA content, and reduced the antioxidant ability of the serum. SVHRP significantly reversed the previous harmful effects of 6-OHDA in early-stage PD model. These findings indicate that SVHRP may contribute to neuroprotection by preventing biochemical and ultrastructure damage changes which occur during early-stage PD. PMID:25516514

  7. Industry to Education Technical Transfer Program & Composite Materials. Composite Materials Course. Fabrication I Course. Fabrication II Course. Composite Materials Testing Course. Final Report.

    ERIC Educational Resources Information Center

    Massuda, Rachel

    These four reports provide details of projects to design and implement courses to be offered as requirements for the associate degree program in composites and reinforced plastics technology. The reports describe project activities that led to development of curricula for four courses: composite materials, composite materials fabrication I,…

  8. Heat resistance and salt hypersensitivity in Lactococcus lactis due to spontaneous mutation of llmg_1816 (gdpP) induced by high-temperature growth.

    PubMed

    Smith, William M; Pham, Thi Huong; Lei, Lin; Dou, Junchao; Soomro, Aijaz H; Beatson, Scott A; Dykes, Gary A; Turner, Mark S

    2012-11-01

    During construction of several gene deletion mutants in Lactococcus lactis MG1363 which involved a high-temperature (37.5°C) incubation step, additional spontaneous mutations were observed which resulted in stable heat resistance and in some cases salt-hypersensitive phenotypes. Whole-genome sequencing of one strain which was both heat resistant and salt hypersensitive, followed by PCR and sequencing of four other mutants which shared these phenotypes, revealed independent mutations in llmg_1816 in all cases. This gene encodes a membrane-bound stress signaling protein of the GdpP family, members of which exhibit cyclic dimeric AMP (c-di-AMP)-specific phosphodiesterase activity. Mutations were predicted to lead to single amino acid substitutions or protein truncations. An independent llmg_1816 mutant (Δ1816), created using a suicide vector, also displayed heat resistance and salt hypersensitivity phenotypes which could be restored to wild-type levels following plasmid excision. L. lactis Δ1816 also displayed improved growth in response to sublethal concentrations of penicillin G. High-temperature incubation of a wild-type industrial L. lactis strain also resulted in spontaneous mutation of llmg_1816 and heat-resistant and salt-hypersensitive phenotypes, suggesting that this is not a strain-specific phenomenon and that it is independent of a plasmid integration event. Acidification of milk by the llmg_1816-altered strain was inhibited by lower salt concentrations than the parent strain. This study demonstrates that spontaneous mutations can occur during high-temperature growth of L. lactis and that inactivation of llmg_1816 leads to temperature resistance and salt hypersensitivity. PMID:22923415

  9. Solute Transport Proteins and the Outer Membrane Protein NmpC Contribute to Heat Resistance of Escherichia coli AW1.7▿

    PubMed Central

    Ruan, Lifang; Pleitner, Aaron; Gänzle, Michael G.; McMullen, Lynn M.

    2011-01-01

    This study aimed to elucidate determinants of heat resistance in Escherichia coli by comparing the composition of membrane lipids, as well as gene expression, in heat-resistant E. coli AW1.7 and heat-sensitive E. coli GGG10 with or without heat shock. The survival of E. coli AW1.7 at late exponential phase was 100-fold higher than that of E. coli GGG10 after incubation at 60°C for 15 min. The cytoplasmic membrane of E. coli AW1.7 contained a higher proportion of saturated and cyclopropane fatty acids than that of E. coli GGG10. Microarray hybridization of cDNA libraries obtained from exponentially growing or heat-shocked cultures was performed to compare gene expression in these two strains. Expression of selected genes from different functional groups was quantified by quantitative PCR. DnaK and 30S and 50S ribosomal subunits were overexpressed in E. coli GGG10 relative to E. coli AW1.7 upon heat shock at 50°C, indicating improved ribosome stability. The outer membrane porin NmpC and several transport proteins were overexpressed in exponentially growing E. coli AW1.7. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of membrane properties confirmed that NmpC is present in the outer membrane of E. coli AW1.7 but not in that of E. coli GGG10. Expression of NmpC in E. coli GGG10 increased survival at 60°C 50- to 1,000-fold. In conclusion, the outer membrane porin NmpC contributes to heat resistance in E. coli AW1.7, but the heat resistance of this strain is dependent on additional factors, which likely include the composition of membrane lipids, as well as solute transport proteins. PMID:21398480

  10. PREDICTIVE MODEL FOR THE COMBINED EFFECT OF TEMPERATURE, SODIUM LACTATE, AND SODIUM DIACETATE ON THE HEAT RESISTANCE OF LISTERIA MONOCYTOGENES IN BEEF

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects and interactions of heating temperature (60 - 73.9C), sodium lactate (NaL; 0.0 - 4.8%, w/w) and/or sodium diacetate SDA; 0.0 - 0.25%, w/w) on the heat resistance of a five-strain mixture of Listeria monocytogenes in 75% lean ground beef were examined. Thermal death times were determined...

  11. Heat Resistance and Salt Hypersensitivity in Lactococcus lactis Due to Spontaneous Mutation of llmg_1816 (gdpP) Induced by High-Temperature Growth

    PubMed Central

    Smith, William M.; Pham, Thi Huong; Lei, Lin; Dou, Junchao; Soomro, Aijaz H.; Beatson, Scott A.; Dykes, Gary A.

    2012-01-01

    During construction of several gene deletion mutants in Lactococcus lactis MG1363 which involved a high-temperature (37.5°C) incubation step, additional spontaneous mutations were observed which resulted in stable heat resistance and in some cases salt-hypersensitive phenotypes. Whole-genome sequencing of one strain which was both heat resistant and salt hypersensitive, followed by PCR and sequencing of four other mutants which shared these phenotypes, revealed independent mutations in llmg_1816 in all cases. This gene encodes a membrane-bound stress signaling protein of the GdpP family, members of which exhibit cyclic dimeric AMP (c-di-AMP)-specific phosphodiesterase activity. Mutations were predicted to lead to single amino acid substitutions or protein truncations. An independent llmg_1816 mutant (Δ1816), created using a suicide vector, also displayed heat resistance and salt hypersensitivity phenotypes which could be restored to wild-type levels following plasmid excision. L. lactis Δ1816 also displayed improved growth in response to sublethal concentrations of penicillin G. High-temperature incubation of a wild-type industrial L. lactis strain also resulted in spontaneous mutation of llmg_1816 and heat-resistant and salt-hypersensitive phenotypes, suggesting that this is not a strain-specific phenomenon and that it is independent of a plasmid integration event. Acidification of milk by the llmg_1816-altered strain was inhibited by lower salt concentrations than the parent strain. This study demonstrates that spontaneous mutations can occur during high-temperature growth of L. lactis and that inactivation of llmg_1816 leads to temperature resistance and salt hypersensitivity. PMID:22923415

  12. Characterization of wear in composite material orthopaedic implants. Part II: The implant/bone interface.

    PubMed

    Albert, K; Schledjewski, R; Harbaugh, M; Bleser, S; Jamison, R; Friedrich, K

    1994-01-01

    Carbon fiber/PEEK polymer (C/PEEK) composite materials are being developed for use as orthopaedic implant materials. Wear is an issue of increasing importance in orthopaedic implants; particulate debris generated by the wearing of biomaterials may be a causal factor leading to osteolysis and implant loosening. Therefore, numerical and experimental studies were completed to characterize the wear of C/PEEK composite materials in comparison to current orthopaedic implant materials. Finite element analyses (FEA) of a composite material hip stem implanted in a femur and loaded at 890 N determined that peak contact stresses will occur at the proximal-medial and distal regions of the implant. These contact stresses were found to be below 1.0 MPa over most of the implant surface; however the peak stress in the proximal-medial region was 1.8 MPa and higher still at the distal portion of the stem. In vivo forces result in contact stress values up to 9.0 MPa. The composite implant exhibited 10-40% lower contact stresses in the distal region compared to a titanium-alloy implant of identical design. Composite material wear samples were slid against porous hydroxylapatite (HA) to simulate the stem/bone interface. An identical series of experiments was run for comparison to a current orthopaedic implant material--Ti6A14V titanium alloy. Two domains of motion were studied; a composite ring-on-HA disc large amplitude sliding wear test; and a composite pin-on-HA disc small amplitude fretting regimen. Nominal contact pressures during testing were 1.4 MPa and 7.6 MPa for sliding and fretting tests, respectively. Fretting and sliding abrasive wear tests resulted in the composite material exhibiting a lower wear rate than the titanium-alloy. The magnitude of the difference was greatly dependent on the contact pressures, sliding amplitudes, and counterface material properties. PMID:7950869

  13. Materials Science and Technology, Volume 17B, Processing of Ceramics Part II

    NASA Astrophysics Data System (ADS)

    Brook, Richard J.

    1996-12-01

    Progress in the processing of ceramics has made these materials very important for current and future technologies. Internationally renowned experts have contributed to this second of two volumes which provide a wealth of information indispensable for materials scientists and engineers. Contents of Volume B: Riedel: Advanced Ceramics from Inorganic Polymers. Calvert: Biomimetic Processing. Eisele: Sintering and Hot Pressing. Kwon: Liquid-Phase Sintering. Leriche/Cambier: Vitrification. Larker/Larker: Hot Isostatic Pressing. Harmer/Chan: Fired Microstructures and Their Charactzerization. Subramanian: Finishing. Nicholas: Joining of Ceramics. Hirai: Functional Gradient Materials.

  14. Analysis of the absorptive behavior of photopolymer materials. Part II. Experimental validation

    NASA Astrophysics Data System (ADS)

    Li, Haoyu; Qi, Yue; Tolstik, Elen; Guo, Jinxin; Sheridan, John T.

    2015-01-01

    In the first part of this paper, a model describing photopolymer materials, which incorporates both the physical electromagnetic and photochemical effects taking place, was developed. This model is now validated by applying it to fit experimental data for two different types of photopolymer materials. The first photopolymer material, acrylamide/polyvinyl alcohol, is studied when four photosensitizers are used, i.e. Erythrosine B, Eosin Y, Phloxine B and Rose Bengal. The second type of photopolymer material involves phenanthrenequinone in a polymethylmethacrylate matrix. Using our model, the values of physical parameters, are extracted by numerical fitting experimentally obtained normalized transmittance growth curves. Experimental data sets for different exposure intensities, dye concentrations, and exposure geometries are studied. The advantages of our approach are demonstrated and it is shown that the parameters proposed by us to quantify the absorptive behavior in our model are both physical and can be estimated.

  15. Growth, spectral and thermal studies of an efficient NLO material: Diaquadicinnamatocadmium(II)

    SciTech Connect

    Roy, Sunalya M.; Sudarsanakumar, M. R.; Dhanya, V. S.

    2014-01-28

    A nonlinear metal–organic crystal, diaquadicinnamatocadmium(II) has been grown by controlled gel diffusion technique. Sodium metasilicate was used to prepare the gel. The chemical composition of the crystal has been determined by CHN analysis. Powder X-ray diffraction studies confirm the crystalline nature of the grown crystal. Functional groups present in the compound were identified by FT-IR spectral analysis. The thermal decomposition of the compound was studied using thermogravimetry (TG). The optical transparency range and the lower cut-off wavelength were identified from the UV-Visible-NIR spectrum. The NLO activity of the grown crystal was confirmed using Kurtz and Perry powder test.

  16. Platinum(II) Metallomesogens: New External-Stimuli-Responsive Photoluminescence Materials.

    PubMed

    Cuerva, Cristián; Campo, José A; Cano, Mercedes; Lodeiro, Carlos

    2016-07-11

    New dicatenar isoquinoline-functionalized pyrazoles, [Hpz(R(n,n)iq) ] (R(n,n)=C6 H3 (OCn H2n+1 )2 ; n=4, 6, 8, 10, 12, 14, 16, 18), have been strategically designed and synthesized to induce mesomorphic and luminescence properties into the corresponding bis(isoquinolinylpyrazolate)platinum(II) complexes [Pt(pz(R(n,n)iq) )2 ]. Thermal studies reveal that all platinum(II) compounds exhibit columnar mesophases over an exceptionally wide temperature range, above 300 °C in most cases. The photophysical behavior was also investigated in solution and in the solid state. As a consequence of the formation of Pt⋅⋅⋅Pt interactions, the weak greenish emission of the platinum derivatives turns bright orange in the mesophase. Additionally, the complexes are sensitive to a great variety of external inputs, such as temperature, mechanical grinding, pressure, solvents, and vapors. On this basis, they are used as dopant agents of a polyvinylpyrrolidone or poly(methyl methacrylate) polymer matrix to achieve stimuli-responsive thin films. PMID:27273696

  17. Insights into the crystal-packing effects on the spin crossover of [Fe(II)(1-bpp)](2+)-based materials.

    PubMed

    Vela, Sergi; Novoa, Juan J; Ribas-Arino, Jordi

    2014-12-28

    Iron(II) complexes of the [Fe(II)(1-bpp2)](2+) type (1-bpp = 2,6-di(pyrazol-1-yl)pyridine) have been intensively investigated in the context of crystal engineering of switchable materials because their spin-crossover (SCO) properties dramatically depend on the counterions. Here, by means of DFT + U calculations at the molecular and solid state levels we provide a rationale for the different SCO behaviour of the BF4(-) and ClO4(-) salts of the parent complex; the former features Fe(II) complexes with a regular coordination geometry and undergoes a spin transition, whereas the Fe(II) complexes of the latter adopt a distorted structure and remain in the high-spin state at all temperatures. The different SCO behaviour of both salts can be explained on the basis of a combination of thermodynamic and kinetic effects. The shape of the SCO units at high temperature is thermodynamically controlled by the intermolecular interactions between the SCO units and counterions within the crystal. The spin trapping at low temperatures in the ClO4(-) salt, in turn, is traced back to a kinetic effect because our calculations have revealed the existence of a more stable polymorph having SCO units in their low-spin state that feature a regular structure. From the computational point of view, it is the first time that the U parameter is fine-tuned on the basis of CASPT2 calculations, thereby enabling an accurate description of the energetics of the spin transition at both molecular and solid-state levels. PMID:25380527

  18. Fracture strength and elastic modulus as a function of porosity for hydroxyapatite and other brittle materials, Part II

    SciTech Connect

    Fan, Xiaofeng; Case, Eldon D; Ren, Fei; Shu, Yutian; Baumann, Melissa

    2012-01-01

    Part I of this paper discussed the Weibull modulus m, versus porosity P behavior of brittle materials, including HA. While the Weibull modulus m deals with the scatter in fracture strength data, this paper (Part II) focuses on two additional key mechanical properties of porous materials, namely the average fracture strength f , and Young s modulus E, for P in the interval from P zero to P PG (the porosity of the unfired compacts). The f versus P data for HA from this study and the literature data for alumina, yttria stabilized zirconia (YSZ) and silicon nitride are describedwell by functions of , where = 1 P/PG = the degree of densification. A similar function of applies to the E versus P behavior of HA from this study and data from the literature for alumina, titanium and YSZ. All of the data analyzed in this study (Part II) are based on partially and fully sintered powder compacts (excluding green powder compacts), thus the f / 0 versus and E /E0 versus relationships may apply only to such specimens.

  19. Development of a Laser Induced Fluorescence (LIF) system on the Plasma Material Interaction System (PLAMIS-II) device

    NASA Astrophysics Data System (ADS)

    Kang, I. J.; Lee, K. Y.; Lee, K. I.; Choi, Y.-S.; Cho, S. G.; Bae, M. K.; Lee, D.-H.; Hong, S. H.; Lho, T.; Chung, K.-S.

    2015-12-01

    A laser induced fluorescence (LIF) system has been developed for the plasma material interaction system (PLAMIS-II) device, which is equipped with a unique plasma gun composed of a LaB6 cathode and two anodes with electromagnets to generate a focused dense plasma. PLAMIS-II simulates the interactions of plasma with different materials and is to be used for the test of plasma facing components of fusion devices. The LIF system is composed of a seed laser with Littmann/Metcalf cavity and a master oscillator power amplifier to pump 3d4F7/2 metastable argon ion to 4p4D5/2 level at the wavelength of 668.61 nm, which has the following input parameters: laser power = 20 mW, line width < 100 kHz, and a mode-hop free tuning range > 70 GHz. For in-situ measurement of laser wavelength, the wavelength spectrum of an iodine cell was measured by a photo-transistor during LIF measurement. To measure argon ion temperature (Ti) and drift velocity (vd) in PLAMIS-II, the fluorescence light with the wavelength of 442.72 nm, emitted from 4p4D5/2 level to 4s4P3/2 level and passing through 1 nm band-width filter, was collected by the photomultiplier tube combined with a lock-in amplifier and a chopper with frequency of 3 kHz. Initial data of Ti and vd were analysed in terms of gas flow rate and applied power.

  20. Pyrolysis of municipal plastic wastes II: Influence of raw material composition under catalytic conditions

    SciTech Connect

    Lopez, A.

    2011-09-15

    Highlights: > ZSM-5 zeolite catalytic pyrolysis transforms municipal plastic waste into liquids and gases useful as fuels or source of chemicals. > The composition of the waste sample plays an important role on the catalyst activity and the products obtained. > ZSM-5 zeolite is somehow deactivated when high proportions of fine inorganic materials are present in the sample. > When the sample contains cellulose-based materials, the formation of a two-phase liquid fraction can be avoided by a low temperature step. - Abstract: In this work, the results obtained in catalytic pyrolysis of three plastic waste streams which are the rejects of an industrial packing wastes sorting plant are presented. The samples have been pyrolysed in a 3.5 dm{sup 3} reactor under semi-batch conditions at 440 {sup o}C for 30 min in nitrogen atmosphere. Commercial ZSM-5 zeolite has been used as catalyst in liquid phase contact. In every case, high HHV gases and liquids which can be useful as fuels or source of chemicals are obtained. A solid fraction composed of the inorganic material contained in the raw materials and some char formed in the pyrolysis process is also obtained. The zeolite has shown to be very effective to produce liquids with great aromatics content and C3-C4 fraction rich gases, even though the raw material was mainly composed of polyolefins. The characteristics of the pyrolysis products as well as the effect of the catalyst vary depending on the composition of the raw material. When paper rich samples are pyrolysed, ZSM-5 zeolite increases water production and reduces CO and CO{sub 2} generation. If stepwise pyrolysis is applied to such sample, the aqueous liquid phase can be separated from the organic liquid fraction in a first low temperature step.

  1. Economic evaluation of closure CAP barrier materials Volume I and Volume II

    SciTech Connect

    Serrato, M.G.; Bhutani, J.S.; Mead, S.M.

    1993-09-01

    This study prepared by the Site Geotechnical Services (SGS) and Environmental Restoration (ER) departments of the WSRC evaluates a generic closure cover system for a hazardous waste site, using 10 different surface areas, ranging from 0.1 acre to 80 acres, and 12 barrier materials. This study presents a revision to the previous study (Rev. 0) published in June 1993, under the same title. The objective of this study was to revise the previous study by incorporating four additional site sizes into the evaluation process and identifying the most cost-effective barrier material for a given closure cover system at the SRS.

  2. Clinical evaluation of a bioabsorbable regenerative material in mandibular class II furcation therapy.

    PubMed

    Bouchard, P; Giovannoli, J L; Mattout, C; Davarpanah, M; Etienne, D

    1997-07-01

    30 periodontally compromised adult subjects with mandibular buccal class II furcation defects were recruited for this study. All selected defects were treated according to the biological principles of guided tissue regeneration. The subjects were randomly assigned to 2 parallel groups. The test group (n=15) received a bioabsorbable polyglycolic-polylactic membrane (PGA/PLA group); the control group (n=15) received a non-resorbable expanded polytetrafluoroethylene membrane (ePTFE group). After initial therapy, baseline measurements were recorded including plaque index, gingival index, vertical and horizontal probing depths, clinical attachment level and depth of the recession. Recall visits were made at 1, 2, 4, 6, 8, 12, and 24 weeks. At 12 months, all baseline clinical parameters were again measured. The data analysis did not demonstrate a significant difference between the 2 groups. The vertical probing depth and attachment level changes were statistically significant in each group. The postoperative recession was 0.6 mm in the ePTFE group (p<0.05) and 0.8 mm (p<0.05) in the PGA/PLA group. Compared to the initial measurements, the mean changes in horizontal probing depth were 2.7 mm and 2.5 mm (p<0.001), corresponding to mean reductions of 41.5% and 40.9% for the ePTFE and the PGA/PLA groups respectively. The results of this study suggest that 12 months after initial surgery, similar clinical improvements can be obtained in GTR therapy of buccal class II furcation lesions, regardless of whether bioabsorbable PGA/PLA membranes or non-resorbable ePTFE membranes are used. PMID:9226393

  3. Basic Bibliography in Political Sociology. Part II. Resource Materials for Teaching.

    ERIC Educational Resources Information Center

    Weil, Frederick D., Comp.; Dobratz, Betty A., Comp.

    Designed to accompany the course syllabi, this five-section bibliography cites over 1,500 books, textbooks, and journal articles for teaching political sociology at the university level. Section I, on general works, contains two categories of resources: materials on the theory of political sociology and general collections and texts. Section 2…

  4. Aviation Machinist's Mate Phase II, 2-6. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    These teacher and student materials, the second section of a two phase secondary/postsecondary-level course on aviation machinists, make up one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. The purpose of the course is to train students to…

  5. Supplemental Driver Safety Program Development Volume II--Pilot and Field Test Module Materials. Final Report.

    ERIC Educational Resources Information Center

    McPherson, Kenard; Weidman, James R.

    This volume contains materials to supplement existing driver education programming offered by high schools to youthful (16- to 18-year old) drivers. Section I contains three drinking/driving modules: an information-only module, a self-image module, and a three-unit peer intervention module. An instructor's guide provided for each module includes…

  6. The Public Defender Service of the District of Columbia: Volume II: Training Materials.

    ERIC Educational Resources Information Center

    National Inst. of Law Enforcement and Criminal Justice (Dept. of Justice/LEAA), Washington, DC.

    The training package is designed to assist public defender agencies in developing an in-house capability for training new staff attorneys. The materials contained in the package were developed by the Public Defender Service of the District of Columbia, a program designated by the Law Enforcement Assistance Administration as an "Exemplary Project."…

  7. Bilingual Education Instructional and Training Materials. Field Test Results and Final Phase II Report.

    ERIC Educational Resources Information Center

    Mahone, Alicia

    The report describes a federally funded project for the development of an innovative approach to bilingual curriculum and instruction and inservice teacher training. A needs assessment and research process resulted in development and field testing of a set of bilingual Spanish-English instructional materials for limited-English-speaking urban…

  8. Masonry Specialist I & II, 3-19. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    These military-developed curriculum materials consist of a course description, plan of instruction, study guides, and workbooks for use in training masonry specialists. Covered in the course blocks are an introduction to masonry and rigid concrete structures. The introduction to masonry, course block I, deals with safety, mathematics and…

  9. Iron(ii)-triazole core-shell nanocomposites: toward multistep spin crossover materials.

    PubMed

    Wang, Yu-Xia; Qiu, Dan; Xi, Sai-Fei; Ding, Zheng-Dong; Li, Zaijun; Li, Yunxing; Ren, Xuehong; Gu, Zhi-Guo

    2016-06-28

    The first SCO@SCO core-shell nanomaterials have been synthesized by the step-by-step microemulsion method. The observed gyroscopic core-shell nanocomposites exhibit three-step spin crossover behaviour with thermal hysteresis at around room temperature. This offers an efficient and novel strategy for the development of multistable SCO materials. PMID:27263855

  10. Newspaper Bargains: Food I and II. Teacher's Guide [and] Student Materials.

    ERIC Educational Resources Information Center

    Kenne, Linda

    The document contains student materials and teacher's guides for two units in which students analyze grocery advertisements in newspapers. The units are appropriate for language arts and mathematics classes in grades 4-6. Objectives for Unit I include discriminating between an advertisement and a news article, identifying foods for sale in ads,…