WorldWideScience

Sample records for chemical resistant materials

  1. Chemical resistance of valve packing and sealing materials to molten nitrate salt

    International Nuclear Information System (INIS)

    Chemical compatibility between a number of compression packings and sealing materials and molten sodium nitrate-potassium nitrate was evaluated at temperatures of 2880C (5500F), 4000C (7500F), and 5650C (10500F). The types of packing materials tested included graphite, asbestos, PTFE, aramid, glass and ceramic fibers; perfluoroelastomers, and boron nitride. Several materials were chemically resistant to the molten salt at 2880C, but the compatibility of packings at 4000C and 5650C was not adequate. The chemical and physical phenomena affecting compatibility are discussed and recommendations concerning materials selection are made

  2. Sulphate resistant shielding material

    International Nuclear Information System (INIS)

    The shielding material of the present invention is provided with sulfuric acid resistance and contains bentonite put to ion exchange treatment with barium ions as an effective ingredient. When mortars and concretes are exposed to the circumstance of sulfate, the effective ingredient functions to take place reaction between intruding sulfate and the barium ions to form insoluble barium sulfate thereby reducing chemical corrosion of mortars and concretes caused by sulfate. Cement materials, water and aggregates can optionally be contained in addition to bentonite and bentonite put to ion exchange treatment. Chemical corrosion of concretes and mortars due to intrusion of the sulfate can be prevented, and it is useful as an artificial barrier, for example, in radioactive active waste processing facilities. (T.M.)

  3. Novel oil resistant cellulosic materials

    OpenAIRE

    Aulin, Christian

    2009-01-01

    The aim of this study has been to prepare and characterise oil resistant cellulosic materials, ranging from model surfaces to papers and aerogels. The cellulosic materials were made oil resistant by chemical and topographic modifications, based on surface energy, surface roughness and barrier approaches. Detailed wetting studies of the prepared cellulosic materials were made using contact angle measurements and standardised penetration tests with different alkanes and oil mixtures. A signific...

  4. The development of DUV chemically amplified resists

    Energy Technology Data Exchange (ETDEWEB)

    Thackeray, J.W.; Fedynyshyn, T.H.; Small, R.D. [Shipley Co. Inc., Marlboro, MA (United States)

    1993-12-31

    The development of deep ultraviolet (DUV) resists has necessitated the introduction of new concepts in resist materials and chemistry. Successful DUV resist systems now employ the concept of chemical amplification. This catalytic reaction leads to a substantial enhancement in the imaging dose. Another benefit of chemical amplified resists is that they allow the design of materials which can be transparent to DUV exposure wavelengths, yet they can still have high sensitivity. Commercial and prototype positive- and negative-tone resists are now readily available and these resists have been used in pilot production to make the most advanced integrated circuits with {le}0.35 {mu}m design rules. At Shipley, we have undertaken to develop both negative- and positive-tone chemically amplified resists for DUV lithography. These resists are capable of high resolution (0.3 {mu}m), fast photospeed ({le}30 mJ/sq. cm), and excellent etch resistance. This presentation will discuss the chemical and lithographic properties of the Shipley negative- and positive-tone DUV chemically amplified resists. General discussion of the importance of activation energy for the catalytic process, catalytic chain length, and environmental stability will be given.

  5. Heat-resistant materials

    CERN Document Server

    1997-01-01

    This handbook covers the complete spectrum of technology dealing with heat-resistant materials, including high-temperature characteristics, effects of processing and microstructure on high-temperature properties, materials selection guidelines for industrial applications, and life-assessment methods. Also included is information on comparative properties that allows the ranking of alloy performance, effects of processing and microstructure on high-temperature properties, high-temperature oxidation and corrosion-resistant coatings for superalloys, and design guidelines for applications involving creep and/or oxidation. Contents: General introduction (high-temperature materials characteristics, and mechanical and corrosion properties, and industrial applications); Properties of Ferrous Heat-Resistant Alloys (carbon, alloy, and stainless steels; alloy cast irons; and high alloy cast steels); Properties of superalloys (metallurgy and processing, mechanical and corrosion properties, degradation, and protective coa...

  6. Chemical Absorption Materials

    DEFF Research Database (Denmark)

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...... are mentioned. References to review papers, papers with experimental data, and papers describing the thermodynamic modelling of the systems are given....

  7. Chemical Absorption Materials

    DEFF Research Database (Denmark)

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...

  8. Chemicals in material cycles

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Eriksson, Eva; Astrup, Thomas Fruergaard

    2015-01-01

    Material recycling has been found beneficial in terms of resource and energy performance and is greatly promoted throughout the world. A variety of chemicals is used in materials as additives and data on their presence is sparse. The present work dealt with paper as recyclable material and...... diisobutyl phthalate (DiBP) as chemical in focus. The results showed variations, between 0.83 and 32 μg/g, in the presence of DiBP in Danish waste paper and board and potential accumulation due to recycling....

  9. Fire Resistant Materials

    Science.gov (United States)

    1982-01-01

    Fire hazard is greater in atmospheres containing a high percentage of oxygen under pressure. NASA intensified its fire safety research after a 1967 Apollo fire. A chemically treated fabric called Durette developed by Monsanto Company, which will not burn or produce noxious fumes, was selected as a material for Apollo astronaut garments. Monsanto sold production rights for this material to Fire Safe Products (FSP). Durette is now used for a wide range of applications such as: sheets, attendants' uniforms in hyperbaric chambers; crew's clothing, furniture and interior walls of diving chambers operated by the U.S. Navy and other oceanographic companies and research organizations. Pyrotect Safety Equipment, Minneapolis, MN produces Durette suits for auto racers, refuelers and crew chiefs from material supplied by FSP. FSP also manufactures Durette bags for filtering gases and dust from boilers, electric generators and similar systems. Durette bags are an alternative to other felted fiber capable of operating at high temperature that cost twice as much.

  10. Chemical processing of lunar materials

    Science.gov (United States)

    Criswell, D. R.; Waldron, R. D.

    1979-01-01

    The paper highlights recent work on the general problem of processing lunar materials. The discussion covers lunar source materials, refined products, motivations for using lunar materials, and general considerations for a lunar or space processing plant. Attention is given to chemical processing through various techniques, including electrolysis of molten silicates, carbothermic/silicothermic reduction, carbo-chlorination process, NaOH basic-leach process, and HF acid-leach process. Several options for chemical processing of lunar materials are well within the state of the art of applied chemistry and chemical engineering to begin development based on the extensive knowledge of lunar materials.

  11. Chemical contamination of material cycles

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Astrup, Thomas Fruergaard

    2015-01-01

    chemicals, which would be re‐introduced into the loop once a product is recycled. Such chemicals may not be removed in the recycling process, persist, and contaminate the newly manufactured products. Chemical contamination could potentially put product consumers at unnecessary risk and jeopardize public......) chemicals in paper and plastic materials, and furthermore discuss the likely impacts of chemical contamination on material recycling. The work is part of the new Danish initiative focusing on Integrated Resource Management and Recovery (IRMAR, grant no. 11‐116775). The outcomes of the work will provide...

  12. Critical challenges for EUV resist materials

    Energy Technology Data Exchange (ETDEWEB)

    Naulleau, Patrick P.; Anderson, Christopher N.; Baclea-an, Lorie-Mae; Denham, Paul; George, Simi; Goldberg, Kenneth A.; Jones, Gideon; McClinton, Brittany; Miyakawa, Ryan; Rekawa, Seno; Smith, Nathan

    2011-02-28

    Although Extreme ultraviolet lithography (EUVL) is now well into the commercialization phase, critical challenges remain in the development of EUV resist materials. The major issue for the 22-nm half-pitch node remains simultaneously meeting resolution, line-edge roughness (LER), and sensitivity requirements. Although several materials have met the resolution requirements, LER and sensitivity remain a challenge. As we move beyond the 22-nm node, however, even resolution remains a significant challenge. Chemically amplified resists have yet to demonstrate the required resolution at any speed or LER for 16-nm half pitch and below. Going to non-chemically amplified resists, however, 16-nm resolution has been achieved with a LER of 2 nm but a sensitivity of only 70 mJ/cm{sup 2}.

  13. Chemical Compatibility of Polymeric Materials.

    Science.gov (United States)

    Solen, Kenneth A.; Kuchar, Marvin C.

    1990-01-01

    Presents some principles for specifying general classes of polymers for predicting relative chemical attack from acids, bases, oxidants, and certain common antagonists. Also discusses predicting relative solvent effects. Suggests uses of this information in two or three lectures in a chemical engineering materials course. (YP)

  14. Recent progress of abrasion-resistant materials: learning from nature.

    Science.gov (United States)

    Meng, Jingxin; Zhang, Pengchao; Wang, Shutao

    2016-01-21

    Abrasion-resistant materials have attracted great attention for their broad applications in industry, biomedicine and military. However, the development of abrasion-resistant materials that have with unique features such as being lightweight and flexible remains a great challenge in order to satisfy unmet demands. The outstanding performance of natural abrasion-resistant materials motivates the development of new bio-inspired abrasion-resistant materials. This review summarizes the recent progress in the investigation of natural abrasion-resistant materials to explore their general design principles (i.e., the correlation between chemical components and structural features). Following natural design principles, several artificial abrasion-resistant materials have shown unique abrasion-resistant properties. The potential challenges in the future and possible solutions for designing bio-inspired abrasion-resistant materials are also briefly discussed. PMID:26335377

  15. Resist materials for proton micromachining

    International Nuclear Information System (INIS)

    The production of high aspect ratio microstructures is a potential growth area. The combination of deep X-ray lithography with electroforming and micromolding (i.e. LIGA) is one of the main techniques used to produce 3D microstructures. The new technique of proton micromachining employs focused MeV protons in a direct write process which is complementary to LIGA, e.g. micromachining with 2 MeV protons results in microstructures with a height of 63 μm and lateral sub-micrometer resolution in PMMA resist. The aim of this paper is to investigate the capabilities of proton micromachining as a lithographic technique. This involves the study of different types of resists. The dose distribution of high molecular weight PMMA is compared with three other types of resist: First the positive photo resist AZ P4620 will be discussed and then PMGI SF 23, which can be used as a deep UV, e-beam or X-ray resist. Finally SU-8, a new deep UV negative type of chemically amplified resist will be discussed. All these polymers are applied using the spin coating technique at thicknesses of between 1 and 36 μm

  16. Fire Reterdant Chemicals Affecting Combustion Resistance of Wood

    OpenAIRE

    Yalçın ÖRS; Sönmez, Abdullah

    1998-01-01

    Wood is an important material used in construction elements. However since it can be affected by biotic and abiotic deteriorating agents, it should be treated with chemical impregnating materials prior to use. In this study, the effects of water-soluble impregnating chemicals on the combustion resistance of wood was investigated. For this purpose, panels were prepared with oriental beech wood (Fagus orientalis L.) and pine wood (Pinus silvestris L.), which are widely used in industry. These ...

  17. Chemical compatibility of cartridge materials

    Science.gov (United States)

    Ambrose, Bryan; Wilcox, R. C.; Zee, R. H.

    1992-01-01

    The objectives were to determine the chemical compatibility of titanium-zirconium-molybdenum (TZM) with GaAs and CdZnTe, and Inconel with HgCdTe and HgZnTe. At the present time, no other studies regarding the compatibility of these crystal components and their respective cartridge materials have been performed. This study was to identify any possible problems between these materials to insure proper containment of possibly hazardous fumes during crystal growth experiments. In this study, the reaction zone between the materials was studied and the amount of degradation to the system was measured. Detailed results are presented.

  18. Frost resistance of building materials

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    In this thesis it is shown that the critical degree of saturation is suitable as parameter for the frost resistance of porous building materials. A numerical model for prediction of critical degrees of saturation based on fracture mechanics and phase geometry of two-phase materials, e.g. porous...... critical degrees of saturation are compared with experimentally determined values and results from standardised freeze-thaw tests. Based on these results, the model, its mode of operation and the conditions of the model is analysed and discussed.Appendices and description of supplementary tests are placed...

  19. Determination of chemical resistance of glass, enamels and glazes

    International Nuclear Information System (INIS)

    The determination is described of chemical resistance of glass, enamels and glazes. 85Kr is incorporated by diffusion or implantation in the material investigated. The material is then exposed to the effects of a corrosion atmosphere or a liquid medium. The decrease in the activity of the radioactive kryptonates in the materials or the activity of the released radioactive krypton is measured. (B.S.)

  20. High Temperature Materials for Chemical Propulsion Applications

    Science.gov (United States)

    Elam, Sandra; Hickman, Robert; O'Dell, Scott

    2007-01-01

    Radiation or passively cooled thrust chambers are used for a variety of chemical propulsion functions including apogee insertion, reaction control for launch vehicles, and primary propulsion for planetary spacecraft. The performance of these thrust chambers is limited by the operating temperature of available materials. Improved oxidation resistance and increased operating temperatures can be achieved with the use of thermal barrier coatings such as zirconium oxide (ZrO2) and hafnium oxide (HfO2). However, previous attempts to include these materials showed cracking and spalling of the oxide layer due to poor bonding. Current research at NASA's Marshall Space Flight Center (MSFC) has generated unique, high temperature material options for in-space thruster designs that are capable of up to 2500 C operating temperatures. The research is focused on fabrication technologies to form low cost Iridium,qF_.henium (Ir/Re) components with a ceramic hot wall created as an integral, functionally graded material (FGM). The goal of this effort is to further de?celop proven technologies for embedding a protective ceramic coating within the Ir/Re liner to form a robust functional gradient material. Current work includes the fabrication and testing of subscale samples to evaluate tensile, creep, thermal cyclic/oxidation, and thermophysical material properties. Larger test articles have also being fabricated and hot-fire tested to demonstrate the materials in prototype thrusters at 1O0 lbf thrust levels.

  1. SELECTION AND MEASUREMENT OF PHYSICAL PROPERTIES FOR CHARACTERIZATION OF CHEMICAL PROTECTIVE CLOTHING MATERIALS

    Science.gov (United States)

    Chemical protective clothing (CPC) must possess certain physical properties if it is to function as an effective barrier to chemicals. he physical characteristics of CPC materials has gone largely unstudied; most attention has been focussecd on chemical resistance. hysical proper...

  2. Time influence in chemical treatment of Brazilian raw materials type

    International Nuclear Information System (INIS)

    Clays are part of raw materials in different industries. The mineralogical composition and purity greatly influence the application thereof. Chemical treatments applied, such as acid attack, modify their properties and thus their possible uses. Taking in to account that, clay minerals, may differ by more or less resistance to chemical attacks, two types of clay were studied with different mineralogical composition to assess the degree of resistance to chemical attack treatment such as acid. Acid treatments that were applied, differ mainly in the contact time between the solid and the liquid. The solids were studied by X-ray diffraction analysis, chemical analysis and infrared analysis

  3. Acid evaporation property in chemically amplified resists

    Science.gov (United States)

    Hashimoto, Shuichi; Itani, Toshiro; Yoshino, Hiroshi; Yamana, Mitsuharu; Samoto, Norihiko; Kasama, Kunihiko

    1997-07-01

    The lithographic performance of a chemically amplified resist system very much depends on the photo-generated acid structure. In a previous paper, we reported the molecular structure dependence of two typical photo-generated acids (aromatic sulfonic acid and alkyl sulfonic acid) from the viewpoints of lithographic performance and acid characteristics such as acid generation efficiency, acid diffusion behavior and acid evaporation property. In this paper, we evaluate the effect of the remaining solvent in a resist film on the acid evaporation property. Four types of two-component chemically amplified positive KrF resists were prepared consisting of tert-butoxycarbonyl (t-BOC) protected polyhydroxystyrene and sulfonic acid derivative photo-acid generator (PAG). Here, a different combination of two types of PAGs [2,4-dimethylbenzenesulfonic acid (aromatic sulfonic acid) derivative PAG and cyclohexanesulfonic acid (alkyl sulfonic acid) derivative PAG] and two types of solvents (propylene glycol monomethyl ether acetate; PGMEA and ethyl lactate; EL) were evaluated. The aromatic sulfonic acid was able to evaporate easily during post exposure bake (PEB) treatment, but the alkyl sulfonic acid was not. The higher evaporation property of aromatic sulfonic acid might be due to the higher vapor pressure and the longer acid diffusion length. Furthermore, the amount of aromatic sulfonic acid in the PGMEA resist was reduced by more than that in the EL resist. The amount of acid loss also became smaller at a higher prebake temperature. The concentration of the remaining solvent in the resist film decreased with the increasing prebake temperature. We think that the acid evaporation property was affected by the remaining solvent in the resist, film; the large amount of remaining solvent promoted the acid diffusion and eventually accelerated the acid evaporation from the resist film surface in the PGMEA resist. In summary, the acid evaporation property depends on both the acid

  4. Corrosion resistance of high-performance materials titanium, tantalum, zirconium

    CERN Document Server

    2012-01-01

    Corrosion resistance is the property of a material to resist corrosion attack in a particular aggressive environment. Although titanium, tantalum and zirconium are not noble metals, they are the best choice whenever high corrosion resistance is required. The exceptionally good corrosion resistance of these high–performance metals and their alloys results from the formation of a very stable, dense, highly adherent, and self–healing protective oxide film on the metal surface. This naturally occurring oxide layer prevents chemical attack of the underlying metal surface. This behavior also means, however, that high corrosion resistance can be expected only under neutral or oxidizing conditions. Under reducing conditions, a lower resistance must be reckoned with. Only very few inorganic and organic substances are able to attack titanium, tantalum or zirconium at ambient temperature. As the extraordinary corrosion resistance is coupled with an excellent formability and weldability these materials are very valua...

  5. Resistance to chemical attack of bittern-resisting cement in high-bittern environment

    Institute of Scientific and Technical Information of China (English)

    Yunbing Hou; Bingwen Wang; Yu Chen; Botao Zhang; Lin Yu

    2005-01-01

    A new kind of bittern-resisting cement (BRC) was introduced. This material is based on the ternary cementitious system of clinker containing C4A3 -S phase, high-activity ground granulated blast-furnace slag (GGBFS) and fly ash (FA). The hydration process and the hydrated products of BRC were studied by means of XRD, TG-DTA and SEM, and the resistance to chemical attack of BRC in high-bittern environment was also examined. The corrosion experiment in seven kinds of brines proved that BRC exhibits an excellent resistance to chemical attack of bittern. The corrosion resistance factors were calculated and all of them were greater than 0.96. It showed that BRC totally controls the cement-based material corrosion in brines from four aspects: (1) making full use of the dominant complementation effect of mineral materials; (2) diminishing the hydrated products easy to be attacked; (3) improving the microstructure of hardened cement mortar; (4) degrading the chemical attack of bittern.

  6. Development of radiation resistant organic composite materials

    International Nuclear Information System (INIS)

    Radiation resistant composite material has been developed. Stress analysis and the matrix choice were made carefully. The stress analysis reveals that the intrinsic radiation induced degradation was brought by the degradation of interlaminar shear strength. It means the preventing the degradation of interlaminar shear strength is important to develop the radiation resistant composite materials. To prevent the degradation of the interlaminar shear strength the three dimensional fabrics are used as the reinforcement and the boron free glass fibers were chosen. The possible method to develop the radiation resistant organic composites are discussed. (author)

  7. High temperature chemically resistant polymer concrete

    Science.gov (United States)

    Sugama, T.; Kukacka, L.E.

    High temperature chemically resistant, non-aqueous polymer concrete composites consist of about 12 to 20% by weight of a water-insoluble polymer binder. The binder is polymerized in situ from a liquid vinyl-type monomer or mixture of vinyl containing monomers such as triallylcyanurate, styrene, acrylonitrile, acrylamide, methacrylamide, methyl-methacrylate, trimethylolpropane trimethacrylate and divinyl benzene. About 5 to 40% by weight of a reactive inorganic filler selected from the group consisting of tricalcium silicate and dicalcium silicate and mixtures containing less than 2% free lime, and about 48 to 83% by weight of silica sand/ and a free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, other orgaic peroxides and combinations to initiate polymerization of the monomer in the presence of the inorganic filers are used.

  8. Novel photoacid generators for chemically amplified resists

    Science.gov (United States)

    Yamato, Hitoshi; Asakura, Toshikage; Matsumoto, Akira; Ohwa, Masaki

    2002-07-01

    Recently we have developed new class of non-ionic oxime sulfonate PAG. The compounds generate various kinds of sulfonic acids, such as n-propane, n-octane, camphor and p-toluene sulfonic acid under Deep-UV exposure and are applicable for chemically amplified (CA) photoresists. The application-relevant properties of the compounds such as solubility in propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, ethyl 3-ethoxypropionate, and 2-heptanone, UV absorption, thermal stability with or without poly(4-hydroxystyrene) (PHS), storage stability in a neat form or in PGMEA solution with or without additives, sensitivity in a model resist formulation, dissolution inhibition efficiency during the development process and volatility were evaluated. The compounds exhibit good solubility in PGMEA, high sensitivity in positive tone CA resist formulations, with Deep-UV exposure, and no significant volatility. Especially it was found that the compounds are superior in terms of thermal stability and storage stability, i.e., high thermal stability up to 188 degree(s)C in a phenolic matrix, and no change during storage in PGMEA at 60 degree(s)C for 5 months.

  9. Resistance to chemical disinfection under conditions of microgravity

    Science.gov (United States)

    Marchin, George L.

    1998-01-01

    In unit gravity, bacteria and disinfecting resin beads co-sediment to the septum in a fluid processing apparatus (FPA) resulting in effective chemical disinfection. In microgravity bacteria in suspension have access to a larger volume of the FPA because of a lack of sedimentation. Further, when disinfecting resin beads are added to the FPA they also remain in suspension reducing their effective concentration. Typically, therefore, disinfection experiments in microgravity return larger numbers of viable bacteria than ground-based controls. Preliminary experiments aboard the MIR Space Station with Pseudomonas aeruginosa additionally suggest that the longer bacteria are retained in microgravity the more resistant they become to chemical disinfection. This phenomenon is probably due to additional time to develop resistant biofilms on the interior of the FPA. To partially solve these problems we have developed additional disinfecting materials to use in conjunction with polyiodide containing resin beads. One of these materials carbon beads coated with 3-trimethoxy silylpropyl dimethyloctadecyl ammonium chloride (Dow-Corning 5700®), acts synergistically with polyiodide resin disinfectants. Carbon beads so treated are still able to remove aqueous iodine from the water stream while providing an additional level of chemical disinfection. This additional capability prevents contamination of the carbon beads with heterotrophic bacteria and insures that bacteria surviving iodine disinfection are efficiently devitalized.

  10. Study on Low Resistance PTC Ceramic Material

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The low resistance PTC ceramic thermistor material with excellent eleectrical properties are successfully fabricated by raw materials at industrial range made in our country on the study of its composition expression and fabrication process by using the addition of Nb, La, Y, Ta , microstructure regulator BN and ASTL phase .The composition and its fabrication method are studied.The relation of electrical properties of the PTC ceramic material to its composition expression and its related electrical properties are discussed.

  11. Chemical reactor and method for chemically converting a first material into a second material

    Science.gov (United States)

    Kong, Peter C.

    2008-04-08

    A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

  12. Proliferation resistance criteria for fissile material disposition

    International Nuclear Information System (INIS)

    The 1994 National Academy of Sciences study open-quotes Management and Disposition of Excess Weapons Plutoniumclose quotes defined options for reducing the national and international proliferation risks of materials declared excess to the nuclear weapons program. This report proposes criteria for assessing the proliferation resistance of these options. The criteria are general, encompassing all stages of the disposition process from storage through intermediate processing to final disposition including the facilities, processing technologies and materials, the level of safeguards for these materials, and the national/subnational threat to the materials

  13. BI-LAYER HYBRID BIOCOMPOSITES: CHEMICAL RESISTANT AND PHYSICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Mohammad Jawaid,

    2012-02-01

    Full Text Available Bi-layer hybrid biocomposites were fabricated by hand lay-up technique by reinforcing oil palm empty fruit bunch (EFB and jute fibre mats with epoxy matrix. Hybrid composites were prepared by varying the relative weight fraction of the two fibres. The physical (void content, density, dimensional stability, and chemical resistant properties of hybrid composites were evaluated. When the jute fibre loading increased in hybrid composites, physical and chemical resistant properties of hybrid composites were enhanced. Void content of hybrid composites decreased with an increase in jute fibre loading because jute fibres showed better fibre/matrix interface bonding, which leads to a reduction in voids. The density of hybrid composite increased as the quantity of jute fibre loading increased. The hybridization of the jute fibres with EFB composite improved the dimensional stability of the hybrid composites. The performance of hybrid composites towards chemical reagents improved with an increase in jute fibre loading as compared to the EFB composite. The combination of oil palm EFB/jute fibres with epoxy matrix produced hybrid biocomposites material that is competitive to synthetic composites.

  14. Refractory wear resistant powder materials for metallurgy

    International Nuclear Information System (INIS)

    Powder materials on the basis of high-alloy nickel alloys containing up to 50 % (in mass) of Co, Cr, Mo, W, Ti, Nb, Al and up to 10 % refractory thermally stable compounds (oxides, carbides, nitrides, carbonitrides) have been developed. They feature a high strength, corrosion- and wear resistance at 800-1000 deg C, a satisfactory ductility at room and working temperatures, a decreased tendency towards crack formation, they are workable by cutting. 4 refs., 4 figs

  15. Nanostructured Tungsten Materials by Chemical Methods

    OpenAIRE

    Wahlberg, Sverker

    2011-01-01

    Tungsten based-materials are used in many different technical fields, particularly in applications requiring good temperature and/or erosion resistance. Nanostructuring of tungsten alloys and composites has the potential to dramatically improve the materials’ properties, enhancing the performance in present applications or enabling totally new possibilities. Nanostructured WC-Co composites have been the focus of researchers and industries for over two decades. New methods for powder fabricati...

  16. Effect of radiation resistance additives for insulation materials

    International Nuclear Information System (INIS)

    For the electric wires and cables used in radiation environment such as nuclear power stations and fuel reprocessing facilities, the properties of excellent radiation resistance are required. For these insulators and sheath materials, ethylene propylene rubber, polyethylene and other polymers have been used, but it cannot be said that they always have good radiation resistance. However, it has been well known that radiation resistance can be improved with small amount of additives, and heat resistance and burning retarding property as well as radiation resistance are given to the insulators of wires and cables for nuclear facilities by mixing various additives. In this research, the measuring method for quantitatively determining the effect of Anti-rad (radiation resistant additive) was examined. Through the measurement of gel fraction, radical formation and decomposed gas generation, the effect of Anti-rad protecting polymers from radiation deterioration was examined from the viewpoint of chemical reaction. The experimental method and the results are reported. The radiation energy for cutting C-H coupling is polymers is dispersed by Anti-rad, and the probability of cutting is lowered. Anti-rad catches and extinguishes radicals that start oxidation reaction. (K.I.)

  17. An evaluation of candidate oxidation resistant materials

    Science.gov (United States)

    Rutledge, Sharon; Banks, Bruce; Mirtich, Michael; Difilippo, Frank; Hotes, Deborah; Labed, Richard; Dever, Terese; Kussmaul, Michael

    1987-01-01

    Ground based testing of materials considered for Kapton solar array blanket protection, graphite epoxy structural member protection, and high temperature radiators was performed in an RF plasma asher. Ashing rates for Kapton were correlated with rates measured on STS-8 to determine the exposure time equivalent to one year in low Earth orbit (LEO) at a constant density space station orbital flux. Protective coatings on Kapton from Tekmat, Andus Corporation, and LeRC were evaluated in the plasma asher and mass loss rates per unit area were measured for each sample. All samples evaluated provided some protection to the underlying surface but ion beam sputter deposited samples of SiO2 and SiO2 with 8% polytetrafluoroethylene (PTFE) showed no evidence of degradation after 47 hours of exposure. Mica paint was evaluated as a protective coating for graphite epoxy structural members. Mica appears to be resistant to attack by atomic oxygen but only offers some limited protection as a paint because the paint vehicles evaluated to date were not resistant to atomic oxygen. Four materials were selected for evaluation as candidate radiator materials: stainless steel, copper, niobium-1% zirconium, and titanium-6% aluminum-4% vanadium. These materials were surface textured by various means to improve their emittance. Emittances as high as 0.93 at 2.5 microns for stainless steel and 0.89 at 2.5 microns for Nb-1 Zr were obtained from surface texturing. There were no significant changes in emittance after asher exposure.

  18. Preparation of atomic oxygen resistant polymeric materials

    Science.gov (United States)

    Tortorelli, Victor J.; Hergenrother, P. M.; Connell, J. W.

    1991-01-01

    Polyphenyl quinoxalines (PPQs) are an important family of high performance polymers that offer good chemical and thermal stability coupled with excellent mechanical properties. These aromatic heterocyclic polymers are potentially useful as films, coatings, adhesives, and composite materials that demand stability in harsh environments. Our approach was to prepare PPQs with pendent siloxane groups using the appropriate chemistry and then evaluate these polymers before and after exposure to simulated atomic oxygen. Either monomer, the bis(o-diamine)s or the bis(alpha-diketone)s can be synthesized with a hydroxy group to which the siloxane chain will be attached. Several novel materials were prepared.

  19. ESC resistance of commercial grade polycarbonates during exposure to butter and related chemicals

    DEFF Research Database (Denmark)

    Kjellander, Carina Koch; Nielsen, Tenna B; Ghanbari-Siahkali, Afshin;

    2008-01-01

    Three commercial grades of polycarbonates (Lexan (R) 144, Lexan (R) 104 and Makrolon Rx1805) were studied with respect to resistance to environmental stress cracking (ESC) when exposed to butter and related chemicals. The polycarbonates (PCs) were extensively characterised to determine whether...... differences in ESC resistance could be related to their structural or chemical properties. MALDI-TOF mass spectrometry revealed that Makrolon Rx:1805 contains a low molar mass material characterised as poly(propylene glycol)p, which was confirmed by ATR-FTIR and H-1 NMR. Some "non-absorbing" chemicals, such...

  20. Metal nano-film resistivity chemical sensor.

    Science.gov (United States)

    Podešva, Pavel; Foret, František

    2016-02-01

    In this work, we present a study on reusable thin metal film resistivity-based sensor for direct measurement of binding of thiol containing molecules in liquid samples. While in bulk conductors the DC current is not influenced by the surface events to a measureable degree in a thin metal layer the electrons close to the surface conduct a significant part of electricity and are influenced by the surface interactions. In this study, the thickness of the gold layer was kept below 100 nm resulting in easily measureable resistivity changes of the metal element upon a surface SH-groups binding. No further surface modifications were necessary. Thin film gold layers deposited on a glass substrate by vacuum sputtering were photolithographically structured into four sensing elements arranged in a Wheatstone bridge to compensate for resistance fluctuations due to the temperature changes. Concentrations as low 100 pM provided measureable signals. The surface after the measurement could be electrolytically regenerated for next measurements. PMID:26040502

  1. Raw material and materials for production of chemical current sources

    Energy Technology Data Exchange (ETDEWEB)

    Olszanski, S.; Brudka, Z.; Rychlewski, J.

    1982-01-01

    During work to replace imported raw material by domestic in the production of chemical sources of current, the central laboratory of storage batteries and elements of the Polish People's Republic has developed: technology for thermal treatment of inexpensive channel carbon black guaranteeing possibility of using it in agglomerate mixture of manganese chemical current sources (thermal treatment of carbon black, wetting by a solution of weak carboxylic acid conducted in an atmosphere of flue gases at 1100/sup 0/C), expander for negative active mass of the Pb-storage batteries based on lignin formed as wastes in the production of vanilin; gluing thyotropic composite for gluing covers and tanks of storage batteries.

  2. Materials selection for oxide-based resistive random access memories

    International Nuclear Information System (INIS)

    The energies of atomic processes in resistive random access memories (RRAMs) are calculated for four typical oxides, HfO2, TiO2, Ta2O5, and Al2O3, to define a materials selection process. O vacancies have the lowest defect formation energy in the O-poor limit and dominate the processes. A band diagram defines the operating Fermi energy and O chemical potential range. It is shown how the scavenger metal can be used to vary the O vacancy formation energy, via controlling the O chemical potential, and the mean Fermi energy. The high endurance of Ta2O5 RRAM is related to its more stable amorphous phase and the adaptive lattice rearrangements of its O vacancy

  3. Improved Y-123 materials by chemical substitutions

    International Nuclear Information System (INIS)

    By using the knowledge accumulated during last decade about the relationship between the structural features and the superconducting properties we have attempted to design an improved Y123 material that would display an increased superconducting transition temperature, Tc, and enhanced critical current, Jc, and irreversibility fields, Birr. Chemical substitutions on various crystallographic sites were made to reduce the buckling of the CuO2-planes. Substitutions of Sr for Ba and transition elements for copper were made to shorten the distance between the double-CuO2-planes while preserving the ''metallicity'' of the blocking layer. The synthesis and annealing conditions were optimized to obtain the highest Tc. Improved critical currents and irreversibility fields were found for (Nd1-xLax)123 and YBaSrCu3-yMoyO7+d compounds. The existence of these materials indicates that it is possible to further enhance superconducting properties of YBa2Cu3O7 materials by clever design of the crystal chemistry. (orig.)

  4. Experimental techniques for design of impact-resistant material (poster)

    OpenAIRE

    Fan, J.; Weerheijm, J.; Sluys, L. J.

    2013-01-01

    Some polymers are not only transparent and lightweight, but also impact and ballistic resistant. Designing and preparing such polymeric materials with a high impact‐resistant performance is of importance to e.g. aviation, military and windscreen applications.

  5. Resistive heating for self-healing materials based on ionomeric polymers.

    OpenAIRE

    Castellucci, Matt

    2009-01-01

    Self-healing materials have received considerable development in the last decade. Recent results have demonstrated healing in polymeric materials via a chemical reaction using a healing agent or response to thermal treatment. The goal of this research is to develop a new composite material, for application in wire insulation, that can detect damage and heal itself using resistance heating. The composite material is composed of a conductive network embedded in a polymer matrix. ...

  6. Coal Ash Corrosion Resistant Materials Testing

    Energy Technology Data Exchange (ETDEWEB)

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2007-12-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a moderate alkali content (0.2% sodium equivalents), thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that aggressive alkali sulfate constituents were present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. Test Section A was removed in November 2001 after about 24 months of service at the desired steam temperature set point, with about 15.5 months of exposure at full temperature. A progress report, issued in October 2002, was written to document the performance of the candidate alloys in that test section. The evaluation described the condition of each tube sample after exposure. It involved a determination of the rate of wall thickness loss for these samples. In cases where there was more than one sample of a candidate material in the test section, an assessment was made of the performance of the alloy as a function of temperature. Test Sections B and C were examined during the November 2001 outage, and it was decided that

  7. Abrasion Resistant Refractory Materials GB/T 23294-2009

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyuan

    2009-01-01

    @@ 1 Scope This standard specifies the definition, classification, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage, and quality certificate of abrasion resistant refractory materials. This standard is applicable to abrasion resistant refractory materials for circulating fluidized bed boilers, daily waste incinerator, industrial waste incinerator, medical waste incinerator, ordinary solid waste incinerator, hazardous waste incinerator, etc.

  8. Chemical characteristics of negative-tone chemically amplified resist for advanced mask making: II

    Science.gov (United States)

    Takeshi, Kazumasa; Tanabe, Masahito; Inokuchi, Daisuke; Fukushima, Yuichi; Okumoto, Yasuhiro; Okuda, Yoshimitsu

    2004-12-01

    We investigated the film property and the lithographic performance of five commercialized NCARs. This report focused on Cr effect and PCD stability which are critical issues on advanced mask making. Results confirmed to solve the Cr effect by controlled dissolution rate of resist film. Furthermore, PCD was occurred by PAG moving and unsuitable reaction in the resist film standing delay time. This report suggests the strategy that was design of chemical structure for the next generation NCARs.

  9. Influence of metakaolin on chemical resistance of concrete

    International Nuclear Information System (INIS)

    Nowadays the most suitable and widely used construction material is concrete. We could develop concrete for every request in connection with the properties of fresh concrete and the quality of hardened concrete, too. The demand is rising in application of special concretes, like high performance and ultra high performance concretes (HPC, UHPC). These are usable in extreme natural circumstances or in very corrosive surroundings (for example: sewage farm, sewer, cooling tower, biogas factories). The pH value of the commercial sewage is between 7–8, but this value is often around 4 or less. The concrete pipes, which transport the sewage, are under corrosion, because above the liquid level sulphuric acid occurs due to microbes. Acidic surroundings could start the corrosion of concrete. When the pH value reduces, the influence of the acids will increase. The most significant influence has the sulphuric acid. The pH value of sulphuric acid is about 1, or less. Earlier in the cooling towers of coal thermal power stations used special coating on the concrete wall. Recently application of high performance concrete without polymeric coating is more general. Cementitious supplementary materials are widely used to protect the concrete from these corrosive surroundings. Usually used cementitious supplementary materials are ground granulated blastfurnace slag (GGBS), flying ash (FA) or silica fume (SF). In the last years there has been a growing interest in the application of metakaolin. Metakaolin is made by heat treatment, calcinations of a natural clay mineral, kaolinite. In our present research the chemical resistance of mortars in different corrosive surroundings (pH=1 sulphuric acid; pH=3 acetic acid) and the chloride ion migration were studied on series of mortar samples using rapid chloride migration test. Cement paste and mortar samples were made with 17% metakaolin replacement or without metakaolin. The following cements were used: CEM II/A-S 42.5 N, CEM I 42.5 N

  10. Human Genetic Marker for Resistance to Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    DR. Howard B. Lieberman

    2001-05-11

    TO characterize the human HRDAD9 gene and evaluate its potential as a biomarker to predict susceptibility to the deleterious health effects potentially caused by exposure to radiations or chemicals present at DOE hazardous waste cleanup sites. HRAD9 is a human gene that is highly conserved throughout evolution. Related genes have been isolated from yeasts and mice, underscoring its biological significance. Most of our previous work involved characterization of the yeast gene cognate, wherein it was determined that the corresponding protein plays a significant role in promoting resistance of cells to radiations and chemicals, and in particular, controlling cell growth in response to DNA damage.

  11. Human Genetic Marker for Resistance to Radiation and Chemicals

    International Nuclear Information System (INIS)

    TO characterize the human HRDAD9 gene and evaluate its potential as a biomarker to predict susceptibility to the deleterious health effects potentially caused by exposure to radiations or chemicals present at DOE hazardous waste cleanup sites. HRAD9 is a human gene that is highly conserved throughout evolution. Related genes have been isolated from yeasts and mice, underscoring its biological significance. Most of our previous work involved characterization of the yeast gene cognate, wherein it was determined that the corresponding protein plays a significant role in promoting resistance of cells to radiations and chemicals, and in particular, controlling cell growth in response to DNA damage

  12. Modeling release of chemicals from multilayer materials into food

    Directory of Open Access Journals (Sweden)

    Huang Xiu-Ling

    2016-01-01

    Full Text Available The migration of chemicals from materials into food is predictable by various mathematical models. In this article, a general mathematical model is developed to quantify the release of chemicals through multilayer packaging films based on Fick's diffusion. The model is solved numerically to elucidate the effects of different diffusivity values of different layers, distribution of chemical between two adjacent layers and between material and food, mass transfer at the interface of material and food on the migration process.

  13. Evaluation of sensitivity for positive tone non-chemically and chemically amplified resists using ionized radiation: EUV, x-ray, electron and ion induced reactions

    Science.gov (United States)

    Oshima, Akihiro; Oyama, Tomoko Gowa; Washio, Masakazu; Tagawa, Seiichi

    2013-03-01

    The different exposure sources induce a different energy deposition in resist materials. Linear energy transfer (LET) effect for resist sensitivity is very important issue from the viewpoint of radiation induced chemical reactions for high-volume nanofabrication. The sensitivities of positive tone non-chemically (non-CA, ZEP) and chemically amplified (CA, UV-3) resist materials are evaluated using various ionized radiation such as EUV, soft X-rays, EB and various ion beams. Since the notations of sensitivity of resist vary with exposure sources, in order to evaluate systematically, the resist sensitivity were estimated in terms of absorbed dose in resist materials. Highly-monochromated EUV and soft X-rays (6.7 nm - 3.1 nm) from the BL27SU of the SPring-8, high energy ion beams (C6+, Ne10+, Mg12+, Si14+ , Ar18+, Kr36+ and Xe54+) with 6 MeV/u from MEXP of HIMAC, EB from low energy EB accelerator (Hamamatsu Photonics, EB-engine®, 100 kV) and EB lithography system (30 keV and 75keV) were used for the exposure. For non-CA and CA resist materials, it was found that LET effects for sensitivity would be hardly observed except for heavier ion beams. Especially, in the case of the high energy ion beam less than Si14+ with 6 MeV/u, it is suggested that the radiation induced chemical reaction would be equivalent to EUV, soft X-ray and EB exposure. Hence, it indicates that the resist sensitivity could be systematically evaluated by absorbed dose in resist materials.

  14. Alkaline cement mortars. Chemical resistance to sulfate and seawater attack

    OpenAIRE

    Puertas, F.; Gutiérrez, R.; Fernández-Jiménez, A.; Delvasto, S.; Maldonado, J.

    2002-01-01

    The durability and chemical resistance of alkali activated slag and fly ash/slag mortars in contact with sulfates and seawater media have been studied. Two methods were used in the evaluation of such durability: Kock-Steinegger and ASTM C1012. A mineralogical and a microstructural characterization of mortars were done at different ages of their conservation in aggressive media through XRD, SEM/ EDX and mercury porosimetry. Results showed a high durability of activated cement mortars in s...

  15. Chemical resistance of optical plastics and resin for level detectors

    Science.gov (United States)

    Omegna, Cicero L.; Fontes Garcia, Jonas; Ramos-Gonzáles, Roddy E.; Barbosa, Luiz C.

    2015-09-01

    A test method was developed to find the ideal optical material that supports the chemical reaction of some fuels. Optical plastics and resin were submerged for long periods of time in reservoirs of ethanol, gasoline, Diesel and biodiesel. The dimensional change and weight change of the submerged samples was measured. A special resin successfully supported the chemical attack of fuels. Samples of acrylic polymer and polycarbonate were used as type of optical plastic.

  16. Evaluation of alcoholic hydroxyl derivatives for chemically amplified extreme ultraviolet resist

    Science.gov (United States)

    Furukawa, Kikuo; Kozawa, Takahiro; Tagawa, Seiichi

    2009-03-01

    Extreme ultraviolet (EUV) lithography is the most favorable process as next-generation lithography. For the development of EUV resists, phenolic materials such as poly (4-hydroxystyrene) have been investigated. Phenolic hydroxyl groups of polymers play an important role in acid diffusion, dissolution kinetics, and adhesion to substrates. Besides these important roles, phenolic hydroxyl groups are also an effective proton source in acid generation in EUV resists. However, the roles of alcohol hydroxyl groups have not been well-studied. To clarify the difference between phenolic and alcoholic hydroxyl groups upon exposure to EUV radiation, we synthesized acrylic terpolymers containing alcoholic hydroxyl groups as model photopolymers and exposed the resist samples based on these polymers to EUV radiation. On the basis of the lithographic performances of these resist samples, we evaluated the characteristics of alcoholic hydroxyl groups upon exposure to EUV radiation. We discuss the relationship between the chemical structures of these derivatives and lithographic performance.

  17. Harnessing entropic and enthalpic contributions to create a negative tone chemically amplified molecular resist for high-resolution lithography

    International Nuclear Information System (INIS)

    Here we present a new resist design concept. By adding dilute cross-linkers to a chemically amplified molecular resist, we synergize entropic and enthalpic contributions to dissolution by harnessing both changes to molecular weight and changes in intermolecular bonding to create a system that outperforms resists that emphasize one contribution over the other. We study patterning performance, resist modulus, solubility kinetics and material redistribution as a function of cross-linker concentration. Cross-linking varies from dilute oligomerization to creating a highly networked system. The addition of small amounts of cross-linker improves resist performance by reducing material diffusion and redistribution during development and stiffening the features to avoid pattern collapse. The new dilute cross-linking system achieves the highest resolution of a sensitive molecular glass resist at 20 nm half-pitch and line-edge roughness (LER) of 4.3 nm and can inform new resist design towards patterned feature control at the molecular level. (paper)

  18. Comparison of abrasion resistance of selected constructional materials

    Directory of Open Access Journals (Sweden)

    M. Adamiak

    2009-12-01

    Full Text Available Purpose: The aim of this work was to define and compare abrasion resistance of selected constructional materials widely used in the industry. Chromium cast iron wear resistant plates were compared with typically used wear resistant plates made from Hardox 400 steel and two different, wear resistant, materials cladded by welding technologies.Design/methodology/approach: The tests of abrasive wear were conducted in accordance to procedure “A” of standard ASTM G 65 - Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus.Findings: Abrasion resistance tests shows that the best properties among investigated samples has chromium cast iron plate. Abrasion wear resistance of this plate is two times higher than wear resistance of layer made by welding technologies and nine times higher than typical Hardox 400 steel plate.Practical implications: Application, of abrasion resistant materials, results in significant material and economy savings, due to wear and costs reduction (decreasing stop times needed to change worn parts for a new one.Originality/value: Wear plates are modern solution in regeneration of worn machines parts and also for producing a new parts which connect high wear and abrasion resistance with costs reduction.

  19. Radiation resistant multicomponent inorganic materials for homogeneous EM-calorimeters

    International Nuclear Information System (INIS)

    With the development of a new generation of particle accelerators the interest for radiation resistant materials using for EM-calorimeters capable of withstanding a high radiation environment (107 rad/yr) has been increasing. The radiation resistance of fluoride solid solutions and heavy crystal oxides is investigated. A series of multicomponent crystals, solid solutions on the base of CeF2 and CdF2 with the radiation resistance above 109 rad is presented. 24 refs.; 4 figs

  20. Chemical resistance, void content and tensile properties of oil palm/jute fibre reinforced polymer hybrid composites

    International Nuclear Information System (INIS)

    Tri layer hybrid composites of oil palm empty fruit bunches (EFB) and jute fibres was prepared by keeping oil palm EFB as skin material and jute as the core material and vice versa. The chemical resistance, void content and tensile properties of oil palm EFB/Jute composites was investigated with reference to the relative weight of oil palm EFB/Jute, i.e. 4:1, the fibre loading was optimized and different layering pattern were investigated. It is found from the chemical resistance test that all the composites are resistant to various chemicals. It was observed that marked reduction in void content of hybrid composites in different layering pattern. From the different layering pattern, the tensile properties were slightly higher for the composite having jute as skin and oil palm EFB as core material. Scanning electron microscopy (SEM) was used to study tensile fracture surfaces of different composites.

  1. Sputter-Resistant Materials for Electric Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase 2 project shall develop sputter-resistant materials for use in electric propulsion test facilities and for plume shields on spacecraft using...

  2. Materials growth and characterization of thermoelectric and resistive switching devices

    Science.gov (United States)

    Norris, Kate J.

    In the 74 years since diode rectifier based radar technology helped the allied forces win WWII, semiconductors have transformed the world we live in. From our smart phones to semiconductor-based energy conversion, semiconductors touch every aspect of our lives. With this thesis I hope to expand human knowledge of semiconductor thermoelectric devices and resistive switching devices through experimentation with materials growth and subsequent materials characterization. Metal organic chemical vapor deposition (MOCVD) was the primary method of materials growth utilized in these studies. Additionally, plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD),ion beam sputter deposition, reactive sputter deposition and electron-beam (e-beam) evaporation were also used in this research for device fabrication. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Electron energy loss spectroscopy (EELS) were the primary characterization methods utilized for this research. Additional device and materials characterization techniques employed include: current-voltage measurements, thermoelectric measurements, x-ray diffraction (XRD), reflection absorption infra-red spectroscopy (RAIRS), atomic force microscopy (AFM), photoluminescence (PL), and raman spectroscopy. As society has become more aware of its impact on the planet and its limited resources, there has been a push toward developing technologies to sustainably produce the energy we need. Thermoelectric devices convert heat directly into electricity. Thermoelectric devices have the potential to save huge amounts of energy that we currently waste as heat, if we can make them cost-effective. Semiconducting thin films and nanowires appear to be promising avenues of research to attain this goal. Specifically, in this work we will explore the use of ErSb thin films as well as Si and InP nanowire networks for thermoelectric applications. First we will discuss the growth of

  3. Corrosion resistance of candidate transportation container materials

    International Nuclear Information System (INIS)

    The Department of Energy is currently remediating several sites that have been contaminated over the years with hazardous, mixed waste and radioactive materials. Regulatory guidelines require strict compliance demonstrating public safety during remediation and the transport of these hazardous, mixed waste and radioactive materials. The compatibility of the metallic transportation containers with the contents they are designed to transport is an ultimate concern that must be satisfied to ensure public safety. The transportation issue is inherently complicated due to the complex, varied, and unknown composition of the hazardous, mixed and radioactive waste that is being, considered for transport by the DOE facilities. Never before have the interactions between the waste being transported and the materials that comprise the transportation packages been more important. Therefore, evaluation of material performance when subjected to a simulated waste will ensure that all regulatory issues and requirements for transportation of hazardous, mixed, and radioactive wastes are satisfied. The tasks encompassed by this study include defining criteria for candidate material selection, defining a test matrix that will provide pertinent information on the material compatibility with the waste stimulant, and evaluation of material performance when subjected to a stimulant waste. Our goal is to provide package design engineers with a choice of materials which exhibit enhanced performance upon exposure to hazardous, mixed, and radioactive waste that is similar in composition to the waste stimulant used in this study. Due to the fact that there are many other possible waste compositions, additional work needs to be done to broaden our materials compatibility/waste stream data base

  4. CHEMICAL COMPOSITIONS AND RESISTANT STARCH CONTENT IN STARCHY FOODS

    Directory of Open Access Journals (Sweden)

    Anuchita Moongngarm

    2013-01-01

    Full Text Available Resistant Starch (RS is one of nature’s most interesting bioactive compounds. There is a wide variety of starchy food plants in Thailand that are good sources of RS, but they have not been well studied. As such, this study was carried out to investigate the potential food source of RS. Twenty-two promising food plants were selected. The samples included (1 cereals comprised of five long grain rice of O. sativa L. and sweet corn, (2 six species of root and tuber crops, (3 green banana fruits (Musa sapientum L. composed of ABB group, AAB group and AAA group at the first stage of ripening and (4 legume seeds included cowpea seeds (3 different cultivars, red bean, red kidney bean and mung bean. All food plants were determined for chemical compositions, resistant starch, non-resistant starch, total starch and amylose content. The study found that the starchy foods varied in their chemical compositions. The major composition of all foods was carbohydrate ranging between 58.19 (in black speck cow pea and 87.21% (in cassava root, whilst the fat, ash and fiber were observed only in small quantities. The protein content was highest in legume seeds (20.78 to 27.22%. For the study on starch compositions, green bananas contained highest amount of resistant starch ranging between 35.14 and 45.87%, indicating that more than a half of total starch in banana RS content varying from 35.14 to 45.87%, whereas the RS content of legumes ranging from 2.33 to 10.63% and 1.16 to 4.85% in cereal grains. Most of the starchy food plants contained moderate to high level of amylose (11.45-34.85%, except the waxy rice (2.72%.

  5. Moisture-resistant TPS Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed NASA Phase I SBIR will generate closed-cell foam thermal protection system materials which do not need waterproofing, and which can be applied as a...

  6. Sustainable Materials and Biorefinery Chemicals from Agriwastes

    OpenAIRE

    Martin-Luengo, M. A.; Yates, M.; M. Ramos; Plou, F.; Salgado, J. L.; Civantos, A.; Lacomba, J.L.; Reilly, G.; Vervaet, C.; Rojo, E. Sáez; Serrano, A.M. Martínez; Diaz, M.; Argomaniz, L. Vega; Trujillo, L. Medina; Nogales, S.

    2012-01-01

    Countries with economies based on agriculture generate vast amounts of low or null value wastes which may even represent an environmental hazard. In our group, agricultural industrial wastes have been converted into value added liquid substances and materials with several aims: decreasing pollution, giving added value to wastes and working in a sustainable manner in which the wastes of an industry can be used as the raw materials of the same or others, as the “cradle to cradle” philosophy sta...

  7. Radiation resistance of polymer materials. Degradation evaluation by accelerated testing for application condition

    International Nuclear Information System (INIS)

    This paper presents re-evaluated radiation resistance property data of polymer materials, which had been tested in past times in TAKASAKI Quantum Beam Science Directorate, for the future study of ageing evaluation of low voltage electric cable insulation materials used in light-water nuclear reactors. The radiation resistance of 25 types of plastics and rubbers materials applied in practical environments was evaluated by the accelerated testing of gamma-ray irradiation under oxygen pressure, and was compared with the radiation resistance determined from the traditional testing by irradiation with a high dose rate in air. The polymer materials were formulated to be similar or equivalent to practical materials, and the most of formulation (chemical compounds and quantities) were described. For all materials, the tensile properties (elongation at break, ultimate strength, 100% or 200% modulus), electric resistivity, gel-fraction, and density were measured after irradiation in oxidation conditions and irradiation in air with a high dose rate (non-oxidation conditions). The data of relations between each properties and total dose at various conditions were compiled, and the relations among the changes of mechanical properties, electrical properties, and radiation induced chemical reactions were discussed. (author)

  8. Chemical Fingerprinting of Materials Developed Due To Environmental Issues

    Science.gov (United States)

    Smith, Doris A.; McCool, A. (Technical Monitor)

    2000-01-01

    This paper presents viewgraphs on chemical fingerprinting of materials developed due to environmental issues. Some of the topics include: 1) Aerospace Materials; 2) Building Blocks of Capabilities; 3) Spectroscopic Techniques; 4) Chromatographic Techniques; 5) Factors that Determine Fingerprinting Approach; and 6) Fingerprinting: Combination of instrumental analysis methods that diagnostically characterize a material.

  9. Development of resistant materials to beam impact and radiation damage

    Science.gov (United States)

    Kawai, Masayoshi; Kokawa, Hiroyuki; Okamura, Hiroshi; Kawasaki, Akira; Yamamura, Tsutomu; Hara, Nobuyoshi; Akao, Noboru; Futakawa, Masatoshi; Kikuchi, Kenji

    2006-09-01

    Materials that have strong resistance to both beam impact (or shock-wave) and radiation damage are required for the beam target of an intense accelerator and space applications. Recently, Futakawa et al. found in their experiments that Kolsterising specimens have a stronger resistance to pitting than SS316 CW. A similar effect can be expected for other hardening treatments, and new material development is hopeful. Accordingly, we have started the development of high-performance materials by organizing the project team from KEK, JAEA and universities. In this paper, the scope of the project is introduced. Recent topics involve the development of intergranular crack (IGC)-resistant austenitic stainless-steel, AlN-TiN ceramics and cladding techniques of thin tantalum or CrN film on a tungsten target by means of a molten-salt method and ion-beam-enhanced deposition. New observations on corrosion resistance are presented.

  10. Thermodynamic and kinetic modelling: creep resistant materials

    DEFF Research Database (Denmark)

    Hald, John; Korcakova, L.; Danielsen, Hilmar Kjartansson;

    2008-01-01

    The use of thermodynamic and kinetic modelling of microstructure evolution in materials exposed to high temperatures in power plants is demonstrated with two examples. Precipitate stability in martensitic 9–12%Cr steels is modelled including equilibrium phase stability, growth of Laves phase part...

  11. Slime mould interactions with chemicals and materials

    Science.gov (United States)

    de Lacy Costello, Benjamin

    2015-03-01

    At first sight a seemingly jumbled selection of images, what links all these together? It is an assessment of how P. polycephalum interacts with a synthetic human-made environment and how this can give indications of its natural environmental interactions but more importantly how these can be harnessed to give tangible outcomes in functional material synthesis and biologically inspired computing...

  12. Chemical control alternatives for sourgrass (Digitaria insularis resistant to glyphosate

    Directory of Open Access Journals (Sweden)

    Marcel Sereguin Cabral de Melo

    2012-08-01

    Full Text Available Herbicides alternatives for controlling sourgrass (Digitaria insularis weed in infested citrus areas are limited, mainly due to the few options of registered herbicides and by the modalities in that these chemical products are used (directed applications. Thus it is important to evaluate other post-emergence herbicides, to be used in association with glyphosate, for the efficient control of glyphosate-resistant biotype of sourgrass (Digitaria insularis, resistant to glyphosate.  The experiment was conducted in Matão County, Sao Paulo State, in area belonging to Cambuhy Farm, during September to October 2009, in areas presenting biotypes of D. insularis resistant to glyphosate. Application occurred when sourgrass plants were with 3 to 5 tillers stage. Treatments consisted of different herbicides in association with glyphosate. It was conducted control visual assesments at 7, 14, 21, 28 and 35 days after application and collecting and weighting of weed dry mass dossel. Treatments that showed better results were glyphosate in association with clethodim, complemented by paraquat + diuron 7 days after the first application and glyphosate in association with clethodim complemented by  ammonium-glufosinate 7 days after the first application. Further, glyphosate treatments mixture to haloxyfop-methyl, glyphosate + fenoxaprop-p-ethyl + clethodim and glyphosate + tepraloxydim showed excelent performance, even with just one application.

  13. Chemical reactor for converting a first material into a second material

    Science.gov (United States)

    Kong, Peter C

    2012-10-16

    A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

  14. Materials and Chemical Sciences Division annual report, 1987

    International Nuclear Information System (INIS)

    Research programs from Lawrence Berkeley Laboratory in materials science, chemical science, nuclear science, fossil energy, energy storage, health and environmental sciences, program development funds, and work for others is briefly described

  15. Materials and Chemical Sciences Division annual report, 1987

    Energy Technology Data Exchange (ETDEWEB)

    1988-07-01

    Research programs from Lawrence Berkeley Laboratory in materials science, chemical science, nuclear science, fossil energy, energy storage, health and environmental sciences, program development funds, and work for others is briefly described. (CBS)

  16. Chemical products induce resistance to Xanthomonas perforans in tomato

    Directory of Open Access Journals (Sweden)

    Adriana Terumi Itako

    2015-09-01

    Full Text Available The bacterial spot of tomato, caused by Xanthomonas spp., is a very important disease, especially in the hot and humid periods of the year. The chemical control of the disease has not been very effective for a number of reasons. This study aimed to evaluate, under greenhouse conditions, the efficacy of leaf-spraying chemicals (acibenzolar-S-methyl (ASM (0.025 g.L−1, fluazinam (0.25 g.L−1, pyraclostrobin (0.08 g.L−1, pyraclostrobin + methiran (0.02 g.L−1 + 2.2 g.L−1, copper oxychloride (1.50 g.L−1, mancozeb + copper oxychloride (0.88 g.L−1 + 0.60 g.L−1, and oxytetracycline (0.40 g.L−1 on control of bacterial spot. Tomatoes Santa Clara and Gisele cultivars were pulverized 3 days before inoculation with Xanthomonas perforans. The production of enzymes associated with resistance induction (peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, β-1,3-glucanase, and protease was quantified from leaf samples collected 24 hours before and 24 hours after chemical spraying and at 1, 2, 4, 6, and 8 days after bacterial inoculation. All products tested controlled bacterial spot, but only ASM, pyraclostrobin, and pyraclostrobin + metiram increased the production of peroxidase in the leaves of the two tomato cultivars, and increased the production of polyphenol oxidase and β-1,3-glucanase in the Santa Clara cultivar.

  17. Volume Resistivity and Mechanical Behavior of Epoxy Nanocomposite Materials

    Directory of Open Access Journals (Sweden)

    M. F. Abdelkarim

    2015-04-01

    Full Text Available Electrical and mechanical properties of polymer composite materials are investigated through the determination of resistivity and hardness for composites samples. Epoxy composite samples have been prepared with different concentrations of certain inorganic fillers such as; Titanium dioxide (TiO2 and Silica (SiO2, of various size (micro, nano and hybrid to study the electrical and mechanical behavior. The volume resistivity reaches 3.23×1014 ohm.cm for the micro silica composite. Surface of composite material has been mechanically examined by hardness test. The results show that the resistivity of microcomposites and nanocmposites are increased with the decrease of filler concentration. But the resistivity of hybrid composites is increased with the increase of filler concentration. Maximum hardness value was obtained from hybrid silica composite with 0.1% filler concentration.

  18. Physical and chemical mechanisms in oxide-based resistance random access memory

    Science.gov (United States)

    Chang, Kuan-Chang; Chang, Ting-Chang; Tsai, Tsung-Ming; Zhang, Rui; Hung, Ya-Chi; Syu, Yong-En; Chang, Yao-Feng; Chen, Min-Chen; Chu, Tian-Jian; Chen, Hsin-Lu; Pan, Chih-Hung; Shih, Chih-Cheng; Zheng, Jin-Cheng; Sze, Simon M.

    2015-03-01

    In this review, we provide an overview of our work in resistive switching mechanisms on oxide-based resistance random access memory (RRAM) devices. Based on the investigation of physical and chemical mechanisms, we focus on its materials, device structures, and treatment methods so as to provide an in-depth perspective of state-of-the-art oxide-based RRAM. The critical voltage and constant reaction energy properties were found, which can be used to prospectively modulate voltage and operation time to control RRAM device working performance and forecast material composition. The quantized switching phenomena in RRAM devices were demonstrated at ultra-cryogenic temperature (4K), which is attributed to the atomic-level reaction in metallic filament. In the aspect of chemical mechanisms, we use the Coulomb Faraday theorem to investigate the chemical reaction equations of RRAM for the first time. We can clearly observe that the first-order reaction series is the basis for chemical reaction during reset process in the study. Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device. As for its materials, silicon oxide is compatible to semiconductor fabrication lines. It is especially promising for the silicon oxide-doped metal technology to be introduced into the industry. Based on that, double-ended graphene oxide-doped silicon oxide based via-structure RRAM with filament self-aligning formation, and self-current limiting operation ability is demonstrated. The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process. Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

  19. Resistance Welding of Advanced Materials and Micro Components

    DEFF Research Database (Denmark)

    Friis, Kasper Storgaard

    , thermal, electrical and metallurgical effects all signifcantly in uencing the process. Modelling is further complicated when down-scaling the process for welding micro components or when welding new advanced high strength steels in the automotive industry. The current project deals with three main themes...... resistance is addressed both theoretically and experimentally. Secondly the consequences of downscaling the process is investigated experimentally and discussed in relation to simulation of the process. Finally resistance welding of advanced high strength steels is addressed aimed at improving the simulation...... of the final weld properties. The temperature dependent material rheology of dierent advanced high strength steels and other materials, often resistance welded, were measured using hot tensile testing and hot compression testing. It is found that the Hollomon equation is capable of modelling material...

  20. Influence of Water Absorption on Volume Resistivity and the Dielectric Properties of Neat Epoxy Material

    KAUST Repository

    Sulaimani, Anwar Ali

    2014-07-15

    Influence of Water Absorption on the Dielectric Properties and Volume Resistivity of Neat Epoxy Material Anwar Ali Sulaimani Epoxy resins are widely used materials in the industry as electrical insulators, adhesives and in aircrafts structural components because of their high mechanical sti ness, strength and high temperature and chemical resistance properties. But still, the in uence of water uptake due to moisture adsorption is not fully understood as it detrimentally modi es the electrical and chemical properties of the material. Here, we investigate the in uence of water moisture uptake on the neat epoxy material by monitoring the change in the volume resistivity and dielectric properties of epoxy material at three di erent thickness con gurations: 0.250 mm, 0.50 mm and 1 mm thicknesses. Gravimetric analysis was done to monitor the mass uptake behaviour, Volume Resistivity was measured to monitor the change in conductivity of the material, and the dielectric properties were mapped to characterise the type of water mechanism available within the material during two ageing processes of sorption and desorption. Two-stage behaviours of di usion and reaction have been identi ed by the mass uptake analysis. Moreover, the plot of volume resistivity versus mass uptake has indi- cated a non-uniform relationship between the two quantities. However, the analysis of the dielectric spectrum at medium range of frequency and time has showed a change 5 in the dipolar activities and also showed the extent to which the water molecules can be segregated between bounding to the resin or existing as free water.

  1. Chemical vapor deposition of atomically thin materials for membrane dialysis applications

    Science.gov (United States)

    Kidambi, Piran; Mok, Alexander; Jang, Doojoon; Boutilier, Michael; Wang, Luda; Karnik, Rohit; Microfluidics; Nanofluidics Research Lab Team

    2015-11-01

    Atomically thin 2D materials like graphene and h-BN represent a new class of membranes materials. They offer the possibility of minimum theoretical membrane transport resistance along with the opportunity to tune pore sizes at the nanometer scale. Chemical vapor deposition has emerged as the preferable route towards scalable, cost effective synthesis of 2D materials. Here we show selective molecular transport through sub-nanometer diameter pores in graphene grown via chemical vapor deposition processes. A combination of pressure driven and diffusive transport measurements shows evidence for size selective transport behavior which can be used for separation by dialysis for applications such as desalting of biomolecular or chemical solutions. Principal Investigator

  2. Borides - a new generation of highly resistant materials?

    International Nuclear Information System (INIS)

    High-duty ceramics are on advance in all sectors where materials with extremely good resistance to high temperatures and wear are required. The group of oxides, nitrides and carbides in use for quite a time now recently has been increased by the metal borides which offer among others economic advantages in certain applications. The drawbacks of these materials still to be reduced are their brittleness and susceptibility to oxidation and corrosion. Current research work on the thermodynamics of such systems, on the interaction between structure and properties, and on means to improve strength and resistance to wear are expected to soon open up new applications. (orig.)

  3. Evaluation on Diseases Resistance of Cotton Material and Its Utilization

    Institute of Scientific and Technical Information of China (English)

    ZENG Hua-lan; HE Lian; YE Peng-sheng; ZHANG Yu; WEI Shu-gu

    2008-01-01

    @@ Fusarium wilt and Verticillium wilt are important worldwide fungal diseases on cotton that cause damage to yield and quality.The pathogens survive in soil as microsclerotia for many years,and can be transmitted through seeds,soil,stream,and plant residues.And currently,no effective chemical control is available for those diseases.Production practices have established that planting wilt diseaseresistance varieties was one of the most effective and safe measures to control those diseases with low cost.However,screening for wilt-resistance germplasm resources is the basis for resistance breeding.

  4. Chemical vapour deposition synthetic diamond: materials, technology and applications

    OpenAIRE

    Balmer, R. S.; Brandon, J R; Clewes, S L; Dhillon, H. K.; Dodson, J M; Friel, I.; Inglis, P. N.; Madgwick, T D; Markham, M. L.; Mollart, T P; Perkins, N.; Scarsbrook, G. A.; Twitchen, D. J.; Whitehead, A J; Wilman, J J

    2009-01-01

    Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synt...

  5. Inventions in the nanotechnological area considerably increase wear- and chemical resistance of construction products

    Directory of Open Access Journals (Sweden)

    VLASOV Vladimir Alexeevich

    2014-08-01

    Full Text Available The invention «Reinforced flaked element made of natural or conglomerate stone and its multilayer protective coating (RU 2520193» is referred to construction materials. Reinforced flaked element made of natural or conglomerate stone consists of: natural or conglomerate materials as the basis; multilayer coating which protects the mentioned basis from chemical substances and wearing mechanical factors influencing on this element where the multilayer coating includes at least three layers formed by one or many film-forming compositions which comprise top layer with scratch-resistant nanoparticles and encircled with polyester, melamine, phenolic, acryl or epoxy resin (or any combination of them which provides protection against scratches; damper intermediate layer made of epoxy and/or acryl resin which provides impact resistant; lower layer adjoining to the basis and containing particles of Al2O3 or silicon carbide plus acryl polymer and providing resistance to abrasive wear. Technical result is increased wear- and chemical resistance of flaked elements from natural or conglomerate materials. The invention «Fine organic suspension of carbon metal-containing nanostructures and the method to produce it (RU 2515858» is referred to the area of physical and colloid chemistry and can be used to obtain polymer compositions. Fine organic suspension of carbon metal-containing nanostructures is produced by interaction between nanostructures and polyethylenepolyamine. At first the powder of carbon metalcontaining nanostructures (which are nanoparticles of 3d-metal such as copper, cobalt, nickel stabilized in carbon nanostructures is mechanically milled, then it is mechanically ground with polyethylenepolyamine introduced portionally unless and until the content of nanostructures is less 1 g/ml. The invention results in decreased power inputs as the obtained fine organic suspension of carbon and metal-containing nanostructures is able to recover due to

  6. Nuclear, chemical, and physical characterization of nuclear materials

    International Nuclear Information System (INIS)

    The goal of nuclear forensics is to establish an unambiguous link between illicitly trafficked nuclear material and its origin. The Los Alamos National Laboratory (LANL) Nuclear Materials Signatures Program has implemented a graded 'conduct of operations' type analysis flow path approach for determining the key nuclear, chemical, and physical signatures needed to identify the manufacturing process, intended use, and origin of interdicted nuclear material. This analysis flow path includes both destructive and non-destructive characterization techniques and has been exercized against different nuclear materials from LANL's special nuclear materials archive. Results obtained from the case study will be presented to highlight analytical techniques that offer the critical attribution information. (author)

  7. Preparation of Wear Resistant Materials by Melting and Diffusion Process

    Institute of Scientific and Technical Information of China (English)

    YU Shihao; WEI Xueping; ZENG Hui

    2012-01-01

    A wear-resistant material reinforced with VCp was manufactured by the in-mold melting process,in which the high-vanadium alloy-rods were melted by high temperature liquid steel and elements diffused into the liquid.Microstructure of the material was examined by OM,SEM,and XRD,and alloy elements in the diffusion layer were studied by EDS,and the hardness of the material was tested by HRS.The experimental results show that the material gradually changes hardness,which is due to the uniformly existents of carbide particles on martensite matrix and the gradient distribution of vanadium and carbide.

  8. Evaluation of the radiation resistance of electrical insulation materials

    International Nuclear Information System (INIS)

    The qualification of insulating materials for electrical cables is often accomplished according to the IEC 60544 standard of the International Electrotechnical Commission. The mechanical properties of the polymeric insulators are tested prior and after irradiation at relatively high dose rates. To assess the ageing of selected materials under realistic service conditions, usually at lower dose rate, an IEC Working Group has proposed extrapolation methods (IEC 61244-2), one of which is applied here for a cable sheathing material from Huber+Suhner. The method is found to be suitable to compare radiation resistance data of different materials irradiated under different conditions

  9. Proliferation resistance criteria for fissile material disposition issues

    International Nuclear Information System (INIS)

    The 1994 National Acdaemy of Sciences study ''Management and Disposition of Excess Weapons Plutonium'' defined options for reducing the national and international proliferation risks of materials declared excess to the nuclear weapons program. This paper proposes criteria for assessing the proliferation resistance of these options as well defining the ''Standards'' from the report. The criteria are general, encompassing all stages of the disposition process from storage through intermediate processing to final disposition including the facilities, processing technologies and materials, the level of safeguards for these materials, and the national/subnational threat to the materials

  10. Standard test method for galling resistance of material couples

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers a laboratory test that ranks the galling resistance of material couples using a quantitative measure. Bare metals, alloys, nonmetallic materials, coatings, and surface modified materials may be evaluated by this test method. 1.2 This test method is not designed for evaluating the galling resistance of material couples sliding under lubricated conditions, because galling usually will not occur under lubricated sliding conditions using this test method. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  11. Designing Radiation Resistance in Materials for Fusion Energy

    Science.gov (United States)

    Zinkle, S. J.; Snead, L. L.

    2014-07-01

    Proposed fusion and advanced (Generation IV) fission energy systems require high-performance materials capable of satisfactory operation up to neutron damage levels approaching 200 atomic displacements per atom with large amounts of transmutant hydrogen and helium isotopes. After a brief overview of fusion reactor concepts and radiation effects phenomena in structural and functional (nonstructural) materials, three fundamental options for designing radiation resistance are outlined: Utilize matrix phases with inherent radiation tolerance, select materials in which vacancies are immobile at the design operating temperatures, or engineer materials with high sink densities for point defect recombination. Environmental and safety considerations impose several additional restrictions on potential materials systems, but reduced-activation ferritic/martensitic steels (including thermomechanically treated and oxide dispersion-strengthened options) and silicon carbide ceramic composites emerge as robust structural materials options. Materials modeling (including computational thermodynamics) and advanced manufacturing methods are poised to exert a major impact in the next ten years.

  12. FIRE-RESISTANCE PROPERTIES RESEARCH OF “WATER GLASS - GRAPHITE MICROPARTICLES” COMPOSITE MATERIAL

    Directory of Open Access Journals (Sweden)

    E. A. Pitukhin

    2016-03-01

    Full Text Available Subject of Research. Research results of the fire-resistance for “water glass - graphite microparticles” composite material (CM are given. The method for fire-resistance test of the micro composition is suggested in order to determine the limit state of the experimental samples under hightemperature action. Method. Test-benchequipment being used for research includes metering devices of temperature and time, as well as laboratory electric furnace PL20 with a maximum temperature in the chamber up to 1250ºC. Fire-resistance limit for the test samples of composite material is determined by the loss of insulating ability (I. For that purpose, the time is obtained from the test beginning with the standard temperature mode up to a limiting condition. Main Results. In accordance with the requirements of regulatory documents fire-resistance limit I15 has been obtained equal to 15 minutes. The qualitative and quantitative phase analysis of the CM structure has been done. By the study of samples by X-ray diffraction and electron microscopy we have determined that the material retains the same chemical structure with a monotonic heating above 700° C. Practical Relevance. The composite material with obtained characteristics can be used as a protective coating for building constructions with the aim of fire-resistance enhancement and fuel hazard reduction.

  13. Materials Growth and Characterization of Thermoelectric and Resistive Switching Devices

    OpenAIRE

    Norris, Kate Jeanne

    2015-01-01

    In the 74 years since diode rectifier based radar technology helped the allied forces win WWII, semiconductors have transformed the world we live in. From our smart phones to semiconductor-based energy conversion, semiconductors touch every aspect of our lives. With this thesis I hope to expand human knowledge of semiconductor thermoelectric devices and resistive switching devices through experimentation with materials growth and subsequent materials characterization. Metal organic chemica...

  14. Fire-resistant materials: European standards and American standards

    International Nuclear Information System (INIS)

    The use of American standards in the Fire protection Systems in Spanish nuclear power plants implies the use of materials with American certification which leads to difficulties in supply and to cost overruns. The current development of Fire protection standards in Europe opens the possibility of using products with European certification. following is a general comparison between tests on fire-resistant materials, in which it can be seen that the similarities in both standards are more notable than the differences. (Author)

  15. Characterization of fatigue resistance in photochromic composite materials for 3D rewritable optical memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Samoylova, Elena, E-mail: Elena.Samoylova@physik.uni-muenchen.de [Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Dallari, William; Allione, Marco; Pignatelli, Francesca; Marini, Lara; Cingolani, Roberto; Diaspro, Alberto [Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Athanassiou, Athanassia, E-mail: athanassia.athanassiou@iit.it [Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Center for Biomolecular Nanotechnologies-Unile, Istituto Italiano di Tecnologia, via Barsanti, 73010 Arnesano, Lecce (Italy)

    2013-06-01

    Highlights: • Fatigue resistance of diarylethene–polymer composites was tested with optical absorption and fluorescence methods upon repetitive UV–VIS irradiation. • Significant differences in fatigue were found in different polymeric matrices and in one-photon and two-photon excitation experiments. • Several explanations for fatigue resistance of the composites are proposed based on the physico-chemical properties of the diarylethenes and polymeric matrices. -- Abstract: Fatigue resistance of the photochromic diarylethene molecules 1,2-bis[2-methylbenzo[b]thyophen-3-yl] -3,3,4,4,5,5-hexafluoro-1-cyclopentene embedded in three different acrylic polymers is studied upon multiple coloration–decoloration cycles. The resistance to photofatigue is found to be different in the three polymeric materials when one-photon excitation was used for the reversible photoconversion experiment. In particular, the photochromic molecules lose their photoisomerization ability faster if they are embedded in poly(methyl methacrylate) (PMMA) with respect to poly(ethyl methacrylate-co-methyl acrylate) (PEMMA) and poly(ethyl methacrylate) (PEMA). We propose several explanations based on the physico-chemical properties of the matrix and of the photochromic molecules. In the case of two-photon excitation, which is necessary for 3D optical writing, the fatigue resistance is found to be poorer than in the one-photon case. The accelerated photodegradation can be assigned to the non-linear nature of interaction between the polymeric composite material and light.

  16. Characterization of fatigue resistance in photochromic composite materials for 3D rewritable optical memory applications

    International Nuclear Information System (INIS)

    Highlights: • Fatigue resistance of diarylethene–polymer composites was tested with optical absorption and fluorescence methods upon repetitive UV–VIS irradiation. • Significant differences in fatigue were found in different polymeric matrices and in one-photon and two-photon excitation experiments. • Several explanations for fatigue resistance of the composites are proposed based on the physico-chemical properties of the diarylethenes and polymeric matrices. -- Abstract: Fatigue resistance of the photochromic diarylethene molecules 1,2-bis[2-methylbenzo[b]thyophen-3-yl] -3,3,4,4,5,5-hexafluoro-1-cyclopentene embedded in three different acrylic polymers is studied upon multiple coloration–decoloration cycles. The resistance to photofatigue is found to be different in the three polymeric materials when one-photon excitation was used for the reversible photoconversion experiment. In particular, the photochromic molecules lose their photoisomerization ability faster if they are embedded in poly(methyl methacrylate) (PMMA) with respect to poly(ethyl methacrylate-co-methyl acrylate) (PEMMA) and poly(ethyl methacrylate) (PEMA). We propose several explanations based on the physico-chemical properties of the matrix and of the photochromic molecules. In the case of two-photon excitation, which is necessary for 3D optical writing, the fatigue resistance is found to be poorer than in the one-photon case. The accelerated photodegradation can be assigned to the non-linear nature of interaction between the polymeric composite material and light

  17. Fast, Contactless Monitoring of the Chemical Composition of Raw Materials

    Science.gov (United States)

    Ivanov, O.; Stoyanov, Zh.; Stoyanov, B.; Nadoliisky, M.; Vaseashta, Ashok

    A technique to monitor chemical composition of materials during manufacturing of ceramic products, in particular - of bricks, is investigated. The technique of monitoring is likely to offset environmental pollution and save energy. For this purpose, we use the Surface photo charge effect, which is generated for each solid body interacting with electromagnetic field. The measurement is express and can be performed in-situ in production conditions. The experimental work has shown that different samples of the investigated materials with different compositions produce different signals specific to each sample. For the same material, the signal varies with the change in chemical composition. More specifically, it is shown that for the material from which the bricks are fired, the signal is a function of the percentage of coal sludge. The results indicate that the characterization technique as a viable technique for control of incoming raw materials.

  18. Airflow resistivity of models of fibrous acoustic materials

    DEFF Research Database (Denmark)

    Tarnow, Viggo

    1996-01-01

    resistivity are given, which are valid for the cylinder (fiber) concentrations found in acoustic materials. A one-dimensional model consisting of parallel plates with random spacing between the plates is first discussed. Then a two-dimensional model consisting of parallel cylinders randomly spaced is treated...

  19. Aesthetics of Chemical Products: Materials, Molecules, and Molecular Models

    OpenAIRE

    Joachim Schummer

    2003-01-01

    By comparing chemistry to art, chemists have recently made claims to the aesthetic value, even beauty, of some of their products. This paper takes these claims seriously and turns them into a systematic investigation of the aesthetics of chemical products. I distinguish three types of chemical products - materials, molecules, and molecular models - and use a wide variety of aesthetic theories suitable for an investigation of the corresponding sorts of objects. These include aesthetics of mate...

  20. Nanostructured materials with biomimetic recognition abilities for chemical sensing

    OpenAIRE

    Bajwa, Sadia Zafar; Ghulam MUSTAFA; Samardzic, Renata; Wangchareansak, Thipvaree; Peter A. Lieberzeit

    2012-01-01

    Binding features found in biological systems can be implemented into man-made materials to design nanostructured artificial receptor matrices which are suitable, e.g., for chemical sensing applications. A range of different non-covalent interactions can be utilized based on the chemical properties of the respective analyte. One example is the formation of coordinative bonds between a polymerizable ligand (e.g., N-vinyl-2-pyrrolidone) and a metal ion (e.g., Cu(II)). Optimized molecularly impri...

  1. Renewable raw materials new feedstocks for the chemical industry

    CERN Document Server

    Ulber, Roland; Hirth, Thomas

    2011-01-01

    One of the main challenges facing the chemical industry is the transition to sustainable operations. Industries are taking initiatives to reduce resource intensities or footprints, and by adopting safer materials and processes. Such efforts need to be supported by techniques that can quantify the broad economic and environmental implications of industrial operations, retrofi t options and provide new design alternatives. This contemporary overview focuses on cradle-to-grave life cycle assessments of existing or conceptual processes for producing valueadded fuels, chemicals, and/or material

  2. Calculation of the dynamic air flow resistivity of fibre materials

    DEFF Research Database (Denmark)

    Tarnow, Viggo

    1997-01-01

    The acoustic attenuation of acoustic fiber materials is mainly determined by the dynamic resistivity to an oscillating air flow. The dynamic resistance is calculated for a model with geometry close to the geometry of real fibre material. The model constists of parallel cylinders placed randomly....... Two case are treated: flow perpendicular to the cylinder axes, and flow parallel to the axes. In each case two new approximate procedures were used. In the first procedure, one solves the equation of flow in a Voronoi cell around the fiber, and averages over the distribution of the Voronoi cells.......The second procedure is an extension to oscillating air flow of the Brinkman self-consistent procedure for dc flow. The procedures are valid for volume concentrations of cylinders less than 0.1. The calculations show that for the density of fibers of interest for acoustic fibre materials the simple self...

  3. Improved Damage Resistant Composite Materials Incorporating Shape Memory Alloys

    Science.gov (United States)

    Paine, Jeffrey S. N.; Rogers, Craig A.

    1996-01-01

    Metallic shape memory alloys (SMA) such as nitinol have unique shape recovery behavior and mechanical properties associated with a material phase change that have been used in a variety of sensing and actuation applications. Recent studies have shown that integrating nitinol-SMA actuators into composite materials increases the composite material's functionality. Hybrid composites of conventional graphite/epoxy or glass/epoxy and nitinol-SMA elements can perform functions in applications where monolithic composites perform inadequately. One such application is the use of hybrid composites to function both in load bearing and armor capacities. While monolithic composites with high strength-to-weight ratios function efficiently as loadbearing structures, because of their brittle nature, impact loading can cause significant catastrophic damage. Initial composite failure modes such as delamination and matrix cracking dissipate some impact energy, but when stress exceeds the composite's ultimate strength, fiber fracture and material perforation become dominant. One of the few methods that has been developed to reduce material perforation is hybridizing polymer matrix composites with tough kevlar or high modulus polyethynylene plies. The tough fibers increase the impact resistance and the stiffer and stronger graphite fibers carry the majority of the load. Similarly, by adding nitinol-SMA elements that absorb impact energy through the stress-induced martensitic phase transformation, the composites' impact perforation resistance can be greatly enhanced. The results of drop-weight and high velocity gas-gun impact testing of various composite materials will be presented. The results demonstrate that hybridizing composites with nitinol-SMA elements significantly increases perforation resistance compared to other traditional toughening elements. Inspection of the composite specimens at various stages of perforation by optical microscope illustrates the mechanisms by which

  4. Cladding of pressure vessel steel with corrosion resistant filler material

    International Nuclear Information System (INIS)

    Pressure vessels are often on the inside clad with corrosion resistant material. Of the various cladding processes surfacing by welding has proved to be most useful, especially for large thick-walled pressure vessels. Submerged arc welding with strip electrode is the most common method. Rather promising results have also been obtained by plasma hot wire welding. In general, Nb-alloyed austenitic stainless steel, over-alloyed with Cr and Ni, is used as filler material. Henceforth, also nickel alloys, e.g. Inconel 600, are used. The surfacing is made in one or several layers, following the requirements on the clad surface and the welding process used. The most dangerous welding defects in the surface are various types of cracks. The corrosion resistance of the cladding can show rather high local variations, depending on the composition of the filler material and various welding process factors. It is proved that the surface layer comparises areas with low chromium martensite. To ensure the corrosion resistance of the cladding, the generation of low-chromium martensite must be prevented by using suitable welding parameters, welding equipment and filler metal. It is also possible to eliminate the negative influence on the corrosion resistance from the low-chromium martensite, e.g. by welding in two layers. In the case of the high demands on quality a welding procedure test should always be made prior to production welding.(author)

  5. Corrosion resistant materials for fluorine and hydrogen fluoride

    International Nuclear Information System (INIS)

    Aluminum and Duralumin are resistant against fluorine and hydrogen fluoride up to 600 and 700 K, respectively. The resistance of nickel and its alloys, particularly monel, against fluorine and hydrogen fluoride is fairly good up to 900 and 800 K. During the attack of nickel-chromium alloys by fluorine between 1000 and 1300 K, it appears an inner fluorination similarly to the inner oxidation. The resistance of titanium in water-free liquid fluorine at lower temperatures with -1 is comparable to that of nickel and monel. However, the corrosion of titanium in gaseous fluorine amounts at 377 K only 0,0082 mm.a-1. In spite of their limited resistance against fluorine and hydrogen fluoride, very pure molybdenum and tungsten are employed as construction materials in the rocket technology because of their large strength at high temperatures if fluorine-hydrogen and fluorine-hydrazine flames are used. Lanthanum and calcium borides are only little attacked by fluorine hydrazine flames between 1400 and 1800 K; they are superior to all special grade alloys. The same is true in a lower temperature region (290-400 K) with fluorcarbon resins. Organic materials substitute in increasing extent metal alloys and non-metal inorganic materials. (orig.)

  6. Development of materials resistant to metal dusting degradation.

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Zeng, Z.; Nuclear Engineering Division

    2007-12-07

    The deposition of carbon from carbonaceous gaseous environments is prevalent in many chemical and petrochemical processes such as, hydrogen-, ammonia-, and methanol-reforming systems, syngas production systems, and iron-ore reduction plants. One of the major consequences of carbon deposition is the degradation of structural materials by a phenomenon known as ''metal dusting''. There are two major issues of importance in metal dusting. First is formation of coke and subsequent deposition of coke on metallic structural components. Second is the initiation and subsequent propagation of metal dusting degradation of the structural alloy. In the past, we reported on the mechanism for metal dusting of Fe- and Ni-base alloys. In this report, we present metal dusting data on both Fe- and Ni-base alloys after exposure in high and atmospheric pressure environments that simulate the gas chemistry in operating hydrogen reformers. We have also measured the progression of pits by measuring the depth as a function of exposure time for a variety of Fe- and Ni-base structural alloys. We have clearly established the role of transport of iron in forming a non-protective spinel phase in the initiation process and presence of carbon transfer channels in the oxide scale for the continued propagation of pits, by nano-beam X-ray analysis using the advance photon source (APS), Raman scattering, and SEM/EDX analysis. In this report, we have developed correlations between weight loss and pit progression rates and evaluated the effects of carbon activity, system pressure, and alloy chemistry, on weight loss and pit propagation. To develop pit propagation data for the alloys without incurring substantial time for the initiation of pits, especially for the Ni-base alloys that exhibit incubation times of thousands of hours, a pre-pitting method has been developed. The pre-pitted alloys exhibited pit propagation rates similar to those of materials tested without pre-pitting. We

  7. Effect of thermal treatment on the chemical resistance of polydimethylsiloxane for microfluidic devices

    International Nuclear Information System (INIS)

    We investigated the use of thermally treated polydimethylsiloxane (PDMS) for chemically-resistant microchannels. When the PDMS underwent the thermal treatment at 300 °C, swelling was reduced and the surface of the PDMS microfluidic channel endured well in the extracting media such as dichloromethane. Furthermore, despite the small decrease in size after thermal treatment, both the channel shape and transparency were maintained without showing fluid leakage. The thermally treated PDMS had more hydrophilic properties compared to the untreated PDMS. A single step post-casting process described in this work does not require complex chemical treatments or introduction of foreign materials to the host PDMS substrate, thus expanding the application area of PDMS-based microfluidics. (paper)

  8. Development of High Temperature/High Sensitivity Novel Chemical Resistive Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chonglin; Nash, Patrick; Ma, Chunrui; Enriquez, Erik; Wang, Haibing; Xu, Xing; Bao, Shangyong; Collins, Gregory

    2013-08-13

    The research has been focused to design, fabricate, and develop high temperature/high sensitivity novel multifunctional chemical sensors for the selective detection of fossil energy gases used in power and fuel systems. By systematically studying the physical properties of the LnBaCo{sub 2}O{sub 5+d} (LBCO) [Ln=Pr or La] thin-films, a new concept chemical sensor based high temperature chemical resistant change has been developed for the application for the next generation highly efficient and near zero emission power generation technologies. We also discovered that the superfast chemical dynamic behavior and an ultrafast surface exchange kinetics in the highly epitaxial LBCO thin films. Furthermore, our research indicates that hydrogen can superfast diffuse in the ordered oxygen vacancy structures in the highly epitaxial LBCO thin films, which suggest that the LBCO thin film not only can be an excellent candidate for the fabrication of high temperature ultra sensitive chemical sensors and control systems for power and fuel monitoring systems, but also can be an excellent candidate for the low temperature solid oxide fuel cell anode and cathode materials.

  9. Usage of abrasion-resistant materials in agriculture

    Directory of Open Access Journals (Sweden)

    J Votava

    2014-06-01

    Full Text Available Agricultural soil-processing machines are subject to an extensive abrasive wear. This paper analyses technical materials and their fitness to exchangeable parts of plough bottoms, such as edge-tools and whole plough cutting edges. There were tested abrasion-resistant steels with different microstructures: austenite, martensite-bainite, and carbide. Steel with the pearlite-ferrite structure was used as an etalon. Abrasion resistance tests were processed in compliance with the norm CSN 01 5084, which is a test of abrasion wear on abrasive cloth.

  10. Real time material accountability in a chemical reprocessing unit

    International Nuclear Information System (INIS)

    Real time material accountability for a pulse column in a chemical reprocessing plant has been investigated using a simple two state Kalman Filter. Operation of the pulse column was simulated by the SEPHIS-MOD4 code. Noisy measurements of the column inventory were obtained from two neutron detectors with various simulated counting errors. Various loss scenarios were simulated and analyzed by the Kalman Filter. In all cases considered the Kalman Filter was a superior estimator of material loss

  11. Investigation of radiation-resistant polyolefin materials used in power reactors

    International Nuclear Information System (INIS)

    It was forecasted that China would spend more than 40 billion US dollars on power reactors with a total of 27 million-kilowatt generation by 2020. This will require a huge quantity of cables and heat-shrinkable materials in the nuclear power stations, as an average GW nuclear power station needs one or two million US dollars of cables and accessories with radiation-resistant insulations. These materials must be heat resistant, radiation resistant, LOCA resistant, low smoke, halogen-free and flame retardant. Typical performance requirements are as follows: 1) Thermal aging experiments: 300 h at 138 degree C according to US standard for 40 years lifetime in power reactors. 2) Irradiation experiments: irradiated by 60Co γ-rays after aging to 700 kGy under mild surrounding conditions and 1500 kGy under rigor conditions, according to US standard. 3) LOCA-Helb experimental simulation: the cables are subjected to repeated tests in a vessel under regulated temperature and vapor pressure in different period of time, with simultaneous spraying of chemical solution (typically 1.5% boracic acid solution of pH=10.5 adjusted by NaOH) in a flux of 34.2 L·min-1·m-2 in the horizontal projection surface. 4) Flame retardant: the oxygen index of low smoke and halogen-free materials is ≥25 for cable insulation, and ≥27 for cable sheath. Our research is aimed at achieving the aging resistance performance with radiation crosslinking. Polyethylene and ethylene-propylene rubber are mixed with selected radiation-resistant reagents and the radiation resistant mechanisms are investigated. In addition, halogen-free flame retardant materials and surface treatment of the inorganic reagents are studied for making cables and heat-shrinkable cable accessories for nuclear power applications. They will meet technical requirements of the LOCA test, with desirable performances on low smoke halogen-free and flame retardant. (authors)

  12. Corrosion resistance diagnosing device for material of incore structure

    International Nuclear Information System (INIS)

    Corrosion resistance is easily diagnosed by judging the presense of stress corrosion crack sensitivity based on the degree of corrosion for incore structural materials in a BWR type reactor. Heretofore, visual detection by using a submerged TV camera has been popular as a detection means for incore structures. However, if the shape of the incore structures is complicate, limit is imposed on the detection and a detection for the strength of the materials themselves can not be conducted in a conventional method. The device of the present invention comprises a device for measuring corrosion sensitivity of materials to be diagnosed, a device for calculating the corrosion resistance based on the degree of corrosion obtained therefrom and a device for displaying the result of the calculation. With such a constitution, the corrosion resistance of the structural materials can be diagnosed based on the correlation between the increase of the degree of the corrosion caused by neutron irradiation and the increase of SCC sensitivity. (I.S.)

  13. Materials and Chemical Sciences Division annual report 1989

    International Nuclear Information System (INIS)

    This report describes research conducted at Lawrence Berkeley Laboratories, programs are discussed in the following topics: materials sciences; chemical sciences; fossil energy; energy storage systems; health and environmental sciences; exploratory research and development funds; and work for others. A total of fifty eight programs are briefly presented. References, figures, and tables are included where appropriate with each program

  14. Materials and Chemical Sciences Division annual report 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-07-01

    This report describes research conducted at Lawrence Berkeley Laboratories, programs are discussed in the following topics: materials sciences; chemical sciences; fossil energy; energy storage systems; health and environmental sciences; exploratory research and development funds; and work for others. A total of fifty eight programs are briefly presented. References, figures, and tables are included where appropriate with each program.

  15. Aesthetics of Chemical Products: Materials, Molecules, and Molecular Models

    Directory of Open Access Journals (Sweden)

    Joachim Schummer

    2003-03-01

    Full Text Available By comparing chemistry to art, chemists have recently made claims to the aesthetic value, even beauty, of some of their products. This paper takes these claims seriously and turns them into a systematic investigation of the aesthetics of chemical products. I distinguish three types of chemical products - materials, molecules, and molecular models - and use a wide variety of aesthetic theories suitable for an investigation of the corresponding sorts of objects. These include aesthetics of materials, idealistic aesthetics from Plato to Kant and Schopenhauer, psychological approaches of Ernst Gombrich and Rudolf Arnheim, and semiotic aesthetics of Nelson Goodman and Umberto Eco. Although the investigation does not support recent claims, I point out where aesthetics does and can play an import role in chemistry. Particularly, Eco's approach helps us understand that and how aesthetic experience can be a driving force in chemical research.

  16. Hybrid nanostructures for SERS: materials development and chemical detection.

    Science.gov (United States)

    Fateixa, Sara; Nogueira, Helena I S; Trindade, Tito

    2015-09-01

    This review focuses on recent developments in hybrid and nanostructured substrates for SERS (surface-enhanced Raman scattering) studies. Thus substrates composed of at least two distinct types of materials, in which one is a SERS active metal, are considered here aiming at their use as platforms for chemical detection in a variety of contexts. Fundamental aspects related to the SERS effect and plasmonic behaviour of nanometals are briefly introduced. The materials described include polymer nanocomposites containing metal nanoparticles and coupled inorganic nanophases. Chemical approaches to tailor the morphological features of these substrates in order to get high SERS activity are reviewed. Finally, some perspectives for practical applications in the context of chemical detection of analytes using such hybrid platforms are presented. PMID:25960180

  17. Chemical Conversion of Energetic Materials to Higher Value Products

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A R; Hsu, P C; Coburn, M D; Schmidt, R D; Pagoria, P F; Lee, G S

    2005-04-19

    The objective of this program is to develop new processes for the disposal of surplus energetic materials. Disposal through open burning/open detonation (OB/OD) is considered less attractive today due to environmental, cost and safety concerns. The use of energetic materials as chemical feedstocks for higher value products can provide environmentally sound and cost-effective alternatives to OB/OD. Our recent studies on the conversion of surplus energetic materials (Explosive D, TNT) to higher value products will be described.

  18. Ab initio studies of equations of state and chemical reactions of reactive structural materials

    Science.gov (United States)

    Zaharieva, Roussislava

    The motivations for the research issues addressed in this thesis are based on the needs of the aerospace structural analysis and the design community. The specific focus is related to the characterization and shock induced chemical reactions of multi-functional structural-energetic materials that are also known as the reactive structural materials and their reaction capabilities. Usually motivation for selection of aerospace structural materials is to realize required strength characteristics and favorable strength to weight ratios. The term strength implies resistance to loads experienced during the service life of the structure, including resistance to fatigue loads, corrosion and other extreme conditions. Thus, basically the structural materials are single function materials that resist loads experienced during the service life of the structure. However, it is desirable to select materials that are capable of offering more than one basic function of strength. Very often, the second function is the capability to provide functions of sensing and actuation. In this thesis, the second function is different. The second function is the energetic characteristics. Thus, the choice of dual functions of the material are the structural characteristics and energetic characteristics. These materials are also known by other names such as the reactive material structures or dual functional structural energetic materials. Specifically the selected reactive materials include mixtures of selected metals and metal oxides that are also known as thermite mixtures, reacting intermetallic combinations and oxidizing materials. There are several techniques that are available to synthesize these structural energetic materials or reactive material structures and new synthesis techniques constitute an open research area. The focus of this thesis, however, is the characterization of chemical reactions of reactive material structures that involve two or more solids (or condensed matter). The

  19. Chemical composition of material fractions in Danish household waste

    DEFF Research Database (Denmark)

    Riber, Christian; Petersen, Claus; Christensen, Thomas Højlund

    2009-01-01

    The chemical composition of Danish household waste was determined by two approaches: a direct method where the chemical composition (61 substances) of 48 material fractions was determined after hand sorting of about 20 tonnes of waste collected from 2200 households; and an indirect method where...... batches of 80-1200 tonnes of unsorted household waste was incinerated and the content of the waste determined from the content of the outputs from the incinerator. The indirect method is believed to better represent the small but highly contaminated material fractions (e,g., batteries) than the direct...... method, because of the larger quantities included and the more homogenous material to sample from. Differences between the direct and the direct methods led to corrections in the of heavy metal concentration of a few fractions. The majority of the energy content of the waste originates from organic waste...

  20. Novel Polymer Resistive-type Humidity Sensitive Materials

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Humidity sensors have been widely investigated in recent years[1,2].In this work,two kinds of polymer resistive-type humidity sensitive materials were prepared as follows: 1) polymer electrolyte with an IPN structure formed by the simultaneous quaternization and crosslinking of poly(4-vinylpyridine) (P4VP) and poly(glycidyl methacrylate) (PGMA) with 1,4-dibromobutane (DBB) and diethyltriamine (DETA) respectively; 2) silicon-containing polyelectrolyte with crosslinking structure formed by a sim...

  1. Fracture resistance of posterior teeth restored with modern restorative materials

    OpenAIRE

    Ibrahim M. Hamouda; Shehata, Salah H.

    2011-01-01

    We studied the fracture resistance of maxillary premolars restored with recent restorative materials. Fifty maxillary premolars were divided into five groups: Group 1 were unprepared teeth; Group 2 were teeth prepared without restoration; Group 3 were teeth restored with tetric ceram HB; Group 4 were teeth restored with InTen S; and Group 5 were teeth restored with Admira. The samples were tested using a universal testing machine. Peak loads at fracture were recorded. The teeth restored with ...

  2. HIGH TEMPERATURE CORROSION RESISTANCE OF METALLIC MATERIALS IN HARSH CONDITIONS

    OpenAIRE

    Novello, Frederic; Dedry, Olivier; De Noose, Vincent; Lecomte-Beckers, Jacqueline

    2014-01-01

    Highly efficient energy recovery from renewable sources and from waste incineration causes new problems of corrosion at high temperature. A similar situation exists for new recycling processes and new energy storage units. These corrosions are generally considered to be caused by ashes or molten salts, the composition of which differs considerably from one plant to another. Therefore, for the assessment of corrosion-resistance of advanced materials, it is essential to precisely evaluate the c...

  3. Corrosion resistance of metal materials for HLW canister

    International Nuclear Information System (INIS)

    In order to verify the materials as an important artificial barrier for canister of vitrified high-level waste from spent fuel reprocessing, data and reports were researched on corrosion resistance of the materials under conditions from glass form production to final disposal. Then, in this report, investigated subjects, improvement methods and future subjects are reviewed. It has become clear that there would be no problem on the inside and outside corrosion of the canister during glass production, but long term corrosion and radiation effect tests and the vitrification methods would be subjects in future on interim storage and final disposal conditions. (author)

  4. Alkaline cement mortars. Chemical resistance to sulfate and seawater attack

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2002-09-01

    Full Text Available The durability and chemical resistance of alkali activated slag and fly ash/slag mortars in contact with sulfates and seawater media have been studied. Two methods were used in the evaluation of such durability: Kock-Steinegger and ASTM C1012. A mineralogical and a microstructural characterization of mortars were done at different ages of their conservation in aggressive media through XRD, SEM/ EDX and mercury porosimetry. Results showed a high durability of activated cement mortars in sulfates and seawater media. NaOH activated mortars are the most sensitive to environment attack with formation of expansive products as gypsum and ettringite, although in very low proportion.

    Se ha estudiado la estabilidad química en medios sulfáticos y de agua de mar de morteros de escorias activadas alcalinamente y morteros de mezclas de escoria y cenizas volantes activadas alcalinamente. Se han empleado dos métodos para evaluar dicha estabilidad: Kock-Steinegger y la norma ASTM C1012. Se ha realizado una caracterización mineralógica y micro estructural de los morteros (a diferentes edades de permanencia en los medios agresivos a través de DRX, SEM/EDX y porosimetría de mercurio. Los resultados obtenidos han demostrado la elevada durabilidad de todos los morteros de cementos activados estudiados frente a la agresividad de los sulfatos y del agua de mar Los morteros de escoria activada con NaOH son los más susceptibles al ataque por esos medios, conformación de productos expansivos como el yeso y la etringita, aunque en proporciones muy bajas.

  5. Study on Blast Pressure Resistance of Foamed Concrete Material

    Directory of Open Access Journals (Sweden)

    A.M. Ahmad Zaidi

    2009-12-01

    Full Text Available Great demand exist for more efficient design to protect personals and critical components against explosion or blast wave, generated both accidentally and deliberately, in various blast scenarios in both civilian and military activities. Concrete is a common material used in protective design of structures. Recently, the demands on producing the lighter concrete material have become interest in concrete research. Foamed concrete is a possible alternative of lightweight concrete for producing intermediate strength capabilities with excellent thermal insulation, freeze-thaw resistance, high-impact resistance and good shock absorption. This paper explores the role and development of Blast Pressure Resistant Materials (BPRM’s on foamed concrete. The explosive tests were conducted to determine the blast mitigating properties. The results show that when the foamed concrete density is increases the blast energy absorption capability will be decreases due to reduce of cavity volume. This is suggested that cavity plays an important role to dissipate and absorb the shock energy of the blast.

  6. Sensitivity enhancement of chemically amplified resists and performance study using EUV interference lithography

    Science.gov (United States)

    Buitrago, Elizabeth; Nagahara, Seiji; Yildirim, Oktay; Nakagawa, Hisashi; Tagawa, Seiichi; Meeuwissen, Marieke; Nagai, Tomoki; Naruoka, Takehiko; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin

    2016-03-01

    Extreme ultraviolet lithography (EUVL, λ = 13.5 nm) is the most promising candidate to manufacture electronic devices for future technology nodes in the semiconductor industry. Nonetheless, EUVL still faces many technological challenges as it moves toward high-volume manufacturing (HVM). A key bottleneck from the tool design and performance point of view has been the development of an efficient, high power EUV light source for high throughput production. Consequently, there has been extensive research on different methodologies to enhance EUV resist sensitivity. Resist performance is measured in terms of its ultimate printing resolution, line width roughness (LWR), sensitivity (S or best energy BE) and exposure latitude (EL). However, there are well-known fundamental trade-off relationships (LRS trade-off) among these parameters for chemically amplified resists (CARs). Here we present early proof-of-principle results for a multi-exposure lithography process that has the potential for high sensitivity enhancement without compromising other important performance characteristics by the use of a Photosensitized Chemically Amplified Resist (PSCAR). With this method, we seek to increase the sensitivity by combining a first EUV pattern exposure with a second UV flood exposure (λ = 365 nm) and the use of a PSCAR. In addition, we have evaluated over 50 different state-of-the-art EUV CARs. Among these, we have identified several promising candidates that simultaneously meet sensitivity, LWR and EL high performance requirements with the aim of resolving line space (L/S) features for the 7 and 5 nm logic node (16 nm and 13 nm half-pitch HP, respectively) for HVM. Several CARs were additionally found to be well resolved down to 12 nm and 11 nm HP with minimal pattern collapse and bridging, a remarkable feat for CARs. Finally, the performance of two negative tone state-of-the-art alternative resist platforms previously investigated was compared to the CAR performance at and

  7. Chemical Pollution from Combustion of Modern Spacecraft Materials

    Science.gov (United States)

    Mudgett, Paul D.

    2013-01-01

    Fire is one of the most critical contingencies in spacecraft and any closed environment including submarines. Currently, NASA uses particle based technology to detect fires and hand-held combustion product monitors to track the clean-up and restoration of habitable cabin environment after the fire is extinguished. In the future, chemical detection could augment particle detection to eliminate frequent nuisance false alarms triggered by dust. In the interest of understanding combustion from both particulate and chemical generation, NASA Centers have been collaborating on combustion studies at White Sands Test Facility using modern spacecraft materials as fuels, and both old and new technology to measure the chemical and particulate products of combustion. The tests attempted to study smoldering pyrolysis at relatively low temperatures without ignition to flaming conditions. This paper will summarize the results of two 1-week long tests undertaken in 2012, focusing on the chemical products of combustion. The results confirm the key chemical products are carbon monoxide (CO), hydrogen cyanide (HCN), hydrogen fluoride (HF) and hydrogen chloride (HCl), whose concentrations depend on the particular material and test conditions. For example, modern aerospace wire insulation produces significant concentration of HF, which persists in the test chamber longer than anticipated. These compounds are the analytical targets identified for the development of new tunable diode laser based hand-held monitors, to replace the aging electrochemical sensor based devices currently in use on the International Space Station.

  8. Erosion resistance in a stationary arc of powder materials on the base of heat resisting alloys

    Energy Technology Data Exchange (ETDEWEB)

    Minakova, R.V.; Kostenetskaya, L.I.; Krusanova, A.P.; Kukhtikov, V.A.; Smirnov, A.V.; Lugovskaya, E.S. (AN Ukrainskoj SSR, Kiev. Inst. Problem Materialovedeniya)

    1983-08-01

    Comparison investigations of some properties of the Mo-Cu, Mo-Ni(Co)-Cu materials and the W-Cu, W-Ni-Cu compositions used at the present time as well as contact pairs prepared from them is conducted. It is shown that electroerosion wear of the contacts is connected not only with the material properties but also with features of structural changes in the working layer under effect of arc discharge. It is shown also that directed alloying with respect to the origin of phase transition in the electrode material and the medium effect during current commutation promotes electroerosion resistance.

  9. Corrosion test of structural materials for thermo-chemical and electrolytic hybrid hydrogen production cycle

    International Nuclear Information System (INIS)

    Corrosion behavior of structural materials for thermo-chemical and electrolytic hydrogen production cycle was investigated in liquid and gaseous sulfuric acid in the temperature range of 200-500degC. The cycle is one of the hydrogen production methods using sulfuric acid and the maximum temperature through the processes is about 500degC. In this study, corrosion tests of candidate structural materials for equipment of the hydrogen production plant were performed at the conditions each equipment will be used. The concentration of sulfuric acid was 95 mass% in all experiments and maximum test duration was 500 h. Only high Si cast iron had good corrosion resistance in the boiling sulfuric acid, whereas high Si cast iron and Hastelloy C276 had good corrosion resistance in the sulfurous acid gas atmosphere (vaporized sulfuric acid or mixture of sulfur dioxide and water vapor). Furthermore, post test analysis by optical microscope and SEM-EDX were performed. (author)

  10. Materials Control System for Enriched Uranium Chemical Processing Facility for Irradiated Nuclear Materials

    International Nuclear Information System (INIS)

    Systems for management and control of nuclear material in an enriched uranium chemical processing facility are not too different from those historically used in the chemical industry. The difference is one of degree rather than substance. The monetary and strategic value of the material being processed as well as the potential health and safety hazards inherent in handling nuclear material often dictate a level of effort and system detail above that which might seem reasonable to the casual observer. Among those areas of consideration which are of particular importance in the development of an effective nuclear materials management (NMM) system as based on experience gained at the Idaho Chemical Processing Plant are the following: organizational structure, accounting system, measurement system, implementation and integration of system, records and reports, internal audit, and inventory management. (author)

  11. Scratch, wear and corrosion resistant organic inorganic hybrid materials for metals protection and barrier

    International Nuclear Information System (INIS)

    Highlights: • Polysiloxane coatings as protective barriers to delay erosion/corrosion of Fe 430 B metal substrates. • Methyl groups feature a very small steric hindrance and confer ductility to the Si–O–Si backbone. • Phenyl groups feature a larger steric hindrance, but they ensure stability and high chemical inertness. • Remarkable adhesion to the substrate, good scratch resistance and high wear endurance. • Innovative ways to design of long lasting protective barriers against corrosion and aggressive chemicals. - Abstract: Polysiloxanes are widely used as protective barriers to delay erosion/corrosion and increase chemical inertness of metal substrates. In the present work, a high molecular weight methyl phenyl polysiloxane resin was designed to manufacture a protective coating for Fe 430 B structural steel. Methyl groups feature very small steric hindrance and confer ductility to the Si–O–Si backbone of the organic inorganic hybrid resin, thus allowing the achievement of high thickness. Phenyl groups feature larger steric hindrance, but they ensure stability and high chemical inertness. Visual appearance and morphology of the coatings were studied by field emission scanning electron microscopy and contact gauge surface profilometry. Micro-mechanical response of the coatings was analyzed by instrumented progressive load scratch, while wear resistance by dry sliding linear reciprocating tribological tests. Lastly, chemical inertness and corrosion endurance of the coatings were evaluated by linear sweep voltammetry and chronoamperometry in aggressive acid environment. The resulting resins yielded protective materials, which feature remarkable adhesion to the substrate, good scratch resistance and high wear endurance, thus laying the foundations to manufacture long lasting protective barriers against corrosion and, more in general, against aggressive chemicals

  12. Chemical vapour deposition synthetic diamond: materials, technology and applications

    Science.gov (United States)

    Balmer, R. S.; Brandon, J. R.; Clewes, S. L.; Dhillon, H. K.; Dodson, J. M.; Friel, I.; Inglis, P. N.; Madgwick, T. D.; Markham, M. L.; Mollart, T. P.; Perkins, N.; Scarsbrook, G. A.; Twitchen, D. J.; Whitehead, A. J.; Wilman, J. J.; Woollard, S. M.

    2009-09-01

    Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synthesized in planar form; however, non-planar geometries are also possible and enable a number of key applications. This paper reviews the material properties and characteristics of single crystal and polycrystalline CVD diamond, and how these can be utilized, focusing particularly on optics, electronics and electrochemistry. It also summarizes how CVD diamond can be tailored for specific applications, on the basis of the ability to synthesize a consistent and engineered high performance product.

  13. Resistance to Fracture of Dental Roots Obturated with Different Materials

    Directory of Open Access Journals (Sweden)

    Berkan Celikten

    2015-01-01

    Full Text Available The aim of this study was to compare the vertical fracture resistance of roots obturated with different root canal filling materials and sealers. Crowns of 55 extracted mandibular premolar teeth were removed to provide root lengths of 13 mm. Five roots were saved as negative control group (canals unprepared and unfilled. Fifty root canals were instrumented and then five roots were saved as positive control group (canals prepared but unfilled. The remaining 45 roots were randomly divided into three experimental groups (n=15 root/group and obturated with the following procedures: in group 1, glass ionomer-based sealer and cone (ActiV GP obturation system; in group 2, bioceramic sealer and cone (EndoSequence BC obturation system; and in group 3, roots were filled with bioceramic sealer and cone (Smartpaste bio obturation system. All specimens were tested in a universal testing machine for measuring fracture resistance. For each root, the force at the time of fracture was recorded in Newtons. The statistical analysis was performed by using Kruskal-Wallis and post hoc test. There were no significant differences between the three experimental groups. The fracture values of three experimental and negative control groups were significantly higher than the positive control group. Within the limitations of this study, all materials increased the fracture resistance of instrumented roots.

  14. Chemical compatibility of structural materials in alkali metals

    International Nuclear Information System (INIS)

    The objectives of this task are to (a) evaluate the chemical compatibility of structural alloys such as V-5 wt.%Cr-5 wt.%Ti alloy and Type 316 stainless steel for application in liquid alkali metals such as lithium and sodium-78 wt.% potassium (NaK) at temperatures in the range that are of interest for International Thermonuclear Experimental Reactor (ITER); (b) evaluate the transfer of nonmetallic elements such as oxygen, nitrogen, carbon, and hydrogen between structural materials and liquid metals; and (c) evaluate the effects of such transfers on the mechanical and microstructural characteristics of the materials for long-term service in liquid-metal-environments

  15. Chemical compatibility of structural materials in alkali metals

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Rink, D.L.; Haglund, R. [Argonne National Lab., Chicago, IL (United States)] [and others

    1995-04-01

    The objectives of this task are to (a) evaluate the chemical compatibility of structural alloys such as V-5 wt.%Cr-5 wt.%Ti alloy and Type 316 stainless steel for application in liquid alkali metals such as lithium and sodium-78 wt.% potassium (NaK) at temperatures in the range that are of interest for International Thermonuclear Experimental Reactor (ITER); (b) evaluate the transfer of nonmetallic elements such as oxygen, nitrogen, carbon, and hydrogen between structural materials and liquid metals; and (c) evaluate the effects of such transfers on the mechanical and microstructural characteristics of the materials for long-term service in liquid-metal-environments.

  16. Transient assembly of active materials fueled by a chemical reaction

    Science.gov (United States)

    Boekhoven, Job; Hendriksen, Wouter E.; Koper, Ger J. M.; Eelkema, Rienk; van Esch, Jan H.

    2015-09-01

    Fuel-driven self-assembly of actin filaments and microtubules is a key component of cellular organization. Continuous energy supply maintains these transient biomolecular assemblies far from thermodynamic equilibrium, unlike typical synthetic systems that spontaneously assemble at thermodynamic equilibrium. Here, we report the transient self-assembly of synthetic molecules into active materials, driven by the consumption of a chemical fuel. In these materials, reaction rates and fuel levels, instead of equilibrium composition, determine properties such as lifetime, stiffness, and self-regeneration capability. Fibers exhibit strongly nonlinear behavior including stochastic collapse and simultaneous growth and shrinkage, reminiscent of microtubule dynamics.

  17. Certification of a uranium dioxide reference material for chemical analyses

    International Nuclear Information System (INIS)

    This report, issued by the Central Bureau for Nuclear Measurements (CBNM), describes the characterization of a uranium dioxide reference material with accurately determined uranium mass fraction for chemical analyses. The preparation, conditioning, homogeneity tests and the analyses performed on this material are described in Annex 1. The evaluation of the individual impurity results, total of impurities and uranium mass fraction are given in Annex 2. Information on a direct determination of uranium by titration is given in Annex 3. The uranium mass fraction (881.34+-0.13) g.kg-1 calculated in Annex 2 is given on the certificate

  18. Understanding and tuning nanostructured materials for chemical energy conversion

    Science.gov (United States)

    Jian, Guoqiang

    The conversion of energy that employs chemical reaction is termed chemical energy conversion. In my dissertation, I have focused on chemical energy conversion systems involving energetic materials and lithium ion batteries, where performance is strongly dependent on the properties of materials and their architecture. The objective of this study is to enhance our understanding and tuning of nanostructured materials that might find application toward energetic materials and electrode materials in lithium ion batteries. Rapid heating diagnostics tools, i.e. temperature-jump techniques, have been used to study the ignition of aluminum nanoparticles, nanothermite reaction mechanism and metal oxides nanoparticles decomposition under rapid heating conditions (˜105-106 K/s). Time-resolved mass spectra results support the hypothesis that Al containing species diffuse outwards through the oxide shell. Low effective activation energies were found for metal oxides nanoparticles decomposition at high heating rates, implying the mass transfer control at high heating rates. The role of oxygen release from oxidizer in nanothermite reactions have been examined for several different systems, including some using microsized oxidizer (i.e., nano-Al/micro-I 2O5). In particular, for periodate based nanothermites, direct evidence from high heating rate SEM and mass spectrometry results support that direct gas phase oxygen release from oxidizer decomposition is critical in its ignition and combustion. Efforts have also been made to synthesize nanostructured materials for nanoenergetic materials and lithium ion batteries applications. Hollow CuO spheres were synthesized by aerosol spray pyrolysis, employing a gas blowing mechanism for the formation of hollow structure during aerosol synthesis. The materials synthesized as oxidizers in nanothermite demonstrated superior performance, and of particular note, periodate salts based nanothermite demonstrated the best gas generating performance

  19. Effects of Confinement on Chemical Reaction Equilibrium in Nanoporous Materials

    Czech Academy of Sciences Publication Activity Database

    Smith, W.R.; Lísal, Martin; Brennan, J.K.

    2006-01-01

    Roč. 3984, - (2006), s. 743-751. ISSN 0302-9743 R&D Projects: GA ČR(CZ) GA203/05/0725; GA AV ČR 1ET400720507 Grant ostatní: NRCC(CA) OGP 1041 Institutional research plan: CEZ:AV0Z40720504 Keywords : nanoporous materials * chemical reaction equilibrium Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.402, year: 2005

  20. Investigation of the surface resistance of superconducting materials

    CERN Document Server

    Junginger, T

    2012-01-01

    In particle accelerators superconducting RF cavities are widely used to achieve high accelerating gradients and low losses. Power consumption is proportional to the surface resistance RS which depends on a number of external parameters, including frequency, temperature, magnetic and electric eld. Presently, there is no widely accepted model describing the increase of Rs with applied eld. In the frame of this project the 400MHz Quadrupole Resonator has been extended to 800 and 1200MHz to study surface resistance and intrinsic critical RF magnetic eld of superconducting samples over a wide parameter range, establishing it as a world-wide unique test facility for superconducting materials. Dierent samples were studied and it was shown that RS is mainly caused by the RF electric eld in the case of strongly oxidized surfaces. This can be explained by interface tunnel exchange of electrons between the superconductor and localized states in adjacent oxides. For well prepared surfaces, however, the majority of the di...

  1. Metal-nanotube composites as radiation resistant materials

    Science.gov (United States)

    González, Rafael I.; Valencia, Felipe; Mella, José; van Duin, Adri C. T.; So, Kang Pyo; Li, Ju; Kiwi, Miguel; Bringa, Eduardo M.

    2016-07-01

    The improvement of radiation resistance in nanocomposite materials is investigated by means of classical reactive molecular dynamics simulations. In particular, we study the influence of carbon nanotubes (CNTs) in an Ni matrix on the trapping and possible outgassing of He. When CNTs are defect-free, He atoms diffuse alongside CNT walls and, although there is He accumulation at the metal-CNT interface, no He trespassing of the CNT wall is observed, which is consistent with the lack of permeability of a perfect graphene sheet. However, when vacancies are introduced to mimic radiation-induced defects, He atoms penetrate CNTs, which play the role of nano-chimneys, allowing He atoms to escape the damaged zone and reduce bubble formation in the matrix. Consequently, composites made of CNTs inside metals are likely to display improved radiation resistance, particularly when radiation damage is related to swelling and He-induced embrittlement.

  2. Investigations of the surface resistance of superconducting materials

    CERN Document Server

    Junginger, Tobias; Welsch, Carsten

    In particle accelerators superconducting RF cavities are widely used to achieve high accelerating gradients and low losses. Power consumption is proportional to the surface resistance RS which depends on a number of external parameters, including frequency, temperature, magnetic and electric field. Presently, there is no widely accepted model describing the increase of Rs with applied field. In the frame of this project the 400 MHz Quadrupole Resonator has been extended to 800 and 1200 MHz to study surface resistance and intrinsic critical RF magnetic field of superconducting samples over a wide parameter range, establishing it as a world-wide unique test facility for superconducting materials. Different samples were studied and it was shown that Rs is mainly caused by the RF electric field in the case of strongly oxidized surfaces. This can be explained by interface tunnel exchange of electrons between the superconductor and localized states in adjacent oxides. For well prepared surfaces, however, the majori...

  3. Progress in corrosion resistant materials for supercritical water reactors

    International Nuclear Information System (INIS)

    Supercritical water reactors (SCWRs) are a kind of high-temperature, high-pressure water-cooled reactors that operate above the thermodynamic critical point of water (374 deg. C, 22.1 MPa). Corrosion and degradation of materials used in supercritical water environments are determined by several environment- and material-dependent factors. In particular, irradiation-induced changes in microstructure and microchemistry are major concerns in a nuclear reactor. Many structural materials including alloys and ceramics have been proposed for use as SCWR components or materials for applying protective coatings in SCWRs. Various surface modification processes are also explored to change the chemical composition and microstructure of the near surface regions. This article aims to provide an overview of recent materials developments for supercritical water reactors focusing mainly on the nuclear reactor applications. The emphasis is placed on the corrosion and degradation mechanisms and the selection criteria of materials. In addition, the development of new processes for surface modification of materials in SCWRs is also briefly reviewed. Finally, some perspectives on the direction of future research in this area are also outlined.

  4. Wear resistance of ion-implanted metallic materials

    International Nuclear Information System (INIS)

    The present work is devoted to the study of the effect of ion implantation on the wear resistance of materials. Steel 3 and copper cylinder specimens were irradiated with 40 keV carbon, zirconium, titanium, niobium, lead, molybdenum and chromium continuous ion beams and a 200 keV pulsed carbon ion beam with fluences of 1017 ions cm-2 and 1013 ions cm-2 respectively. The loss of mass during friction of the butt surface against the rotating disk was taken as the measure of wear. For materials irradiated with continuous ion beams the depth of the layer with increased wear resistance was about 80-100μm, which is two orders of magnitude greater than the depth of penetration of the implanted ions. In the case of ion implantation with a pulsed ion beam for a short period of time, a great amount of heat was generated. The speed of its dissipation into the bulk of a specimen depends on the thermal conductivity of the material, and hardening of the wear-surface layer starts with cooling at some speed. (orig.)

  5. Novel aerobic tetracycline resistance gene that chemically modifies tetracycline.

    OpenAIRE

    Speer, B S; Salyers, A A

    1989-01-01

    A tetracycline resistance gene that was found originally on the Bacteroides plasmid pBF4 confers resistance on Escherichia coli but only when cells are growing aerobically. When E. coli EM24 carrying this aerobic tetracycline resistance (*Tcr) gene is grown in medium containing tetracycline, the resulting spent medium is no longer toxic to tetracycline-sensitive (Tcs) E. coli EM24 (B.S. Speer and A.A. Salyers, J. Bacteriol. 170: 1423-1429, 1988). To determine whether the *Tcr gene product mod...

  6. Corrosion-Resistant Container for Molten-Material Processing

    Science.gov (United States)

    Stern, Theodore G.; McNaul, Eric

    2010-01-01

    In a carbothermal process, gaseous methane is passed over molten regolith, which is heated past its melting point to a temperature in excess of 1,625 C. At this temperature, materials in contact with the molten regolith (or regolith simulant) corrode and lose their structural properties. As a result, fabricating a crucible to hold the molten material and providing a method of contact heating have been problematic. Alternative containment approaches use a large crucible and limit the heat zone of the material being processed, which is inefficient because of volume and mass constraints. Alternative heating approaches use non-contact heating, such as by laser or concentrated solar energy, which can be inefficient in transferring heat and thus require higher power heat sources to accomplish processing. The innovation is a combination of materials, with a substrate material having high structural strength and stiffness and high-temperature capability, and a coating material with a high corrosion resistance and high-temperature capability. The material developed is a molybdenum substrate with an iridium coating. Creating the containment crucible or heater jacket using this material combination requires only that the molybdenum, which is easily processed by conventional methods such as milling, electric discharge machining, or forming and brazing, be fabricated into an appropriate shape, and that the iridium coating be applied to any surfaces that may come in contact with the corrosive molten material. In one engineering application, the molybdenum was fashioned into a container for a heat pipe. Since only the end of the heat pipe is used to heat the regolith, the container has a narrowing end with a nipple in which the heat pipe is snugly fit, and the external area of this nipple, which contacts the regolith to transfer heat into it, is coated with iridium. At the time of this reporting, no single material has been found that can perform the functions of this combination

  7. Surface chemical modification for exceptional wear life of MEMS materials

    Directory of Open Access Journals (Sweden)

    R. Arvind Singh

    2011-12-01

    Full Text Available Micro-Electro-Mechanical-Systems (MEMS are built at micro/nano-scales. At these scales, the interfacial forces are extremely strong. These forces adversely affect the smooth operation and cause wear resulting in the drastic reduction in wear life (useful operating lifetime of actuator-based devices. In this paper, we present a surface chemical modification method that reduces friction and significantly extends the wear life of the two most popular MEMS structural materials namely, silicon and SU-8 polymer. The method includes surface chemical treatment using ethanolamine-sodium phosphate buffer, followed by coating of perfluoropolyether (PFPE nanolubricant on (i silicon coated with SU-8 thin films (500 nm and (ii MEMS process treated SU-8 thick films (50 μm. After the surface chemical modification, it was observed that the steady-state coefficient of friction of the materials reduced by 4 to 5 times and simultaneously their wear durability increased by more than three orders of magnitude (> 1000 times. The significant reduction in the friction coefficients is due to the lubrication effect of PFPE nanolubricant, while the exceptional increase in their wear life is attributed to the bonding between the -OH functional group of ethanolamine treated SU-8 thin/thick films and the -OH functional group of PFPE. The surface chemical modification method acts as a common route to enhance the performance of both silicon and SU-8 polymer. It is time-effective (process time ≤ 11 min, cost-effective and can be readily integrated into MEMS fabrication/assembly processes. It can also work for any kind of structural material from which the miniaturized devices are/can be made.

  8. Surface chemical modification for exceptional wear life of MEMS materials

    Science.gov (United States)

    Singh, R. Arvind; Satyanarayana, N.; Sinha, Sujeet Kumar

    2011-12-01

    Micro-Electro-Mechanical-Systems (MEMS) are built at micro/nano-scales. At these scales, the interfacial forces are extremely strong. These forces adversely affect the smooth operation and cause wear resulting in the drastic reduction in wear life (useful operating lifetime) of actuator-based devices. In this paper, we present a surface chemical modification method that reduces friction and significantly extends the wear life of the two most popular MEMS structural materials namely, silicon and SU-8 polymer. The method includes surface chemical treatment using ethanolamine-sodium phosphate buffer, followed by coating of perfluoropolyether (PFPE) nanolubricant on (i) silicon coated with SU-8 thin films (500 nm) and (ii) MEMS process treated SU-8 thick films (50 μm). After the surface chemical modification, it was observed that the steady-state coefficient of friction of the materials reduced by 4 to 5 times and simultaneously their wear durability increased by more than three orders of magnitude (> 1000 times). The significant reduction in the friction coefficients is due to the lubrication effect of PFPE nanolubricant, while the exceptional increase in their wear life is attributed to the bonding between the -OH functional group of ethanolamine treated SU-8 thin/thick films and the -OH functional group of PFPE. The surface chemical modification method acts as a common route to enhance the performance of both silicon and SU-8 polymer. It is time-effective (process time ≤ 11 min), cost-effective and can be readily integrated into MEMS fabrication/assembly processes. It can also work for any kind of structural material from which the miniaturized devices are/can be made.

  9. Meeting the challenges related to material issues in chemical industries

    Indian Academy of Sciences (India)

    Baldev Raj; U Kamachi Mudali; T Jayakumar; K V Kasiviswanathn; K Natarajan

    2000-12-01

    Reliable performance and profitability are two important requirements for any chemical industry. In order to achieve high level of reliability and excellent performance, several issues related to design, materials selection, fabrication, quality assurance, transport, storage, inputs from condition monitoring, failure analysis etc. have to be adequately addressed and implemented. Technology related to nondestructive testing and monitoring of the plant is also essential for precise identification of defect sites and to take appropriate remedial decision regarding repair, replacement or modification of process conditions. The interdisciplinary holistic approach enhances the life of critical engineering components in chemical plants. Further, understanding the failure modes of the components through the analysis of failed components throws light on the choice of appropriate preventive measures to be taken well in advance, to have a control over the overall health of the plant. The failure analysis also leads to better design modification and condition monitoring methodologies, for the next generation components and plants. At the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, a unique combination of the expertise in design, materials selection, fabrication, NDT development, condition monitoring, life prediction and failure analysis exists to obtain desired results for achieving high levels of reliability and performance assessment of critical engineering components in chemical industries. Case studies related to design, materials selection and fabrication aspects of critical components in nuclear fuel reprocessing plants, NDT development and condition monitoring of various components of nuclear power plants, and important failure investigations on critical engineering components in chemical and allied industries are discussed in this paper. Future directions are identified and planned approaches are briefly described.

  10. The Chemical And Radiation Resistance Of Polyphenylene Sulfide As Encountered In The Nuclear Waste Cleaning Processes

    International Nuclear Information System (INIS)

    Polyphenylene sulfide (PPS) is extremely resistant to gamma irradiation, caustic solution, and dilute nitric acid. PPS is the material of construction for the coalescers used in the Modular Caustic-Side Solvent Extraction Unit (MCU). After applying the equivalent of 16 years of gamma irradiation and several months of exposures to caustic solution, no dimensional changes nor chemical changes were detected in PPS whether the PPS was in fiber form or in a composite with E-glass fibers. However, PPS acts as a media for heterogeneous nucleation. In particular, PPS appears to favor aluminosilicate formation in saturated solutions of aluminum and silicon in caustic environments. Parallel testing, in progress, is examining the stability of PPS when exposed to the new solvent formulation under development for MCU. Preliminary data, after two months of exposure, PPS is remarkably stable to the new solvent.

  11. THE CHEMICAL AND RADIATION RESISTANCE OF POLYPHENYLENE SULFIDE AS ENCOUNTERED IN THE NUCLEAR WASTE CLEANING PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.

    2011-10-20

    Polyphenylene sulfide (PPS) is extremely resistant to gamma irradiation, caustic solution, and dilute nitric acid. PPS is the material of construction for the coalescers used in the Modular Caustic-Side Solvent Extraction Unit (MCU). After applying the equivalent of 16 years of gamma irradiation and several months of exposures to caustic solution, no dimensional changes nor chemical changes were detected in PPS whether the PPS was in fiber form or in a composite with E-glass fibers. However, PPS acts as a media for heterogeneous nucleation. In particular, PPS appears to favor aluminosilicate formation in saturated solutions of aluminum and silicon in caustic environments. Parallel testing, in progress, is examining the stability of PPS when exposed to the new solvent formulation under development for MCU. Preliminary data, after two months of exposure, PPS is remarkably stable to the new solvent.

  12. Neutron activation analysis applied to the chemical composition of metallic materials

    International Nuclear Information System (INIS)

    The physical properties of metallic materials, such as mechanical properties, corrosion resistance and others are determined by their chemical composition, which influences the various steps of the production process and the economic value attained by the materials. Instrumental neutron activation analysis was used in this work to evaluate the chemical composition of iron, steel, silicon and ferrosilicon reference materials. The concentration of the elements As, Co, Cr, Mn, Mo, Ni, V and W were analyzed in the iron and steel samples whereas As, Br, Co, Cr, K, Eu, Fe, La, Mn, Mo, Na, Nd, U, Th, Sb, Sc, Sm, Tb, V, W and Yb were determined in silicon and ferrosilicon samples. Accuracy was assessed comparing obtained results to reference materials certified values. Results of about 10 % were achieved for most of the elements. Precision was assessed by replicate measurements, and the results of about 10 % were also achieved. Accuracy and precision results showed that the technique is suitable for the metallic materials composition analysis. Interferences of Cr and Mn in V, Fe and Co in Mn; Co in Fe and Cr in Ti were quantified and only the last one was critical to the analysis of the materials employed in this work. (author)

  13. Radiation resistance diagnostics of wide-gap optical materials

    Science.gov (United States)

    Feldbach, Eduard; Tõldsepp, Eliko; Kirm, Marco; Lushchik, Aleksandr; Mizohata, Kenichiro; Räisänen, Jyrki

    2016-05-01

    Novel approach in the detection of radiation damage created by ion beams in optical materials was demonstrated. Protons of the energy of 100 keV and fluence of 1017 cm-2 create sufficient amount of crystal lattice defects in the thin surface layer for testing of optical materials needed for future fusion reactors. These structural defects can be detected and analysed using the spectra of cathodoluminescence excited in the irradiated layer by an electron beam with adjustable energy. The method was verified by the enhanced intensity of F-type luminescence that reflects the creation of radiation-induced oxygen vacancies in MgO and Al2O3 crystals. Low radiation resistance of nominally pure (Lu1-xGdx)2SiO5 crystals was demonstrated by almost total suppression of intrinsic luminescence after the same irradiation.

  14. XCHEM-1D: A Heat Transfer/Chemical Kinetics Computer Program for multilayered reactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Gross, R.J.; Baer, M.R.; Hobbs, M.L.

    1993-10-01

    An eXplosive CHEMical kinetics code, XCHEM, has been developed to solve the reactive diffusion equations associated with thermal ignition of energetic materials. This method-of-lines code uses stiff numerical methods and adaptive meshing to resolve relevant combustion physics. Solution accuracy is maintained between multilayered materials consisting of blends of reactive components and/or inert materials. Phase change and variable properties are included in one-dimensional slab, cylindrical and spherical geometries. Temperature-dependent thermal properties have been incorporated and the modification of thermal conductivities to include decomposition effects are estimated using solid/gas volume fractions determined by species fractions. Gas transport properties, including high pressure corrections, have also been included. Time varying temperature, heat flux, convective and thermal radiation boundary conditions, and layer to layer contact resistances have also been implemented.

  15. Development of superior radiation resistant materials and cables. 2

    International Nuclear Information System (INIS)

    Many nuclear power plants have been constructed in Japan and electric power generation is now highly dependent on this technology. Therefore, the needs for facilities that will enrich and reprocess nuclear fuel from nuclear power stations will be high. As there are areas with high levels of radiation, the cables which can be used in these environments are needed. We have developed a superior radiation-resistant cable which uses halogen flame-retardant materials. This radiation-resistant cable consists of Ethylene-propylene rubber (EPDM) insulation and Chlorosulfonated polyethylene (CSM) sheath can be safely used in areas with high levels of radiation. We developed this product to aid in disaster prevention. Non-halogen, flame-retardant EPDM is used for the insulation, and low-halogen, flame-retardant CSM and new non-halogen, flame-retardant materials are used for the sheath. These cables have superior flame-retardant properties and generate little smoke on corrosive gas. This products can hence reduce the danger of a secondary disaster in a fire. We expect that these cables will find application in areas with high levels of radiation. (author)

  16. PRELIMINARY STUDY ON ENHANCED PROPERTIES AND BIOLOGICAL RESISTANCE OF CHEMICALLY MODIFIED ACACIA SPP.

    Directory of Open Access Journals (Sweden)

    H. P. S. Abdul Khalil

    2010-11-01

    Full Text Available A preliminary experimental study was carried out to examine the ability of a chemically modified Acacia spp. to resist biodegradation. The modifications of Acacia mangium and Acacia hybrid were carried out by propionic anhydride and succinic anhydride in the presence of sodium formate as a catalyst. The treated samples were found resistant to microbial attack, while the untreated ones were damaged on 12 months exposure to a soil burial. The appearance grading, mass loss, mechanical properties, and scanning electron microscopy results revealed that chemical modification enhances the resistance of Acacia mangium and Acacia hybrid wood species to biodegradation.

  17. Materials of 44. Scientific Assembly of Polish Chemical Society and Association of Engineers and Technicians of Chemical Industry

    International Nuclear Information System (INIS)

    Scientific assemblies of Polish Chemical Society and Association of Engineers and Technicians of Chemical Industry are the most important chemical meeting organised annually in Poland. Basic as well as application studies in all chemical branches have been extensively presented. The next subjects was proposed as scientific sessions and symposia topics: solid state chemistry; didactics of chemistry; electrochemistry; biologically active compounds; geochemistry; organic chemistry; physical chemistry; environment quality and protection; coordination chemistry; chemical technology; polymers; explosive materials; analytical chemistry; theoretical chemistry

  18. Cellulose nanobiocomposites with reinforcement of boron nitride: study of thermal, oxygen barrier and chemical resistant properties.

    Science.gov (United States)

    Swain, Sarat K; Dash, Satyabrata; Behera, Chandini; Kisku, Sudhir K; Behera, Lingaraj

    2013-06-20

    A series of cellulose based nanobiocomposites (cellulose/BN) were prepared with incorporation of various percentage of nano boron nitride (BN). The interaction between cellulose and boron nitride was studied by Fourier transform infrared spectroscopy (FTIR). The structure of cellulose/BN nanobiocomposites was investigated by XRD, FESEM, and HRTEM. It was observed that the boron nitride nanoparticles were dispersed within cellulose matrix due to intercalation and partial exfoliation. The quantitative identification of nanobiocomposites was investigated by selected area electron diffraction (SAED). Thermal stabilities of the prepared nanobiocomposites were measured by thermo gravimetric analysis (TGA) and it was found that thermal stability of the nanobiocomposites was higher than the virgin cellulose. The oxygen barrier property of cellulose/BN nanobiocomposites was measured using a gas permeameter and a substantial reduction in oxygen permeability due to increase in boron nitride loading was observed. Further it was noticed that the chemical resistance of the nanobiocomposites was more than the virgin cellulose. Hence, the prepared nanobiocomposite may be widely used for insulating and temperature resistant packaging materials. PMID:23648034

  19. Measurement of Charging and Discharging of High Resistivity Materials Spacecraft Materials by Electron Beams

    OpenAIRE

    Hoffman, Ryan; Hodges, Joshua L.; Hayes, Jesse; Dennison, JR

    2009-01-01

    New instrumentation has been developed for in situ measurements of the electron beam- induced surface voltage of high resistivity spacecraft materials in an existing ultra-high vacuum electron emission analysis chamber. Design details, calibration and characterization measurements of the system are presented, showing sensitivity to a range of surface voltages from12000 V, with resolutionsurface, using a paddle attached to a vacuum compatible stepper motor mounted within a hemispherical grid r...

  20. Nanostructured materials with biomimetic recognition abilities for chemical sensing

    Science.gov (United States)

    Bajwa, Sadia Zafar; Mustafa, Ghulam; Samardzic, Renata; Wangchareansak, Thipvaree; Lieberzeit, Peter A.

    2012-06-01

    Binding features found in biological systems can be implemented into man-made materials to design nanostructured artificial receptor matrices which are suitable, e.g., for chemical sensing applications. A range of different non-covalent interactions can be utilized based on the chemical properties of the respective analyte. One example is the formation of coordinative bonds between a polymerizable ligand (e.g., N-vinyl-2-pyrrolidone) and a metal ion (e.g., Cu(II)). Optimized molecularly imprinted sensor layers lead to selectivity factors of at least 2 compared to other bivalent ions. In the same way, H-bonds can be utilized for such sensing purposes, as shown in the case of Escherichia coli. The respective molecularly imprinted polymer leads to the selectivity factor of more than 5 between the W and B strains, respectively. Furthermore, nanoparticles with optimized Pearson hardness allow for designing sensors to detect organic thiols in air. The `harder' MoS2 yields only about 40% of the signals towards octane thiol as compared to the `softer' Cu2S. However, both materials strongly prefer molecules with -SH functionality over others, such as hydrocarbon chains. Finally, selectivity studies with wheat germ agglutinin (WGA) reveal that artificial receptors yield selectivities between WGA and bovine serum albumin that are only about a factor of 2 which is smaller than natural ligands.

  1. Thin film resistive materials: past, present and future

    Science.gov (United States)

    Cherian Lukose, C.; Zoppi, G.; Birkett, M.

    2016-01-01

    This paper explores the key developments in thin film resistive materials for use in the fabrication of discrete precision resistors. Firstly an introduction to the preparation of thin films and their fundamental properties is given with respect to well established systems such as NiCr, TaN and CrSiO. The effect of doping these systems in both solid and gaseous forms to further refine their structural and electrical properties is then discussed before the performance of more recent materials systems such as CuAlMo and MmAgCuN are reviewed. In addition to performance of the materials themselves, the effect of varying processing parameters such as deposition pressure and temperature and subsequent annealing environment, as well as laser trimming energy and geometry are also studied. It is shown how these parameters can be systematically controlled to produce films of the required properties for varying applications such as high precision, long term stability and high power pulse performance.

  2. TEACHING "CORROSION AND CORROSION-RESISTANT MATERIALS" CLASS AS A MUST COURSE IN MATERIAL AND MATERIAL PROCESSING TECHNOLOGIES PROGRAM

    OpenAIRE

    GERENGİ, Hüsnü; KURTAY, Mine

    2013-01-01

    Corrosion has become a main problem due to the rise in the use of metal with the developing technology. Corrosion is the degradation of metal or metal alloys as a result of chemical or electrochemical reactions. Corrosion education is a matter of concern for all material types. The aim of this study is to demonstrate and discuss the importance of “Corrosion and Corrosion Materials Technology Course” indicating the importance of corrosion science and taught in all programs under the Department...

  3. Resistivity measurements on the neutron irradiated detector grade silicon materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng

    1993-11-01

    Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Meanwhile, the effective doping concentration N{sub eff} in the space charge region (SCR) obtained from the C-V measurements of fully depleted p{sup +}/n silicon junction detectors has been found to increase nearly linearly with {phi}{sub n} at high fluences ({phi}{sub n} > 10{sup 13} n/cm{sup 2}). The experimental results are explained by the deep levels crossing the Fermi level in the SCR and near perfect compensation in the ENB by all deep levels, resulting in N{sub eff} (SCR) {ne} n or p (free carrier concentrations in the ENB).

  4. Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B

    2006-06-01

    Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking.

  5. Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

    International Nuclear Information System (INIS)

    Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories, alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking

  6. Application of newly developed heat resistant materials for USC boilers

    International Nuclear Information System (INIS)

    This paper describes the research on the development and improvement of new high strength heat resistant steels such as SUPER304H (18Cr-9Ni-3Cu-Nb-N), NF709 (20Cr-25Ni-1.5Mo-Nb-Ti-N) and HR3C (25Cr-20Ni-Nb-N) as boiler tube, and NF616 (9Cr-0.5Mo-1.8W-Nb-V) and HCM12A (11Cr-0.4Mo-2W-Nb-V-Cu) as thick section pipe. The latest manufacturing techniques applied for these steels are introduced. In addition the high temperature strength of Alloy617 (52Ni-22Cr-13Co-9Mo-Ti-Al) that is one of the candidate materials for the next generation 700 □ USC boilers is described. (orig.)

  7. Time influence in chemical treatment of Brazilian raw materials type; Influencia del tiempo en el tratamiento quimico sobre materias primas brasileras del tipo acilloso

    Energy Technology Data Exchange (ETDEWEB)

    Argolo, F.; Dias, C.; Machado, A. [Centro de Inovacao e Tecnologia Ambiental (CITA/CETREL), Camacari, BA (Brazil); Volzone, C.; Ortiga, J. [Centro de Tecnologia de Recursos Minerales y Ceramica (CETMIC/CCT/CONICET/La Plata/CICPBA) (Argentina); Valenzuela Diaz, F. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

    2012-07-01

    Clays are part of raw materials in different industries. The mineralogical composition and purity greatly influence the application thereof. Chemical treatments applied, such as acid attack, modify their properties and thus their possible uses. Taking in to account that, clay minerals, may differ by more or less resistance to chemical attacks, two types of clay were studied with different mineralogical composition to assess the degree of resistance to chemical attack treatment such as acid. Acid treatments that were applied, differ mainly in the contact time between the solid and the liquid. The solids were studied by X-ray diffraction analysis, chemical analysis and infrared analysis.

  8. Chemical Acidic Attack Resistance of Lightweight Concrete with Additives

    Directory of Open Access Journals (Sweden)

    Salwa H. Ahmed

    2013-04-01

    Full Text Available  This research was studied the effect of H2SO4(8% , HCl (8% acidic and wastewaterpH= 5.1, SO4= = 850mg/L, Cl-=750 mg/L , TDS = 2500 mg/L( on the lightweight concrete by using limestone as lightweight aggregate and using the foam material (LightCrete. Super plasticizers (SP also used to enhance the properties of the lightweight concrete. Studying the effect of acidic solution and wastewater was done by calculating the percentage of decrease in weight and compressive strength of concrete prisms (100 * 100 * 400 mm, where the small portion of the flexural modulus test was submerged completely in the above solutions,  and the salt rising was observed by immersion (100 mm depth from the second portion of the prism in the above solutions. اظهرت نتائج الفحوصات ان H 2 SO 4 يكون تأثيره اكثر من HCl بالنسبة للنقصان بالوزن على الخرسانة الاعتيادية  بينما يكون تأثير HCl كبير على الخرسانة خفيفة الوزن بأستخدام الركام خفيف الوزن (Limestone وتأثيره اقل من H 2 SO 4 بالنسبة للخرسانة خفيفة الوزن باستخدام المادة الرغوية . Results show that the H2SO4 have influence larger than HCl for the decrease of weight on the normal concrete while the effect of HCl was larger than H2SO4  on lightweight concrete with limestone and its effect was less than H2SO4 on the lightweight concrete with foam. وكذلك تبين ان تأثير H 2 SO 4 على الخرسانة الاعتيادية بالنسبة للنقصان بالمقاومة يكون اقل من تاثير HCl بينما يكون تاثير H 2 SO 4 كبير على الخرسانة خفيفة الوزن الحاوية على المادة الرغوية وتاثيره اقل على الخرسانة خفيفة الوزن الحاوية على SP و Limestone . The results also shown that the effect of H2SO4 on the normal

  9. Fatigue Characterization of Fire Resistant Syntactic Foam Core Material

    Science.gov (United States)

    Hossain, Mohammad Mynul

    Eco-Core is a fire resistant material for sandwich structural application; it was developed at NC A&T State University. The Eco-Core is made of very small amount of phenolic resin and large volume of flyash by a syntactic process. The process development, static mechanical and fracture, fire and toxicity safety and water absorption properties and the design of sandwich structural panels with Eco-Core material was established and published in the literature. One of the important properties that is needed for application in transportation vehicles is the fatigue performance under different stress states. Fatigue data are not available even for general syntactic foams. The objective of this research is to investigate the fatigue performance of Eco-Core under three types of stress states, namely, cyclic compression, shear and flexure, then document failure modes, and develop empherical equations for predicting fatigue life of Eco-Core under three stress states. Compression-Compression fatigue was performed directly on Eco-Core cylindrical specimen, whereas shear and flexure fatigue tests were performed using sandwich beam made of E glass-Vinyl Ester face sheet and Eco-Core material. Compression-compression fatigue test study was conducted at two values of stress ratios (R=10 and 5), for the maximum compression stress (sigmamin) range of 60% to 90% of compression strength (sigmac = 19.6 +/- 0.25 MPa) for R=10 and 95% to 80% of compression strength for R=5. The failure modes were characterized by the material compliance change: On-set (2% compliance change), propagation (5%) and ultimate failure (7%). The number of load cycles correspond to each of these three damages were characterized as on-set, propagation and total lives. A similar approach was used in shear and flexure fatigue tests with stress ratio of R=0.1. The fatigue stress-number of load cycles data followed the standard power law equation for all three stress states. The constant of the equation were

  10. Characterisation of the Thermal and Chemical Effects of Energetic Materials not Likely to Detonate

    OpenAIRE

    Biteau, Hubert; Marlair, Guy; Drysdale, Dougal; Torero, Jose L.

    2006-01-01

    Energetic materials encompass a wide range of chemical compounds all associated with a significant risk of fire and explosion. They include explosives, pyrotechnic materials, powders, fertilizers and other unsteady chemicals. These materials store a high level of chemical energy and are able to release it rapidly without external contribution of oxygen or other oxidizer. The aim of this work is the analysis of thermal and chemical characteristics of energy-rich materials under conditions t...

  11. Synthesis and Engineering Materials Properties of Fluid Phase Chemical Hydrogen Storage Materials for Automotive Applications

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Joon; Westman, Matthew P.; Karkamkar, Abhijeet J.; Chun, Jaehun; Ronnebro, Ewa

    2015-09-01

    Among candidates for chemical hydrogen storage in PEM fuel cell automotive applications, ammonia borane (AB, NH3BH3) is considered to be one of the most promising materials due to its high practical hydrogen content of 14-16 wt%. This material is selected as a surrogate chemical for a hydrogen storage system. For easier transition to the existing infrastructure, a fluid phase hydrogen storage material is very attractive and thus, we investigated the engineering materials properties of AB in liquid carriers for a chemical hydrogen storage slurry system. Slurries composed of AB and high temperature liquids were prepared by mechanical milling and sonication in order to obtain stable and fluidic properties. Volumetric gas burette system was adopted to observe the kinetics of the H2 release reactions of the AB slurry and neat AB. Viscometry and microscopy were employed to further characterize slurries engineering properties. Using a tip-sonication method we have produced AB/silicone fluid slurries at solid loadings up to 40wt% (6.5wt% H2) with viscosities less than 500cP at 25°C.

  12. The Idaho Chemical Processing Plant Special Nuclear Material vault upgrade

    International Nuclear Information System (INIS)

    This document discusses storage space in a Special Nuclear Material (SNM) product storage vault at the Idaho Chemical Processing Plant (ICPP) which has been recently expanded by approximately 175%. This expansion required a minimum of space and funding and resulted in a large increase in net storage capacity. Security for the additional storage is provided by standard intrusion sensors and by a real-time monitoring system, which monitors the weight of the material as it rests on weight sensors (load cells). The monitoring system also feeds weight data to a Safeguards processor which provides further confidence to Safeguards personnel. The Department of Energy requirements for bimonthly inventories for SNM stored in a particular part of this facility have been eliminated because of the guarantees provided by a real-time monitoring system. A higher efficiency has been obtained by using the expensive real estate inside a hardened product storage vault. This project has provided the ICPP with a relatively inexpensive vault upgrade and when product material is placed in this area of the vault the manpower requirements to inventory it will be reduced, resulting in a net reduction in plant worker radiation exposure

  13. Development of oxidation/corrosion-resistant composite materials and interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.; Besmann, T.M.; Shanmugham, S. [and others

    1995-06-01

    Continuous fiber ceramic composites (CFCCs) are being developed for high temperature structural applications, many of which are in oxidative environments. Such composites are attractive since they are light-weight and possess the desired mechanical properties at elevated temperature and in aggressive environments. The most significant advantage is their toughness and their non-catastrophic failure behavior. The mechanical properties of CFCCs have been characteristically linked with the nature of the interfacial bond between the fibers and the matrix. Weakly bonded fiber-matrix intefaces allow an impinging matrix crack to be deflected such that the fracture process occurs through several stages: Crack deflection, debonding at the interface, fiber slip and pull-out, and ultimately fiber failure. Such a composite will fail in a graceful manner and exhibit substantial fracture toughness. Currently, carbon interface coatings are used to appropriately tailor interface properties, however their poor oxidation resistance has required a search of an appropriate replacement. Generally, metal oxides are inherently stable to oxidation and possess thermal expansion coefficients relatively close to those of Nicalon and SiC. However, the metal oxides must also be chemically compatible with the fiber and matrix. If the fiber/interface/matrix system is chemically compatible, then the interfacial bonding stress is influenced by the thermal residual stresses that are generated as the composite is cooled from processing to room temperature. In the current work, thermomechanical computational results were obtained from a finite element model (FEM) for calculating the thermal residual stresses. This was followed by experimental evaluation of Nicalon/SiC composites with carbon, alumina, and mullite interfacial coatings.

  14. Characterization of marine bacteria highly resistant to mercury exhibiting multiple resistances to toxic chemicals

    Digital Repository Service at National Institute of Oceanography (India)

    De, J.; Ramaiah, N.

    on colony characteristics, 13 isolates originating mainly from coastal samples collected off Goa on the West Coast and off Chennai and Gopalpur on the East Coast of India were selected for 16S rDNA sequencing and further detailed experimentation were...) reported that the genome sequence of Pseudomonas putida KT2440 has 61 open reading frames (ORFs) involved in different metal tolerance/resistance. Pain and Cooney (1998) reported that most of the TBT-resistant bacteria are also resistant to six heavy...

  15. Pressure Resistance Welding of High Temperature Metallic Materials

    Energy Technology Data Exchange (ETDEWEB)

    N. Jerred; L. Zirker; I. Charit; J. Cole; M. Frary; D. Butt; M. Meyer; K. L. Murty

    2010-10-01

    Pressure Resistance Welding (PRW) is a solid state joining process used for various high temperature metallic materials (Oxide dispersion strengthened alloys of MA957, MA754; martensitic alloy HT-9, tungsten etc.) for advanced nuclear reactor applications. A new PRW machine has been installed at the Center for Advanced Energy Studies (CAES) in Idaho Falls for conducting joining research for nuclear applications. The key emphasis has been on understanding processing-microstructure-property relationships. Initial studies have shown that sound joints can be made between dissimilar materials such as MA957 alloy cladding tubes and HT-9 end plugs, and MA754 and HT-9 coupons. Limited burst testing of MA957/HT-9 joints carried out at various pressures up to 400oC has shown encouraging results in that the joint regions do not develop any cracking. Similar joint strength observations have also been made by performing simple bend tests. Detailed microstructural studies using SEM/EBSD tools and fatigue crack growth studies of MA754/HT-9 joints are ongoing.

  16. Resistance study of packaging materials to rice insects pest

    International Nuclear Information System (INIS)

    The resistance of several packaging materials to penetration by 4 species of rice insect pests was determined. Five insects of adult or larval stage were confined in pouches made from 9 different packaging materials with or without irradiated rice. It was observed that both adults and larvae of species Tribolium castaneum Herbst., Sitophilus zeamais L., Oryzaephilus surinamensis L. and Cocyra cephalonica Stainton, were incapable of penetrating pouches made from white polyvinychloride of 0.175mm thickness, low density polyethylene of 0.130mm thickness and 0.150mm thick low density polyethylene. However, penetrations marks were found in pouches made from hard paper with a thickness of 0.155mm, clear polivinylchloride of 0.130mm thickness, low density polyethylene of 0.085mm thickness, low density polyethylene 0.100mm thick, high density polyethylene of 0.06mm thickness and 0.080mm thick polypropylene. Tribolium castaneum could be considered as a weak penetrator whilst Cocyra cephalonica was the main pouch penetrator. Penetrations of pouches mostly occured within the first week. This study showed that gamma irradiation at a dose of 1.0 kGy was effective in inhibiting egg development and killing larvae of insects found in rice within this study period

  17. Nano-FTIR chemical mapping of minerals in biological materials

    Directory of Open Access Journals (Sweden)

    Sergiu Amarie

    2012-04-01

    Full Text Available Methods for imaging of nanocomposites based on X-ray, electron, tunneling or force microscopy provide information about the shapes of nanoparticles; however, all of these methods fail on chemical recognition. Neither do they allow local identification of mineral type. We demonstrate that infrared near-field microscopy solves these requirements at 20 nm spatial resolution, highlighting, in its first application to natural nanostructures, the mineral particles in shell and bone. "Nano-FTIR" spectral images result from Fourier-transform infrared (FTIR spectroscopy combined with scattering scanning near-field optical microscopy (s-SNOM. On polished sections of Mytilus edulis shells we observe a reproducible vibrational (phonon resonance within all biocalcite microcrystals, and distinctly different spectra on bioaragonite. Surprisingly, we discover sparse, previously unknown, 20 nm thin nanoparticles with distinctly different spectra that are characteristic of crystalline phosphate. Multicomponent phosphate bands are observed on human tooth sections. These spectra vary characteristically near tubuli in dentin, proving a chemical or structural variation of the apatite nanocrystals. The infrared band strength correlates with the mineral density determined by electron microscopy. Since nano-FTIR sensitively responds to structural disorder it is well suited for the study of biomineral formation and aging. Generally, nano-FTIR is suitable for the analysis and identification of composite materials in any discipline, from testing during nanofabrication to even the clinical investigation of osteopathies.

  18. Thermal and chemical degradation of inorganic membrane materials. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, G.N.; Sanjurjo, A.; Wood, B.J.; Lau, K.H.

    1994-04-01

    This report describes the results of a literature review to evaluate the long-term thermal and chemical degradation of inorganic membranes that are being developed to separate gaseous products produced by the gasification or combustion of coal in fixed-, fluidized-, and entrained-bed gasifiers, direct coal-fired turbines, and pressurized-fluidized-bed combustors. Several impurities, such as H{sub 2}S, NH{sub 3}, SO{sub 2}, NO{sub x}, and trace metal compounds are generated during coal conversion, and they must be removed from the coal gas or the combustor flue gas to meet environmental standards. The use of membranes to separate these noxious gases is an attractive alternative to their removal by sorbents such as zinc titanate or calcium oxide. Inorganic membranes that have a high separation efficiency and exhibit both thermal and chemical stability would improve the economics of power generation from coal. The U.S. Department of Energy is supporting investigations to develop inorganic membranes for separating hydrogen from coal gas streams and noxious impurities from hot coal- and flue-gas streams. Membrane materials that have been investigated in the past include glass (silica), alumina, zirconia, carbon, and metals (Pd and Pt).

  19. Chemically Deposited Thin-Film Solar Cell Materials

    Science.gov (United States)

    Raffaelle, R.; Junek, W.; Gorse, J.; Thompson, T.; Harris, J.; Hehemann, D.; Hepp, A.; Rybicki, G.

    2005-01-01

    We have been working on the development of thin film photovoltaic solar cell materials that can be produced entirely by wet chemical methods on low-cost flexible substrates. P-type copper indium diselenide (CIS) absorber layers have been deposited via electrochemical deposition. Similar techniques have also allowed us to incorporate both Ga and S into the CIS structure, in order to increase its optical bandgap. The ability to deposit similar absorber layers with a variety of bandgaps is essential to our efforts to develop a multi-junction thin-film solar cell. Chemical bath deposition methods were used to deposit a cadmium sulfide (CdS) buffer layers on our CIS-based absorber layers. Window contacts were made to these CdS/CIS junctions by the electrodeposition of zinc oxide (ZnO). Structural and elemental determinations of the individual ZnO, CdS and CIS-based films via transmission spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy and energy dispersive spectroscopy will be presented. The electrical characterization of the resulting devices will be discussed.

  20. Impact of chemical quality of source material on sintering recovery

    International Nuclear Information System (INIS)

    'Full text:' Nuclear Fuel Complex (NFC), a constituent unit of Department of Atomic Energy (DAE), manufactures and supplies Pressurised Heavy Water Reactor (PHWR) fuel bundles for all the power reactors in India. The raw material is supplied by Uranium Corporation of India Limited (UCIL) in the form of Magnesium-Di-Uranate (MDU). The chemical quality of MDU plays a major role in the performance of various process steps in the Uranium di-Oxide (UO2) powder and pellets. MDU being received hitherto was from only one mill and the conversion process steps were quite well established for obtaining sinterable grade UO powder, which has resulted in very good sintered density pellets with good integrity. With the opening of new mines and setting up of new mill the chemical characteristics of the ore and MDU thus produced have different characteristics. These differences have called for re-setting of many process parameters in the powder conversion and pellet production plants to ensure consistent quality and recoveries. The paper gives in detail the corrective measures attempted, observations made and the conclusions drawn.

  1. Chemical characterization of materials by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    An Inductively Coupled Plasma Mass Spectrometer was procured for trace elemental determination in diverse samples. Since its installation a number of analytical measurements have been carried out on different sample matrices. These include chemical quality control measurements of nuclear fuel and other materials such as uranium metal. Uranium peroxide, ADU, ThO2, UO2; isotopic composition of B, Li; chemical characterization of simulated ThO2 + 2%UO2 fuel; sodium zirconium phosphate and trace metallic elements in zirconium; Antarctica rock samples and wet phosphoric acid. Necessary separation methodologies required for effective removal of matrix were indigenously developed. In addition, a rigorous analytical protocol, which includes various calibration methodologies such as mass calibration, response calibration, detector cross calibration and linearity check over the entire dynamic range of 109 required for quantitative determination of elements at trace and ultra trace level,, has been standardized. This report summarizes efforts of RACD that have been put in this direction for the application of ICP-MS for analytical measurements. (author)

  2. Compressive Strength, Chloride Permeability, and Freeze-Thaw Resistance of MWNT Concretes under Different Chemical Treatments

    Directory of Open Access Journals (Sweden)

    Xingang Wang

    2014-01-01

    Full Text Available This study investigated compressive strength, chloride penetration, and freeze-thaw resistance of multiwalled carbon nanotube (MWNT concrete. More than 100 cylindrical specimens were used to assess test variables during sensitivity observations, including water-cement ratios (0.75, 0.5, and 0.4 and exposure to chemical agents (including gum arabic, propanol, ethanol, sodium polyacrylate, methylcellulose, sodium dodecyl sulfate, and silane. To determine the adequate sonication time for MWNT dispersal in water, the compressive strengths of MWNT concrete cylinders were measured after sonication times ranging from 2 to 24 minutes. The results demonstrated that the addition of MWNT can increase the compressive strength of concrete by up to 108%. However, without chemical treatment, MWNT concretes tend to have poor freeze-thaw resistance. Among the different chemical treatments, MWNT concrete treated with sodium polyacrylate has the best compressive strength, chloride resistance, and freeze-thaw durability.

  3. Compressive strength, chloride permeability, and freeze-thaw resistance of MWNT concretes under different chemical treatments.

    Science.gov (United States)

    Wang, Xingang; Rhee, Inkyu; Wang, Yao; Xi, Yunping

    2014-01-01

    This study investigated compressive strength, chloride penetration, and freeze-thaw resistance of multiwalled carbon nanotube (MWNT) concrete. More than 100 cylindrical specimens were used to assess test variables during sensitivity observations, including water-cement ratios (0.75, 0.5, and 0.4) and exposure to chemical agents (including gum arabic, propanol, ethanol, sodium polyacrylate, methylcellulose, sodium dodecyl sulfate, and silane). To determine the adequate sonication time for MWNT dispersal in water, the compressive strengths of MWNT concrete cylinders were measured after sonication times ranging from 2 to 24 minutes. The results demonstrated that the addition of MWNT can increase the compressive strength of concrete by up to 108%. However, without chemical treatment, MWNT concretes tend to have poor freeze-thaw resistance. Among the different chemical treatments, MWNT concrete treated with sodium polyacrylate has the best compressive strength, chloride resistance, and freeze-thaw durability. PMID:25140336

  4. Chemical resistance/thermal and mechanical properties of unsaturated polyester-based nanocomposites

    Science.gov (United States)

    Jaya Vinse Ruban, Y.; Ginil Mon, S.; Vetha Roy, D.

    2013-01-01

    Nanocomposites were synthesized using unsaturated polyester as the matrix and organically modified montmorillonite (CA-MMT) as the reinforcing agent. XRD pattern of the modified montmorillonite showed that the interlayer spacing expanded from 1.21 to 1.9 nm, indicating intercalation. TGA and DTA show loss of organic surfactant from interlayer galleries. Glass transition temperature (T g) of these composites increased from 71 °C in the unfilled unsaturated polyester to 79 °C in the composites with 5 % organically modified montmorillonite. Chemical resistance and mechanical properties of the UP/organo-clay nanocomposites were studied. Chemical resistance was studied under aqueous conditions in acetic acid, nitric acid, hydrochloric acid, sodium hydroxide, aqueous ammonia and sodium carbonate. Chemical resistance studies reveal maximum weight gain/loss with increasing clay content. Mechanical studies show maximum characteristics for the composites-clay filled 5 % (w/w).

  5. Hydrazine Borane and Hydrazinidoboranes as Chemical Hydrogen Storage Materials

    Directory of Open Access Journals (Sweden)

    Romain Moury

    2015-04-01

    Full Text Available Hydrazine borane N2H4BH3 and alkali derivatives (i.e., lithium, sodium and potassium hydrazinidoboranes MN2H3BH3 with M = Li, Na and K have been considered as potential chemical hydrogen storage materials. They belong to the family of boron- and nitrogen-based materials and the present article aims at providing a timely review while focusing on fundamentals so that their effective potential in the field could be appreciated. It stands out that, on the one hand, hydrazine borane, in aqueous solution, would be suitable for full dehydrogenation in hydrolytic conditions; the most attractive feature is the possibility to dehydrogenate, in addition to the BH3 group, the N2H4 moiety in the presence of an active and selective metal-based catalyst but for which further improvements are still necessary. However, the thermolytic dehydrogenation of hydrazine borane should be avoided because of the evolution of significant amounts of hydrazine and the formation of a shock-sensitive solid residue upon heating at >300 °C. On the other hand, the alkali hydrazinidoboranes, obtained by reaction of hydrazine borane with alkali hydrides, would be more suitable to thermolytic dehydrogenation, with improved properties in comparison to the parent borane. All of these aspects are surveyed herein and put into perspective.

  6. Apparatus for measuring the Seebeck coefficients of highly resistive organic semiconducting materials

    Science.gov (United States)

    Cai, H. Y.; Cui, D. F.; Li, Y. T.; Chen, X.; Zhang, L. L.; Sun, J. H.

    2013-04-01

    A Seebeck coefficient measurement apparatus for high resistance organic semiconductor materials has been designed and built. It can measure materials with resistance over 7 × 1012 Ω. This is the highest material resistance value ever reported for Seebeck coefficient measurement. A cyclic temperature gradient generation technique and a corresponding algorithm are proposed to eliminate the negative effects of the long term drift of Seebeck voltage. Sources of errors in these measurements are discussed.

  7. Chemical characteristics of negative-tone chemically amplified resist for advanced mask making

    Science.gov (United States)

    Takeshi, Kazumasa; Ito, Naoko; Inokuchi, Daisuke; Nishiyama, Yasushi; Fukushima, Yuichi; Okumoto, Yasuhiro

    2004-08-01

    We investigated the film property and the lithographic performance of five commercialized NCARs. This report shows the relationship between chemical structure and EB lithographic performance, such as resolution, sensitivity and environmental stability. In this study, we found the good matching the matrix polymer, the cross linker and the photo acid generator(PAG) against NCARs issues. Furthermore, we could demonstrate the trade-off relation for lithographic factor and stabilized factor by chemical characteristics. This report suggests the strategy that was design of chemical structure for the next generation NCARs.

  8. PRELIMINARY STUDY ON ENHANCED PROPERTIES AND BIOLOGICAL RESISTANCE OF CHEMICALLY MODIFIED ACACIA SPP.

    OpenAIRE

    H. P. S. Abdul Khalil; Irshad ul Haq Bhat,; Khairul B. Awang

    2010-01-01

    A preliminary experimental study was carried out to examine the ability of a chemically modified Acacia spp. to resist biodegradation. The modifications of Acacia mangium and Acacia hybrid were carried out by propionic anhydride and succinic anhydride in the presence of sodium formate as a catalyst. The treated samples were found resistant to microbial attack, while the untreated ones were damaged on 12 months exposure to a soil burial. The appearance grading, mass loss, mechanical properties...

  9. Synthesis and chemical modification of carbon nanostructures for materials applications

    Science.gov (United States)

    Higginbotham, Amanda Lynn

    This dissertation explores the structure, chemical reactivities, electromagnetic response, and materials properties of various carbon nanostructures, including single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphite, and graphene nanoribbons (GNRs). Efficient production and modification of these unique structures, each with their own distinct properties, will make them more accessible for applications in electronics, materials, and biology. A method is reported for controlling the permittivity from 1--1000 MHz of SWCNT-polymer composites (0.5 wt%) for radio frequency applications including passive RF antenna structures and EMI shielding. The magnitude of the real permittivity varied between 20 and 3.3, decreasing as higher fractions of functionalized-SWCNTs were added. The microwave absorbing properties and subsequent heating of carbon nanotubes were used to rapidly cure ceramic composites. With less than 1 wt% carbon nanotube additives and 30--40 W of directed microwave power (2.45 GHz), bulk composite samples reached temperatures above 500°C within 1 min. Graphite oxide (GO) polymer nanocomposites were developed at 1, 5, and 10 wt% for the purpose of evaluating the flammability reduction and materials properties of the resulting systems. Microscale oxygen consumption calorimetry revealed that addition of GO reduced the total heat release in all systems, and GO-polycarbonate composites demonstrated very fast self-extinguishing times in vertical open flame tests. A simple solution-based oxidative process using potassium permanganate in sulfuric acid was developed for producing nearly 100% yield of graphene nanoribbons (GNRs) by lengthwise cutting and unraveling of MWCNT sidewalls. Subsequent chemical reduction of the GNRs resulted in restoration of electrical conductivity. The GNR synthetic conditions were investigated in further depth, and an improved method which utilized a two-acid reaction medium was found to produce GNRs with

  10. EPOXY-BASED ORGANIC-INORGANIC HYBRID MATERIALS BY SOL-GEL METHOD: CHEMICAL TAILORING AND MULTI-SCALE CHARACTERIZATION.

    OpenAIRE

    Piscitelli, Filomena

    2010-01-01

    The epoxy resins are organic matrices with excellent heat, moisture, and chemical resistance and good adhesion to many substrates, therefore they are mostly applied in the field of coatings, adhesives, casting, composites, laminates and encapsulation of semiconductor devises. However, due to their low mechanical properties and high coefficient of thermal expansion value compared with inorganic materials, the epoxy resins cannot meet all the requirements, especially for the electrical and stru...

  11. Chemical Acidic Attack Resistance of Lightweight Concrete with Additives

    OpenAIRE

    Salwa H. Ahmed

    2013-01-01

     This research was studied the effect of H2SO4(8%) , HCl (8%) acidic and wastewater)pH= 5.1, SO4= = 850mg/L, Cl-=750 mg/L , TDS = 2500 mg/L( on the lightweight concrete by using limestone as lightweight aggregate and using the foam material (LightCrete). Super plasticizers (SP) also used to enhance the properties of the lightweight concrete. Studying the effect of acidic solution and wastewater was done by calculating the percentage of decrease in weight and compressive strength of concrete p...

  12. Designing Multiagent Dental Materials for Enhanced Resistance to Biofilm Damage at the Bonded Interface.

    Science.gov (United States)

    Melo, Mary Anne; Orrego, Santiago; Weir, Michael D; Xu, Huakun H K; Arola, Dwayne D

    2016-05-11

    The oral environment is considered to be an asperous environment for restored tooth structure. Recurrent dental caries is a common cause of failure of tooth-colored restorations. Bacterial acids, microleakage, and cyclic stresses can lead to deterioration of the polymeric resin-tooth bonded interface. Research on the incorporation of cutting-edge anticaries agents for the design of new, long-lasting, bioactive resin-based dental materials is demanding and provoking work. Released antibacterial agents such as silver nanoparticles (NAg), nonreleased antibacterial macromolecules (DMAHDM, dimethylaminohexadecyl methacrylate), and released acid neutralizer amorphous calcium phosphate nanoparticles (NACP) have shown potential as individual and dual anticaries approaches. In this study, these agents were synthesized, and a prospective combination was incorporated into all the dental materials required to perform a composite restoration: dental primer, adhesive, and composite. We focused on combining different dental materials loaded with multiagents to improve the durability of the complex dental bonding interface. A combined effect of bacterial acid attack and fatigue on the bonding interface simulated the harsh oral environment. Human saliva-derived oral biofilm was grown on each sample prior to the cyclic loading. The oral biofilm viability during the fatigue performance was monitored by the live-dead assay. Damage of the samples that developed during the test was quantified from the fatigue life distributions. Results indicate that the resultant multiagent dental composite materials were able to reduce the acidic impact of the oral biofilm, thereby improving the strength and resistance to fatigue failure of the dentin-resin bonded interface. In summary, this study shows that dental restorative materials containing multiple therapeutic agents of different chemical characteristics can be beneficial toward improving resistance to mechanical and acidic challenges in oral

  13. Thermo-mechano-chemical stability of ceramic materials during the electrowinning process using liquid metal electrodes in molten salts

    International Nuclear Information System (INIS)

    Pyroprocessing, which results in proliferation resistance, shows promise as an alternative to wet processing in the recycling of transuranics. However, the ceramic crucible used in the electrowinning process poses an issue during pyroprocessing. The crucible is chemically unstable and prone to thermal fatigue. In this study, the thermodynamic simulation software HSC (enthalpy, entropy and heat capacity) Chemistry was employed to evaluate the chemical stabilities of different ceramic crucibles containing liquid cadmium as well as liquid bismuth cathodes, which also contained rare earth elements and lithium. The chemical stabilities were experimentally validated by measuring the contact angles between the liquid cathode (LC) materials and four ceramic materials (Al2O3, MgO, Y2O3, and BeO) in situ. The infiltration depths of the liquid bismuth cathode elements were measured using X-ray photoelectron spectroscopy. To determine the Weibull distributions of the investigated ceramics, thermal fatigue tests were performed using plates of the ceramics. (author)

  14. Efficiency and resistance of the artificial oxalate protection treatment on marble against chemical weathering

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, B. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Pamplona, M. [Centro de Petrologia e Geoquimica do Instituto Superior Tecnico Universidade Tecnica de Lisboa, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); Selvaggi, R. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Miliani, C. [Istituto CNR di Scienze e Tecnologie Molecolari (ISTM), Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy)]. E-mail: miliani@thch.unipg.it; Matteini, M. [CNR Istituto, Conservazione e Valorizzazione dei Beni Culturali (ICVBC), Via Madonna del Piano, 10, Edifico C-50019, Florence (Italy); Sgamellotti, A. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Istituto CNR di Scienze e Tecnologie Molecolari (ISTM), Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Brunetti, B. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy)

    2007-03-15

    The artificial oxalate protection method was analyzed in laboratory experiments in order to achieve an optimum treatment application and concentration giving rise to its most effective protective nature. Spectroscopic (Fourier transform infrared, Micro-Raman and UV-vis colorimetry), microscopic (scanning electron microscope) and contact-angle analyses were carried out to characterize Carrara marble samples before and after application of the treatment to validate its efficiency. The resistance effects against chemical weathering were subsequently observed in a lab-controlled weak acid rain experiment. An acid spray at pH 5.5, representative of normal rain was used to provoke degrade of natural marble, marble treated with the artificial oxalate protective at concentrations of 0.4 and 5% and marble treated with a commercial organic silicon product. Run-off solutions sampled at timely intervals were tested for any change in pH followed by ion chromatography measurements for the presence of calcium ions in solution. The chromatography results of the oxalate treatment applied at a 5% concentration are analogous to an organic commercial product indicating its validity as a method for the conservation of carbonate substrates conferring protection to stone materials against acid environments.

  15. CONVERSION OF LIGNOCELLULOSIC MATERIAL TO CHEMICALS AND FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Edwin S. Olson

    2001-06-30

    A direct conversion of cellulosic wastes, including resin-bonded furniture and building waste, to levulinate esters is being investigated with the view to producing fuels, solvents, and chemical intermediates as well as other useful by-products in an inexpensive process. The acid-catalyzed reaction of cellulosic materials with ethanol or methanol at 200 C gives good yields of levulinate and formate esters, as well as useful by-products, such as a solid residue (charcoal) and a resinous lignin residue. An initial plant design showed reasonable rates of return for production of purified ethyl levulinate and by-products. In this project, investigations have been performed to identify and develop reactions that utilize esters of levulinic acid produced during the acid-catalyzed ethanolysis reaction. We wish to develop uses for levulinate esters that allow their marketing at prices comparable to inexpensive polymer intermediates. These prices will allow a sufficient rate of return to justify building plants for utilizing the waste lignocellulosics. If need is demonstrated for purified levulinate, the initial plant design work may be adequate, at least until further pilot-scale work on the process is performed.

  16. CONVERSION OF LIGNOCELLULOSIC MATERIAL TO CHEMICALS AND FUELS; TOPICAL

    International Nuclear Information System (INIS)

    A direct conversion of cellulosic wastes, including resin-bonded furniture and building waste, to levulinate esters is being investigated with the view to producing fuels, solvents, and chemical intermediates as well as other useful by-products in an inexpensive process. The acid-catalyzed reaction of cellulosic materials with ethanol or methanol at 200 C gives good yields of levulinate and formate esters, as well as useful by-products, such as a solid residue (charcoal) and a resinous lignin residue. An initial plant design showed reasonable rates of return for production of purified ethyl levulinate and by-products. In this project, investigations have been performed to identify and develop reactions that utilize esters of levulinic acid produced during the acid-catalyzed ethanolysis reaction. We wish to develop uses for levulinate esters that allow their marketing at prices comparable to inexpensive polymer intermediates. These prices will allow a sufficient rate of return to justify building plants for utilizing the waste lignocellulosics. If need is demonstrated for purified levulinate, the initial plant design work may be adequate, at least until further pilot-scale work on the process is performed

  17. Chemical Processing and Characterization of Fiber Reinforced Nanocomposite Silica Materials

    Science.gov (United States)

    Burnett, Steven Shannon

    Ultrasound techniques, acoustic and electroacoustic spectroscopy, are used to investigate and characterize concentrated fluid phase nanocomposites. In particular, the data obtained from ultrasound methods are used as tools to improve the understanding of the fundamental process chemistry of concentrated, multicomponent, nanomaterial dispersions. Silicon nitride nanofibers embedded in silica are particularly interesting for lightweight nanocomposites, because silicon nitride is isostructural to carbon nitride, a super hard material. However, the major challenge with processing these composites is retarding particle-particle aggregation, to maintain highly dispersed systems. Therefore, a systematic approach was developed to evaluate the affect of process parameters on particle-particle aggregation, and improving the chemical kinetics for gelation. From the acoustic analysis of the nanofibers, this thesis was able to deduce that changes in aspect ratio affects the ultrasound propagation. In particular, higher aspect ratio fibers attenuate the ultrasound wave greater than lower aspect fibers of the same material. Furthermore, our results confirm that changes in attenuation depend on the hydrodynamical interactions between particles, the aspect ratio, and the morphology of the dispersant. The results indicate that the attenuation is greater for fumed silica due to its elastic nature and its size, when compared to silica Ludox. Namely, the larger the size, the greater the attenuation. This attenuation is mostly the result of scattering loss in the higher frequency range. In addition, the silica nanofibers exhibit greater attenuation than their nanoparticle counterparts because of their aspect ratio influences their interaction with the ultrasound wave. In addition, this study observed how 3M NH 4 Cl's acoustic properties changes during the gelation process, and during that change, the frequency dependency deviates from the expected squared of the frequency, until the

  18. All-Russia conference on chemical analysis of substances and materials. Abstracts of reports

    International Nuclear Information System (INIS)

    Collection contains abstracts of reports on chemical analysis of foods, drugs, environmental materials. Methods of chemical analysis used in such regions as chemical control in agriculture, criminology, art and archaeology, biotechnology, geology, chemistry and petrochemistry, metallurgy, metrology are presented. Theoretical, methodological and applied aspects of chemical analysis are considered

  19. Design of improved heat resistant materials by use of computational thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schaffernak, B.; Cerjak, H. [Graz University of Technology Institute for Materials Science, Welding and Forming, Graz (Austria)

    2001-07-01

    Ferritic-martensitic steels are widely used for high temperature applications. Compared with austenitic materials they own a better thermal conductivity, lower thermal expansion coefficient, lower costs and a better resistance against stress corrosion cracking. In this contribution the modelling of the microstructure based on thermodynamic calculations has been used for the description and further alloy design for this steel group. The results are phase diagrams showing the precipitates to be expected as well as driving forces, phase compositions and diffusion coefficients as base for further modelling activities. A calculation model based on the determination of the (calculated) transformation temperatures A{sub e1}, and A{sub e3}; and the diffusion coefficients is proposed, which can help to predict the microstructural stability and the creep strength from the chemical composition. Based on this model test melts for some new alloys has been produced. First creep tests of these alloys confirm the presented approach. (orig.)

  20. Nondestructive evaluation of composite materials by electrical resistance measurement

    Science.gov (United States)

    Mei, Zhen

    This dissertation investigates electrical resistance measurement for nondestructive evaluation of carbon fiber (CF) reinforced polymer matrix composites. The method involves measuring the DC electrical resistance in either the longitudinal or through thickness direction. The thermal history and thermal properties of thermoplastic/CF composites were studied by longitudinal and through-thickness resistance measurements. The resistance results were consistent with differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) results. The resistance measurements gave more information on the melting of the polymer matrix than TMA. They were more sensitive to the glass transition of the polymer matrix than DSC. The through-thickness resistance decreased as autohesion progressed. The activation energy of autohesion was 21.2 kJ/mol for both nylon-6 and polyphenylene sulfide (PPS)/CF composites. Adhesive bonding and debonding were monitored in real-time by measurement of the through-thickness resistance between the adherends in an adhesive joint during heating and subsequent cooling. Debonding occurred during cooling when the pressure or temperature during prior bonding was not sufficiently high. A long heating time below the melting temperature (T m) was found to be detrimental to subsequent PPS adhesive joint development above Tm, due to curing reactions below Tm and consequent reduced mass flow response above Tm. A high heating rate (small heating time) enhanced the bonding more than a high pressure. The longitudinal resistance measurement was used to investigate the effects of temperature and stress on the interface between a concrete substrate and its epoxy/CF composite retrofit. The resistance of the retrofit was increased by bond degradation, whether the degradation was due to heat or stress. The degradation was reversible. Irreversible disturbance in the fiber arrangement occurred slightly as thermal or load cycling occurred, as indicated by the

  1. Electrical properties of materials for elevated temperature resistance strain gage application. Ph.D. Thesis

    International Nuclear Information System (INIS)

    The objective was to study the electrical resistances of materials that are potentially useful as resistance strain gages at 1000 C. Transition metal carbides and nitrides, boron carbide and silicon carbide were selected for the experimental phase of this research. Due to their low temperature coefficient of resistance and good stability, TiC, ZrC, B sub 4 C and beta-SiC are suggested as good candidates for high temperature resistance strain gage applications

  2. Improvement on Corrosion Resistance of Zirconia-Graphite Material for Powder Line of SEN

    Institute of Scientific and Technical Information of China (English)

    LI Hongxia; YANG Bin; YANG Jinsong; LIU Guoqi

    2003-01-01

    The influence of anti-oxidation additions and microstructure characters off used zirconia raw materials on the corrosion resistance of ZrO2-C were studied. The results show that BN addition can enhance the corrosion resistance of ZrO2-C due to the prevention of graphite oxidation,and zirconia raw material with good crystallization and densification will give better corrosion resistance by restrain the reaction between slag and zirconia.

  3. ZrO2 thin films to improve the chemical resistance of calcium matt glazes

    International Nuclear Information System (INIS)

    The chemical resistance of ceramic glazes susceptible to it, and more specifically the glazes formulated with a calcium matt frit, is enhanced by depositing on the surface a thin layer of zirconium oxide. A stabilized zirconia sol is the precursor of the layer, which is deposited by spray painting over the glaze, and with a mild heat treatment (Tmax ∼∼ 400 degree centigrade) is transformed into ZrO2 and anchored to the glazes surface. Chemical resistance tests show that the protected glaze does not suffer a visually significant attack by concentrated hydrochloric acid, conditions under which the same glaze without the coating is severely damaged. The used precursor generates a zirconium oxide layer that protects the underlying glaze, so that the chemical attack by the hydrochloric acid is confined to cracks and discontinuities in the deposited layer. (Author) 22 refs.

  4. Deposition of TiC film on titanium for abrasion resistant implant material by ion-enhanced triode plasma CVD

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Yuhe, E-mail: zyh1120@hotmail.co.jp [School of Stomatology, China Medical University, Shen Yang (China); Wang Wei; Jia Xingya [School of Stomatology, China Medical University, Shen Yang (China); Akasaka, Tsukasa [Department of Health Science, School of Dental Medicine Hokkaido University, Sapporo (Japan); Liao, Susan [School of Materials Science and Engineering, Nanyang Technological University (Singapore); Watari, Fumio [Department of Health Science, School of Dental Medicine Hokkaido University, Sapporo (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Deposition of Titanium Carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method. Black-Right-Pointing-Pointer The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance. Black-Right-Pointing-Pointer Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. - Abstract: Deposition of titanium carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method using a TiCl{sub 4} + CH{sub 4} + H{sub 2} gas mixture. Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. X-ray diffraction (XRD) showed that the specimen was consisted of TiC and Ti. Carbide layer of about 6 {mu}m thickness was observed on the cross section of the specimen by scanning electron microscopy (SEM). The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance.

  5. Deposition of TiC film on titanium for abrasion resistant implant material by ion-enhanced triode plasma CVD

    International Nuclear Information System (INIS)

    Highlights: ► Deposition of Titanium Carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method. ► The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance. ► Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. - Abstract: Deposition of titanium carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method using a TiCl4 + CH4 + H2 gas mixture. Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. X-ray diffraction (XRD) showed that the specimen was consisted of TiC and Ti. Carbide layer of about 6 μm thickness was observed on the cross section of the specimen by scanning electron microscopy (SEM). The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance.

  6. Development of resistance to chemical disinfection by Pseudomonas aeruginosa during long-term space flight

    Science.gov (United States)

    Marchin, George L.

    1999-01-01

    Two long-term experiments have been conducted aboard the Mir Space Station to evaluate the development of resistance by Pseudomonas aeruginosa to chemical disinfection by polyiodide quaternary ammonium strong base resin disinfectants. The first preliminary experiment was launched aboard STS 79 and a second more extensive experiment aboard STS 86. During both experiments, after two months in a microgravity environment, aqueous suspensions of P. aeruginosa contained viable bacteria after having the iodinated resin added to them. In the second experiment identical ground based controls did not exhibit a similar phenomenon. Also in the second experiment, individual colonies from the surviving bacteria were evaluated for resistance to aqueous iodine disinfection. Compared to individual colonies from the original inoculum no resistance was observed. The data are consistent with slow development of a resistant biofilm in the bacterial suspensions flown aboard the Mir Space Station.

  7. Environmental Cracking of Corrosion Resistant Alloys in the Chemical Process Industry - A Review

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B

    2006-12-04

    A large variety of corrosion resistant alloys are used regularly in the chemical process industry (CPI). The most common family of alloys include the iron (Fe)-based stainless steels, nickel (Ni) alloys and titanium (Ti) alloys. There also other corrosion resistant alloys but their family of alloys is not as large as for the three groups mentioned above. All ranges of corrosive environments can be found in the CPI, from caustic solutions to hot acidic environments, from highly reducing to highly oxidizing. Stainless steels are ubiquitous since numerous types of stainless steels exist, each type tailored for specific applications. In general, stainless steels suffer stress corrosion cracking (SCC) in hot chloride environments while high Ni alloys are practically immune to this type of attack. High nickel alloys are also resistant to caustic cracking. Ti alloys find application in highly oxidizing solutions. Solutions containing fluoride ions, especially acid, seem to be aggressive to almost all corrosion resistant alloys.

  8. Chemical Evolution of Interstellar Dust into Planetary Materials

    Science.gov (United States)

    Fomenkova, M. N.; Chang, S.; DeVincenzi, Donald L. (Technical Monitor)

    1995-01-01

    Comets are believed to retain some interstellar materials, stored in fairly pristine conditions since-their formation. The composition and properties of cometary dust grains should reflect those of grains in the outer part of the protosolar nebula which, at least in part, were inherited from the presolar molecular cloud. However, infrared emission features in comets differ from their interstellar counterparts. These differences imply processing of interstellar material on its way to incorporation in comets, but C and N appear to be retained. Overall dust evolution from the interstellar medium (ISM) to planetary materials is accompanied by an increase in proportion of complex organics and a decrease in pure carbon phases. The composition of cometary dust grains was measured in situ during fly-by missions to comet Halley in 1986. The mass spectra of about 5000 cometary dust grains with masses of 5 x 10(exp -17) - 5 x 10(exp -12) g provide data about the presence and relative abundances of the major elements H, C, N, O,Na, Mg, Al, Si, S, Cl, K, Ca, Ti, Cr, Fe, Ni. The bulk abundances of major rock-forming elements integrated over all spectra were found to be solar within a factor of 2, while the volatile elements H, C, N, O in dust are depleted in respect to their total cosmic abundances. The abundances of C and N in comet dust are much closer to interstellar than to meteoritic and are higher than those of dust in the diffuse ISM. In dense molecular clouds dust grains are covered by icy mantles, the average composition of which is estimated to be H:C:N:O = 96:14:1:34. Up to 40% of elemental C and O may be sequestered in mantles. If we use this upper limit to add H, C, N and O as icy mantle material to the abundances residing in dust in the diffuse ISM, then the resulting values for H. C, and N match cometary abundances. Thus, ice mantles undergoing chemical evolution on grains in the dense ISM appear to have been transformed into less volatile and more complex organic

  9. Development status of EUV resist materials and processing at Selete

    Science.gov (United States)

    Matsunaga, Kentaro; Shiraishi, Gousuke; Santillian, Julius Joseph; Kaneyama, Koji; Oizumi, Hiroaki; Itani, Toshiro

    2011-04-01

    The Selete R&D program evaluates the feasibility of the Extreme ultraviolet (EUV) lithography process for manufacturing semiconductor devices. We therefore conducted a yield analysis of hp-2x-nm test chips by using the EUV1 (Nikon) full-field exposure tool. However, the resist performance did not comply with the stringent requirements of ultimate resolution, sensitivity, and line-width roughness. We subsequently reported two new Selete standard resists (SSRs), i.e., SSR6 and SSR7. SSR6 is the polymer resist used in hp-2x-nm test chip evaluation in which an ultimate resolution of 22 nm line-and-space (L/S) pattern was achieved. SSR7 is the first molecular resist that was evaluated for feasibility at Selete. SSR7 is a fullerene based resist with strong etching durability. By using this resist, an ultimate resolution of 24 nm L/S pattern was achieved. We have also evaluated resist processing by using SSRs for hp-2x-nm test chip evaluation. An ultrathin underlayer was evaluated for the improvement of pattern transferability. This optimized ultrathin underlayer was coated on the test chip substrate that was devoid of nano-sized-pinholes, and a fine pattern was observed on this ultrathin underlayer. In the evaluation of the development process, SSRs were evaluated with tetramethylammonium hydroxide (TMAH) and tetrabutylammonium hydroxide (TBAH) developer solutions. In summary, it was clear that the lithographic performance improvement varies depending on the type of polymer resist used with a particular developer solution. Furthermore, a significant improvement in the prevention of pattern collapse was demonstrated using a combination of the TBAH developer solution and alternative rinse solutions.

  10. Determination of residual monomers resulting from the chemical polymerization process of dental materials

    Energy Technology Data Exchange (ETDEWEB)

    Boboia, S. [Babes Bolyai University, Raluca Ripan Chemistry Research Institute, Department of Polymer Composites, 400294 Cluj-Napoca, Romania and Technical University of Cluj-Napoca, Physics and Chemistry Department, 400114 Cluj-Napoca (Romania); Moldovan, M. [Babes Bolyai University, Raluca Ripan Chemistry Research Institute, Department of Polymer Composites, 400294 Cluj-Napoca (Romania); Ardelean, I. [Technical University of Cluj-Napoca, Physics and Chemistry Department, 400114 Cluj-Napoca (Romania)

    2013-11-13

    The residual monomer present in post-polymerized dental materials encourages premature degradation of the reconstructed tooth. That is why the residual monomer should be quantified in a simple, fast, accurate and reproducible manner. In our work we propose such an approach for accurate determination of the residual monomer in dental materials which is based on low-field nuclear magnetic resonance (NMR) relaxometry. The results of the NMR approach are compared with those of the high performance liquid chromatography (HPLC) technique. The samples under study contain the main monomers (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane and triethylene glycol dimethacrylate) constituting the liquid phase of most dental materials and an initiator. Two samples were analyzed with different ratios of chemical initiation systems: N,N-dimethyl-p-toluide: benzoyl peroxide (1:2 and 0.7:1.2). The results obtained by both techniques highlight that by reducing the initiator the polymerization process slows down and the amount of residual monomer reduces. This prevents the premature degradation of the dental fillings and consequently the reduction of the biomaterial resistance.

  11. Determination of residual monomers resulting from the chemical polymerization process of dental materials

    International Nuclear Information System (INIS)

    The residual monomer present in post-polymerized dental materials encourages premature degradation of the reconstructed tooth. That is why the residual monomer should be quantified in a simple, fast, accurate and reproducible manner. In our work we propose such an approach for accurate determination of the residual monomer in dental materials which is based on low-field nuclear magnetic resonance (NMR) relaxometry. The results of the NMR approach are compared with those of the high performance liquid chromatography (HPLC) technique. The samples under study contain the main monomers (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane and triethylene glycol dimethacrylate) constituting the liquid phase of most dental materials and an initiator. Two samples were analyzed with different ratios of chemical initiation systems: N,N-dimethyl-p-toluide: benzoyl peroxide (1:2 and 0.7:1.2). The results obtained by both techniques highlight that by reducing the initiator the polymerization process slows down and the amount of residual monomer reduces. This prevents the premature degradation of the dental fillings and consequently the reduction of the biomaterial resistance

  12. Beverton-Holt discrete pest management models with pulsed chemical control and evolution of pesticide resistance

    Science.gov (United States)

    Liang, Juhua; Tang, Sanyi; Cheke, Robert A.

    2016-07-01

    Pest resistance to pesticides is usually managed by switching between different types of pesticides. The optimal switching time, which depends on the dynamics of the pest population and on the evolution of the pesticide resistance, is critical. Here we address how the dynamic complexity of the pest population, the development of resistance and the spraying frequency of pulsed chemical control affect optimal switching strategies given different control aims. To do this, we developed novel discrete pest population growth models with both impulsive chemical control and the evolution of pesticide resistance. Strong and weak threshold conditions which guarantee the extinction of the pest population, based on the threshold values of the analytical formula for the optimal switching time, were derived. Further, we addressed switching strategies in the light of chosen economic injury levels. Moreover, the effects of the complex dynamical behaviour of the pest population on the pesticide switching times were also studied. The pesticide application period, the evolution of pesticide resistance and the dynamic complexity of the pest population may result in complex outbreak patterns, with consequent effects on the pesticide switching strategies.

  13. Comparative study on the materials of resistance to spall in the asphalt pavement

    Directory of Open Access Journals (Sweden)

    Wu Dengrui

    2015-04-01

    Full Text Available Water damage phenomenon is widespread in our country, especially in southern rainy regions. This article adopts the method of indoor experimental comparison to study on road performance of a variety of spalling resistance material, like cement、quick lime、hydrated lime、amine、no-amine. The results found that: the comprehensive performance of quick lime as the spalling resistance material is better than other materials on the performance of overall road.

  14. Comparison of the fracture resistance of reattached incisor tooth fragments using 4 different materials

    OpenAIRE

    R Singhal; Pathak, A.

    2012-01-01

    Aim: To evaluate and compare the fracture resistance of reattached teeth using four different materials. Materials and Methods: 150 extracted human permanent maxillary incisors were randomly divided into five groups of 30 teeth each of one control and four experimental groups. Teeth in experimental groups were sectioned 2.5 mm from incisal edge and reattached using four different materials. The reattached teeth were subjected to evaluate fracture resistance. Results: The mean fracture resista...

  15. IBM-JSR 193-nm negative tone resist: polymer design, material properties, and lithographic performance

    Science.gov (United States)

    Patel, Kaushal S.; Lawson, Margaret C.; Varanasi, Pushkara Rao; Medeiros, David R.; Wallraff, Gregory M.; Brock, Phillip J.; DiPietro, Richard A.; Nishimura, Yukio; Chiba, Takashi; Slezak, Mark

    2004-05-01

    It has been previously proposed that negative-tone resist process would have an intrinsic advantage for printing narrow trench geometry. To demonstrate this for 193nm lithography, a negative resist with performance comparable to a leading positive resist is required. In this paper we report the joint development of a hexafluoroalcohol containing, 193nm, negative-tone, chemically amplified resist based on the crosslinking approach. Lithographic performance is presented which includes the ability of the negative-tone resist to print 90nm line/space and isolated trenches with standard resist processing. The impact of the fluorinated polymer on etch performance is also quantified. Finally, key resist characteristics and their influence on performance and limiting factors such as microbridging are discussed.

  16. Self-Decontaminating Fibrous Materials Reactive toward Chemical Threats.

    Science.gov (United States)

    Bromberg, Lev; Su, Xiao; Martis, Vladimir; Zhang, Yunfei; Hatton, T Alan

    2016-07-13

    Polymers that possess highly nucleophilic pyrrolidinopyridine (Pyr) and primary amino (vinylamine, VAm) groups were prepared by free-radical copolymerization of N,N-diallylpyridin-4-amine (DAAP) and N-vinylformamide (NVF) followed by acidic hydrolysis of NVF into VAm. The resulting poly(DAAP-co-VAm-co-NVF) copolymers were water-soluble and reacted with water-dispersible polyurethane possessing a high content of unreacted isocyanate groups. Spray-coating of the nylon-cotton (NYCO), rayon, and poly(p-phenylene terephthalamide) (Kevlar 119) fibers pretreated with phosphoric acid resulted in covalent bonding of the polyurethane with the hydroxyl groups on the fiber surface. A second spray-coating of aqueous solutions of poly(DAAP-co-VAm-co-NVF) on the polyurethane-coated fiber enabled formation of urea linkages between unreacted isocyanate groups of the polyurethane layer and the amino groups of poly(DAAP-co-VAm-co-NVF). Fibers with poly(DAAP-co-VAm-co-NVF) attached were compared with fibers modified by adsorption of water-insoluble poly(butadiene-co-pyrrolidinopyridine) (polyBPP) in terms of the stability against polymer leaching in aqueous washing applications. While the fibers modified by attachment of poly(DAAP-co-VAm-co-NVF) exhibited negligible polymer leaching, over 65% of adsorbed polyBPP detached and leached from the fibers within 7 days. Rayon fibers modified by poly(DAAP-co-VAm-co-NVF) were tested for sorption of dimethyl methylphosphonate (DMMP) in the presence of moisture using dynamic vapor sorption technique. Capability of the fibers modified with poly(DAAP-co-VAm-co-NVF) to facilitate hydrolysis of the sorbed DMMP in the presence of moisture was uncovered. The self-decontaminating property of the modified fibers against chemical threats was tested using a CWA simulant diisopropylfluorophosphate (DFP) in aqueous media at pH 8.7. Fibers modified with poly(DAAP-co-VAm-co-NVF) facilitated hydrolysis of DFP with the half-lives up to an order of magnitude

  17. Chemicals in the process chain from raw material to product

    International Nuclear Information System (INIS)

    As described in this presentation, chemicals are added at various points along the physical flow from oil/gas well to sold products. They have several functions and are added in different amounts. The chemicals may have a negative impact on the environment by emission to sea. But they can also reduce the regularity of the processing equipment and the prices of the products. Therefore, Statoil has begun a research project that aims to develop improved methods and tools for the prediction of the distribution of chemicals in the process chain and the unwanted effects they might have on the environment, on downstream installations and on the products. 4 refs., 11 figs

  18. Awareness of toxic chemicals in entertainment and educational materials

    Directory of Open Access Journals (Sweden)

    Fontalvo-Rivera Dilia

    2012-06-01

    Full Text Available Introduction: security offered by the materials used to manufacture some tools forrecreational activities and/or educational assistance may not have been adequatelycontrolled. Some of the substances most frequently involved are heavy metals like leadand cadmium in toys made out of polyvinyl chloride (PVC also known as vinyl.Objective: to perform a review of potential toxicity generated by toys and educationalmaterials, and raise awareness among health professionals in order to promote clinicalsuspicion of intoxication due to use of toys and school supplies.Methodology: review articles, case reports and consensus about the relationshipbetween chemicals in toys and educational materials with toxic pathologies, involvingpediatric patients of both sexes, were evaluated. Electronic search was conducted inRIMA database, MEDLINE, PubMed and MESCAPE from 2003 to 2009. A newspapersearch also was made.Results: we found 78 publications, including regular news websites. Thirty one met theinclusion criteria and all were taken into consideration. The substances most frequentlyinvolved with toxicity were lead, cadmium, phthalates and bronze, which have beenassociated with subtle manifestations or potentially severe disorders. There is acommunity alarm about the way products for children are manufactured and dispensed.Conclusions: there are toxic elements in recreational and educational materialsfor children; therefore adequate quality control is necessary. Children´s health careprograms should promote awareness among community to prevent potential risks.RESUMEN:Introducción: la seguridad ofrecida por los materiales usados para la fabricación dealgunas herramientas destinadas a actividades lúdicas y/o asistencia educativa, puedeque no se controlen adecuadamente. Algunas de las sustancias más frecuentementeimplicadas son los metales pesados como el plomo y el cadmio, presentes en losjuguetes a través del policloruro de vinilo (PVC también denominado

  19. Influence of chemical composition on volume resistivity of alumina and zirconia plasma deposits

    Czech Academy of Sciences Publication Activity Database

    Ctibor, Pavel; Sedláček, J.

    Bratislava: FCHPT STU Bratislava, 2001 - (Koman, M.; Mikloš, D.). s. 23-24 ISBN 80-85330-90-3. [Development of Materials Science in Research and Education /11./. 09.09.2001-13.09.2001, Kežmarské Žlaby] Institutional research plan: CEZ:AV0Z2043910 Keywords : alumina, plasma Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  20. Effects of industrial chemicals and radioactive materials in biological systems

    International Nuclear Information System (INIS)

    Much has been written on the effects of radiation and toxic chemicals on biological systems. In this communication general considerations regarding these topics will be discussed very briefly; the major emphasis will be focused on the effects of chemicals, namely ethyl methane sulfonate (EMS) on Amoeba, Advantages to the use of amoeba for studying the effects of radiation and chemicals include the following: large mononucleate unicellular organisms having a long generation time; opportunity to study cellular organelles and biochemical and genetic alterations in a single cell system; and a long cell cycle, the stages of which can be synchronized without resorting to chemical treatment or temperature shock and thereby readily permitting study at defined stages of the cell's life cycle. This, in turn, is discussed in light of current disposal methods for this type of waste and how it might be safely disposed of

  1. A study on light-aging resistance of instrument panel materials and bumper materials on the automobile

    Institute of Scientific and Technical Information of China (English)

    Wang Wentao; Liu Qiang; Li Li; Li Huilian

    2014-01-01

    The light-aging test method commonly used in the automotive industry is utilized to carry out light-aging research on automotive instrument panel (IP) materials and bumper materials. On one hand,the impacts of common light-aging test methods on aging degree of automotive component materials are reviewed;on the other hand,the light-aging resistances of different component materials are compared. The results show that, for light-aging behavior of IP materials,the aging degree of the third test method is not severer than that of the second method,but it is severer than that of the first method. The light-aging resistance of IP material A is al-most the same as that of IP material B. With reference to light-aging behavior of bumper materials,the aging de-gree of three common test methods indicates that the aging degree of the sixth test method is not severer than that of the fourth method,but it is severer than that of the fifth method. The light-aging resistance of bumper material D is superior to that of bumper material C.

  2. A study on light-aging resistance of instrument panel materials and bumper materials on the automobile

    Institute of Scientific and Technical Information of China (English)

    Wang Wentao; Liu Qiang; Li Li; Li Huilian

    2014-01-01

    The light-aging test method commonly used in the automotive industry is utilized to carry out light- aging research on automotive instrument panel (IP) materials and bumper materials. On one hand, the impacts of common light-aging test methods on aging degree of automotive component materials are reviewed; on the other hand, the light-aging resistances of different component materials are compared. The results show that, for light-aging behavior of IP materials, the aging degree of the third test method is not severer than that of the second method, but it is severer than that of the first method. The light-aging resistance of IP material A is al- most the same as that of IP material B. With reference to light-aging behavior of bumper materials, the aging de- gree of three common test methods indicates that the aging degree of the sixth test method is not severer than that of the fourth method, but it is severer than that of the fifth method. The light-aging resistance of bumper material D is superior to that of bumper material C.

  3. Establishment and Application of a Set of Material System for Studying the Resistance to Blast in Rice

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-fang; LUO Wen-yong; XIAO Xin; MAO Xing-xue; LIU Yan-zhuo

    2003-01-01

    The study used Waixuan35, a blast resistant rice material adopted widely previously in South China, Yuexiangzhan, a rice variety with the largest planting area in Guangdong Province at present and with the characteristics of horizontal blast resistance and high harvest index, and Qisizhan, the earliest good eating quality variety in Guangdong Province as parent materials, and created an important material systems for studying agricultural characters such as rice blast resistance genes, their resistance mechanisms and quality by hybridization offspring single grain transfer method and DNA hybridization method, namely recombination inbred line RIL, extend recombination inbred line ERIL and transferred-mutant recombination inbred line TRIL assemblages. In RIL assemblage, various materials of resistance gene combinations for identifying rice blast pathogen strains had been identified from the material system, providing direct material evidence for gene to gene theory. Using the same control and same method, in ERIL assemblage, it was proved that there were several main resistance genes and several minor resistance genes in horizontal resistant Yuexiangzhan,providing preliminary evidences for multigene control in horizontal resistance. A set of stable material assemblage for studying future horizontal resistance had been created. A mutation material of Yuexiangzhan from horizontal resistance to vertical resistance was obtained by wild rice external DNA electric stimulation introduction, and variation in mutation assemblage was certified by SSLP. These studies and materials provided important new materials for studying rice blast resistance mechanisms, gene cloning, resistance genes especially horizontal resistance.

  4. Electromechanical Behavior of Chemically Reduced Graphene Oxide and Multi-walled Carbon Nanotube Hybrid Material.

    Science.gov (United States)

    Benchirouf, Abderrahmane; Müller, Christian; Kanoun, Olfa

    2016-12-01

    In this paper, we propose strain-sensitive thin films based on chemically reduced graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) without adding any further surfactants. In spite of the insulating properties of the thin-film-based GO due to the presence functional groups such as hydroxyl, epoxy, and carbonyl groups in its atomic structure, a significant enhancement of the film conductivity was reached by chemical reduction with hydro-iodic acid. By optimizing the MWCNT content, a significant improvement of electrical and mechanical thin film sensitivity is realized. The optical properties and the morphology of the prepared thin films were studied using ultraviolet-visible spectroscopy (UV-Vis) and scanning electron microscope (SEM). The UV-Vis spectra showed the ability to tune the band gap of the GO by changing the MWCNT content, whereas the SEM indicated that the MWCNTs were well dissolved and coated by the GO. Investigations of the piezoresistive properties of the hybrid nanocomposite material under mechanical load show a linear trend between the electrical resistance and the applied strain. A relatively high gauge factor of 8.5 is reached compared to the commercial metallic strain gauges. The self-assembled hybrid films exhibit outstanding properties in electric conductivity, mechanical strength, and strain sensitivity, which provide a high potential for use in strain-sensing applications. PMID:26732277

  5. Electromechanical Behavior of Chemically Reduced Graphene Oxide and Multi-walled Carbon Nanotube Hybrid Material

    Science.gov (United States)

    Benchirouf, Abderrahmane; Müller, Christian; Kanoun, Olfa

    2016-01-01

    In this paper, we propose strain-sensitive thin films based on chemically reduced graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) without adding any further surfactants. In spite of the insulating properties of the thin-film-based GO due to the presence functional groups such as hydroxyl, epoxy, and carbonyl groups in its atomic structure, a significant enhancement of the film conductivity was reached by chemical reduction with hydro-iodic acid. By optimizing the MWCNT content, a significant improvement of electrical and mechanical thin film sensitivity is realized. The optical properties and the morphology of the prepared thin films were studied using ultraviolet-visible spectroscopy (UV-Vis) and scanning electron microscope (SEM). The UV-Vis spectra showed the ability to tune the band gap of the GO by changing the MWCNT content, whereas the SEM indicated that the MWCNTs were well dissolved and coated by the GO. Investigations of the piezoresistive properties of the hybrid nanocomposite material under mechanical load show a linear trend between the electrical resistance and the applied strain. A relatively high gauge factor of 8.5 is reached compared to the commercial metallic strain gauges. The self-assembled hybrid films exhibit outstanding properties in electric conductivity, mechanical strength, and strain sensitivity, which provide a high potential for use in strain-sensing applications.

  6. Onium salts as radiation-sensitive acid generators for resists with chemical amplification (review)

    International Nuclear Information System (INIS)

    The necessity of mastering alternative lithographic processes for development and production of 64 and 256 Mbit dynamic random-access memory units has been substantiated. It is shown that conventional positive photoresists based on diazonaphthoquinone and novalac resins do not meet the requirements of modern microlithography. The concept of chemical amplification offered a means for developing adequate topological structures with sizes of resist components of 0.35 μm or less. Onium salts are universal and efficient acid generators for resists with chemical amplification. Studies in the field of photo- and radiochemistry of onium salts have been summarized and correlated. It has been shown that the quantum yield and distribution of photolysis products are governed to a major extent by geminal and bulk recombination. Specific features of photolysis and radiolysis of onium salts in a polymer matrix are considered

  7. Study on dry friction and wear resistance of a WC-Co particle reinforced iron matrix composite material

    OpenAIRE

    Zhang Peng; Zeng Shaolian; Zhang Zhiguo

    2013-01-01

    In order to select a suitable material for the rolling mill guide application, the dry sliding friction and wear resistance of a tungsten carbide combining cobalt (WC-Co) particle reinforced chromium cast iron composite material were studied. In particular, the wear resistance was discussed in detail. The results showed that the composite material demonstrates 25 times the wear resistance of high Cr cast iron, and 9 times the wear resistance of heat resistant steel. However, the average frict...

  8. Compressive Strength, Chloride Permeability, and Freeze-Thaw Resistance of MWNT Concretes under Different Chemical Treatments

    OpenAIRE

    Xingang Wang; Inkyu Rhee; Yao Wang; Yunping Xi

    2014-01-01

    This study investigated compressive strength, chloride penetration, and freeze-thaw resistance of multiwalled carbon nanotube (MWNT) concrete. More than 100 cylindrical specimens were used to assess test variables during sensitivity observations, including water-cement ratios (0.75, 0.5, and 0.4) and exposure to chemical agents (including gum arabic, propanol, ethanol, sodium polyacrylate, methylcellulose, sodium dodecyl sulfate, and silane). To determine the adequate sonication time for MWNT...

  9. Effect of basic additives on sensitivity and diffusion of acid in chemical amplification resists

    Science.gov (United States)

    Asakawa, Koji; Ushirogouchi, Tohru; Nakase, Makoto

    1995-06-01

    The effect of amine additives in chemical amplification resists is discussed. Phenolic amines such as 4-aminophenol and 2-(4-aminophenyl)-2-(4-hydroxyphenyl) propane were investigated as model compounds from the viewpoint of sensitivity, diffusion and resolution. Equal molar amounts of acid and amine deactivated at the very beginning of post-exposure bake, and could not participate in decomposing the inhibitor as a catalyst. Only the acid which survived from the deactivation diffuses in the resist, decomposing the inhibitors from the middle to late stage of PEB. The basic additives reduce the diffusion range of the acid, especially for long-range diffusion, resulting in higher contrast at the interfaces between the exposed and unexposed areas. In addition, the amine concentration required is found to be less than the concentration which causes the resist sensitivity to start decreasing.

  10. Process techniques for improving post-exposure delay stability in chemically amplified resists

    Science.gov (United States)

    Nour, Sassan; Pavelchek, Edward K.; Lindsay, Tracy K.; Moynihan, Matthew L.; Gambin, Lori

    1997-07-01

    The post-exposure delay (PED) stability of several chemically amplified DUV resists in unfiltered environments is shown to be strongly dependent on the standing wave intensity. The use of a bottom antireflective layer diminishes the rate of CD change for UVIIHSTM, UVIIITM, APEX-E and UV5TM resists by a factor of three or greater. Increasing the post exposure bake to diffuse outstanding waves results in a three to six fold improvement with UVIIHS, UVIII, UV5 and UV6TM. These resists show the greatest stability when soft baked at high temperatures to reduce the diffusion rate of airborne contaminants, and post-exposure baked at high temperatures to diffuse out the standing wave pattern.

  11. A complementary metal oxide semiconductor—integrable conditioning circuit for resistive chemical sensor management

    International Nuclear Information System (INIS)

    This paper presents a new interface circuit (for MOX-based resistive chemical sensors) capable of overcoming the main limit of the circuits based on the resistance-to-time approach, i.e. the long measuring time with high-value resistances. The system is designed to operate with a single supply of 3.3 V, thus facilitating an ASIC implementation together with digital electronics for a first data analysis and transmission. This is particularly advantageous when the elaboration process requires a large computational load and a data pre-elaboration is advisable. Simulations of the integrable solution of the system have shown the feasibility of the proposed approach. A prototype with discrete components has been furthermore fabricated and experimentally tested, showing good performance in the range 0.5 MΩ to 10 GΩ with a maximum measuring time of 60 ms

  12. Reactor choices for chemical looping combustion (CLC) dependencies on materials characteristics

    NARCIS (Netherlands)

    Kimball, E.; Lambert, A.; Fossdal, A.; Leenman, R.N.; Comte, E.; Bos, W.A.P. van den; Blom, R.

    2013-01-01

    The physio-chemical stability of the oxygen carrier material during chemical looping combustion (CLC) operation is crucial. In the present paper we discuss the challenges connected to operating a metal oxide base material in a cyclic manner between oxidizing and reducing atmospheres. Especially, foc

  13. Peculiarities of Enhancing Resistant Starch in Ruminants Using Chemical Methods: Opportunities and Challenges

    Directory of Open Access Journals (Sweden)

    Qendrim Zebeli

    2013-06-01

    Full Text Available High-producing ruminants are fed high amounts of cereal grains, at the expense of dietary fiber, to meet their high energy demands. Grains consist mainly of starch, which is easily degraded in the rumen by microbial glycosidases, providing energy for rapid growth of rumen microbes and short-chain fatty acids (SCFA as the main energy source for the host. Yet, low dietary fiber contents and the rapid accumulation of SCFA lead to rumen disorders in cattle. The chemical processing of grains has become increasingly important to confer their starch resistances against rumen microbial glycosidases, hence generating ruminally resistant starch (RRS. In ruminants, unlike monogastric species, the strategy of enhancing resistant starch is useful, not only in lowering the amount of carbohydrate substrates available for digestion in the upper gut sections, but also in enhancing the net hepatic glucose supply, which can be utilized by the host more efficiently than the hepatic gluconeogenesis of SCFA. The use of chemical methods to enhance the RRS of grains and the feeding of RRS face challenges in the practice; therefore, the present article attempts to summarize the most important achievements in the chemical processing methods used to generate RRS, and review advantages and challenges of feeding RRS to ruminants

  14. Analysis of stochastic effects in chemically amplified poly(4-hydroxystyrene-co-t-butyl methacrylate) resist

    Science.gov (United States)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2016-07-01

    Understanding of stochastic phenomena is essential to the development of a highly sensitive resist for nanofabrication. In this study, we investigated the stochastic effects in a chemically amplified resist consisting of poly(4-hydroxystyrene-co-t-butyl methacrylate), triphenylsulfonium nonafluorobutanesulfonate (acid generator), and tri-n-octylamine (quencher). Scanning electron microscopy (SEM) images of resist patterns were analyzed by Monte Carlo simulation on the basis of the sensitization and reaction mechanisms of chemically amplified extreme ultraviolet resists. It was estimated that a ±0.82σ fluctuation of the number of protected units per polymer molecule led to line edge roughness formation. Here, σ is the standard deviation of the number of protected units per polymer molecule after postexposure baking (PEB). The threshold for the elimination of stochastic bridge generation was 4.38σ (the difference between the average number of protected units after PEB and the dissolution point). The threshold for the elimination of stochastic pinching was 2.16σ.

  15. Overview: Damage resistance of graded ceramic restorative materials

    OpenAIRE

    Zhang, Yu

    2012-01-01

    Improving mechanical response of materials is of great interest in a wide range of disciplines, including biomechanics, tribology, geology, optoelectronics, and nanotechnology. It has been long recognized that spatial gradients in surface composition and structure can improve the mechanical integrity of a material. This review surveys recent results of sliding-contact, flexural, and fatigue tests on graded ceramic materials from our laboratories and elsewhere. Although our findings are examin...

  16. Contact resistance of ceramic interfaces between materials used for solid oxide fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Koch, S.

    2002-01-01

    The contact resistance can be divided into two main contributions. The small area of contact between ceramic components results in resistance due to current constriction. Resistive phases or potential barriers at the interface result in an interface contribution to the contact resistance, which may be smaller or larger than the constriction resistance. The contact resistance between pairs of three different materials were analysed (strontium doped lanthanum manganite, yttria stabilised zirconia and strontium and nickel doped lanthanum cobaltite), and the effects of temperature, atmosphere, polarisation and mechanical load on the contact resistance were investigated. The investigations revealed that the mechanical load of a ceramic contact has a high influence on the contact resistance, and generally power law dependence between the contact resistance and the mechanical load was found. The influence of the mechanical load on the contact resistance was ascribed to an area effect. The contact resistance of the investigated materials was dominated by current constriction at high temperatures. The measured contact resistance was comparable to the resistance calculated on basis of the contact areas found by optical and electron microscopy. At low temperatures, the interface contribution to the contact resistance was dominating. The cobaltite interface could be described by one potential barrier at the contact interface, whereas the manganite interfaces required several consecutive potential barriers to model the observed behaviour. The current-voltage behaviour of the YSZ contact interfaces was only weakly non-linear, and could be described by 22{+-}1 barriers in series. Contact interfaces with sinterable contact layers were also investigated, and the measured contact resistance for these interfaces were more than 10 times less than for the other interfaces. (au)

  17. Chemical digestion of low level nuclear solid waste material

    International Nuclear Information System (INIS)

    A method is described for processing low level, light weight, bulky, combustible nuclear solid waste material comprising the steps of reacting said solid waste material with concentrated sulfuric acid at a temperature within the range of 230 deg - 300 deg C and simultaneously, subsequently, or both simultaneously and subsequently contacting said waste with concentrated nitric acid or nitrogen oxides whereby carbonaceous material is oxidized to gaseous byproducts and a low volume residue. (author)

  18. Chemically modified carbon nanotubes as material enhanced laser desorption ionisation (MELDI) material in protein profiling

    International Nuclear Information System (INIS)

    Biomarkers play a potential role in the early detection and diagnosis of a disease. Our aim is to derivatize carbon nanotubes for exploration of the differences in human body fluids e.g. serum, through matrix assisted laser desorption ionisation/time of flight mass spectrometry (MALDI/TOF-MS) that can be related to disease and subsequently to be employed in the biomarker discovery process. This application we termed as the material enhanced laser desorption ionisation (MELDI). The versatility of this technology is meant to increase the amount of information from biological samples on the protein level, which will have a major impact to serve the cause of diagnostic markers. Serum peptides and proteins are immobilized on derivatized carbon nanotubes, which function as binding material. Protein-loaded suspension is placed on a stainless steel target or buckypaper on aluminum target for direct analysis with MALDI-MS. The elution method to wash the bound proteins from carbon nanotubes was employed to compare with the direct analysis procedure. Elution is carried out by MALDI matrix solution to get them out of the entangled nanotubes, which are difficult to desorb by laser due to the complex nanotube structures. The advantage of these optimized methods compared to the conventional screening methods is the improved sensitivity, selectivity and the short analysis time without prior albumin and immunoglobulin depletion. The comparison of similarly modified diamond and carbon nanotubes exhibit differences in their nature to bind the proteins out of serum due to the differences in their physical characteristics. Infrared (IR) spectroscopy provided hint for the presence of tertiary amine peak at the crucial chemical step of iminodiacetic acid addition to acid chloride functionality on carbon nanotubes. Atomic absorption spectroscopy (AAS) was utilized to quantitatively measure the copper capacity of these derivatized carbon nanotubes which is a direct measure of capacity of

  19. Chemically modified carbon nanotubes as material enhanced laser desorption ionisation (MELDI) material in protein profiling

    Energy Technology Data Exchange (ETDEWEB)

    Najam-ul-Haq, M. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria); Rainer, M. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria); Schwarzenauer, T. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria); Huck, C.W. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria)]. E-mail: christian.w.huck@uibk.ac.at; Bonn, G.K. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria)

    2006-03-02

    Biomarkers play a potential role in the early detection and diagnosis of a disease. Our aim is to derivatize carbon nanotubes for exploration of the differences in human body fluids e.g. serum, through matrix assisted laser desorption ionisation/time of flight mass spectrometry (MALDI/TOF-MS) that can be related to disease and subsequently to be employed in the biomarker discovery process. This application we termed as the material enhanced laser desorption ionisation (MELDI). The versatility of this technology is meant to increase the amount of information from biological samples on the protein level, which will have a major impact to serve the cause of diagnostic markers. Serum peptides and proteins are immobilized on derivatized carbon nanotubes, which function as binding material. Protein-loaded suspension is placed on a stainless steel target or buckypaper on aluminum target for direct analysis with MALDI-MS. The elution method to wash the bound proteins from carbon nanotubes was employed to compare with the direct analysis procedure. Elution is carried out by MALDI matrix solution to get them out of the entangled nanotubes, which are difficult to desorb by laser due to the complex nanotube structures. The advantage of these optimized methods compared to the conventional screening methods is the improved sensitivity, selectivity and the short analysis time without prior albumin and immunoglobulin depletion. The comparison of similarly modified diamond and carbon nanotubes exhibit differences in their nature to bind the proteins out of serum due to the differences in their physical characteristics. Infrared (IR) spectroscopy provided hint for the presence of tertiary amine peak at the crucial chemical step of iminodiacetic acid addition to acid chloride functionality on carbon nanotubes. Atomic absorption spectroscopy (AAS) was utilized to quantitatively measure the copper capacity of these derivatized carbon nanotubes which is a direct measure of capacity of

  20. A Schematic Method for Sustainable Material Selection of Toxic Chemicals in Design and Manufacturing

    OpenAIRE

    Yuan, Chris Yingchun; David Dornfeld

    2010-01-01

    Toxic chemicals used in product design and manufacturing are grave concerns due to their toxic impact on human health. Implementing sustainable material selection strategies on toxic chemicals can substantially improve the sustainability of products in both design and manufacturing processes. In this paper, a schematic method is presented for characterizing and benchmarking the human health impact of toxic chemicals, as a visual aid to facilitate decision-making in the material selection proc...

  1. Substantiation of an express-method for determining the freeze-thaw resistance of cellular materials

    OpenAIRE

    S.G. Nikolskiy; O.N. Pertseva; V.I. Ivanova

    2015-01-01

    An express method for determining the freeze-thaw resistance of cellular materials was offered and substantiated in this article. The proposed measurement technology of concrete frost resistance is based on the computation of the value z which is the ratio of the relative decrease of compression resistance R to the relative permanent set ε in the direction which is perpendicular to the pressure. It was found that this ratio is constant for a given composition of the concrete and does not depe...

  2. Wear and abrasion resistance selection maps of biological materials.

    Science.gov (United States)

    Amini, Shahrouz; Miserez, Ali

    2013-08-01

    The mechanical design of biological materials has generated widespread interest in recent years, providing many insights into their intriguing structure-property relationships. A critical characteristic of load-bearing materials, which is central to the survival of many species, is their wear and abrasion tolerance. In order to be fully functional, protective armors, dentitious structures and dynamic appendages must be able to tolerate repetitive contact loads without significant loss of materials or internal damage. However, very little is known about this tribological performance. Using a contact mechanics framework, we have constructed materials selection charts that provide general predictions about the wear performance of biological materials as a function of their fundamental mechanical properties. One key assumption in constructing these selection charts is that abrasion tolerance is governed by the first irreversible damage at the contact point. The maps were generated using comprehensive data from the literature and encompass a wide range of materials, from heavily mineralized to fully organic materials. Our analysis shows that the tolerance of biological materials against abrasion depends on contact geometry, which is ultimately correlated to environmental and selective pressures. Comparisons with experimental data from nanoindentation experiments are also drawn in order to verify our predictions. With the increasing amount of data available for biological materials also comes the challenge of selecting relevant model systems for bioinspired materials engineering. We suggest that these maps will be able to guide this selection by providing an overview of biological materials that are predicted to exhibit the best abrasion tolerance, which is of fundamental interest for a wide range of applications, for instance in restorative implants and protective devices. PMID:23643608

  3. A new material for chemical industry - wood polymer composites

    International Nuclear Information System (INIS)

    The paper outlines the advantages of the radiation cured wood-polymer composites (WPC) for application in certain critical areas of chemical industry. The wood-polymer composite made filterpress frames and plates were tested in a chemical plant. The entire exercise is elaborated. The radiation cured wood exhibited a considerably extended useful life in alkaline and acidic solutions. Composites based on teak wood showed a remarkable improvement with a nominal polymer loading of 10%. The reports of accelerated aging test of WPC are also presented. (auth.)

  4. Thermodynamic analysis of chemical compatibility of several reinforcement materials with niobium aluminides. Final contractor report

    International Nuclear Information System (INIS)

    Chemical compatibility of several reinforcement materials with three niobium aluminides, Nb3Al, Nb2Al, and NbAl3, were examined from thermodynamic considerations. The reinforcement materials considered in this study include carbides, borides, nitrides, oxides, silicides, and Engel-Brewer compounds. Thermodynamics of the Nb-Al system were reviewed and activities of Nb and Al were derived at desired calculation temperatures. Criteria for chemical compatibility between the reinforcement material and Nb-Al compounds have been defined and several chemically compatible reinforcement materials have been identified

  5. Molecular modeling for the design of novel performance chemicals and materials

    CERN Document Server

    Rai, Beena

    2012-01-01

    Molecular modeling (MM) tools offer significant benefits in the design of industrial chemical plants and material processing operations. While the role of MM in biological fields is well established, in most cases MM works as an accessory in novel products/materials development rather than a tool for direct innovation. As a result, MM engineers and practitioners are often seized with the question: ""How do I leverage these tools to develop novel materials or chemicals in my industry?"" Molecular Modeling for the Design of Novel Performance Chemicals and Materials answers this important questio

  6. Thermodynamic analysis of chemical compatibility of ceramic reinforcement materials with niobium aluminides

    Science.gov (United States)

    Misra, Ajay K.

    1990-01-01

    Chemical compatibility of several reinforcement materials with three niobium aluminides, Nb3Al, Nb2Al, and NbAl3, were examined from thermodynamic considerations. The reinforcement materials considered in this study include carbides, borides, nitrides, oxides, silicides, and Engel-Brewer compounds. Thermodynamics of the Nb-Al system were reviewed and activities of Nb and Al were derived at desired calculation temperatures. Criteria for chemical compatibility between the reinforcement material and Nb-Al compounds have been defined and several chemically compatible reinforcement materials have been identified.

  7. Thermodynamic analysis of chemical compatibility of several reinforcement materials with niobium aluminides

    Science.gov (United States)

    Misra, Ajay K.

    1989-01-01

    Chemical compatibility of several reinforcement materials with three niobium aluminides, Nb3Al, Nb2Al, and NbAl3, were examined from thermodynamic considerations. The reinforcement materials considered in this study include carbides, borides, nitrides, oxides, silicides, and Engel-Brewer compounds. Thermodynamics of the Nb-Al system were reviewed and activities of Nb and Al were derived at desired calculation temperatures. Criteria for chemical compatibility between the reinforcement material and Nb-Al compounds have been defined and several chemically compatible reinforcement materials have been identified.

  8. Effects of pressure and temperature on thermal contact resistance between different materials

    Directory of Open Access Journals (Sweden)

    Zhao Zhe

    2015-01-01

    Full Text Available To explore whether pressure and temperature can affect thermal contact resistance, we have proposed a new experimental approach for measurement of the thermal contact resistance. Taking the thermal contact resistance between phenolic resin and carbon-carbon composites, cuprum, and aluminum as the examples, the influence of the thermal contact resistance between specimens under pressure is tested by experiment. Two groups of experiments are performed and then an analysis on influencing factors of the thermal contact resistance is presented in this paper. The experimental results reveal that the thermal contact resistance depends not only on the thermal conductivity coefficient of materials, but on the interfacial temperature and pressure. Furthermore, the thermal contact resistance between cuprum and aluminum is more sensitive to pressure and temperature than that between phenolic resin and carbon-carbon composites.

  9. Application of polymer-powder slurry for fabrication of abrasion resistant coatings on tool materials

    Directory of Open Access Journals (Sweden)

    G. Matula

    2011-03-01

    Full Text Available Purpose: Development of a new generation tool materials on the basis of M2 high speed-steel or 41Cr4 steel covered with the carbides. Application of pressureless forming of powder as a manufacturing method of anti-wear coatings gives the possibility to produce this materials with relative low cost of production.Design/methodology/approach: Powder metallurgy, pressureless forming of powder, sintering, microstructure examination, X-ray dispersive energy examination, hardness examination.Findings: Putting down coatings with this method does not call for using the costly equipment for the physical or chemical deposition of coatings from the gaseous phase. Coating thickness may be easily regulated by applying the powder-binder slurry layer once or several times on the prepared substrate surface. Hardness of coatings in the sintered state is higher compared to the HS6-5-2 and 41Cr4 steels by about 400 and 700 HV respectively. It is expected that hardness of the coatings and substrate will grow after their heat treatment.Practical implications: Application of powder metallurgy and especially pressureless forming of powder to manufacturing of steel covered with anti-wear coatings gives the possibility to obtain tool materials with the relative high ductility characteristic of steel and high hardness and wear resistance typical for cemented carbides.Originality/value: One can state, based on the investigations carried out, that the pressureless forming of the powder may be used for depositing the anti-wear coatings onto the tool materials and other elements in the abrasion wear service conditions.

  10. The dependence of carbon materials thermal shock resistance on their physical properties

    International Nuclear Information System (INIS)

    The results of thermal shock tests on various structural carbon materials in different conditions of electron pulses duration are summarized. From the estimations done follows that the level of thermal shock resistance decreasing is higher for lower irradiation temperature and higher accumulated neutron fluency. Experimental results on thermal shock resistance reduction after neutron irradiation obtained by Japanese researches confirm our estimations

  11. Investigation on low velocity impact resistance of SMA composite material

    Science.gov (United States)

    Hu, Dianyin; Zhang, Long; Wang, Rongqiao; Zhang, Xiaoyong

    2016-04-01

    A method to improve low velocity impact resistance of aeroengine composite casing using shape memory alloy's properties of shape memory(SM) and super-elasticity(SE) is proposed in this study. Firstly, a numerical modeling of SMA reinforced composite laminate under low velocity impact load with impact velocity of 10 m/s is established based on its constitutive model implemented by the VUMAT subroutine of commercial software ABAQUS. Secondly, the responses of SMA composite laminate including stress and deflection distributions were achieved through transient analysis under low velocity impact load. Numerical results show that both peak stress and deflection values of SMA composite laminate are less than that without SMA, which proves that embedding SMA into the composite structure can effectively improve the low velocity impact performance of composite structure. Finally, the influence of SM and SE on low velocity impact resistance is quantitatively investigated. The values of peak stress and deflection of SMA composite based on SM property decrease by 18.28% and 9.43% respectively, compared with those without SMA, instead of 12.87% and 5.19% based on SE. In conclusion, this proposed model described the impact damage of SMA composite structure and turned to be a more beneficial method to enhance the impact resistance by utilizing SM effect.

  12. Chemically modified Si(111) surfaces simultaneously demonstrating hydrophilicity, resistance against oxidation, and low trap state densities

    Science.gov (United States)

    Brown, Elizabeth S.; Hlynchuk, Sofiya; Maldonado, Stephen

    2016-03-01

    Chemically modified Si(111) surfaces have been prepared through a series of wet chemical surface treatments that simultaneously show resistance towards surface oxidation, selective reactivity towards chemical reagents, and areal defect densities comparable to unannealed thermal oxides. Specifically, grazing angle attenuated total reflectance infrared and X-ray photoelectron (XP) spectroscopies were used to characterize allyl-, 3,4-methylenedioxybenzene-, or 4-[bis(trimethylsilyl)amino]phenyl-terminated surfaces and the subsequently hydroxylated surfaces. Hydroxylated surfaces were confirmed through reaction with 4-(trifluoromethyl)benzyl bromide and quantified by XP spectroscopy. Contact angle measurements indicated all surfaces remained hydrophilic, even after secondary backfilling with CH3sbnd groups. Surface recombination velocity measurements by way of microwave photoconductivity transients showed the relative defect-character of as-prepared and aged surfaces. The relative merits for each investigated surface type are discussed.

  13. Chemically-functionalized microcantilevers for detection of chemical, biological and explosive material

    Science.gov (United States)

    Pinnaduwage, Lal A [Knoxville, TN; Thundat, Thomas G [Knoxville, TN; Brown, Gilbert M [Knoxville, TN; Hawk, John Eric [Olive Branch, MS; Boiadjiev, Vassil I [Knoxville, TN

    2007-04-24

    A chemically functionalized cantilever system has a cantilever coated on one side thereof with a reagent or biological species which binds to an analyte. The system is of particular value when the analyte is a toxic chemical biological warfare agent or an explosive.

  14. Effect of Environmental Variables on the Flammability of Fire Resistant Materials

    OpenAIRE

    Osorio, Andres Felipe

    2014-01-01

    This work investigates the effects of external radiation, ambient pressure and microgravity on the flammability limits of fire-resistant (FR) materials. Future space missions may require spacecraft cabin environments different than those used in the International Space Station, 21%O2, 101.3kPa. Environmental variables include flow velocity, oxygen concentration, ambient pressure, micro or partial-gravity, orientation, presence of an external radiant flux, etc. Fire-resistant materials are use...

  15. Process Simulation of Resistance Weld Bonding and Automotive Light-weight Materials

    OpenAIRE

    Zhang, Wenqi; Chergui, Azeddine; Nielsen, Chris Valentin

    2012-01-01

    This paper presents the latest developments in numerical simulation of resistance welding especially with the new functions for simulation of microstructures, weld bonding and spot welding of new light-weight materials. The fundamental functions in SORPAS® are built on coupled modeling of mechanical, electrical, thermal and metallurgical processes, which are essential for simulation of resistance welding process to predict the welding results and evaluate the weldability of materials. These f...

  16. Evaluation of Water Resistance and Diffusion Properties of Paint Materials

    Directory of Open Access Journals (Sweden)

    J. Drchalová

    2001-01-01

    Full Text Available A simple method is presented for evaluating the water-proofness quality of paints on lining materials. The method is based on measuring the integral capillarity in dependence on time, and then comparing this value to the value determined for the basic lining material. Measurements of the effective water vapor permeability then provide information on the risk of condensation which may increase after applying the paint. A practical application of the method is performed with four Karlocolor paints on glass concrete substrates. All the Karlocolor paints are found to be very effective materials for driven rain protection. The diffusion properties of all the paints are found to be excellent.

  17. Inventions in the nanotechnological area considerably increase wear- and chemical resistance of construction products

    OpenAIRE

    VLASOV Vladimir Alexeevich

    2014-01-01

    The invention «Reinforced flaked element made of natural or conglomerate stone and its multilayer protective coating (RU 2520193)» is referred to construction materials. Reinforced flaked element made of natural or conglomerate stone consists of: natural or conglomerate materials as the basis; multilayer coating which protects the mentioned basis from chemical substances and wearing mechanical factors influencing on this element where the multilayer coating includes at least three layers f...

  18. Sustainable Material Selection of Toxic Chemicals in Design and Manufacturing From Human Health Impact Perspective

    OpenAIRE

    Yuan, Chris; Dornfeld, David

    2009-01-01

    Toxic chemicals used in product design and manufacturing are grave concerns due to their significant impact on human health. Sustainable material selections are needed by industry to reduce the overall impact of toxic chemicals in both design and manufacturing. In this paper, we integrate the human health impact assessment into standard material selection process for developing a sustainable material selection metric for decision support in design and manufacturing. A schematic method is pres...

  19. High-sensitivity green resist material with organic solvent-free spin-coating and tetramethylammonium hydroxide-free water-developable processes for EB and EUV lithography

    Science.gov (United States)

    Takei, Satoshi; Hanabata, Makoto; Oshima, Akihiro; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

    2015-03-01

    We investigated the eco-friendly electron beam (EB) and extreme-ultraviolet (EUV) lithography using a high-sensitive negative type of green resist material derived from biomass to take advantage of organic solvent-free water spin-coating and tetramethylammonium hydroxide(TMAH)-free water-developable techniques. A water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB lithography was developed for environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of TMAH. The material design concept to use the water-soluble resist material with acceptable properties such as pillar patterns with less than 100 nm in high EB sensitivity of 10 μC/cm2 and etch selectivity with a silicon-based middle layer in CF4 plasma treatment was demonstrated for EB and EUV lithography.

  20. Physico-chemical characterisation of material fractions in household waste

    DEFF Research Database (Denmark)

    Götze, Ramona; Boldrin, Alessio; Scheutz, Charlotte;

    2016-01-01

    to the data selection from literature. Overall, 97 publications were reviewed with respect to employed characterisation method, regional origin of the waste, number of investigated parameters and material fractions and other qualitative aspects. Descriptive statistical analysis of the reported physico...

  1. Corrosion problems of materials for mechanical, power and chemical engineering

    International Nuclear Information System (INIS)

    The proceedings contain 47 contributions, out of which 8 have been inputted in INIS. These are concerned with various corrosion problems of WWER primary circuit components and their testing. The factors affecting the corrosion resistance are analyzed, the simultaneous corrosion action of decontamination of steels is assessed, and the corrosion cracking of special steels is dealt with. The effects of deformation on the corrosion characteristics are examined for steel to be used in fast reactors. The corrosion potentials were measured for various steels. A testing facility for corrosion-mechanical tests is briefly described. (M.D.). 5 figs., 5 tabs., 25 refs

  2. Materials for Chemical-Looping with Oxygen Uncoupling

    OpenAIRE

    Tobias Mattisson

    2013-01-01

    Chemical-looping with oxygen uncoupling (CLOU) is a novel combustion technology with inherent separation of carbon dioxide. The process is a three-step process which utilizes a circulating oxygen carrier to transfer oxygen from the combustion air to the fuel. The process utilizes two interconnected fluidized bed reactors, an air reactor and a fuel reactor. In the fuel reactor, the metal oxide decomposes with the release of gas phase oxygen (step 1), which reacts directly with the fuel through...

  3. Preparation of High Impermeable and Crack-resistance Chemical Admixture and Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A kind of high impermeable and crack-resistance chemical admixture (HICRCA) was prepared, which is a compound chemical admixture composed of an expansion ingredient,density ingredient, and organic hydrophobic poreblocking ingredient. The results of the experiments indicate that the addition of HICRCA improves mortar and concrete in the following performances:(1) perfect workability: slump is more than 22cm, the slump after 3h is about 16cm; (2)high impermeability:for the mortar,the pervious height under a water pressure of 1.5MPa is 1.5cm,for the concrete, the pervious height under a water pressure of 5.0MPa is 2.2cm;(3)high crack-resistance:there is a micro-expansion at the age of 90d;(4)high compressivestrength:compared with the controlled concrete,the compressive strengths at the age of 3d and 28d are improved by 66.4% and 62.0%, respectively.At the same time,the effects of different curing condition on mortar and concrete expansive and shrinkage performance were studied.In addition,the impermeable and crack-resistance mechanism was investigated in the present paper.

  4. The effect of chemical composition on the behaviour of austenitic corrosion-resistant steels in high-temperature sodium

    International Nuclear Information System (INIS)

    Nonstabilized and stabilized chromium-nickel and chromium-nickel-molybdenum steels were studied in an experimental sodium loop. Sodium volume in the loop was ca. 6 l, sodium circulation rate was 0.1 m/s at the temperature gradient ΔT=100 degC. Steel samples were in the shape of slabs 60x12x1 mm in dimension. Prior to exposure, the samples were ground with metallographic paper, gradually of finer grits, cleaned in diluted ammonia, degreased and weighed. After the 1000-hour exposure the samples were removed under the argon atmosphere, cleaned, dried, and weighed. The chemical composition of steels is tabulated. The effect of chemical composition was shown on the corrosion behaviour of austenitic corrosion resistant steels in high-temperature sodium at convection flow. The obtained results indicate the action of carbon, molybdenum and the stabilizer (Ti). For chromium-nickel nonstabilized steels the possibility was shown of interpreting the weight changes using the carbon transfer analysis. In other materials the observed weight changes were interpreted using the concept of competition behaviour of alphagenous and gammagenous elements during the change in alloy elements diffusion in sodium. It was also shown that after high-temperature exposure in either the sodium or the argon atmosphere the mechanical properties of austenitic steels mainly depended on the process of the carbon exchange of these materials with sodium. (J.B.)

  5. Test results of chemical reactivity test (CRT) analysis of structural materials and explosives

    Energy Technology Data Exchange (ETDEWEB)

    Back, P.S.; Barnhart, B.V.; Walters, R.R.; Haws, L.D.; Collins, L.W.

    1980-03-21

    The chemical reactivity test, CRT, is a procedure used to screen the compatibility of component structure materials with explosives. This report contains the results of CRT materials evaluations conducted at Mound Facility. Data about materials combinations are catalogued both under the name of the explosive and the nonexplosive.

  6. Preparation of reference materials for frit chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gazulla, M.F.; Gomez, M.P.; Barba, A.; Orduna, M. [Inst. de Tecnologia Ceramica, Univ. Jaume I., Castellon (Spain)

    2002-08-01

    A study was undertaken on how to prepare frit reference materials in which the following elements are analysed: Si, Al, Fe, Ca, Mg, N, K, Ti, Zr, Ba, Pb, Zn, Hf, P, B and Li. The following analytical techniques were used: X-ray fluorescence spectrometry (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES), atomic absorption spectrophotometry (AAS) and titrimetry. Boron and lithium were analysed by ICP-OES, sodium and lithium by AAS, and boron by titrimetry, while the remaining frit elements and sodium were analysed by XRF. The results found by the different methods were compared and each method was validated by means of reference materials. A procedure was established for preparing frit reference materials for calibrating and validating working methods on an industrial scale. (orig.)

  7. Paper's resistance to wetting - A review of internal sizing chemicals and their effects

    Directory of Open Access Journals (Sweden)

    Hubbe, M. A.

    2007-02-01

    Full Text Available This review considers research related to internal sizing agents. Such chemicals, when added as emulsions or in micellar form to slurries of cellulosic fibers before paper is made, can make the product resist water and other fluids. Significant progress has been achieved to elucidate the modes of action of alkylketene dimer (AKD, alkenylsuccinic anhydride (ASA, rosin products, and other sizing chemicals. Recent findings generally support a traditional view that efficient hydrophobation requires that the sizing chemicals contain hydrophobic groups, that they are efficiently retained on fiber surfaces during the papermaking process, that they become well distributed on a molecular scale, and that they need to be chemically anchored. A variety of studies have quantified ways in which internal sizing treatments tend to be inefficient, compared to what is theoretically possible. The inefficient nature of chemical and physical processes associated with internal sizing, as well as competing reactions and some interfering or contributing factors, help to explain apparent inconsistencies between the results of some recent studies.

  8. Using Quantitative Reverse Transcriptase PCR and Cell Culture Plaque Assays to Determine Resistance of Toxoplasma gondii Oocysts to Chemical Sanitizers

    Science.gov (United States)

    Toxoplasma gondii oocysts are highly resistant to many chemical sanitizers. Current methods used to determine oocyst infectivity have relied exclusively on mouse, chicken, and feline bioassays. Although considered gold standards, they only provide a qualitative assessment of oocyst infectivity. I...

  9. [Salt resistance and its mechanism of cucumber under effects of exogenous chemical activators].

    Science.gov (United States)

    Song, Shiqing; Liu, Wei; Guo, Shirong; Shang, Qingmao; Zhang, Zhigang

    2006-10-01

    With root injection and foliar spray, this paper studied the effects of different concentrations salicylic acid, brassinolide, chitosan and spermidine on the growth, morphogenesis, and physiological and biochemical characters of cucumber ( Cucumis sativus L. ) seedlings under 200 mmol x L(-1) NaCl stress. The results showed that at proper concentrations, these four exogenous chemical activators could markedly decrease the salt stress index and mortality of cucumber seedlings, and the decrement induced by 0. 01 mg x L (-1) brassinolide was the largest, being 63. 0% and 75. 0% , respectively. The activities of superoxide dismutase (SOD) , peroxidase (POD) and catalase (CAT) increased significantly, resulting in a marked decrease of malondialdehyde (MDA) content and electrolyte leakage. The dry weight water content and morphogenesis of cucumber seedlings improved, and the stem diameter, leaf number, and healthy index increased significantly. All of these suggested that exogenous chemical activators at proper concentrations could induce the salt resistance of cucumber, and mitigate the damage degree of salt stress. The salt resistance effect of test exogenous chemical activators decreased in the sequence of 0.005 -0.05 mg (L-1) brassinolide, 150 -250 mg x L (-1) spermidine, 100 -200 mg x L(-1) chitosan, and 50 -150 mg x L(-1) salicylic acid. PMID:17209385

  10. INVESTIGATION ON NEW CREEP- AND OXIDATION-RESISTANT MATERIALS

    Czech Academy of Sciences Publication Activity Database

    Khalaj, O.; Mašek, B.; Jirková, H.; Ronešová, A.; Svoboda, Jiří

    2015-01-01

    Roč. 49, č. 4 (2015), s. 645-651. ISSN 1580-2949 R&D Projects: GA ČR(CZ) GA14-24252S Institutional support: RVO:68081723 Keywords : ODS steel * alloys * composite * creep * Fe-Al Subject RIV: JI - Composite Materials Impact factor: 0.548, year: 2014

  11. Gamma radiation resistance of tale-polypropylene composite materials

    International Nuclear Information System (INIS)

    Samples of isostatic polypropylene mixed with 10, 20 and 30 wt.% Talc were prepared. Sample films were gamma irradiated at 10 - 300 k Gy under air. The results from DSC suggested that fine particles of Talc showed pronounced nucleating effect by increasing the rate of crystallization and thermal stability. However, Talc-filled composites did not showed radiation resistant property. Absorbance intensity of carbonyl and hydroperoxide indicated the amount of oxidative degradation were increased with increasing radiation dose but would not depend on the Talc content. Talc was found to enhance polypropylene embrittlement and to lower the mechanical properties. However at appropriate concentration of Talc and low gamma dose. It is possible to improve the mechanical properties of the composites. In the field of environmental study, Talc-filled composites of iso tactic polypropylene may be used as a degradable plastic

  12. Pressure Resistance Welding of High Temperature Metallic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Larry Zirker; Craig Tyler

    2010-08-01

    Engineers from the Idaho National Laboratory (INL) have demonstrated an innovative method for seal or pinch welding stainless steel tubing. Sometimes a tube has fuel or contamination that must be contained, or the tube needs to be shortened or cut for handling, and the tube needs to have a guaranteed sealed weld that is both quick and easy. This technique was demonstrated in a laboratory using a resistance welding system with specially designed electrodes to ensure a tube end is seal welded or if a long tube is to be shortened, the severed ends are seal welded. The unique electrodes design is integral to achieving the sealed ends. This process could readily be adapted for robotic--remote handling or for contact handling in a glovebox or hood.

  13. Radiation Resistance Studies of Amorphous Silicon Alloy Photovoltaic Materials

    Science.gov (United States)

    Woodyard, James R.

    1994-01-01

    The radiation resistance of commercial solar cells fabricated from hydrogenated amorphous silicon alloys was investigated. A number of different device structures were irradiated with 1.0 MeV protons. The cells were insensitive to proton fluences below 1E12 sq cm. The parameters of the irradiated cells were restored with annealing at 200 C. The annealing time was dependent on proton fluence. Annealing devices for one hour restores cell parameters for fluences below lE14 sq cm require longer annealing times. A parametric fitting model was used to characterize current mechanisms observed in dark I-V measurements. The current mechanisms were explored with irradiation fluence, and voltage and light soaking times. The thermal generation current density and quality factor increased with proton fluence. Device simulation shows the degradation in cell characteristics may be explained by the reduction of the electric field in the intrinsic layer.

  14. Reliability of chemical microanalyses for solid waste materials

    International Nuclear Information System (INIS)

    Highlights: ► Key role of solid speciation of contaminants in hazardous waste materials. ► Nanophases affect the accuracy of electron probe microanalysis (EPMA). ► High-resolution methods (FEG-SEM, FIB-TEM) proposed for solid speciation. - Abstract: The investigation of solid speciation of metals and metalloids is required for accurate assessment of the hazardous properties of solid waste materials from high-temperature technologies (slag, bottom ash, fly ash, air-pollution-control residues). This paper deals with the problem of reliability of microanalyses using a combination of electron microprobe analysis (EPMA) and scanning electron microscopy (SEM) only. These methods do not permit to detect nanophases in host-crystals and lead to erroneous interpretation of analytical results, considering the elements of nanophases as belonging to the crystal structure of the main phase. More detailed analysis using transmission electron microscopy (TEM) on foils prepared by focused ion beam (FIB) can be used to solve this analytical problem. In this study, lamellar aggregates of potassium-rich clinopyroxenes were detected in copper smelting slags by a combination of SEM and EPMA. However, FIB-TEM indicated the presence of leucite inclusions (tens to hundreds nm in size) within the clinopyroxene lamellae. Based on examples from smelting slags and other solid waste materials, recommendations for standard SEM and EPMA applications and the need for methods with higher resolution for mineralogical investigation of waste materials are discussed.

  15. Reliability of chemical microanalyses for solid waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Ettler, Vojtech, E-mail: ettler@natur.cuni.cz [Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University in Prague, Faculty of Science, Albertov 6, 128 43 Prague 2 (Czech Republic); Johan, Zdenek [Bureau des Recherches Geologiques et Minieres (BRGM), av. Claude Guillemin, 45060 Orleans, Cedex 2 (France); Vitkova, Martina [Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University in Prague, Faculty of Science, Albertov 6, 128 43 Prague 2 (Czech Republic); Skala, Roman [Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University in Prague, Faculty of Science, Albertov 6, 128 43 Prague 2 (Czech Republic); Institute of Geology of the ASCR, v.v.i., Rozvojova 269, 165 00 Prague 6 (Czech Republic); Kotrly, Marek [Institute of Criminalistics Prague, P.O. Box 62/KUP, Strojnicka 27, 170 89 Prague 7 (Czech Republic); Habler, Gerlinde [Department of Lithospheric Research, University of Vienna, Althanstrasse 14, A-1090 Vienna (Austria); Klementova, Mariana [Institute of Inorganic Chemistry of the AS CR, v.v.i., 250 68 Husinec-Rez (Czech Republic)

    2012-06-30

    Highlights: Black-Right-Pointing-Pointer Key role of solid speciation of contaminants in hazardous waste materials. Black-Right-Pointing-Pointer Nanophases affect the accuracy of electron probe microanalysis (EPMA). Black-Right-Pointing-Pointer High-resolution methods (FEG-SEM, FIB-TEM) proposed for solid speciation. - Abstract: The investigation of solid speciation of metals and metalloids is required for accurate assessment of the hazardous properties of solid waste materials from high-temperature technologies (slag, bottom ash, fly ash, air-pollution-control residues). This paper deals with the problem of reliability of microanalyses using a combination of electron microprobe analysis (EPMA) and scanning electron microscopy (SEM) only. These methods do not permit to detect nanophases in host-crystals and lead to erroneous interpretation of analytical results, considering the elements of nanophases as belonging to the crystal structure of the main phase. More detailed analysis using transmission electron microscopy (TEM) on foils prepared by focused ion beam (FIB) can be used to solve this analytical problem. In this study, lamellar aggregates of potassium-rich clinopyroxenes were detected in copper smelting slags by a combination of SEM and EPMA. However, FIB-TEM indicated the presence of leucite inclusions (tens to hundreds nm in size) within the clinopyroxene lamellae. Based on examples from smelting slags and other solid waste materials, recommendations for standard SEM and EPMA applications and the need for methods with higher resolution for mineralogical investigation of waste materials are discussed.

  16. Frost susceptibility of granular subbase materials contaminated by deicing chemicals

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Orlander, Tobias; Doré, Guy

    2013-01-01

    in order to determine the frost susceptibility of the material when it is contaminated by a deicing agent. Two series of three freezing tests with isothermal cooling has been conducted using identical saline gradient added through brine. Two types of cooling ramp, an automatic cooling and a manual cooling...

  17. Nanostructured materials for biological imaging and chemical sensing

    OpenAIRE

    Yıldırım, Adem

    2014-01-01

    Ankara : Materials Science and Nanotechnology Program of the Graduate School of Engineering and Science of Bilkent University, 2014. Thesis (Ph.D.) -- Bilkent University, 2014. Includes bibliographical references leaves 116-139. Yıldırım, Adem Ph. D.

  18. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  19. Progress in resolution, sensitivity, and critical dimensional uniformity of EUV chemically amplified resists

    Science.gov (United States)

    Thackeray, James; Cameron, James; Jain, Vipul; LaBeaume, Paul; Coley, Suzanne; Ongayi, Owendi; Wagner, Mike; Rachford, Aaron; Biafore, John

    2013-03-01

    This paper will discuss further progress obtained at Dow for the improvement of the Resolution, Contact critical dimension uniformity(CDU), and Sensitivity of EUV chemically amplified resists. For resolution, we have employed the use of polymer-bound photoacid generator (PBP) concept to reduce the intrinsic acid diffusion that limits the ultimate resolving capability of CA resists. For CDU, we have focused on intrinsic dissolution contrast and have found that the photo-decomposable base (PDB) concept can be successfully employed. With the use of a PDB, we can reduce CDU variation at a lower exposure energy. For sensitivity, we have focused on more efficient EUV photon capture through increased EUV absorption, as well as more highly efficient PAGs for greater acid generating efficiency. The formulation concepts will be confirmed using Prolith stochastic resist modeling. For the 26nm hp contact holes, we get excellent overall process window with over 280nm depth of focus for a 10% exposure latitude Process window. The 1sigma Critical dimension uniformity [CDU] is 1.1 nm. We also obtain 20nm hp contact resolution in one of our new EUV resists.

  20. Species and diet related resistance to chemical carcinogens: biochemical mechanisms of aflatoxin B1 detoxification

    International Nuclear Information System (INIS)

    To provide insight into the biochemical mechanisms mediating species and diet related resistance to chemical carcinogens, the biotransformation and covalent binding to DNA of the potent hepatocarcinogen aflatoxin B1(AFB) was investigated in resistant and susceptible species fed standard and butylated hydroxyanisole (BHA)-supplemented diets. The rat is sensitive to the hepatocarcinogenic effects of AFB, whereas the mouse, and rats fed BHA-supplemented diet, are resistant. To differentiate between enzyme induction and direct antioxidant effects, BHA was administered to rats for 9 days, or as a single dose 4-7 hrs prior to i.p. injection of 3H-AFB. Long-term treatment with BHA doubled the biliary excretion of the glutathione conjugate of AFB and the AFP1-glucuronide, and reduced the binding of AFB to hepatic DNA to 16% of control. Single-dose BHA treatment had no effect. To determine if glutathione S-transferase (GST) activity towards the AFB-epoxide mediates both treatment and species related resistance to AFB carcinogenesis, a method was developed to measure the rate of formation of the AFB-epoxide, and the rate of inactivation of the epoxide via GST. To demonstrate the importance of GST-mediated detoxification of the AFB-epoxide in the mouse in vivo, depletion of hepatic GSH was accomplished by administration of L-buthionine-S,R-sulfoximine and diethyl maleate, prior to administration of AFB. GSH depletion was associated with a 30-fold increase in AFB-DNA binding

  1. Chemical modeling of cementitious grout materials alteration in HLW repositories

    International Nuclear Information System (INIS)

    This paper reports on an investigation initiated into the nature of the chemical alteration of cementitious grout in HLW repository seals, and the implications for long-term seal performance. The equilibrium chemical reaction of two simplified portland cement-based grout models with natural Canadian Shield groundwater compositions was modeled with the computer codes PHREEQE and EQ3NR/EQ6. Increases in porosity and permeability of the grout resulting from dissolution of grout phases and precipitation of secondary phases were estimated. Two bounding hydrologic scenarios were evaluated, one approximating a high gradient, high flow regime, the other a low-gradient, sluggish flow regime. Seal longevity depends in part upon the amount of groundwater coming into intimate contact with, and dissolving, the grout per unit time. Results of the analyses indicate that, given the assumptions and simplifications inherent in the models, acceptable seal performance (i.e., acceptable increases in hydraulic conductivity of the seals) may be expected for at least thousands of years in the worst cases analyzed, and possibly much longer

  2. Low resistance polycrystalline diamond thin films deposited by hot filament chemical vapour deposition

    Indian Academy of Sciences (India)

    Mahtab Ullah; Ejaz Ahmed; Abdelbary Elhissi; Waqar Ahmed

    2014-05-01

    Polycrystalline diamond thin films with outgrowing diamond (OGD) grains were deposited onto silicon wafers using a hydrocarbon gas (CH4) highly diluted with H2 at low pressure in a hot filament chemical vapour deposition (HFCVD) reactor with a range of gas flow rates. X-ray diffraction (XRD) and SEM showed polycrystalline diamond structure with a random orientation. Polycrystalline diamond films with various textures were grown and (111) facets were dominant with sharp grain boundaries. Outgrowth was observed in flowerish character at high gas flow rates. Isolated single crystals with little openings appeared at various stages at low gas flow rates. Thus, changing gas flow rates had a beneficial influence on the grain size, growth rate and electrical resistivity. CVD diamond films gave an excellent performance for medium film thickness with relatively low electrical resistivity and making them potentially useful in many industrial applications.

  3. Ultrastrong, Chemically Resistant Reduced Graphene Oxide-based Multilayer Thin Films with Damage Detection Capability.

    Science.gov (United States)

    Guin, Tyler; Stevens, Bart; Krecker, Michelle; D'Angelo, John; Humood, Mohammad; Song, Yixuan; Smith, Ryan; Polycarpou, Andreas; Grunlan, Jaime C

    2016-03-01

    Multilayer thin films of graphene oxide (GO) and poly(vinylamine) (PVAm) were deposited via layer-by-layer assembly. Poly(vinylamine) pH was used to tailor film thickness and GO layer spacing. Graphene oxide concentration in the films was controlled through simple pH adjustment. Thermal reduction of the PVAm/GO multilayer thin films rendered them electrically conductive, which could be further tailored with PVAm pH. These reduced films also exhibited exceptionally high elastic modulus of 30 GPa and hardness of 1.8 GPa, which are among the highest of any graphene-filled polymer composite values ever reported. Cross-linking of these films with glutaraldehyde improved their chemical resistance, allowing them to survive strongly acidic or salty solutions. Additionally, scratches in the films can be instantaneously detected by a simple electrical resistance measurement. These films are promising for a variety of packaging and electronic applications. PMID:26885558

  4. Influence of electropolishing and anodic oxidation on morphology, chemical composition and corrosion resistance of niobium

    International Nuclear Information System (INIS)

    The work presents results of the studies performed on electropolishing of pure niobium in a bath that contained: sulphuric acid, hydrofluoric acid, ethylene glycol and acetanilide. After the electropolishing, the specimens were subjected to anodic passivation in a 1 mol dm−3 phosphoric acid solution at various voltages. The surface morphology, thickness, roughness and chemical composition of the resulting oxide layers were analysed. Thusly prepared niobium samples were additionally investigated in terms of their corrosion resistance in Ringer's solution. The electropolished niobium surface was determined to be smooth and lustrous. The anodisation led to the growth of barrier-like oxide layers, which were enriched in phosphorus species. - Highlights: • Pure niobium was electropolished and subsequently anodised in a H3PO4 solution. • Phosphorus was successfully introduced into the oxide layers after the treatment. • Corrosion resistance of niobium in Ringer's solution was improved after anodising

  5. Influence of electropolishing and anodic oxidation on morphology, chemical composition and corrosion resistance of niobium

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, Maciej; Greń, Katarzyna [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland); Kukharenko, Andrey I. [Institute of Metal Physics, Russian Academy of Sciences-Ural Division, S. Kovalevskoi Street 18, 620990 Yekaterinburg (Russian Federation); Ural Federal University, Mira Street 19, 620002 Yekaterinburg, Mira str. 19 (Russian Federation); Korotin, Danila M. [Institute of Metal Physics, Russian Academy of Sciences-Ural Division, S. Kovalevskoi Street 18, 620990 Yekaterinburg (Russian Federation); Michalska, Joanna [Faculty of Materials Engineering and Metallurgy, Silesian University of Technology, Krasińskiego Street 8, 40-019 Katowice (Poland); Szyk-Warszyńska, Lilianna; Mosiałek, Michał [Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek Street 8, 30-239 Kraków (Poland); Żak, Jerzy [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland); Pamuła, Elżbieta [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza Avenue 30, 30-059 Kraków (Poland); Kurmaev, Ernst Z. [Institute of Metal Physics, Russian Academy of Sciences-Ural Division, S. Kovalevskoi Street 18, 620990 Yekaterinburg (Russian Federation); Cholakh, Seif O. [Ural Federal University, Mira Street 19, 620002 Yekaterinburg, Mira str. 19 (Russian Federation); Simka, Wojciech, E-mail: wojciech.simka@polsl.pl [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland)

    2014-09-01

    The work presents results of the studies performed on electropolishing of pure niobium in a bath that contained: sulphuric acid, hydrofluoric acid, ethylene glycol and acetanilide. After the electropolishing, the specimens were subjected to anodic passivation in a 1 mol dm{sup −3} phosphoric acid solution at various voltages. The surface morphology, thickness, roughness and chemical composition of the resulting oxide layers were analysed. Thusly prepared niobium samples were additionally investigated in terms of their corrosion resistance in Ringer's solution. The electropolished niobium surface was determined to be smooth and lustrous. The anodisation led to the growth of barrier-like oxide layers, which were enriched in phosphorus species. - Highlights: • Pure niobium was electropolished and subsequently anodised in a H{sub 3}PO{sub 4} solution. • Phosphorus was successfully introduced into the oxide layers after the treatment. • Corrosion resistance of niobium in Ringer's solution was improved after anodising.

  6. Weld nugget formation in resistance spot welding of new lightweight sandwich material

    DEFF Research Database (Denmark)

    Sagüés Tanco, J.; Nielsen, Chris Valentin; Chergui, Azeddine;

    2015-01-01

    Weldability of a new lightweight sandwich material, LITECOR®, by resistance spot welding is analyzed by experiments and numerical simulations. The spot welding process is accommodated by a first pulse squeezing out the non-conductive polymer core of the sandwich material locally to allow metal–me...

  7. Discovery of Novel Materials with Broad Resistance to Bacterial Attachment Using Combinatorial Polymer Microarrays

    OpenAIRE

    Hook, Andrew L; Chang, Chien-Yi; YANG Jing; Atkinson, Steve; Langer, Robert; Anderson, Daniel G.; Davies, Martyn C; Williams, Paul; Alexander, Morgan R.

    2012-01-01

    A new class of bacteria-attachment-resistant materials is discovered using a multi-generation polymer microarray methodology that reduces bacterial attachment by up to 99.3% compared with a leading commercially available silver hydrogel anti-bacterial material. The coverage of three bacterial species, Pseudomonas aeruginosa, Staphylococcus aureus, and uropathogenic Escherichia coli is assessed.

  8. Discovery of novel materials with broad resistance to bacterial attachment using combinatorial polymer microarrays

    OpenAIRE

    Hook, Andrew L; Chang, Chien-Yi; YANG Jing; Atkinson, Steve; Langer, Robert; Anderson, Daniel G.; Davies, Martyn C; Williams, Paul; Alexander, Morgan R.

    2013-01-01

    A new class of bacteria-attachment-resistant materials is discovered using a multi-generation polymer microarray methodology that reduces bacterial attachment by up to 99.3% compared with a leading commercially available silver hydrogel anti-bacterial material. The coverage of three bacterial species, Pseudomonas aeruginosa, Staphylococcus aureus, and uropathogenic Escherichia coli is assessed.

  9. Radiation resistance of the natural microbial population in buffer materials

    Energy Technology Data Exchange (ETDEWEB)

    Stroes-Gascoyne, S.; Lucht, L.M.; Borsa, J.; Delaney, T.L.; Haveman, S.A.; Hamon, C.J. [AECL Research, Pinawa, Manitoba (Canada). Whiteshell Labs.

    1995-12-31

    The radiation sensitivity of naturally occurring microorganisms in buffer materials was investigated as well as the sensitivity of Bacillus subtillis spores and Acinetobacter radioresistens in a buffer matrix. The D{sub 10} values obtained in these radiation experiments varied from 0.34 to 1.68 kGy and it was calculated that the surface of a nuclear fuel waste container would be sterilized in 9 to 33 d after emplacement, depending on the type of container, and the initial bioburden. This suggests that formation of biofilms and microbially influenced corrosion would not be of concern of some time after emplacement. The results also indicated that sterilization throughout a 25 cm thick buffer layer is unlikely and that repopulation of the container surface after some time is a possibility, depending on the mobility of microbes in compacted buffer material.

  10. Radiation resistance of the natural microbial population in buffer materials

    International Nuclear Information System (INIS)

    The radiation sensitivity of naturally occurring microorganisms in buffer materials was investigated as well as the sensitivity of Bacillus subtillis spores and Acinetobacter radioresistens in a buffer matrix. The D10 values obtained in these radiation experiments varied from 0.34 to 1.68 kGy and it was calculated that the surface of a nuclear fuel waste container would be sterilized in 9 to 33 d after emplacement, depending on the type of container, and the initial bioburden. This suggests that formation of biofilms and microbially influenced corrosion would not be of concern of some time after emplacement. The results also indicated that sterilization throughout a 25 cm thick buffer layer is unlikely and that repopulation of the container surface after some time is a possibility, depending on the mobility of microbes in compacted buffer material

  11. Oxygen permeation and thermo-chemical stability of oxygen separation membrane materials for the oxyfuel process

    Energy Technology Data Exchange (ETDEWEB)

    Ellett, Anna Judith

    2009-07-01

    The reduction of CO{sub 2} emissions, generally held to be one of the most significant contributors to global warming, is a major technological issue. CO{sub 2} Capture and Storage (CCS) techniques applied to large stationary sources such as coal-fired power plants could efficiently contribute to the global carbon mitigation effort. The oxyfuel process, which consists in the burning of coal in an oxygen-rich atmosphere to produce a flue gas highly concentrated in CO{sub 2}, is a technology considered for zero CO{sub 2} emission coal-fired power plants. The production of this O{sub 2}-rich combustion gas from air can be carried out using high purity oxygen separation membranes. Some of the most promising materials for this application are mixed ionic-electronic conducting (MIEC) materials with perovskite and K{sub 2}NiF{sub 4} perovskite-related structures. The present work examines the selection of La{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF58), La{sub 2}NiO{sub 4+{delta}}, Pr{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (PSCF58) and Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF50) as membrane materials for the separation of O{sub 2} and N{sub 2} in the framework of the oxyfuel process with flue gas recycling. Annealing experiments were carried out on pellets exposed to CO{sub 2}, water vapour, O{sub 2} and Cr{sub 2}O{sub 3} in order to determine the thermo-chemical resistance to the atmospheres and the high temperature conditions present during membrane operation in a coal-fired power plant. The degradation of their microstructure was investigated using Scanning Electron Microscopy (SEM) in combination with electron dispersive spectroscopy (EDS) as well as X-Ray Diffraction (XRD). Also, the oxygen permeation fluxes of selected membranes were investigated as a function of temperature. The membrane materials selected were characterised using thermo-analytical techniques such as precision thermogravimetric

  12. Measurement of tritium permeation through resistant materials near room temperature

    International Nuclear Information System (INIS)

    To measure tritium permeation through low-permeability materials at 50 to 1700C, we use highly-sensitive liquid scintillation counting to detect the permeating tritium. To validate our method, we conducted extensive experiments with copper, for which much data exists for comparison. We report permeability of tritium through copper at 50, 100, and 1700C, and discuss details of the experimental technique. Further plans are outlined. 15 refs., 5 figs., 1 tab

  13. Advanced Nanoporous Materials for Micro-Gravimetric Sensing to Trace-Level Bio/Chemical Molecules

    Directory of Open Access Journals (Sweden)

    Pengcheng Xu

    2014-10-01

    Full Text Available Functionalized nanoporous materials have been developed recently as bio/chemical sensing materials. Due to the huge specific surface of the nano-materials for molecular adsorption, high hopes have been placed on gravimetric detection with micro/nano resonant cantilevers for ultra-sensitive sensing of low-concentration bio/chemical substances. In order to enhance selectivity of the gravimetric resonant sensors to the target molecules, it is crucial to modify specific groups onto the pore-surface of the nano-materials. By loading the nanoporous sensing material onto the desired region of the mass-type transducers like resonant cantilevers, the micro-gravimetric bio/chemical sensors can be formed. Recently, such micro-gravimetric bio/chemical sensors have been successfully applied for rapid or on-the-spot detection of various bio/chemical molecules at the trace-concentration level. The applicable nanoporous sensing materials include mesoporous silica, zeolite, nanoporous graphene oxide (GO and so on. This review article focuses on the recent achievements in design, preparation, functionalization and characterization of advanced nanoporous sensing materials for micro-gravimetric bio/chemical sensing.

  14. Development of high electric resistant functionally gradient material for fusion reactor components

    International Nuclear Information System (INIS)

    Electric insulation is required in a tokamak fusion reactor to prevent damages of pipes and vessels due to a transient electromagnetic force during a plasma disruption. Stainless steel/ceramic/stainless steel functionally gradient material (FGM) has been proposed and developed as the high electric resistant element for the components. It can be welded to a usual pipe or vessel wall at both ends of the material, and expected as a reliable highly resistant element under fusion reactor environment. In this study, an elastic stress analysis was performed to prevent crack generation after sintering of the material. Following the result, several tubular FGM elements were successfully manufactured. (author)

  15. Investigation of possibility of creation of radiation resistance sensors for physical information based on fiber materials

    Science.gov (United States)

    Baskov, P. B.; Chebyshov, S. B.; Kadilin, V. V.; Sakharov, V. V.; Mosyagina, I. V.

    2016-02-01

    The results of physical and material science and technological development of new materials of radiation photonics - nano- and microstructure of radiation-sensitive and radiation- resistant optical glass and fibers based on quartz are presented in the report. The possibility of their application in neutron diagnostics devices of nuclear power objects are considered. Component and construction options for the radiation-sensitive fiber and glass materials (with isotopes 10B, 6Li, Gd, ions of Nd3+, Ce3+ etc.), in which radiation resistance is achieved through the organization of areas of "drain" and annihilation of radiation-induced defects are considered.

  16. Quantum Hall resistance standards from graphene grown by chemical vapor deposition on silicon carbide

    OpenAIRE

    Lafont, F.; Ribeiro-Palau, R.; Kazazis, D.; Michon, A.; Couturaud, O.; Consejo, C.; Chassagne, T.; Zielinski, M; Portail, M.; Jouault, B.; F. Schopfer; Poirier, W.

    2014-01-01

    Replacing GaAs by graphene to realize more practical quantum Hall resistance standards (QHRS), accurate to within $10^{-9}$ in relative value, but operating at lower magnetic fields than 10 T, is an ongoing goal in metrology. To date, the required accuracy has been reported, only few times, in graphene grown on SiC by sublimation of Si, under higher magnetic fields. Here, we report on a device made of graphene grown by chemical vapour deposition on SiC which demonstrates such accuracies of th...

  17. Composite piping: basic materials, manufacturing methods, hydrolysis resistance. Bibliographical data and state of the art

    International Nuclear Information System (INIS)

    EDF has decided to replace traditional materials by glass reinforced plastic for the manufacture of certain PWR water piping. However, these are liable to in-service degradation through the hydrolysis of the operating conditions which can involve mechanical stresses or specific temperature and humidity conditions. These resins have been the subject of bibliographical surveys and laboratory experiments providing the following main results: the water diffusion in the selected thermoset resins (polyester, vinyl-ester, epoxy) can reach one percent in weight, according to the relative humidity and temperature; the water absorption is a reversible phenomenon, at the beginning and is followed by hydrolysis, an irreversible deterioration affecting the chemical functions of the polymeric chain. Thermally activated, the reaction limits the temperature for the use of these resins; polyester resins are made of a large number of ester bonds and are highly sensitive to hydrolysis. These resins can be classified on the basis of the alcohol and acid which they come acid. A possible hydrolytic degradation does not prevent from using these resins in humid environments. The cooling towers in Belleville, Nogent ad Chooz are equipped with water collecting channels made of polyester laminates which have behaved satisfactorily since their installation in 1982. In acid environments, even concentrated, resins have a better behavior than in a neutral medium. However, they can be liable to stress corrosion. Polyester resins ar not suitable for use in concentrated base media. Vinyl-ester resins are more appropriate for this purpose, although their resistance will be lower than in a neutral environment. When resins are used as a matrix for composites, the presence of glass fibers modifies their behavior. The physico-chemical protection of the fiber/matrix interfaces and of the surface of the glass itself through the sizing of the fibers plays key role in the durability of the composites, which

  18. Down Select Report of Chemical Hydrogen Storage Materials, Catalysts, and Spent Fuel Regeneration Processes - May 2008

    Energy Technology Data Exchange (ETDEWEB)

    Ott, Kevin C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Linehan, Sue [Rohm and Haas, Philadelphia, PA (United States); Lipiecki, Frank [Rohm and Haas, Philadelphia, PA (United States); Christopher, Aardahl L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2008-05-12

    Chemical Hydrogen Storage Center of Excellence FY2008 Second Quarter Milestone Report: Technical report describing assessment of hydrogen storage materials and progress towards meeting DOE’s hydrogen storage targets.

  19. Solution-based Chemical Strategies to Purposely Control the Microstructure of Functional Materials

    Institute of Scientific and Technical Information of China (English)

    Fei LIU; Congting SUN; Chenglin YAN; Dongfeng XUE

    2008-01-01

    Micro/nanostructured crystals with controlled architectures are desirable for many applications in optics, electronics, biology, medicine, and energy conversions. Low-temperature, aqueous chemical routes have been widely investigated for the synthesis of particles, and arrays of oriented nanorods and nanotubes. In this paper, based on the ideal crystal shapes predicted by the chemical bonding theory, we have developed some potential chemical strategies to tune the microstructure of functional materials, ZnS and Nb2O5 nanotube arrays, MgO wiskers and nestlike spheres, and cubic phase Cu2O microcrystals were synthesized here to elucidate these strategies. We describe their controlled crystallization processes and illustrate the detailed key factors controlling their growth by examining various reaction parameters. Current results demonstrate that our designed chemical strategies for tuning microstructure of functional materials are applicable to several technologically important materials, and therefore may be used as a versatile and effective route to the controllable synthesis of other inorganic functional materials.

  20. Down Select Report of Chemical Hydrogen Storage Materials, Catalysts, and Spent Fuel Regeneration Processes

    International Nuclear Information System (INIS)

    The DOE Hydrogen Storage Program is focused on identifying and developing viable hydrogen storage systems for onboard vehicular applications. The program funds exploratory research directed at identifying new materials and concepts for storage of hydrogen having high gravimetric and volumetric capacities that have the potential to meet long term technical targets for onboard storage. Approaches currently being examined are reversible metal hydride storage materials, reversible hydrogen sorption systems, and chemical hydrogen storage systems. The latter approach concerns materials that release hydrogen in endothermic or exothermic chemical bond-breaking processes. To regenerate the spent fuels arising from hydrogen release from such materials, chemical processes must be employed. These chemical regeneration processes are envisioned to occur offboard the vehicle

  1. Down Select Report of Chemical Hydrogen Storage Materials, Catalysts, and Spent Fuel Regeneration Processes

    Energy Technology Data Exchange (ETDEWEB)

    Ott, Kevin; Linehan, Sue; Lipiecki, Frank; Aardahl, Christopher L.

    2008-08-24

    The DOE Hydrogen Storage Program is focused on identifying and developing viable hydrogen storage systems for onboard vehicular applications. The program funds exploratory research directed at identifying new materials and concepts for storage of hydrogen having high gravimetric and volumetric capacities that have the potential to meet long term technical targets for onboard storage. Approaches currently being examined are reversible metal hydride storage materials, reversible hydrogen sorption systems, and chemical hydrogen storage systems. The latter approach concerns materials that release hydrogen in endothermic or exothermic chemical bond-breaking processes. To regenerate the spent fuels arising from hydrogen release from such materials, chemical processes must be employed. These chemical regeneration processes are envisioned to occur offboard the vehicle.

  2. Materials ``alchemy'': Shape-preserving chemical transformation of micro-to-macroscopic 3-D structures

    Science.gov (United States)

    Sandhage, Kenneth H.

    2010-06-01

    The scalable fabrication of nano-structured materials with complex morphologies and tailorable chemistries remains a significant challenge. One strategy for such synthesis consists of the generation of a solid structure with a desired morphology (a “preform”), followed by reactive conversion of the preform into a new chemistry. Several gas/solid and liquid/solid reaction processes that are capable of such chemical conversion into new micro-to-nano-structured materials, while preserving the macroscopic-to-microscopic preform morphologies, are described in this overview. Such shape-preserving chemical transformation of one material into another could be considered a modern type of materials “alchemy.”

  3. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  4. Nanoscale layered double hydroxide materials for corrosion resistance

    OpenAIRE

    Rangel, C. M.; Travassos, Maria Antónia

    2007-01-01

    Layered Double Hydroxides (LDHμs), represented by the general formula [MII (1-x)MIIIx(OH)2[An-x/n].zH2O or [MIMIII2(OH)6[An-1/n].zH2O], where MI, MII, MIII are mono-, di- and tri-valent metal cations, are being researched as anion-exchange materials which interesting intercalation chemistry that accommodate a wide range of applications from heterogeneous catalysis to storage and subsequent controlled release of bioactive agents. In this work, layered double hydroxides containing a monovalent...

  5. Seismic resistant materials-handling machines for NPPs

    International Nuclear Information System (INIS)

    Basic concepts of the theory of seismic stability of load-carrying metalworks of movable materials-handling machines (MHM) using the linear-spectral method and the method of spatial finite elements are developed for the first time in monography in native practice. Calculational and mathematical models are formed for systems with distributed and concentrated parameters. Special attention is paid to software of computerized designing and to the methods of estimation of reliability of spatial MHM metalworks under operation loadings and seismic effects. Illustrations of such calculations are presented. 140 refs

  6. Cell Colonization Control by Physical and Chemical Modification of Materials

    Czech Academy of Sciences Publication Activity Database

    Bačáková, Lucie; Švorčík, V.

    New York : Nova Science Publisher, 2008 - (Kimura, D.), s. 5-56 ISBN 978-1-60456-132-6 R&D Projects: GA AV ČR(CZ) KAN400480701; GA AV ČR(CZ) KAN101120701; GA AV ČR(CZ) IAA5011301; GA AV ČR(CZ) 1QS500110564; GA ČR(CZ) GA204/06/0225; GA ČR(CZ) GA101/06/0226 Grant ostatní: GA Mšk(CZ) LC06041 Institutional research plan: CEZ:AV0Z50110509 Keywords : material surface modification * nanostructure * cell culture Subject RIV: EI - Biotechnology ; Bionics

  7. Study on stochastic phenomena induced in chemically amplified poly(4-hydroxystyrene-co-t-butyl methacrylate) resist (high performance model resist for extreme ultraviolet lithography)

    Science.gov (United States)

    Kozawa, Takahiro; Santillan, Julius J.; Itani, Toshiro

    2016-03-01

    Understanding of stochastic phenomena is essential to the development of highly sensitive resist for nanofabrication. In this study, we investigated the stochastic effects in a chemically amplified resist consisting of poly(4-hydroxystyrene-co-t-butyl methacrylate), triphenylsulfonium nonafluorobutanesulfonate (an acid generator), and tri-n-octylamine (a quencher). The SEM images of resist patterns were analyzed, using Monte Carlo simulation on the basis of the sensitization and reaction mechanisms of chemically amplified extreme ultraviolet resists. It was estimated that +/-0.82σ fluctuation of the number of protected units per polymer molecule led to line edge roughness formation. Here, σ is the standard deviation of the number of protected units per polymer molecule after postexposure baking.

  8. Numerical Simulation for Thermal Shock Resistance of Thermal Protection Materials Considering Different Operating Environments

    OpenAIRE

    Li, Weiguo; Li, Dingyu; Wang, Ruzhuan; Fang, Daining

    2013-01-01

    Based on the sensitivities of material properties to temperature and the complexity of service environment of thermal protection system on the spacecraft, ultrahigh-temperature ceramics (UHTCs), which are used as thermal protection materials, cannot simply consider thermal shock resistance (TSR) of the material its own but need to take the external constraint conditions and the thermal environment into full account. With the thermal shock numerical simulation on hafnium diboride (HfB2), a det...

  9. Safeguards on nuclear materials and chemical analyses for fuel fabrication

    International Nuclear Information System (INIS)

    Spectrofluorimetry with benzoin and spectrophotometry with methylene blue have been tried to develop a routine analytical method of determining trace amount of boron in nuclear and cladding materials. Both methods may be utilized for the boron micro-analysis although many technical difficulties are still expected. A satisfactory procedure by a pyrohydrolysis technique is established and applicable to the determination of fluoride in nuclear materials with ion selective electrode after separation from the uranium matrix. Beryllium in the Be-coating laboratory has been monthly monitored and its contamination stays well below the maximum permissible concentration. A preliminary survey on the possible recovery of NH4NO3 from the liquid waste of the uranium conversion process reveals that it is more practical to recover NH3 and NO3 independently rather than to treat the liquid waste directly to obtain in the form of NH4NO3. Several methods should be combined to solve the problem more efficiently. Finally, safeguards activities are summarized

  10. Chemical materials and their regulation of the movement of molecules.

    Science.gov (United States)

    Langer, Robert

    2015-11-01

    Materials chemistry has been fundamental to the enormous field that encompasses the delivery of molecules both to desired sites and/or at desired rates and durations. The field encompasses the delivery of molecules including fertilizers, pesticides, herbicides, food ingredients, fragrances and biopharmaceuticals. A personal perspective is provided on our early work in this field that has enabled the controlled release of ionic substances and macromolecules. Also discussed are new paradigms in creating biomaterials for human use, the non-invasive delivery of molecules through the skin and lungs, the development of intelligent delivery systems and extensions to nanomedicine. With the advent of potentially newer biopharmaceutics such as siRNA, mRNA and gene editing approaches and their use being limited by delivery, future research in this field may be more critical than ever before. PMID:26537401

  11. Chemical analysis and biological testing of materials from the EDS coal liquefaction process: a status report

    Energy Technology Data Exchange (ETDEWEB)

    Later, D.W.; Pelroy, R.A.; Wilson, B.W.

    1984-05-01

    Representative process materials were obtained from the EDS pilot plant for chemical and biological analyses. These materials were characterized for biological activity and chemical composition using a microbial mutagenicity assay and chromatographic and mass spectrometric analytical techniques. The two highest boiling distillation cuts, as well as process solvent (PS) obtained from the bottoms recycle mode operation, were tested for initiation of mouse skin tumorigenicity. All three materials were active; the crude 800/sup 0 +/F cut was substantially more potent than the crude bottoms recycle PS or 750 to 800/sup 0/F distillate cut. Results from chemical analyses showed the EDS materials, in general, to be more highly alkylated and have higher hydroaromatic content than analogous SRC II process materials (no in-line process hydrogenation) used for comparison. In the microbial mutagenicity assays the N-PAC fractions showed greater activity than did the aliphatic hydrocarbon, hydroxy-PAH, or PAH fractions, although mutagenicity was detected in certain PAH fractions by a modified version of the standard microbial mutagenicity assay. Mutagenic activities for the EDS materials were lower, overall, than those for the corresponding materials from the SRC II process. The EDS materials produced under different operational modes had distinguishable differences in both their chemical constituency and biological activity. The primary differences between the EDS materials studied here and their SRC II counterparts used for comparison are most likely attributable to the incorporation of catalytic hydrogenation in the EDS process. 27 references, 28 figures, 27 tables.

  12. Physical–chemical properties, separation performance, and fouling resistance of mixed-matrix ultrafiltration membranes

    KAUST Repository

    Hoek, Eric M.V.

    2011-12-01

    Herein we report on the formation and characterization of mixed-matrix ultrafiltration (UF) membranes hand-cast by nonsolvent induced phase inversion. We evaluated nanometer-to-micrometer sized inorganic fillers (silver, copper, silica, zeolite, and silver-zeolite) materials with polysulfone (PSf) as the polymeric dispersing matrix. In general, mixed-matrix membranes were rougher, more hydrophilic, and more mechanically robust. Only sub-micron zeolite-PSf mixed-matrix membranes exhibited simultaneous improvements in water permeability and solute selectivity; all other mixed-matrix membranes were more permeable, but less selective due to defects associated with poor polymer-filler binding. Protein and bacterial fouling resistance of mixed-matrix membranes containing silver, zeolite, and silver-zeolite nanoparticles were compared to a low-fouling, poly(acrylonitrile) (PAN) UF membrane. Zeolite and silver containing membranes exhibited better protein fouling resistance (due to higher hydrophilicity), whereas silver and silver-zeolite based membranes produce better bacterial fouling resistance due to antimicrobial properties. Overall, zeolite-PSf and silver exchanged zeolite-PSf membranes offered the best combination of improved permeability, selectivity, and fouling resistance - superior to the commercial PAN membrane. © 2011 Elsevier B.V.

  13. Optimization of chemical structure of Schottky-type selection diode for crossbar resistive memory.

    Science.gov (United States)

    Kim, Gun Hwan; Lee, Jong Ho; Jeon, Woojin; Song, Seul Ji; Seok, Jun Yeong; Yoon, Jung Ho; Yoon, Kyung Jean; Park, Tae Joo; Hwang, Cheol Seong

    2012-10-24

    The electrical performances of Pt/TiO(2)/Ti/Pt stacked Schottky-type diode (SD) was systematically examined, and this performance is dependent on the chemical structures of the each layer and their interfaces. The Ti layers containing a tolerable amount of oxygen showed metallic electrical conduction characteristics, which was confirmed by sheet resistance measurement with elevating the temperature, transmission line measurement (TLM), and Auger electron spectroscopy (AES) analysis. However, the chemical structure of SD stack and resulting electrical properties were crucially affected by the dissolved oxygen concentration in the Ti layers. The lower oxidation potential of the Ti layer with initially higher oxygen concentration suppressed the oxygen deficiency of the overlying TiO(2) layer induced by consumption of the oxygen from TiO(2) layer. This structure results in the lower reverse current of SDs without significant degradation of forward-state current. Conductive atomic force microscopy (CAFM) analysis showed the current conduction through the local conduction paths in the presented SDs, which guarantees a sufficient forward-current density as a selection device for highly integrated crossbar array resistive memory. PMID:22999222

  14. Disruptive environmental chemicals and cellular mechanisms that confer resistance to cell death.

    Science.gov (United States)

    Narayanan, Kannan Badri; Ali, Manaf; Barclay, Barry J; Cheng, Qiang Shawn; D'Abronzo, Leandro; Dornetshuber-Fleiss, Rita; Ghosh, Paramita M; Gonzalez Guzman, Michael J; Lee, Tae-Jin; Leung, Po Sing; Li, Lin; Luanpitpong, Suidjit; Ratovitski, Edward; Rojanasakul, Yon; Romano, Maria Fiammetta; Romano, Simona; Sinha, Ranjeet K; Yedjou, Clement; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Brown, Dustin G; Ryan, Elizabeth P; Colacci, Annamaria; Hamid, Roslida A; Mondello, Chiara; Raju, Jayadev; Salem, Hosni K; Woodrick, Jordan; Scovassi, A Ivana; Singh, Neetu; Vaccari, Monica; Roy, Rabindra; Forte, Stefano; Memeo, Lorenzo; Kim, Seo Yun; Bisson, William H; Lowe, Leroy; Park, Hyun Ho

    2015-06-01

    Cell death is a process of dying within biological cells that are ceasing to function. This process is essential in regulating organism development, tissue homeostasis, and to eliminate cells in the body that are irreparably damaged. In general, dysfunction in normal cellular death is tightly linked to cancer progression. Specifically, the up-regulation of pro-survival factors, including oncogenic factors and antiapoptotic signaling pathways, and the down-regulation of pro-apoptotic factors, including tumor suppressive factors, confers resistance to cell death in tumor cells, which supports the emergence of a fully immortalized cellular phenotype. This review considers the potential relevance of ubiquitous environmental chemical exposures that have been shown to disrupt key pathways and mechanisms associated with this sort of dysfunction. Specifically, bisphenol A, chlorothalonil, dibutyl phthalate, dichlorvos, lindane, linuron, methoxychlor and oxyfluorfen are discussed as prototypical chemical disruptors; as their effects relate to resistance to cell death, as constituents within environmental mixtures and as potential contributors to environmental carcinogenesis. PMID:26106145

  15. Corrosion resistant chemical vapor deposited coatings for SiC and Si3N4

    OpenAIRE

    Graham, David W

    1993-01-01

    Silicon carbide and silicon nitride turbine engine components are susceptible to hot corrosion by molten sodium sulfate salts which are formed from impurities in the engine's fuel and air intake. Several oxide materials were identified which may be able to protect these components from corrosion and preserve their structural properties. Ta20, coatings were identified as one of the most promising candidates. Thermochemical calculations showed that the chemical vapor deposition(CVD) of tantalum...

  16. Influence Of Volcanic Scoria On Mechanical Strength, Chemical Resistance And Drying Shrinkage Of Mortars

    Directory of Open Access Journals (Sweden)

    Al-Swaidani A.

    2014-09-01

    Full Text Available In the study, three types of cement have been prepared; one CEM I type (the control sample and two blended cements: CEM II/A-P and CEM II/B-P (EN 197-1, each of them with three replacement levels of volcanic scoria: (10 %, 15 %, 20 % wt. and (25 %, 30 %, 35 % wt., respectively. Strength development of mortars has been investigated at 2, 7, 28 and 90 days curing. Evaluation of chemical resistance of mortars containing scoria-based cements has been investigated through exposure to 5 % sulphate and 5 % sulphuric acid solutions in accordance with ASTM C1012 & ASTM 267, respectively. Drying shrinkage has been evaluated in accordance with ASTM C596. Test results showed that at early ages, the mortars containing CEM II/B-P binders had strengths much lower than that of the control mortar. However, at 90 days curing, the strengths were comparable to the control mortar. In addition, the increase of scoria significantly improved the sulphate resistance of mortars. Further, an increase in scoria addition improved the sulphuric acid resistance of mortar, especially at the early days of exposure. The results of drying shrinkage revealed that the CEM II/B-P mortar bars exhibited a greater contraction when compared to the control mortar, especially at early ages. However, drying shrinkage of mortars was not influenced much at longer times.

  17. Enhancing the Scratch Resistance by Introducing Chemical Bonding in Highly Stretchable and Transparent Electrodes.

    Science.gov (United States)

    Guo, Chuan Fei; Chen, Yan; Tang, Lu; Wang, Feng; Ren, Zhifeng

    2016-01-13

    Stretchable transparent electrodes are key elements in flexible electronics and e-skins. However, existing stretchable transparent electrodes, including graphene sheets, carbon nanotube, and metal nanowire networks, weakly adheres to the substrate by van der Waals forces. Such electrodes suffer from poor scratch-resistance or poor durability, and this issue has been one of the biggest problems for their applications in industry. Here we show that, by introducing a Au-S bond between a Au nanomesh (AuNM) and the underlying elastomeric substrate, the AuNM strongly adheres to the substrate and can withstand scratches of a pressure of several megapascals. We find that the strong chemical bond, on the other hand, leads to a stiffening effect and localized rupture of the AuNM upon stretching; thus the stretchability is poor. A prestraining process is applied to suppress the localized rupture and has successfully improved the stretchability: electrical resistance of the prestrained AuNM exhibits modest change by one-time stretching to 160%, or repeated stretching to 50% for 25 000 cycles. This conductor is an ideal platform for robust stretchable photoelectronics. The idea of introducing a covalent bond to improve the scratch-resistance may also be applied to other systems including Ag nanowire films, carbon nanotube films, graphene, and so forth. PMID:26674364

  18. Determination of the EOS maragingsteel MS1 material resistance at low temperatures

    Directory of Open Access Journals (Sweden)

    J. Dobránsky

    2016-07-01

    Full Text Available This article deals with determination of the EOS MaragingSteel MS1 material resistance at different low temperatures. Material resistance was evaluated in two types of standardized specimens. The impact energy at the specimens tested at 10 °C, values for the specimens with no notch were compared to the V - notch specimens, higher by approximately one - third. When the temperature dropped to 0 °C, the values of the impact energy slightly decreased as well. It therefore follows that lower temperatures result in decrease in the values of the impact strength. This experiment provided us with the opportunity to find out whether the decrease in temperature impacts the resistance of the tested material.

  19. Supercritical fluid processing: opportunities for new resist materials and processes

    Science.gov (United States)

    Gallagher-Wetmore, Paula M.; Ober, Christopher K.; Gabor, Allen H.; Allen, Robert D.

    1996-05-01

    Over the past two decades supercritical fluids have been utilized as solvents for carrying out separations of materials as diverse as foods, polymers, pharmaceuticals, petrochemicals, natural products, and explosives. More recently they have been used for non-extractive applications such as recrystallization, deposition, impregnation, surface modification, and as a solvent alternative for precision parts cleaning. Today, supercritical fluid extraction is being practiced in the foods and beverage industries; there are commercial plants for decaffeinating coffee and tea, extracting beer flavoring agents from hops, and separating oils and oleoresins from spices. Interest in supercritical fluid processing of polymers has grown over the last ten years, and many new purification, fractionation, and even polymerization techniques have emerged. One of the most significant motivations for applying this technology to polymers has been increased performance demands. More recently, with increasing scrutiny of traditional solvents, supercritical fluids, and in particular carbon dioxide, are receiving widespread attention as 'environmentally conscious' solvents. This paper describes several examples of polymers applications, including a few involving photoresists, which demonstrate that as next- generation advanced polymer systems emerge, supercritical fluids are certain to offer advantages as cutting edge processing tools.

  20. Counterfeit-resistant materials and a method and apparatus for authenticating materials

    Science.gov (United States)

    Ramsey, J. Michael; Klatt, Leon N.

    2000-01-01

    Fluorescent dichroic fibers randomly incorporated within a media provide an improved method for authentication and counterfeiting protection. The dichroism is provided by an alignment of fluorescent molecules along the length of the fibers. The fluorescent fibers provide an authentication mechanism of varying levels of capability. The authentication signature depends on four parameters; the x,y position, the dichroism and the local environment. The availability of so many non-deterministic variables makes production of counterfeit articles (e.g., currency, credit cards, etc.) essentially impossible. Counterfeit-resistant articles, an apparatus for authenticating articles, and a process for forming counterfeit-resistant media are also provided.

  1. Electrical, structural and chemical characterization of Si sheet material

    Science.gov (United States)

    Ast, D. G.

    Web Dendritic Si ribbons are deformed under a well-defined four point bending stress. Since the mechanical properties of Si are known to depend on the 0 content of the material, 0 measurements using Fourier Transform Infrared Spectroscopy were done to determine a proper control sample of non-defected single crystal Si. Four point bending revealed a unique two step bending behavior for the Web Si ribbons. An initial theory for this behavior involves the interaction of the dislocations generated by the deformation with the central twin planes of the ribbons. Measurements showed a uniformly high 0 content for the Web Si ribbons, approximately 10 to the 18th power atoms/cu.cm. The Web samples had a much broader absorption peak at 9 microns than is usually seen for well-annealed single crystal Si. This broadening is thought to be related to stress in the Web Si ribbons. Two samples containing a known amount of residual stress support this hypothesis. Also, a shoulder on the infrared absorption peak associated with interstitial 0 in Si appears in the transmission vs. wavenumber plots for some of the Web samples. This shoulder has been associated with 0-vacancy complexes or with 0 at dislocations. The O content and configuration do not seem to correlate with the growth configuration of the Web Si ribbon.

  2. Materials of 45. Scientific Assembly of Polish Chemical Society. Volumes 1-3

    International Nuclear Information System (INIS)

    Scientific assemblies of Polish Chemical Society are the most important chemical meeting organised annually in Poland. Basic as well as application studies in all chemical branches have been extensively presented. The next subjects was proposed as scientific sessions and symposia topics: organic chemistry, inorganic chemistry, physical chemistry, analytical chemistry, technology and chemical engineering, polymer chemistry, solid state chemistry, catalysis, biological chemistry, chemistry and technology of coal, environmental protection, didactics of chemistry, history of chemistry, young scientist forum, flow analysis, and high-energy materials

  3. Los Alamos National Laboratory Center for direct chemical analysis of materials

    International Nuclear Information System (INIS)

    The Center for Direct Chemical Analysis at Los Alamos National Laboratory is undertaking a major effort to develop, improve, and implement direct analysis techniques for radionuclide, organic, and inorganic constituents. The Center consists of a multidisciplinary team of researchers who possess expertise in the quantitative and qualitative characterization of solid materials using a variety of analytical technologies. Materials include soils and sludges, building materials, foods, chemicals, and atmospheric gases. Direct chemical analysis techniques measure the analytes directly in the solid material with minimal sample pretreatment, whereas conventional techniques, such as atomic absorption and emission spectrochemistry, require that the solid materials be rendered in aqueous solution using concentrated acids prior to measurement. Direct chemical analysis completely bypasses the digestion process, thereby increasing the sample throughout and saving both time and money. Direct chemical analysis is unique in that it alone can conduct certain specialized but highly useful types of analysis, such as depth-profiling and the chemical structural characterization of surfaces. In addition, some direct analytical techniques eliminate the sampling step and permit rapid analysis of samples at the point of origin. Direct analysis in situ would further reduce costs and potential hazards related to sample collection and transport to the analytical laboratory

  4. Thermal and Chemical Characterization of Non-Metallic Materials Using Coupled Thermogravimetric Analysis and Infrared Spectroscopy

    Science.gov (United States)

    Huff, Timothy L.

    2002-01-01

    Thermogravimetric analysis (TGA) is widely employed in the thermal characterization of non-metallic materials, yielding valuable information on decomposition characteristics of a sample over a wide temperature range. However, a potential wealth of chemical information is lost during the process, with the evolving gases generated during thermal decomposition escaping through the exhaust line. Fourier Transform-Infrared spectroscopy (FT-IR) is a powerful analytical technique for determining many chemical constituents while in any material state, in this application, the gas phase. By linking these two techniques, evolving gases generated during the TGA process are directed into an appropriately equipped infrared spectrometer for chemical speciation. Consequently, both thermal decomposition and chemical characterization of a material may be obtained in a single sample run. In practice, a heated transfer line is employed to connect the two instruments while a purge gas stream directs the evolving gases into the FT-IR. The purge gas can be either high purity air or an inert gas such as nitrogen to allow oxidative and pyrolytic processes to be examined, respectively. The FT-IR data is collected realtime, allowing continuous monitoring of chemical compositional changes over the course of thermal decomposition. Using this coupled technique, an array of diverse materials has been examined, including composites, plastics, rubber, fiberglass epoxy resins, polycarbonates, silicones, lubricants and fluorocarbon materials. The benefit of combining these two methodologies is of particular importance in the aerospace community, where newly developing materials have little available data with which to refer. By providing both thermal and chemical data simultaneously, a more definitive and comprehensive characterization of the material is possible. Additionally, this procedure has been found to be a viable screening technique for certain materials, with the generated data useful in

  5. Materials of the yearly scientific assembly of the Polish Chemical Society - Torun'93: chemistry of new materials

    International Nuclear Information System (INIS)

    Scientific conference accompanied the assembly of Polish Chemical Society has been held in 1993 in Torun. The conference has been divided into 12 sections and 4 symposia covering the most important research fields in chemistry. The general view on scientific progress has been presented during the plenary session. Then proceedings have performed in specialist sessions on: contemporary methods in organic chemistry chemistry, chemistry and physico-chemistry of polymers, coordination chemistry state-of-the-art prospects, absorption and absorbents, new chemical technologies of organic compounds, new chemical technologies of inorganic compounds, environment protection, new methods in analytical chemistry, photochemistry and chemical kinetics, crystallochemistry, history of chemistry and didactics, new substances in health protection, membranes and membrane techniques, electroactive organic compounds, zeolites - material properties

  6. Study of heat resistance in the materials under high-speed heating

    International Nuclear Information System (INIS)

    The method and installation to determine heat resistance in materials at high heating rates (up to 106 K/s) according to the temperautre gradient between the surface and the core of the specimen which results in the destruction of the material tested are described. The temperature gradient occurs because of the skin effect when a high-frequency current pulse passes through the specimen. Using the method suggested investigation of molybdenum and tantalum heat resistance is carried out. It is shown that under conditions of pulse heating tantalum heat resistsance is higher

  7. Effects of chemical kinetics and starting material regeneration on the efficiency of an iodine laser amplifier

    International Nuclear Information System (INIS)

    A model of the chemical kinetics occurring in an iodine laser amplifier is presented and used to calculate the degree to which the starting material is consumed as a result of laser operation. The cost of purchasing new starting material is estimated and shown to be prohibitive. A scheme for regenerating the starting material from the species present in the amplifier after lasing is proposed. It is shown that the estimated efficiency of this chemical regeneration process is appreciably higher than the projected optimum efficiency of the pumping process

  8. Effects of chemical kinetics and starting material regeneration on the efficiency of an iodine laser amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, G.A.

    1977-05-01

    A model of the chemical kinetics occurring in an iodine laser amplifier is presented and used to calculate the degree to which the starting material is consumed as a result of laser operation. The cost of purchasing new starting material is estimated and shown to be prohibitive. A scheme for regenerating the starting material from the species present in the amplifier after lasing is proposed. It is shown that the estimated efficiency of this chemical regeneration process is appreciably higher than the projected optimum efficiency of the pumping process.

  9. Human genetic marker for resistance to radiations and chemicals. 1998 annual progress report

    International Nuclear Information System (INIS)

    'The broad objective of the project is to understand the molecular basis for the response of cells to radiations and chemicals, with the pragmatic goal of being able to identify human subpopulations that are exceptionally sensitive to DNA damaging agents. The project focuses on HRAD9, a human orthologue of the fission yeast Schizosaccharomyces pombe gene rad9. S. pombe rad9::ura4+ mutant cells are highly sensitive to ionizing radiation, UV and many chemicals, such as the DNA synthesis inhibitor hydroxyurea. They also lack the ability to delay cycling transiently in S phase or in G2 following a block in DNA replication or after incurring DNA damage, respectively -i.e., they lack checkpoint controls. The attempt by mutant cells to progress through mitosis in the absence of fully intact DNA accounts at least in part for their sensitivity to DNA damaging agents. Cells bearing rad9::ura4+ also aberrantly regulate UVDE, an enzyme that participates in a secondary DNA excision repair pathway. The key role played by S. pombe rad9 in promoting resistance to chemicals and radiations suggests that the evolutionarily conserved human cognate also has important functions in mammals. The first set of aims in this proposal centers on characterizing the structure and expression of HRAD9, to assess structure/function relationships and potentially link protein activity to a specific tissue. The next set of aims focuses on determining the role of HRAD9 in radio/chemoresponsiveness and cancer.'

  10. NUMATH: a nuclear-material-holdup estimator for unit operations and chemical processes

    International Nuclear Information System (INIS)

    A computer program, NUMATH (Nuclear Material Holdup Estimator), has been developed to estimate compositions of materials in vessels involved in unit operations and chemical processes. This program has been implemented in a remotely operated nuclear fuel processing plant. NUMATH provides estimates of the steady-state composition of materials residing in process vessels until representative samples can be obtained and chemical analyses can be performed. Since these compositions are used for inventory estimations, the results are determined for the cataloged in container-oriented files. The estimated compositions represent materials collected in applicable vessels - including consideration for materials previously acknowledged in these vessels. The program utilizes process measurements and simple performance models to estimate material holdup and distribution within unit operations. In simulated run-testing, NUMATH typically produced estimates within 5% of the measured inventories for uranium and within 8% of the measured inventories for thorium during steady-state process operation

  11. Not Just Lumber—Using Wood in the Sustainable Future of Materials, Chemicals, and Fuels

    Science.gov (United States)

    Jakes, Joseph E.; Arzola, Xavier; Bergman, Rick; Ciesielski, Peter; Hunt, Christopher G.; Rahbar, Nima; Tshabalala, Mandla; Wiedenhoeft, Alex C.; Zelinka, Samuel L.

    2016-07-01

    Forest-derived biomaterials can play an integral role in a sustainable and renewable future. Research across a range of disciplines is required to develop the knowledge necessary to overcome the challenges of incorporating more renewable forest resources in materials, chemicals, and fuels. We focus on wood specifically because in our view, better characterization of wood as a raw material and as a feedstock will lead to its increased utilization. We first give an overview of wood structure and chemical composition and then highlight current topics in forest products research, including (1) industrial chemicals, biofuels, and energy from woody materials; (2) wood-based activated carbon and carbon nanostructures; (3) development of improved wood protection treatments; (4) massive timber construction; (5) wood as a bioinspiring material; and (6) atomic simulations of wood polymers. We conclude with a discussion of the sustainability of wood as a renewable forest resource.

  12. Not Just Lumber--Using Wood in the Sustainable Future of Materials, Chemicals, and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Jakes, Joseph E.; Arzola, Xavier; Bergman, Rick; Ciesielski, Peter; Hunt, Christopher G.; Rahbar, Nima; Tshabalala, Mandla; Wiedenhoeft, Alex C.; Zelinka, Samuel L.

    2016-09-01

    Forest-derived biomaterials can play an integral role in a sustainable and renewable future. Research across a range of disciplines is required to develop the knowledge necessary to overcome the challenges of incorporating more renewable forest resources in materials, chemicals, and fuels. We focus on wood specifically because in our view, better characterization of wood as a raw material and as a feedstock will lead to its increased utilization. We first give an overview of wood structure and chemical composition and then highlight current topics in forest products research, including (1) industrial chemicals, biofuels, and energy from woody materials; (2) wood-based activated carbon and carbon nanostructures; (3) development of improved wood protection treatments; (4) massive timber construction; (5) wood as a bioinspiring material; and (6) atomic simulations of wood polymers. We conclude with a discussion of the sustainability of wood as a renewable forest resource.

  13. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Directory of Open Access Journals (Sweden)

    Mehmet Isik

    2014-07-01

    Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

  14. Chemical and Structural Stability of Lithium-Ion Battery Electrode Materials under Electron Beam

    OpenAIRE

    Feng Lin; Isaac M. Markus; Doeff, Marca M.; Xin, Huolin L.

    2014-01-01

    The investigation of chemical and structural dynamics in battery materials is essential to elucidation of structure-property relationships for rational design of advanced battery materials. Spatially resolved techniques, such as scanning/transmission electron microscopy (S/TEM), are widely applied to address this challenge. However, battery materials are susceptible to electron beam damage, complicating the data interpretation. In this study, we demonstrate that, under electron beam irradiati...

  15. TM-MC: a database of medicinal materials and chemical compounds in Northeast Asian traditional medicine

    OpenAIRE

    Kim, Sang-Kyun; Nam, SeJin; Jang, Hyunchul; Kim, Anna; Lee, Jeong-Ju

    2015-01-01

    Background In traditional medicine, there has been a great deal of research on the effects exhibited by medicinal materials. To study the effects, resources that can systematically describe the chemical compounds in medicinal materials are necessary. In recent years, numerous databases on medicinal materials and constituent compounds have been constructed. However, because these databases provide differing information and the sources of such information are unclear or difficult to verify, it ...

  16. EVALUATION AND RECOMMENDATION OF SALTSTONE MIXER AUGER/PADDLES MATERIALS OF CONSTRUCTION FOR IMPROVED WEAR RESISTANCE

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.; Torres, R.

    2012-08-15

    Wear and corrosion testing were conducted to evaluate alternate materials of construction for the Saltstone mixer auger and paddles. These components have been degraded by wear from the slurry processed in the mixer. Material test options included PVD coatings (TiN, TiCN, and ZrN), weld overlays (Stellite 12 and Ultimet) and higher hardness steels and carbides (D2 and tungsten carbide). The corrosion testing demonstrated that the slurry is not detrimental to the current materials of construction or the new candidates. The ASTM G75 Miller wear test showed that the high hardness materials and the Stellite 12 weld overlay provide superior wear relative to the Astralloy and CF8M stainless steel, which are the current materials of construction, as well as the PVD coatings and Ultimet. The following recommendations are made for selecting new material options and improving the overall wear resistance of the Saltstone mixer components: A Stellite 12 weld overlay or higher hardness steel (with toughness equivalent to Astralloy) be used to improve the wear resistance of the Saltstone mixer paddles; other manufacturing specifications for the mixer need to be considered in this selection. The current use of the Stellite 12 weld overlay be evaluated so that coverage of the 316 auger can be optimized for improved wear resistance of the auger. The wear surfaces of the Saltstone mixer auger and paddles be evaluated so that laboratory data can be better correlated to actual service. The 2-inch Saltstone mixer prototype be used to verify material performance.

  17. Rutting and Fatigue Cracking Resistance of Waste Cooking Oil Modified Trinidad Asphaltic Materials

    Directory of Open Access Journals (Sweden)

    Rean Maharaj

    2015-01-01

    Full Text Available The influence of waste cooking oil (WCO on the performance characteristics of asphaltic materials indigenous to Trinidad, namely, Trinidad Lake Asphalt (TLA, Trinidad Petroleum Bitumen (TPB, and TLA : TPB (50 : 50 blend, was investigated to deduce the applicability of the WCO as a performance enhancer for the base asphalt. The rheological properties of complex modulus (G∗ and phase angle (δ were measured for modified base asphalt blends containing up to 10% WCO. The results of rheology studies demonstrated that the incremental addition of WCO to the three parent binders resulted in incremental decreases in the rutting resistance (decrease in G∗/sinδ values and increases in the fatigue cracking resistance (decrease in G∗sinδ value. The fatigue cracking resistance and rutting resistance for the TLA : TPB (50 : 50 blends were between those of the blends containing pure TLA and TPB. As operating temperature increased, an increase in the resistance to fatigue cracking and a decrease in the rutting resistance were observed for all of the WCO modified asphaltic blends. This study demonstrated the capability to create customized asphalt-WCO blends to suit special applications and highlights the potential for WCO to be used as an environmentally attractive option for improving the use of Trinidad asphaltic materials.

  18. Corrosion resistance of Ni-Cr-Mo alloys. Chemical composition and metallurgical condition's effects

    International Nuclear Information System (INIS)

    Ni-Cr-Mo alloys offer an outstanding corrosion resistance in a wide variety of highly-corrosive environments. This versatility is due to the excellent performance of nickel in hot alkaline solutions and the beneficial effect of chromium and molybdenum in oxidizing and reducing conditions, respectively. Alloy C-22 (22 % Cr-13 % Mo-3% W) is a well known versatile member of this family. Due to its excellent corrosion resistance in a wide variety of environments, Alloy C-22 has been selected for the fabrication of the corrosion-resistant outer shell of the high-level nuclear waste container. The increasing demand of the industry for corrosion resistant alloys with particular properties of corrosion and mechanical resistance has led to the development of new alloys. Alloy C-22HS (Ni-21 % Cr-17 % Mo) is a new high-strength corrosion resistant material recently developed and introduced into the market. This alloy provides a corrosion resistance comparable with that of other C-type alloys, and it can also be age hardened to effectively double its yield strength. HASTELLOY HYBRID-BC1 (Ni-22 % Mo-15 % Cr) is a new development intended for filling the gap between Ni-Mo and Ni-Cr-Mo alloys. This novel alloy is able to withstand HCl and H2SO4, even in the presence of dissolved oxygen and other oxidizing species. Its resistance to chloride-induced pitting corrosion, crevice corrosion and stress corrosion cracking is also remarkable. Thermal aging of Ni-Cr-Mo alloys leads to microstructure changes depending on the temperature range and exposure time at temperature. A Long Range Ordering (LRO) reaction can occur in the range of 350 C degrees to 600 C degrees, producing an ordered Ni2(Cr,Mo) phase. This ordering reaction does not seem to affect the corrosion resistance and produces only a slight loss in ductility. LRO transformation is homogeneous and has proven to be useful to fabricate the age-hard enable Alloy C22-HS. Tetrahedral Close Packed (TCP) phases, like μ, σ and P, may

  19. Development of oxidation resistant SiC/C compositionally gradient materials

    International Nuclear Information System (INIS)

    For the evaluation of oxidation characteristic for the trial production of SiC/C compositionally gradient carbon and SiC/C compositionally gradient carbon fiber reinforced carbon (CFRC) materials, which are composed of a surface SiC coating layer, an intermediate SiC/C layer and substrate material, the oxidation test in air at 800degC for up to 100 h was performed compared with each other three kinds version, i.e., substrate material, one with intermediate SiC/C layer and one coated by SiC layer. It was shown that SiC/C compositionally gradient material exhibited the best oxidation resistance among each substrate series, and the conception of SiC/C compositionally gradient material could be applied to carbon and CFRC materials as well as graphite material. (author)

  20. Behavior of leather as a protective heat barrier and fire resistant material

    OpenAIRE

    Bacardit Dalmases, Anna; Borràs Fillat, Maria Dolors; Soler Solé, Jaume; Herrero, Vicente; Jorge Sánchez, Juan; Ollé Otero, Lluís

    2010-01-01

    Leather is a natural material with many applications: automotive, domestic upholstery, buildings, aviation, maritime, personal safety, etc. For each of these sectors, fire behavior is a field of particular interest. Unfortunately, there are many testing methods and different flammability standards depending on material application and end use. Therefore, there are different ways of approaching the whole flammability issue. In this work, different approaches for analyzing the fire resistance o...

  1. The Influence of Material Type, Preparation Design, and Tooth Substrate on Fracture Resistance of Molar Onlays

    OpenAIRE

    Al Khalifah, Shahed Ali M.

    2016-01-01

    Tooth colored all ceramic restorations have been the treatment preference of many patients for esthetics and biocompatibility. This study aimed to test the fracture resistance of posterior ceramic onlays milled with computer-aided design and computer aided manufacturing (CAD/CAM) machines.The effects of material type, preparation design, and tooth substrate were evaluated using a full-block design. Ninety teeth were tested. Three different CAD/CAM ceramic onlay material types were included: a...

  2. Evaluation on electrical resistivity of silicon materials after electron beam melting

    Indian Academy of Sciences (India)

    Hafiz Muhammad Noor Ul Huda Khan Asghar; Shuang Shi; Dachuan Jiang; Yi Tan

    2015-09-01

    This research deals with the study of electron beam melting (EBM) methodology utilized in melting silicon material and subsequently discusses on the effect of oxygen level on electrical resistivity change after EBM process. The oxygen content was reduced from 6.177 to less than 0.0517 ppmw when refining time exceeded 10 min with removal efficiency of more than 99.08%. The average value of electrical resistivity of silicon before EBM processing was recorded to be 2.25 cm but with the increase in melting time that was applied through EBM, the electrical resistivity was recorded to go high in the range of 4–13 cm for different regions. The electrical resistivity values were greater in the top and the bottom regions, whereas lowest in the central region at all conditions of melting time. It is the result of the evaporation of oxygen during melting process and the segregation of metal impurities during solidification.

  3. Chemical insight into origin of forming-free resistive random-access memory devices

    KAUST Repository

    Wu, X.

    2011-09-29

    We demonstrate the realization of a forming-step free resistive random access memory (RRAM) device using a HfOx/TiOx/HfOx/TiOxmultilayer structure, as a replacement for the conventional HfOx-based single layer structure. High-resolution transmission electron microscopy (HRTEM), along with electron energy loss spectroscopy(EELS)analysis has been carried out to identify the distribution and the role played by Ti in the RRAM stack. Our results show that Ti out-diffusion into the HfOx layer is the chemical cause of forming-free behavior. Moreover, the capability of Ti to change its ionic state in HfOx eases the reduction-oxidation (redox) reaction, thus lead to the RRAM devices performance improvements.

  4. Corrosion resistance, composition and structure of RE chemical conversion coating on magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Golden yellow rare earths chemical conversion coating was obtained on the surface of magnesium alloy by immersing in cerium sulfate solution.The corrosion resistance of RE conversion coating was evaluated using immersion test and potentiodynamic polarization measurements in 3.5%NaCl solution.The morphologies of samples before corrosion and after corrosion were observed by SEM.The structures and compositions of the RE conversion coating were studied by means of XPS.XRD and IR.The results show that,the conversion coating consists of mainly two kinds of element Ce and O,the valences of cerium are+3 and+4.and OH exists in the coating.The anti-corrosion property of magnesium alloy is increased obviously by rare earths conversion coating,Its self-corrosion current density decreases and the coating has self-repairing capability in the corrosion process in 3.5%NaCl solution.

  5. The resistance of bacterial isolates from spacecraft assembly cleanrooms against physical and chemical treatments

    Science.gov (United States)

    Rettberg, Petra; Kloss, Maria; Barczyk, Simon; Reitz, Guenther

    The COSPAR planetary protection guidelines define bioburden limits for spacecraft to protect solar system bodies from contamination by terrestrial life, and to protect Earth from possible life forms that may be returned from other solar system bodies. The cleaning and sterilisation methods to be selected for space hardware have to be as efficient as necessary to reach the maximal allowed bioburden limit. To be able to asses the suitability of different methods it is mandatory to investigate the physiological potential of the microbial isolates from cleanrooms. In the ESA project BioDiv the bioburden and biodiversity was determined in cleanrooms where the satellite Herschel was integrated and tested. From all bacterial isolates obtained in sev-eral measurement campaigns 30 strains were selected. Their resistance as vegetative cells was tested against different physical and chemical treatments: drying under ambient conditions, desiccation under defined relative humidity, vacuum exposure, UVC radiation exposure, freeze-thaw cycles under martian atmosphere and pressure, exposure to high and low pH values, and exposure to alcohols. The results of these tests can be summarised as follows: i) Most of the tested microorganisms from cleanrooms exhibit a certain resistance against one or more of the tested conditions. This is in contrast to strains which have already been cultured for long-periods in time under optimal laboratory conditions. They tend to loose their original resistance against different environmental parameters. ii) Different isolates from the same species can exhibit significantly different resistances. Therefore, the sole identification of microorgnisms by 16S rDNA sequencing does not give insights into their physiological potential. iii) The first hours of drying have a substantial inactiviation effect, longer periods of drying or even vacuum exposure reduce the surviving fraction only slightly more. iv) The sensitivity against UVC radiation varies

  6. An in vitro comparative evaluation of fracture resistance of endodontically treated teeth obturated with different materials

    Directory of Open Access Journals (Sweden)

    Rupali Chadha

    2010-01-01

    Full Text Available The aim of this study was to evaluate the in vitro effect of various obturating materials on fracture resistance of root canal treated teeth. Sixty freshly extracted human mandibular premolars were used. After standardizing the length to 13 mm, the teeth were biomechanically prepared and divided into four groups based on type of obturating materials used. Teeth were embedded in acrylic resin and fracture strength was measured using a universal testing machine. Data obtained was evaluated statistically using one-way ANOVA and the unpaired t-test. Teeth obturated with AH Plus and gutta percha showed higher fracture resistance than those obturated with Resilon-Epiphany. The results suggested that the group obturated with gutta percha and zinc oxide-eugenol sealer had the lowest fracture resistance. No statistically significant difference was found between the unobturated (control group and the zinc oxide-eugenol group.

  7. A simple approach to measure the surface resistivity of insulating materials

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Wang, Qian

    2011-01-01

    A simple approach for measuring high surface resistivity of insulating materials using standard laboratory equipments is proposed. The developed system consists of a DC power transformer, a concentric ring probe assembly and a digital multi-meter. The DC power transformer can provide either 500V or...

  8. HBCUs as Sites of Resistance: The Malignity of Materialism, Western Masculinity, and Spiritual Malefaction

    Science.gov (United States)

    Douglas, Ty-Ron M. O.

    2012-01-01

    In this paper, the author challenges stakeholders (i.e., administrators, educators, students) of historically Black colleges and universities (HBCUs) to examine how HBCUs can continue to serve as sites of resistance against the prevailing cultural norms of materialism, Western masculinity, and spiritual malefaction. The author traces his…

  9. Fracture resistance of direct inlay-retained adhesive bridges : Effect of pontic material and occlusal morphology

    NARCIS (Netherlands)

    Breuklander, Marijn; Salihoglu-Yener, Esra; Ozcan, Mutlu

    2012-01-01

    This study evaluated the effect of a) pontic materials and b) occlusal morphologies on the fracture resistance of fiber-reinforced composite (FRC) inlay-retained fixed dental prostheses (FDP). Inlay-retained FRC FPDs (N=45, n=9) were constructed using a) resin composite (deep anatomy), b) natural to

  10. Investigation of Resistance to Mechanical Effect of Braille Formed on Different Materials

    Directory of Open Access Journals (Sweden)

    Ingrida VENYTĖ

    2014-06-01

    Full Text Available Qualitative analysis of stresses emerged in paperboard during Braille embossing, using specialized polarimetric equipment, was carried out. Resistance to mechanical effect of Braille dot surfaces, formed with different printing types on different materials (paper, paperboard, polymer, textile, Al foil was investigated. It was determined that Braille dot height change after period mechanical effect is different.

  11. Process Simulation of Resistance Weld Bonding and Automotive Light-weight Materials

    DEFF Research Database (Denmark)

    Zhang, Wenqi; Chergui, Azeddine; Nielsen, Chris Valentin

    This paper presents the latest developments in numerical simulation of resistance welding especially with the new functions for simulation of microstructures, weld bonding and spot welding of new light-weight materials. The fundamental functions in SORPAS® are built on coupled modeling of mechani...

  12. PRODUCTION OF POROUS POWDER MATERIALS OF SPHERICAL POWDERS OF CORROSION-RESISTANT STEEL

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevskij

    2012-01-01

    Full Text Available Production of porous powder materials from spherical powders of corrosion-resistant steel 12Х18н10Т with formation at low pressures 120–140 mpa in the mold with the subsequent activated sintering became possible due to increase of duration of process of spattering and formation of condensate particles (Si–C or (Mo–Si on surface.

  13. PRODUCTION OF POROUS POWDER MATERIALS OF SPHERICAL POWDERS OF CORROSION-RESISTANT STEEL

    OpenAIRE

    V. N. Kovalevskij; L. P. Pilincnich; A. V. Kovalevskaya; V. V. Savich; I. V. Fomihina; S. V. Grigorjev; A. E. Zhuk

    2012-01-01

    Production of porous powder materials from spherical powders of corrosion-resistant steel 12Х18н10Т with formation at low pressures 120–140 mpa in the mold with the subsequent activated sintering became possible due to increase of duration of process of spattering and formation of condensate particles (Si–C) or (Mo–Si) on surface.

  14. Experimental verification of tearing moduli as the material resistance against ductile crack growth

    International Nuclear Information System (INIS)

    There is the stage of stable crack propagation prior to the final unstable break-down in the large structures made of the materials with high toughness such as reactor pressure vessel steel. The transient phenomenon from the stable crack propagation to the unstable break-down is divided into ductile cleavage transition and tearing unstable break-down. Such unstable break-down is caused by the unbalance in the give and take of energy between materials and loading systems, and in order to analyze the tearing unstable break-down, it is important to determine the resistance to break-down peculiar to materials in the process of stable crack propagation. In this study, the fracture toughness test pieces with side grooves of A533 B-1 steel were used, and the tearing moduli for J-integral resistance curves, the change of plastic work and crack opening angle were comparatively examined. Also, the simple method for evaluating the resistance to ductile crack propagation peculiar to materials was proposed. The experimental method, the observation of fractured surfaces, and the effect of the dimensions and side grooves of test pieces on crack propagation resistance are reported. (Kako, I.)

  15. High carrier mobility in chemically modified graphene on an atomically flat high-resistive substrate

    International Nuclear Information System (INIS)

    Special high-resistive substrates for graphene sheets are suggested with the aim of providing high conductivity and mobility of charge carriers in graphene. The substrates were created from N-methylpyrrolidone-intercalated few-layer graphene (FLG) using anneals given to FLG samples in the temperature range 100–180 °C. Structures containing a highly conductive single-layer graphene on an atomically flat, high-resistive substrate were produced by recovering the top-layer conductivity. The obtained structures have potential in electronic applications due to a high carrier mobility (up to 16 000–42 000 cm2 V−1 s−1) and strong gate-voltage-induced modulation (by 4–5 orders of magnitude) of the current in the top graphene layer. The strong gate-voltage-induced modulation of the current clearly demonstrated that the top layer was chemically modified graphene. The possibility of governing the surface conductivity in the described structures offers a unique tool for two-dimensional nanodesign. (paper)

  16. Resistive Switching of Individual, Chemically Synthesized TiO2 Nanoparticles.

    Science.gov (United States)

    Schmidt, Dirk Oliver; Hoffmann-Eifert, Susanne; Zhang, Hehe; La Torre, Camilla; Besmehn, Astrid; Noyong, Michael; Waser, Rainer; Simon, Ulrich

    2015-12-22

    Resistively switching devices are considered promising for next-generation nonvolatile random-access memories. Today, such memories are fabricated by means of "top-down approaches" applying thin films sandwiched between nanoscaled electrodes. In contrast, this work presents a "bottom-up approach" disclosing for the first time the resistive switching (RS) of individual TiO2 nanoparticles (NPs). The NPs, which have sizes of 80 and 350 nm, respectively, are obtained by wet chemical synthesis and thermally treated under oxidizing or vacuum conditions for crystallization, respectively. These NPs are deposited on a Pt/Ir bottom electrode and individual NPs are electrically characterized by means of a nanomanipulator system in situ, in a scanning electron microscope. While amorphous NPs and calcined NPs reveal no switching hysteresis, a very interesting behavior is found for the vacuum-annealed, crystalline TiO(2-x) NPs. These NPs reveal forming-free RS behavior, dominantly complementary switching (CS) and, to a small degree, bipolar switching (BS) characteristics. In contrast, similarly vacuum-annealed TiO2 thin films grown by atomic layer deposition show standard BS behavior under the same conditions. The interesting CS behavior of the TiO(2-x) NPs is attributed to the formation of a core-shell-like structure by re-oxidation of the reduced NPs as a unique feature. PMID:26540646

  17. Ni(II) immobilization by bio-apatite materials: Appraisal of chemical, thermal and combined treatments

    OpenAIRE

    Šljivić-Ivanović Marija; Milenković Aleksandra; Jović Mihajlo; Dimović Slavko; Mraković Ana; Smičiklas Ivana

    2016-01-01

    Animal bones are natural and rich source of calcium hydroxyapatite (HAP), which was found to be a good sorbent material for heavy metals and radionuclides. Various treatments can reduce the content of bone organic phase and improve sorption properties. In this study, sorption capacities of raw bovine bones (B) and samples obtained by chemical treatment with NaOH (BNaOH), by heating at 400 oC (B400) and by combined chemical and thermal treatment (BNaOH+400),...

  18. Development of new materials and structures based on managed physical-chemical factors of local interaction

    Science.gov (United States)

    Urakov, A. L.

    2016-04-01

    The paper states that assigning certain physical and chemical characteristics to pills and medical drugs solutions can substitute for the development of new drugs (which is essentially equivalent to the creation of new medicines). It is established that the purposeful change of physical and chemical characteristics of the standard ("old") materials (in other words, the known substances) is fundamental for the production of solid and liquid medicines, which allows us to get "new" structures and materials. The paper shows that assigning new physical and chemical properties to "old" materials and their further usage for the production of tablets and solutions from the "old" and well-known medicines can turn even very "old" medicine into very "novel" (moreover, even very fashionable) one with unprecedented (fantastic) pharmacological activity and new mechanisms of action.

  19. PREMATH: a Precious-Material Holdup Estimator for unit operations and chemical processes

    International Nuclear Information System (INIS)

    A computer program, PREMATH (Precious Material Holdup Estimator), has been developed to permit inventory estimation in vessels involved in unit operations and chemical processes. This program has been implemented in an operating nuclear fuel processing plant. PREMATH's purpose is to provide steady-state composition estimates for material residing in process vessels until representative samples can be obtained and chemical analyses can be performed. Since these compositions are used for inventory estimation, the results are determined for and cataloged in container-oriented files. The estimated compositions represent material collected in applicable vessels - including consideration for material previously acknowledged in these vessels. The program utilizes process measurements and simple material balance models to estimate material holdups and distribution within unit operations. During simulated run testing, PREMATH-estimated inventories typically produced material balances within 7% of the associated measured material balances for uranium and within 16% of the associated, measured material balances for thorium (a less valuable material than uranium) during steady-state process operation

  20. Cranberry Resistance to Dodder Parasitism: Induced Chemical Defenses and Behavior of a Parasitic Plant.

    Science.gov (United States)

    Tjiurutue, Muvari Connie; Sandler, Hilary A; Kersch-Becker, Monica F; Theis, Nina; Adler, Lynn A

    2016-02-01

    Parasitic plants are common in many ecosystems, where they can structure community interactions and cause major economic damage. For example, parasitic dodder (Cuscuta spp.) can cause up to 80-100 % yield loss in heavily infested cranberry (Vaccinium macrocarpon) patches. Despite their ecological and economic importance, remarkably little is known about how parasitic plants affect, or are affected by, host chemistry. To examine chemically-mediated interactions between dodder and its cranberry host, we conducted a greenhouse experiment asking whether: (1) dodder performance varies with cranberry cultivar; (2) cultivars differ in levels of phytohormones, volatiles, or phenolics, and whether such variation correlates with dodder parasitism; (3) dodder parasitism induced changes in phytohormones, volatiles, or phenolics, and whether the level of inducible response varied among cultivars. We used five cranberry cultivars to assess host attractiveness to dodder and dodder performance. Dodder performance did not differ across cultivars, but there were marginally significant differences in host attractiveness to dodder, with fewer dodder attaching to Early Black than to any other cultivar. Dodder parasitism induced higher levels of salicylic acid (SA) across cultivars. Cultivars differed in overall levels of flavonols and volatile profiles, but not phenolic acids or proanthocyanidins, and dodder attachment induced changes in several flavonols and volatiles. While cultivars differed slightly in resistance to dodder attachment, we did not find evidence of chemical defenses that mediate these interactions. However, induction of several defenses indicates that parasitism alters traits that could influence subsequent interactions with other species, thus shaping community dynamics. PMID:26905738

  1. Materials Safety Data Sheets: the basis for control of toxic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Ketchen, E.E.; Porter, W.E.

    1979-09-01

    The Material Safety Data Sheets contained in this volume are the basis for the Toxic Chemical Control Program developed by the Industrial Hygiene Department, Health Division, ORNL. The three volumes are the update and expansion of ORNL/TM-5721 and ORNL/TM-5722 Material Safety Data Sheets: The Basis for Control of Toxic Chemicals, Volume I and Volume II. As such, they are a valuable adjunct to the data cards issued with specific chemicals. The chemicals are identified by name, stores catalog number where appropriate, and sequence numbers from the NIOSH Registry of Toxic Effects of Chemical Substances, 1977 Edition, if available. The data sheets were developed and compiled to aid in apprising the employees of hazards peculiar to the handling and/or use of specific toxic chemicals. Space limitation necessitate the use of descriptive medical terms and toxicological abbreviations. A glossary and an abbreviation list were developed to define some of those sometimes unfamiliar terms and abbreviations. The page numbers are keyed to the catalog number in the chemical stores at ORNL.

  2. Melting behavior of typical thermoplastic materials – An experimental and chemical kinetics study

    International Nuclear Information System (INIS)

    Highlights: • A new medium-scale melting and pyrolysis experiment instrument for thermoplastics was designed. • The thermal hazard induced by melting and dripping of thermoplastics was studied. • The medium-scale experimental results on the thermoplastics pyrolysis suggest some limit for TGA tests. -- Abstract: A medium-scale melting experiment rig was designed and constructed in this study. A detailed experimental study was conducted on the melting behavior and the chemical kinetic characteristics of three typical thermoplastic materials, including polypropylene (PP), polyethylene (PE) and polystyrene (PS). It is observed that the thermal decomposition of the thermoplastic materials mainly consists of three stages: the initial heating stage, the melting-dominated stage and the gasification-dominated stage. Melting of the materials examined takes place within a certain temperature range. The melting temperature of PS is the lowest, moreover, it takes the shortest time to be completely liquefied. To quantitatively represent the chemical kinetics, an nth-order reaction model was employed to interpret the thermal decomposition behavior of the materials. The calculated reaction order is largely in accordance with the small-scale thermal gravimetric analysis (TGA). The small difference between the results and TGA data suggests that there are some limitations in the small-scale experiments in simulating the behavior of thermoplastic materials in a thermal hazard. Therefore, investigating the thermal physical and chemical properties of the thermoplastic materials and their thermal hazard prevention in medium or large-scale experiments is necessary for the fire safety considerations of polymer materials

  3. Cyrogenic and radiation resistant properties of three dimensional fabric reinforced composite materials

    International Nuclear Information System (INIS)

    The insulating and/or structural materials for the fusion superconducting magnets are used under such strict environments as the cryogenic temperatures, high stresses and radiation environments. It is recognized that the usual laminated composite materials reinforced by glass clothes (2D-GFRP) are difficult to be used in such strict conditions. The three dimensional glass fabric reinforced composite materials (3D-GFRP) have high interlaminar shear strength due to the fibers in thickness direction. The cryogenic and radiation resistance properties of 3D-GFRP had been measured and the results compared with those of the 2D-GFRP

  4. Sulphur polymer concrete - a corrosion-resistant material for Middle East construction

    Energy Technology Data Exchange (ETDEWEB)

    Vroom, A.H.; Vroom, C.H. [Starcrete Technologies Inc., Calgary, AB (Canada); Hyne, J.B [Alberta Sulphur Research Ltd., Calgary, AB (Canada)

    1995-07-01

    The Canadian development of sulphur polymer concrete (SPC) and its applications as a construction material, was described. The process for producing SPC uses a stable concentrate of polymeric sulphur (SRX polymer) to modify and stabilize additional elemental sulphur. The characteristics of sulphur-based concretes include high strength, corrosion resistance, complete resistance to salt, impermeability and fast setting. Although these concretes have shown poor durability on exposure to changing temperatures, this does not impair their usefulness in areas such as the Middle East. The raw materials for SPC include sulphur, aggregates which can be unwashed desert sand and other salt-containing aggregates, mineral fillers, and SRX polymer. The mix requires no water. Some of the applications for the material include construction block, marine structures, roads, bridges, building foundations, sewer pipes, railway ties and hazardous waste containers. 2 tabs.

  5. Present status of study on development of materials resistant to radiation and beam impact

    International Nuclear Information System (INIS)

    Pulsed spallation neutron sources for the materials structure science are severely influenced by beam impact and radiation damage. We have developed the materials strong to these influence since 2004. In this paper, recent topics are described concerning the development of intergranular corrosion (IGC)-resistant austenitic stainless steel for target vessel and window, radiation-resistant ultra-fine grained tungsten materials (W-TiC) for a solid target, CrN film on a tungsten target by means of a molten-salt method, surface treatment of stainless steel for pitting damage in mercury target. Bubble behavior at the interface of mercury and window glass was also observed to clarify the phenomenon of the pitting damage

  6. Thermal/chemical degradation of ceramic cross-flow filter materials

    Energy Technology Data Exchange (ETDEWEB)

    Alvin, M.A.; Lane, J.E.; Lippert, T.E.

    1989-11-01

    This report summarizes the 14-month, Phase 1 effort conducted by Westinghouse on the Thermal/Chemical Degradation of Ceramic Cross-Flow Filter Materials program. In Phase 1 expected filter process conditions were identified for a fixed-bed, fluid-bed, and entrained-bed gasification, direct coal fired turbine, and pressurized fluidized-bed combustion system. Ceramic cross-flow filter materials were also selected, procured, and subjected to chemical and physical characterization. The stability of each of the ceramic cross-flow materials was assessed in terms of potential reactions or phase change as a result of process temperature, and effluent gas compositions containing alkali and fines. In addition chemical and physical characterization was conducted on cross-flow filters that were exposed to the METC fluid-bed gasifier and the New York University pressurized fluidized-bed combustor. Long-term high temperature degradation mechanisms were proposed for each ceramic cross-flow material at process operating conditions. An experimental bench-scale test program is recommended to be conducted in Phase 2, generating data that support the proposed cross-flow filter material thermal/chemical degradation mechanisms. Papers on the individual subtasks have been processed separately for inclusion on the data base.

  7. CHIPPING FRACTURE RESISTANCE OF DENTAL CAD/CAM RESTORATIVE MATERIALS: PART I, PROCEDURES AND RESULTS

    Science.gov (United States)

    Quinn, G. D.; Giuseppetti, A. A.; Hoffman, K. H.

    2014-01-01

    Objective The edge chipping test was used to measure the fracture resistance of CAD/CAM dental restoration ceramics and resin composites. Methods An edge chipping machine was used to evaluate six materials including one feldspathic porcelain, two glass ceramics, a filled resin-composite, a yttria-stabilized zirconia, and a new ceramic-resin composite material. Force versus edge distance data were collected over a broad range of forces and distances. Data were analyzed by several approaches and several chipping resistance parameters were evaluated. The effects of using different indenter types were explored. Results The force versus distance trends were usually nonlinear with good fits to a power law equation with exponents usually ranging from 1.2 to 1.9. The order of chipping resistance (from least to greatest) was: feldspathic porcelain and a leucite glass ceramic (which were similar), followed by the lithium disilicate glass ceramic and the two resin composites (which were similar), and finally the zirconia which had the greatest resistance to chipping. Chipping with a Vickers indenter required 28% to 45% more force than with the sharp conical 120° indenter. The two indenters rank materials approximately the same way. The power law exponents were very similar for the two indenters for a particular material, but the exponents varied with material. The Rockwell C indenter gives different power law trends and rankings. Significance Despite the variations in the trends and indenters, simple comparisons between materials can be made by chipping with sharp conical 120° or Vickers indenters at 0.50 mm. Broad distance ranges are recommended for trend evaluation. PMID:24685178

  8. Substantiation of an express-method for determining the freeze-thaw resistance of cellular materials

    Directory of Open Access Journals (Sweden)

    S.G. Nikolskiy

    2015-12-01

    Full Text Available An express method for determining the freeze-thaw resistance of cellular materials was offered and substantiated in this article. The proposed measurement technology of concrete frost resistance is based on the computation of the value z which is the ratio of the relative decrease of compression resistance R to the relative permanent set ε in the direction which is perpendicular to the pressure. It was found that this ratio is constant for a given composition of the concrete and does not depend on the values of R and ε. It was also proved that the values are not sensitive to the replacement of mechanical thermal cycles. These aspects will decrease the time for determining the freeze-thaw resistance of concrete and reduce the labor intensity of the tests conducted. The proposed method has been implemented on 10 samples of concrete with the following composition: Portland cement 400 (12.3 %, sand (24.7 %, granite macadam of dimensions 5…20 mm (55.6 %, water (7.4 %. Specimen cubes, according to the proposed method, were saturated with water, measured, subjected to alternate freezing and thawing and axial compression to achieve extreme loads. Then the frost resistance for each sample and the mean sample value F were calculated. The resulting value was compared with the freeze-thaw resistance, which was received for the mixture by the basic method. Thus, a new accelerated method for the determination of the freeze-thaw resistance of cellular materials was substantiated. It is highly efficient, simple, and has a low cost.

  9. Effect that radiation exerts to insulation breakdown of heat resistant polymer materials

    International Nuclear Information System (INIS)

    Artificial satellites are always exposed to cosmic rays which contain the radiations which do not reach the ground, therefore, the radiation resistance of the polymer insulators for cables and others used in such environment becomes a problem. Also the polymer insulator materials used for nuclear facilities require excellent radiation resistance. It is important to examine the effect that radiation exerts to electric insulation characteristics from the viewpoint of material development. In this paper, the insulation breakdown characteristics of heat resistant polymer films and the mini-cables made for trial of heat resistant polymer materials in the case without irradiation and in the case of gamma ray irradiation, and the results of the structural analysis are reported. The specimens tested, the experimental method and the results are described. The insulation breakdown strength of PFA and FEP films lowered from 0.15-0.2 MGy, but that of PEEK film did not change up to 5 MGy. It was found that fluorine group resins were apt to deteriorate by oxidation as dose increased. (K.I.)

  10. Fracture resistance of endodontically treated teeth restored with ceramic inlays and different base materials.

    Science.gov (United States)

    Saridag, Serkan; Sari, Tugrul; Ozyesil, Atilla Gokhan; Ari Aydinbelge, Hale

    2015-01-01

    This study evaluated the fracture resistance of endodontically treated teeth restored with different base materials and mesioocclusal-distal (MOD) ceramic inlays. Fifty mandibular molars were assigned into five groups (n=10 per group). Group1 (control) comprised intact molar teeth without any treatment. Teeth in other groups were subjected to root canal treatment and restored with MOD ceramic inlays on different base materials. In Group 2, base material was zinc phosphate cement; Group 3's was glass ionomer cement; Group 4's was composite resin, and Group 5's was composite resin reinforced with fiber. Finally, a continuous occlusal load was applied until fracture occurred. Mean fracture resistance of Group 1 (3,027 N) was significantly higher than the other groups (890, 1,070, 1,670, 1,226 N respectively). Fracture resistance of Group 4 was statistically comparable with Group 5 and significantly higher than Groups 2 and 3 (pinlay restorations could affect the fracture resistance of endodontically treated teeth. PMID:25740162

  11. INTEGRATED DEVELOPMENT OF CHEMICAL TEACHING MATERIALS ON MATERIAL BASED THERMOCHEMICAL SOFT SKILLS FOR VOCATIONAL STUDENTS

    Directory of Open Access Journals (Sweden)

    S. D. Purnawan

    2015-11-01

    Full Text Available Business and industrial field need workers who have not only good academic achievement but also the ability of hard skills and soft skills.  In order to prepare students who have a good academic skills, hard skills, soft skills it has to be done in all subjects including chemistry expertise to integrate the competencies of Motorcycle Engineering.  The research design uses One Group Pretest Posttest Design imposed on students in class XI SMK 1 Kedung TSM. Validator assessment results indicate that teaching materials developed very feasible for use in learning chemistry.  The result show that the learning device by using the integrated chemistry materials can increase students understanding of the thermo chemistry material with the acquisition of N-gain is at 0.63 or in the medium category.  Group of high-achieving students have the score of N-gain of 0.65, while the medium-achieving students get 0.63 and low-achieving students get 0.61, all have medium category.  Percentage  of students who passes the mastery learning  if mastery learning (KKM > 75 or reach 87 %.  The percentage of students’ soft skills in at least good criteria is at 87.10 %.  Students gave positive responses  90.71 % towards the learning material that is developed.

  12. The technique of Raman spectroscopy in the characterization physical, chemical and structural ferroelectric of the materials

    International Nuclear Information System (INIS)

    The ferroelectric ceramics have been one of the most studied compounds in the literature both in obtaining the same growth as in behavior of chemical and physical properties. In its growth the materials can go through other phases or to change their magnetic ferroelectric properties due to vacancies generated as PbTiO3 material. This material structural changes its phase also applying pressure with temperature, concentration and allowing anharmonic study behavior [1]. Raman spectroscopy is a technique which provides high resolution in seconds chemical and structural information of almost any organic or inorganic compound. As a technique which does not require a special atmosphere or vacuum, is one technique that has been used extensively in the characterization of ferroelectric materials in particular of PbTiO3

  13. Impact resistance of sustainable construction material using light weight oil palm shells reinforced geogrid concrete slab

    International Nuclear Information System (INIS)

    This paper investigate the performance of lightweight oil palm shells (OPS) concrete slab with geogrid reinforcement of 300mm × 300mm size with 20mm, 30mm and 40 mm thick casted with different geogrid orientation and boundary conditions subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.2 kg drop at 1 m height has been used in this research work. The main variables for the study is to find the relationship of the impact resistance the slab thickness, boundary conditions and geogrid reinforcement orientation. Test results indicate that the used of the geogrid reinforcement increased the impact resistance under service (first) limit crack up to 5.9 times and at ultimate limit crack up to 20.1 times against the control sample (without geogrid). A good linear relationship has been established between first and ultimate crack resistance against the slab thickness. The orientation of the geogrid has minor significant to the crack resistance of the OPS concrete slab. OPS geogrid reinforced slab has a good crack resistance properties that can be utilized as a sustainable impact resistance construction materials.

  14. Database of refractories for explosive and fire resistant steel cask for packaging and transportation of radioactive and hazardous materials

    International Nuclear Information System (INIS)

    This paper contains the results of mechanical and thermophysical properties investigations of the dense and porous refractory concretes (silicate (building), chamotte (metallurgical), alumina, zirconia (including ceramics)). Porosities of these materials were 20 - 50 %. Compression strength, thermal conductivity, thermal expansion, heat capacity and operation temperature for this refractories are discussed. The split-Hopkinson bar method was used for investigation of the strain rate about 1000 sec-1. For damage assessment of the severe events connected with overheating of the metal and oxides contents of cask and terrorist attack by means of the anti-tank weapons to cask we discussed resistance of a zirconia ceramics(concrete) to melted mixture Zr, UO2, Fe2O3 and Monroe jet. Our results testify that the porous zirconia ceramics can use in the impact limiter system of casks under mechanical, thermal and chemical attacks. (authors)

  15. Physical, chemical, and mineralogical characterization of vertisols to determine their parent material

    OpenAIRE

    Erasto Domingo Sotelo Ruiz; María del Carmen Gutiérrez Castorena; Carlos Alberto Ortiz Solorio

    2013-01-01

    Haplusterts, Typic Haplusterts, and Mollic Ustifluvents. Sedimentary origin soils were classified as Chromic Calciusterts The response of soils to weathering processes depends upon their parent material. Proper identification of the primary and secondary minerals in Vertisols provides information about the parent material that gives origin to these soils. Thus, the objec-tives of this study were 1) to determine the physical and chemi-cal properties of Vertisols in order to characterize and cl...

  16. Chemical, mineralogical and ceramic properties of kaolinitic materials from the Tresnuraghes mining district (Western Sardinia, Italy)

    OpenAIRE

    Dondi, Michele; Guarini, Guia; Ligas, Paola; Raimondo, Mariarosa; Palomba, Marcella; Uras, Ivo

    2001-01-01

    Kaolinitic materials crop out in the Tresnuraghes mining district (Western Sardinia, Italy). Three main kaolinitic deposits, located in the Patalza, Salamura and Su Fongarazzu areas, respectively, were investigated in order to assess their potential in the ceramic industry. The parent rock-types of this raw material are the Oligocene-Miocene rhyolitic-rhyodacitic ignimbrites. Chemical and mineralogical analyses were performed on representative samples of each deposit, by XRD and XRF methodolo...

  17. Chemical properties of gutta-percha endodontic filling material: investigation of five commercial brands

    International Nuclear Information System (INIS)

    Chemical composition e thermal stability of five brands of gutta-percha endodontic filling material were investigated. Samples with higher amount of organic materials possess higher thermal stability. Investigation of gutta-percha polymer extracted from the endodontic filling by IR and NMR shows that the polymer is predominantly trans-polyisoprene. The thermal stability and molar mass were similar for four brands, however the 'Tanari' brand has got lower molar mass value than the other ones. (author)

  18. Size effects of TiO2 on stress corrosion cracking resistance of steam generator tube materials

    International Nuclear Information System (INIS)

    In nuclear power plants, steam generator (SG) tubes have certain characteristic features in their design to endure a severe problem, a stress corrosion cracking (SCC) - thin boundary wall of a high temperature and pressure, a heat transition through a wall thickness, a contact with a steam phase, the formation of a sludge pile and a crevice etc. Most SCCs have occurred near the top of a sludge pile on a tubesheet and within a tube support plate crevice in which it is thought to be concentrated by ion impurities such as sodium which might cause a caustic and corrosive environment. Many inhibitors have been studied to reduce these SCC problems for SG tube materials. Several chemicals were also studied to suppress the damage due to a stress corrosion cracking (SCC) of the steam generator (SG) tubes in nuclear power plants. In this study SCC tests were carried out to investigate both the effect of corrosion inhibitor (TiO2) and the size effect of the TiO2 particle on several types of SG tube materials. The SCC tests were conducted by using an m-RUB specimen in a 10% NaOH solution at a temperature of 315o. In order to enhance the corrosion resistance on the SCC of SG materials the size of the TiO2 particles were reduced to nano-sized ranges by applying a sonochemical technique. From the SCC tests with the RUB specimen and penetration test with crevice chemistry and analyzing system, the SG tube materials showed the higher resistance in corrosion cracking with the addition of nano-TiO2. (author)

  19. Resistance to ionizing radiations of materials installed at the CERN accelerators

    International Nuclear Information System (INIS)

    All materials installed in high energy accelerators along the lines of primary and secondary beams are exposed to ionizing radiation. This can in certain cases cause a degradation of the properties of these materials and consequently affect the good function of the installation. The author has taken at CERN large number of samples of materials in order to determine their radioresistance. Generally the organic materials and the electronic components are more sensitive to ionizing radiation. The author presents the results of these studies which concern the isolations of the cables (polyethylene, polyvinyl chloride, caoutchouc ethylene propylene, etc.), the isolations for the magnets on the base of epoxy resins, as well as other thermoresistant and thermoplastic products. The author equally presents a choice of materials and components which are used at CERN and which are resistant to radiations above an integral dose of 107-108 Gy. (orig.)

  20. Resistance of HEPA filter separator materials to humid air--hydrogen fluoride--fluorine environments

    International Nuclear Information System (INIS)

    The U. S. Energy Research and Development Administration (ERDA) is interested in the development of a high-efficiency particulate air (HEPA) filter that is resistant to such corrosive reagents as hydrogen fluoride (HF) and fluorine (F2) in air environments of normal relative humidity (about 50% RH). Several types of separator materials are used in the fabrication of commercial filters. The basic types of separator materials are asbestos, Kraft paper, plastic, and aluminum. At the request of the ERDA Division of Operational Safety, the different types of separator materials have been evaluated for their resistance to corrosive attack by HF and F2. The separator materials were dynamically tested in the 4-stage multiunit tester located in the Oak Ridge Gaseous Diffusion Plant laboratories. This is the system previously used in the evaluation of the Herty Foundation filter paper samples. Concurrent with the testing of filter media for its resistance to HF and F2, another component of the completed filter, the separator, was tested. All samples were exposed to a constant air flow (50% RH) of 32 liters/min, at 1000F, containing 900 ppM HF and 300 ppM F2. Exposure periods varied from 2 to 1000 h; however, the longer exposures were made only on the stronger candidates. Test results show the plastic and aluminum separator materials to be superior to the other types in resistance to HF and F2. The asbestos separators disintegrated after a relatively short exposure time; the Kraft paper types were the next weakest. The Clear Plastic S was the best performer of the plastics tested

  1. Experimental and numerical investigation on cladding of corrosion-erosion resistant materials by a high power direct diode laser

    Science.gov (United States)

    Farahmand, Parisa

    In oil and gas industry, soil particles, crude oil, natural gas, particle-laden liquids, and seawater can carry various highly aggressive elements, which accelerate the material degradation of component surfaces by combination of slurry erosion, corrosion, and wear mechanisms. This material degradation results into the loss of mechanical properties such as strength, ductility, and impact strength; leading to detachment, delamination, cracking, and ultimately premature failure of components. Since the failure of high valued equipment needs considerable cost and time to be repaired or replaced, minimizing the tribological failure of equipment under aggressive environment has been gaining increased interest. It is widely recognized that effective management of degradation mechanisms will contribute towards the optimization of maintenance, monitoring, and inspection costs. The hardfacing techniques have been widely used to enhance the resistance of surfaces against degradation mechanisms. Applying a surface coating improves wear and corrosion resistance and ensures reliability and long-term performance of coated parts. A protective layer or barrier on the components avoids the direct mechanical and chemical contacts of tool surfaces with process media and will reduce the material loss and ultimately its failure. Laser cladding as an advanced hardfacing technique has been widely used for industrial applications in order to develop a protective coating with desired material properties. During the laser cladding, coating material is fused into the base material by means of a laser beam in order to rebuild a damaged part's surface or to enhance its surface function. In the hardfacing techniques such as atmospheric plasma spraying (APS), high velocity oxygen-fuel (HVOF), and laser cladding, mixing of coating materials with underneath surface has to be minimized in order to utilize the properties of the coating material most effectively. In this regard, laser cladding offers

  2. Conduction mechanism in low-resistivity n-type ZnSe prepared by organometallic chemical vapor deposition

    Science.gov (United States)

    Stutius, W.

    1982-01-01

    n-type ZnSe layers with a room-temperature resistivity of less than 0.05 Ω cm and mobilities of ˜400 cm2/(V sec) have been grown on (100) GaAs by organometallic chemical vapor deposition (OM-CVD), using triethylaluminum as a dopant. No further treatment after the layer growth is necessary in order to achieve the high electrical conductivity. An analysis of the low-temperature electrical transport data and of the photoluminescence data, however, suggests that the physical properties of the layers differ from those of ZnSe prepared by other methods. Charge transport occurs via impurity-band conduction in the more heavily doped layers and via thermally activated hopping in the more lightly doped layers rather than via thermally activated extrinsic conductivity. The degree of compensation of donors is larger than 0.5. The exact nature of the compensating centers in the material prepared by OM-CVD is uncertain at this point, although the photoluminescence data suggest the presence of Al-VZn complexes.

  3. THE CHEMICAL AND RADIATION RESISTANCE OF POLYPHENYLENE SULFIIDE AS ENCOUNTERED IN THE MODULAR CAUSTIC SIDE SOLVENT EXTRACTION PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Herman, D.; Poirier, M.; Fink, S.

    2011-06-30

    Polyphenylene sulfide (PPS) is a semicrystalline polymer with excellent engineering plastic properties and suitable processing temperatures. PPS can also be made containing branches (using a trifunctional monomer) and with crosslinked microstructure (when curing the monomer at high temperature in the presence of oxygen). PPS is made from the condensation reaction between para-dichlorobenzene and sodium sulfide with the assistance of a catalyst (to lower the activation barrier). The synthesis conditions for making PPS has evolved since its invention in the 1960's to the optimal conditions developed by the Philips Corporation in the 1970's. The resulting polymer consists of chemically stable molecular moieties such as benzene rings and ether like sulfur linkages between the aromatic rings. Polyphenylene sulfide (PPS) is extremely resistant to gamma irradiation, caustic solution, and dilute nitric acid. PPS is the material of construction for the coalescers used in the Modular Caustic-Side Solvent Extraction Unit (MCU). After applying the equivalent of 3.3 E8 rad (330 Mrad), or the equivalent of 11 years of gamma irradiation (assuming a stripping solution concentration of 7.5 Ci/gal), and several months of exposures to 3M caustic solution and caustic salt simulant, no dimensional changes nor chemical changes were detected in PPS whether the PPS was in fiber form or in a composite with E-glass fibers. However, PPS acts as a media for heterogeneous nucleation. In particular, PPS appears to favor aluminosilicate formation in saturated solutions of aluminum and silicon in caustic environments. Parallel testing, in progress, is examining the stability of PPS when exposed to the new solvent formulation under development for MCU. Preliminary data, after two months of exposure, demonstrates PPS is stable to the new solvent.

  4. Study of dimensional changes during redox cycling of oxygen carrier materials for chemical looping combustion

    NARCIS (Netherlands)

    Fossdal, A.; Darell, O.; Lambert, A.; Schols, E.; Comte, E.; Leenman, R.N.; Blom, R.

    2015-01-01

    Dimensional and phase changes of four candidate oxygen carrier materials for chemical looping combustion are investigated by dilatometry and high-temperature X-ray diffraction during four redox cycles. NiO/Ni2AlO4 does not exhibit significant dimensional changes during cycling, and it is shown that

  5. Chemical identification of contaminants in paper and board food contact materials

    DEFF Research Database (Denmark)

    Bengtström, Linda

    Paper and board are used for a variety of food contact materials, such as baking paper, microwave popcorn bags and packaging for cereals as well as fast foods. Despite this extensive use, there are currently large data gaps about the chemical composition of different paper and board food contact...

  6. Application of chemical structure and bonding of actinide oxide materials for forensic science

    International Nuclear Information System (INIS)

    We are interested in applying our understanding of actinide chemical structure and bonding to broaden the suite of analytical tools available for nuclear forensic analyses. Uranium- and plutonium-oxide systems form under a variety of conditions, and these chemical species exhibit some of the most complex behavior of metal oxide systems known. No less intriguing is the ability of AnO2 (An: U, Pu) to form non-stoichiometric species described as AnO2+x. Environmental studies have shown the value of utilizing the chemical signatures of these actinide oxide materials to understand transport following release into the environment. Chemical speciation of actinide-oxide samples may also provide clues as to the age, source, or process history of the material. The scientific challenge is to identify, measure and understand those aspects of speciation of actinide analytes that carry information about material origin and history most relevant to forensics. Here, we will describe our efforts in material synthesis and analytical methods development that we will use to provide the fundamental science to characterize actinide oxide molecular structures for forensic science. Structural properties and initial results to measure structural variability of uranium oxide samples using synchrotron-based X-ray Absorption Fine Structure will be discussed.

  7. Application of chemical structure and bonding of actinide oxide materials for forensic science

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Marianne Perry [Los Alamos National Laboratory

    2010-01-01

    We are interested in applying our understanding of actinide chemical structure and bonding to broaden the suite of analytical tools available for nuclear forensic analyses. Uranium- and plutonium-oxide systems form under a variety of conditions, and these chemical species exhibit some of the most complex behavior of metal oxide systems known. No less intriguing is the ability of AnO{sub 2} (An: U, Pu) to form non-stoichiometric species described as AnO{sub 2+x}. Environmental studies have shown the value of utilizing the chemical signatures of these actinide oxide materials to understand transport following release into the environment. Chemical speciation of actinide-oxide samples may also provide clues as to the age, source, or process history of the material. The scientific challenge is to identify, measure and understand those aspects of speciation of actinide analytes that carry information about material origin and history most relevant to forensics. Here, we will describe our efforts in material synthesis and analytical methods development that we will use to provide the fundamental science to characterize actinide oxide molecular structures for forensic science. Structural properties and initial results to measure structural variability of uranium oxide samples using synchrotron-based X-ray Absorption Fine Structure will be discussed.

  8. Toxicological characterization of chemicals produced from laser irradiation of graphite composite materials

    International Nuclear Information System (INIS)

    One of the major potential hazards associated with laser machining of graphite composite materials is the toxic fumes and gases that are generated. When exposed to the intense energy of the laser beam, the organic polymer matrix of the composite material may decompose into various toxic by-products. To advance the understanding of the laser machining process from a health and safety viewpoint, this particular study consisted of the following steps: collect and analyze gaseous by-products generated during laser machining; collect particulates generated during laser machining and chemically extract them to determine the chemical species that may have absorbed or recondensed onto these particles; and review and evaluate the toxicity of the identified chemical species

  9. Engineering serendipity: High-throughput discovery of materials that resist bacterial attachment☆

    Science.gov (United States)

    Magennis, E.P.; Hook, A.L.; Davies, M.C.; Alexander, C.; Williams, P.; Alexander, M.R.

    2016-01-01

    Controlling the colonisation of materials by microorganisms is important in a wide range of industries and clinical settings. To date, the underlying mechanisms that govern the interactions of bacteria with material surfaces remain poorly understood, limiting the ab initio design and engineering of biomaterials to control bacterial attachment. Combinatorial approaches involving high-throughput screening have emerged as key tools for identifying materials to control bacterial attachment. The hundreds of different materials assessed using these methods can be carried out with the aid of computational modelling. This approach can develop an understanding of the rules used to predict bacterial attachment to surfaces of non-toxic synthetic materials. Here we outline our view on the state of this field and the challenges and opportunities in this area for the coming years. Statement of significance This opinion article on high throughput screening methods reflects one aspect of how the field of biomaterials research has developed and progressed. The piece takes the reader through key developments in biomaterials discovery, particularly focusing on need to reduce bacterial colonisation of surfaces. Such bacterial resistant surfaces are increasingly required in this age of antibiotic resistance. The influence and origin of high-throughput methods are discussed with insights into the future of biomaterials development where computational methods may drive materials development into new fertile areas of discovery. New biomaterials will exhibit responsiveness to adapt to the biological environment and promote better integration and reduced rejection or infection. PMID:26577984

  10. Materials for Advanced Turbine Engines (MATE). Project 4: Erosion resistant compressor airfoil coating

    Science.gov (United States)

    Rashid, J. M.; Freling, M.; Friedrich, L. A.

    1987-01-01

    The ability of coatings to provide at least a 2X improvement in particulate erosion resistance for steel, nickel and titanium compressor airfoils was identified and demonstrated. Coating materials evaluated included plasma sprayed cobalt tungsten carbide, nickel carbide and diffusion applied chromium plus boron. Several processing parameters for plasma spray processing and diffusion coating were evaluated to identify coating systems having the most potential for providing airfoil erosion resistance. Based on laboratory results and analytical evaluations, selected coating systems were applied to gas turbine blades and evaluated for surface finish, burner rig erosion resistance and effect on high cycle fatigue strength. Based on these tests, the following coatings were recommended for engine testing: Gator-Gard plasma spray 88WC-12Co on titanium alloy airfoils, plasma spray 83WC-17Co on steel and nickel alloy airfoils, and Cr+B on nickel alloy airfoils.

  11. Enhanced performance of electrostatic precipitators through chemical modification of particle resistivity and cohesion

    Energy Technology Data Exchange (ETDEWEB)

    Durham, M.D.; Baldrey, K.E.; Bustard, C.J. [ADA Technologies, Inc., Englewood, CO (United States)

    1995-11-01

    Control of fine particles, including particulate air toxics, from utility boilers is required near-term by state and federal air regulations. Electrostatic precipitators (ESP) serve as the primary air pollution control device for the majority of coal-fired utility boilers in the Eastern and Midwestern united States. Cost-effective retrofit technologies for fine particle control, including flue gas conditioning, are needed for the large base of existing ESPs. Flue has conditioning is an attractive option because it requires minimal structural changes and lower capital costs. For flue gas conditioning to be effective for fine particle control, cohesive and particle agglomerating agents are needed to reduce reentrainment losses, since a large percentage of particulate emissions from well-performing ESPs are due to erosion, rapping, and non-rapping reentrainment. A related and somewhat ironic development is that emissions reductions of SO{sub 2} from utility boilers, as required by the Title IV acid rain program of the 1990 Clean Air Act amendments, has the potential to substantially increase particulate air toxics from existing ESPs. The switch to low-sulfur coals as an SO{sub 2} control strategy by many utilities has exacerbated ESP performance problems associated with high resistivity flyash. The use of flue gas conditioning has increased in the past several years to maintain adequate performance in ESPs which were not designed for high resistivity ash. However, commercially available flue gas conditioning systems, including NH{sub 3}/SO{sub 3} dual gas conditioning systems, have problems and inherent drawbacks which create a need for alternative conditioning agents. in particular, NH{sub 3}/SO{sub 3} systems can create odor and ash disposal problems due to ammonia outgassing. In addition, there are concerns over chemical handling safety and the potential for accidental releases.

  12. Nanoimprint lithography in the cyclic olefin copolymer, Topas, a highly ultraviolet-transparent and chemically resistant thermoplast

    DEFF Research Database (Denmark)

    Nielsen, T.; Nilsson, D.; Bundgaard, F.; Shi, P.; Szabo, Peter; Geschke, O.; Kristensen, Anders

    2004-01-01

    Thermal nanoimprint lithography (NIL) of the cyclic olefin copolymeric thermoplast Topas® isdemonstrated. Topas® is highly UV-transparent, has low water absorption, and is chemically resistant to hydrolysis, acids and organic polar solvents which makes it suitable for lab-on-a-chipapplications. In...

  13. Material compatibility and corrosion control of the KWU chemical cleaning process

    International Nuclear Information System (INIS)

    The concentrations of salt impurities within the deposits on the tube sheet and in the tube to tube-support-plate crevices can induce a variety of corrosion mechanisms on steam generator tubes. One of the most effective ways of counteracting corrosion mechanisms and thus of improving steam generator performance is to clean the steam generators and keep them in a clean condition. As shown by field results chemical cleaning is a way of removing hazardous deposits from steam generators. All available chemical cleaning processes use inhibitors to control the corrosion except the KWU chemical cleaning process. In this article the corrosion control technique of KWU Chemical Cleaning Process without using conventional inhibitors will be explained and the state of the field experience with respect to material compatibility will be presented. (author). 4 figs., 1 tab., 8 refs

  14. Thermo-chemical properties and electrical resistivity of Zr-based arsenide chalcogenides

    Directory of Open Access Journals (Sweden)

    A. Schlechte, R. Niewa, M. Schmidt, G. Auffermann, Yu. Prots, W. Schnelle, D. Gnida, T. Cichorek, F. Steglich and R. Kniep

    2007-01-01

    Full Text Available Ternary phases in the systems Zr–As–Se and Zr–As–Te were studied using single crystals of ZrAs1.40(1Se0.50(1 and ZrAs1.60(2Te0.40(1 (PbFCl-type of structure, space group P4/nmm as well as ZrAs0.70(1Se1.30(1 and ZrAs0.75(1Te1.25(1 (NbPS-type of structure, space group Immm. The characterization covers chemical compositions, crystal structures, homogeneity ranges and electrical resistivities. At 1223 K, the Te-containing phases can be described with the general formula ZrAsxTe2−x, with 1.53(1≤x≤1.65(1 (As-rich and 0.58(1≤x≤0.75(1 (Te-rich. Both phases are located directly on the tie-line between ZrAs2 and ZrTe2, with no indication for any deviation. Similar is true for the Se-rich phase ZrAsxSe2−x with 0.70(1≤x≤0.75(1. However, the compositional range of the respective As-rich phase ZrAsx−ySe2−x (0.03(1≤y≤0.10(1; 1.42(1≤x≤1.70(1 is not located on the tie-line ZrAs2–ZrSe2, and exhibits a triangular region of existence with intrinsic deviation of the composition towards lower non-metal contents. Except for ZrAs0.75Se1.25, from the homogeneity range of the Se-rich phase, all compounds under investigation show metallic characteristics of electrical resistivity at temperatures >20 K. Related uranium and thorium arsenide selenides display a typical magnetic field-independent rise of the resistivity towards lower temperatures, which has been explained by a non-magnetic Kondo effect. However, a similar observation has been made for ZrAs1.40Se0.50, which, among the Zr-based arsenide chalcogenides, is the only system with a large concentration of intrinsic defects in the anionic substructure.

  15. Iron-Based Amorphous Metals:The High Performance Corrosion Resistant Materials(HPCRM) Program

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J

    2007-07-09

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional

  16. Iron-Based Amorphous-Metals: High-Performance Corrosion-Resistant Material (HPCRM) Development

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Choi, J S; Saw, C; Haslam, J; Day, D; Hailey, P; Lian, T; Rebak, R; Perepezko, J; Payer, J; Branagan, D; Beardsley, B; D' Amato, A; Aprigliano, L

    2008-01-09

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional

  17. Iron-Based Amorphous Metals:The High Performance Corrosion Resistant Materials(HPCRM) Program

    International Nuclear Information System (INIS)

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) and SAM1651 (Fe48Mo14Cr15Y2C15B6) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional stainless steel and nickel-based materials, and are proving to have excellent wear

  18. Iron-Based Amorphous Metals: High-Performance Corrosion-Resistant Material Development

    Science.gov (United States)

    Farmer, Joseph; Choi, Jor-Shan; Saw, Cheng; Haslam, Jeffrey; Day, Dan; Hailey, Phillip; Lian, Tiangan; Rebak, Raul; Perepezko, John; Payer, Joe; Branagan, Daniel; Beardsley, Brad; D'Amato, Andy; Aprigliano, Lou

    2009-06-01

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was cosponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the U.S. Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition, materials synthesis, thermal stability, corrosion resistance, environmental cracking, mechanical properties, damage tolerance, radiation effects, and important potential applications. Amorphous alloys identified as SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) and SAM1651 (Fe48Mo14Cr15Y2C15B6) have been produced as meltspun ribbons (MSRs), dropcast ingots, and thermal-spray coatings. Chromium (Cr), molybdenum (Mo), and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of MSRs and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently, thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests; good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while the open-circuit corrosion potentials (OCPs) were simultaneously monitored; reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber and suitable for criticality-control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional stainless steel and Ni-based materials, and are proving to have excellent wear

  19. Design and development of a space station hazardous material system for assessing chemical compatibility

    Science.gov (United States)

    Congo, Richard T.

    1990-01-01

    As the Space Station nears reality in funding support from Congress, NASA plans to perform over a hundred different missions in the coming decade. Incrementally deployed, the Space Station will evolve into modules linked to an integral structure. Each module will have characteristic functions, such as logistics, habitation, and materials processing. Because the Space Station is to be user friendly for experimenters, NASA is anticipating that a variety of different chemicals will be taken on-board. Accidental release of these potentially toxic chemicals and their chemical compatibility is the focus of this discourse. The Microgravity Manufacturing Processing Facility (MMPF) will contain the various facilities within the U.S. Laboratory (USL). Each facility will have a characteristic purpose, such as alloy solidification or vapor crystal growth. By examining the proposed experiments for each facility, identifying the chemical constituents, their physical state and/or changes, byproducts and effluents, those payloads can be identified which may contain toxic, explosive, or reactive compounds that require processing or containment in mission peculiar waste management systems. Synergistic reactions from mixed effluent streams is of major concern. Each experiment will have it own data file, complete with schematic, chemical listing, physical data, etc. Chemical compatibility information from various databases will provide assistance in the analysis of alternate disposal techniques (pretreatment, separate storage, etc.). Along with data from the Risk Analysis of the Proposed USL Waste Management System, accidental release of potentially toxic and catastrophic chemicals would be eliminated or reduced.

  20. HRI catalytic two-stage liquefaction (CTSL) process materials: chemical analysis and biological testing

    Energy Technology Data Exchange (ETDEWEB)

    Wright, C.W.; Later, D.W.

    1985-12-01

    This report presents data from the chemical analysis and biological testing of coal liquefaction materials obtained from the Hydrocarbon Research, Incorporated (HRI) catalytic two-stage liquefaction (CTSL) process. Materials from both an experimental run and a 25-day demonstration run were analyzed. Chemical methods of analysis included adsorption column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, low-voltage probe-inlet mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The biological activity was evaluated using the standard microbial mutagenicity assay and an initiation/promotion assay for mouse-skin tumorigenicity. Where applicable, the results obtained from the analyses of the CTSL materials have been compared to those obtained from the integrated and nonintegrated two-stage coal liquefaction processes. 18 refs., 26 figs., 22 tabs.

  1. Chemical compatibility study of melilite-type gallate solid electrolyte with different cathode materials

    Science.gov (United States)

    Mancini, Alessandro; Felice, Valeria; Natali Sora, Isabella; Malavasi, Lorenzo; Tealdi, Cristina

    2014-05-01

    Chemical reactivity between cathodes and electrolytes is a crucial issue for long term SOFCs stability and performances. In this study, chemical reactivity between selected cathodic materials and the ionic conducting melilite La1.50Sr0.50Ga3O7.25 has been extensively investigated by X-ray powder diffraction in a wide temperature range (up to 1573 K). Perovskite-type La0.8Sr0.2MnO3-d and La0.8Sr0.2Fe0.8Cu0.2O3-d and K2NiF4-type La2NiO4+d were selected as cathode materials. The results of this study allow identifying the most suitable electrode material to be used in combination with the melilite-type gallate electrolyte and set the basis for future work on this novel system.

  2. A spinosyn-sensitive Drosophila melanogaster nicotinic acetylcholine receptor identified through chemically induced target site resistance, resistance gene identification, and heterologous expression.

    Science.gov (United States)

    Watson, Gerald B; Chouinard, Scott W; Cook, Kevin R; Geng, Chaoxian; Gifford, Jim M; Gustafson, Gary D; Hasler, James M; Larrinua, Ignacio M; Letherer, Ted J; Mitchell, Jon C; Pak, William L; Salgado, Vincent L; Sparks, Thomas C; Stilwell, Geoff E

    2010-05-01

    Strains of Drosophila melanogaster with resistance to the insecticides spinosyn A, spinosad, and spinetoram were produced by chemical mutagenesis. These spinosyn-resistant strains were not cross-resistant to other insecticides. The two strains that were initially characterized were subsequently found to have mutations in the gene encoding the nicotinic acetylcholine receptor (nAChR) subunit Dalpha6. Subsequently, additional spinosyn-resistant alleles were generated by chemical mutagenesis and were also found to have mutations in the gene encoding Dalpha6, providing convincing evidence that Dalpha6 is a target site for the spinosyns in D. melanogaster. Although a spinosyn-sensitive receptor could not be generated in Xenopus laevis oocytes simply by expressing Dalpha6 alone, co-expression of Dalpha6 with an additional nAChR subunit, Dalpha5, and the chaperone protein ric-3 resulted in an acetylcholine- and spinosyn-sensitive receptor with the pharmacological properties anticipated for a native nAChR. PMID:19944756

  3. Resistive Oxygen Sensor Using Ceria-Zirconia Sensor Material and Ceria-Yttria Temperature Compensating Material for Lean-Burn Engine

    OpenAIRE

    Ichiro Matsubara; Maiko Nishibori; Toshio Itoh; Woosuck Shin; Sayaka Nishizaki; Noriya Izu

    2009-01-01

    Temperature compensating materials were investigated for a resistive oxygen sensor using Ce0.9Zr0.1O2 as a sensor material for lean-burn engines. The temperature dependence of a temperature compensating material should be the same as the sensor material; therefore, the Y concentration in CeO2-Y2O3 was optimized. The resistance of Ce0.5Y0.5O2-δ was independent of the air-to-fuel ratio (oxygen partial pressure), so that it was confirmed to function as a temperature compensating material. Sensor...

  4. Proliferation Resistance and Material Type considerations within the Collaborative Project for a European Sodium Fast Reactor

    International Nuclear Information System (INIS)

    The collaborative project for a European Sodium Fast Reactor (CP‑ESFR) is an international project where 25 European partners developed Research & Development solutions and concepts for a European sodium fast reactor. The project was funded by the 7. European Union Framework Programme and covered topics such as the reactor architectures and components, the fuel, the fuel element and the fuel cycle, and the safety concepts. Within sub‑project 3, dedicated to safety, a task addressed proliferation resistance considerations. The Generation IV International Forum (GIF) Proliferation Resistance and Physical Protection (PR and PP) Evaluation Methodology has been selected as the general framework for this work, complemented by punctual aspects of the IAEA‑INPRO Proliferation Resistance methodology and other literature studies - in particular for material type characterization. The activity has been carried out taking the GIF PR and PP Evaluation Methodology and its Addendum as the general guideline for identifying potential nuclear material diversion targets. The targets proliferation attractiveness has been analyzed in terms of the suitability of the targets’ nuclear material as the basis for its use in nuclear explosives. To this aim the PR and PP Fissile Material Type measure was supplemented by other literature studies, whose related metrics have been applied to the nuclear material items present in the considered core alternatives. This paper will firstly summarize the main ESFR design aspects relevant for PR following the structure of the GIF PR and PP White Paper template. An analysis on proliferation targets is then discussed, with emphasis on their characterization from a nuclear material point of view. Finally, a high‑level ESFR PR analysis according to the four main proliferation strategies identified by the GIF PR and PP Evaluation Methodology (concealed diversion, concealed misuse, breakout, clandestine production in clandestine facilities) is

  5. Evaluation of chemical properties of super stainless steel for nuclear internal materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Soo [Yonsei University, Seoul (Korea); Kim, Young Sik [Andong National University, Andong (Korea)

    2002-03-01

    This work dealt with the evaluation of super stainless steels for heat exchanger tubing of internal of NPP. Experimental alloys were designed on the base of UNS S32050. SCC resistance of UNS S32050 was affected by nitrogen content of alloys and grain size. Increasing nitrogen content facilitates the formation of the planar dislocation. TT(thermal treatment at 550oC 15hrs) facilitates cross slip of dislocation and reduces the residual stress of materials and increases the grain size and enhances SCC-resistance than that of mill annealed specimen. Increasing cold rolling percent improves yield strength and ultimate tensile strength but greatly reduces the elongation. Thus, SCC resistance of cold rolled alloys is largely reduced with increasing rolling percent. Increasing Mn and N improves the SCC resistance but cold rolling over 50% reduces the resistance mainly due to the loss of mechanical properties. In 1500 psi, 315oC 10% NaOH solution, increased Ni-content of alloys improves passivation behavior in anodic polarization test and U-bend test shows cold rolling increases the mean crack propagation rate, but TT decreases the mean crack propagation rate. In ambient environment, 110oC 40% NaOH solution, SCC is a little observed in only outside of cross section and fracture mode is intergranular cracking. 73 refs., 92 figs., 4 tabs. (Author)

  6. Aluminium Alloy-Based Metal Matrix Composites: A Potential Material for Wear Resistant Applications

    OpenAIRE

    Rupa Dasgupta

    2012-01-01

    Aluminium alloy-based metal matrix composites (AMMCs) have been by now established themselves as a suitable wear resistant material especially for sliding wear applications. However, in actual practice engineering components usually encounter combination of wear types. An attempt has been made in the present paper to highlight the effect of dispersing SiC in 2014 base alloy adopting the liquid metallurgy route on different wear modes like sliding, abrasion, erosion, and combinations of wear m...

  7. Engineered barrier experiments and analytical studies on coupled thermal - hydraulic - chemical processes in bentonite buffer material

    International Nuclear Information System (INIS)

    It is anticipated that thermal - hydraulic - mechanical - chemical (THMC) processes will be coupled in the bentonite buffer material of a high-level radioactive waste repository. The main contributors to these processes are heat arising from the radioactive decay of the vitrified waste, infiltration of groundwater from the host rock and/or leachate from the cementitious component of the repository, and the consequent increase in swelling pressure and chemical reactions. In order to evaluate these coupled processes in the bentonite buffer material, it is necessary to take steps towards the development of a credible and robust THMC model. The current paper describes the measured data of an engineering-scale coupled THC process experiment and the calculated results of a THC model undergoing development. The coupled experiment used an electric heater, bentonite blocks and a mortar block, subjected to infiltrating water to simulate a high-alkaline porewater derived from the concrete tunnel support seeping into the bentonite buffer material under a thermal gradient provided by the vitrified waste. Temperature and water content of the bentonite buffer material were measured by several sensors continuously for several months. After this time, the buffer material was sampled. The results of mineral analysis of the samples suggested that the precipitate of amorphous hydrate with silica was found in the buffer material in contact with the mortar. The developing THC model simulated C-S-H gel precipitation as a secondary mineral in the exact same locality because of the solution being saturated with respect to portlandite and chalcedony, thereby providing some confidence in the chemical feature of the developing THC model. Some important issues in the future development of the model were also identified, including the concentration of porewater being influenced by vapor movement in the bentonite buffer material due to heating from the vitrified waste and geochemical reactions

  8. Collection of radiation resistant characteristics reports for instruments and materials in high dose rate environment

    International Nuclear Information System (INIS)

    This document presents the collected official reports of radiation irradiation study for the candidate materials to be used in high dose rate environment as J-PARC facility. The effect of radiation damage by loss-beam or secondary particle beam of the accelerators influences the performance and the reliability of various instruments. The knowledge on the radiation resistivity of the materials is important to estimate the life of the equipments, the maintenance interval and dose evaluation for the personnel at the maintenance period. The radiation damage consists with mechanical property, electrical property and gas-evolution property. (author)

  9. Radiation resistance of low density polyethylene and polymer materials having benzene rings

    International Nuclear Information System (INIS)

    The research on the improvement of the radiation resistance of organic polymer insulator materials is the indispensable theme for the countermeasures to such urgent problem as the improvement of safety in nuclear power generation and for coping with such near future technologies as nuclear fusion power generation and space environment utilization. So far the evaluation of the radiation resistance of organic polymer materials has been mainly the studies on the change of mechanical properties due to large dose irradiation. The authors have attempted to clarify the deterioration mechanism in organic polymer materials at relatively early stage by studying on the change of electrical properties due to relatively low dose irradiation. In this study, in order to investigate the effect that an antiradiation agent exerts to the improvement of radiation resistance, by irradiating low dose gamma ray on the low density polyethylene and cross-linked polyethylene being added with ultraviolet ray absorbent, the electrical characteristics were measured, and the comparison of the results with those obtained by using ethylene-styrene copolymer was carried out. The samples, the experimental method and the results are reported. (K.I.)

  10. Ni-W coatings electrodeposited on carbon steel: Chemical composition, mechanical properties and corrosion resistance

    International Nuclear Information System (INIS)

    Highlights: → Hard, ductile and adherent nanostructured Ni-W coatings on carbon steel. → New procedures for achieving deposits by current pulse techniques. → Current pulse frequency was the dominant factor to define coating characteristics. → Ni-W coatings protect the carbon steel from corrosion induced by sulphate anions. - Abstract: Hard, ductile and adherent nanostructured Ni-W coatings were electrodeposited on carbon steel from electrolyte solutions containing sodium tungstate, nickel sulfate and sodium citrate, using different current pulse programs. Current pulse frequency was the dominant factor to define chemical composition, grain size, thickness and hardness. According to the electrodeposition conditions the deposited coatings showed 15-30 at% W, the grain size ranged from 65 to 140 nm, and the hardness varied from 650 to 850 Hv. Tungsten carbide also present in the coating contributed to its hardness. The corrosion resistance of the Ni-W coated steel was tested by potentiodynamic polarization in a neutral medium containing sulphate ions. The Ni-W coating protected the carbon steel from localized corrosion induced by sulphate anions.

  11. Preliminary experimental studies on the chemical and radiation degradation of combustible plutonium contaminated material

    International Nuclear Information System (INIS)

    The chemical and radiation degradation of combustible plutonium contaminated material (PCM) in a cement matrix has been investigated. Experimental studies have been carried out to establish the influence of any water soluble chemical and radiation degradation products on the solubility of plutonium at high pHs. The influence of complexing agents (e.g. EDTA, citric acid), which may be present in wastes, on plutonium solubility has been assessed. The extent of sorption on cement in the presence of organic degradation products has been measured. (author)

  12. Materials of jubilee scientific assembly of the Polish Chemical Society, Warsaw'94. Homo chemicus

    International Nuclear Information System (INIS)

    The Jubilee Scientific Assembly of the Polish Chemical Society has been held in 1994 in Warsaw. The general view on scientific progress in chemistry in Poland has been presented during plenary session. The conference has been divided into 15 sessions and 3 microsymposia covering the most important research fields in chemistry. Sessions topics were: analytical chemistry, chemistry of solid state materials, physical chemistry, coordination chemistry, medical chemistry, chemistry of metalorganic compounds, inorganic chemistry, organic chemistry, chemistry of polymers, young scientists forum, didactics and history of chemistry, catalysis, crystallochemistry, chemical technology, environment protection. Microsymposia's topics were as follows: chemistry of saccharides, electrochemistry, membranes and membrane processes

  13. FY98 Final Report Initial Interfacial Chemical Control for Enhancement of Composite Material Strength; TOPICAL

    International Nuclear Information System (INIS)

    The U.S. Army Armament Research Development and Engineering Center (ARDEC) sponsored this research project to support the development of new self-assembled monolayer fiber coatings. These coatings can greatly increase the bond strength between the fiber and the resin matrix of a composite material. Composite ammunition components molded from such materials will exhibit higher strength than current materials, and will provide a major improvement in the performance of composites in military applications. Use of composite materials in military applications is desirable because of the lighter weight of the materials and their high strengths. The FY97 project investigated initial interfacial chemical control for enhancement of composite material strength. The core of the project was to modify the covalent interface of glass fibers (or other reinforcing fibers) to induce strong, uniform, defect-free adhesion between the fibers' surfaces and the polymer matrix. Installing a self-assembled monolayer tailored to the specific matrix resin accomplished this. Simply, the self-assembled monolayer modifies the fiber to make it appear to have the same chemical composition as the resin matrix. The self-assembled monolayer creates a receptive, hydrophobic interface that the thermoset resin (or polymer precursors) would wet more effectively, leading to a higher contact surface area and more efficient adhesion. The FY97 work phase demonstrated that it is possible to increase the adhesive strength, as well as increase the heat deflection temperature through the use of self-assembled monolayer

  14. Novel EUV resist materials design for 14nm half pitch and below

    Science.gov (United States)

    Tsubaki, Hideaki; Tarutani, Shinji; Fujimori, Toru; Takizawa, Hiroo; Goto, Takahiro

    2014-04-01

    Polymers with a different Tg and activation energy were prepared to clarify influences of acid diffusion on resolution at 15 nm half-pitch (hp) and 14 nm hp using a EUV micro-field exposure tool (MET) at LBNL. Resolution on such a narrow pattern was limited by collapse and pinching. Clear relationship between pinching numbers and polymer Tg indicates that acid diffusion is one of major contributors on the pinching. In addition, polymers with a low thermal activation energy (Ea) on deprotection were effective for reducing pinching. This is probably originated from its high chemically amplification character even in low post-exposure bake (PEB) temperature to obtain both large chemical contrast and short acid diffusion. On the other hand, a good correlation between a cleanable outgassing amount and Ea indicates trade-off relationship between outgassing and resolution. Advantages of n-butyl acetate (nBA) developer have been investigated in viewpoint of dissolution uniformity. Surface roughness of a non-patterned resist film at half-exposed area, which was well correlated with LWR, was measured by AFM as indicator of uniformity in development process. To avoid any differences in resist chemistry other than development process, cross linking negative tone resist was applied for this study. The surface roughness obtained by nBA, which is conventional negative-tone imaging (NTI) developer, was 32 % lower than that obtained by 2.38 % TMAH solution. NTI resist system with a nBA developer and optimized resist reduced LWR from 4.8 nm to 3.0 nm in comparison with conventional positive tone resist with a 2.38 % TMAH developer. In addition, advantage on semi-dense trench patterning was well defined. New EUV sensitizer with 1.15 times higher EUV absorption resulted in 1.15 times higher acid yield by EUV exposure. Lithography performance of the new EUV sensitizer has been investigated by MET at SEMATECH Albany. Sensitivity was indeed improved from 20 mJ/cm2 to 17 mJ/cm2 according

  15. Freeze-thaw performance of chemically stabilized natural and recycled highway materials

    Institute of Scientific and Technical Information of China (English)

    Tuncer B Edil; Bora Cetin

    2015-01-01

    This article provides an overview of several previous studies that investigated the stiffness and strength performance of chemically stabilized roadway materials under winter conditions (freeze-thaw cycling). The objective of this research was to understand the behavior of different materials stabilized with different type of binders when they were subjected to freeze-thaw cycling. Nine different materials including natural soils (organic soil, clay, silt, sand, and road surface gravel), reclaimed pavement material, and recycled asphalt pavement stabilized with nine different binders (five different fly ashes, lime, cement, lime kiln dust, cement kiln dust) were discussed. This article investigated how the volume, resilient modulus and unconfined compressive strength of soils/materials stabilized with different binders change in response to freeze-thaw cycling. Overall, the review results indicate that the stiffness and strength of all stabilized materials decrease somewhat with freeze-thaw cycling. However, the reduced strength and stiffness of stabilized materials after freeze-thaw cycling was still higher than that of unstabilized-unfrozen original soils and materials. In addition, materials stabilized with cement kiln dust provided the best performance against freeze-thaw cycling.

  16. Chemical surety material decontamination and decommissioning of Los Alamos National Laboratory Chemical Surety Material Laboratory area TA-3, building SM-29, room 4009

    International Nuclear Information System (INIS)

    From 1982 through 1987, Los Alamos National Laboratory (LANL) performed surety laboratory operations for the U.S. Army Medical Research and Development Command (MRDC). Room 4009 in building SM-29, TA-3, was used as the laboratory for work with the following chemical surety material (CSM) agents: sarin (GB), soman (GD), lewisite (L), and distilled mustard (HD) radio-labelled with H3 or C14. The work was confined to three CSM-certified fume hoods, located in room 4009 (see diagram in Appendix C). The laboratory ceased all active operations during the late 1986 and early 1987 period. From 1987 until 1993 the laboratory was secured and the ventilation system continued to operate. During late 1992, the decision was made to utilize this laboratory space for other operations, thus a decision was made to dismantle and reconfigure this room. LANL sub-contracted Battelle Memorial Institute (BMI) to draw upon the CSM experience of the technical staff from the Hazardous Materials Research Facility (HMRF) to assist in developing a decontamination and decommissioning plan. BMI was subcontracted to devise a CSM safety training course, and a sampling and air monitoring plan for CSM material to ensure personnel safety during all disassembly operations. LANL subcontracted Johnson Controls personnel to perform all disassembly operations. Beginning in early 1993 BMI personnel from the HMRF visited the laboratory to develop both the safety plan and the sample and air monitoring plan. Execution of that plan began in September 1993 and was completed in January 1994

  17. Wear resistance of PM composite materials reinforced with the Ti(C,N ceramic particles

    Directory of Open Access Journals (Sweden)

    A. Włodarczyk-Fligier

    2008-10-01

    Full Text Available Purpose: of the project was evaluation of the effect of heat treatment and of the reinforcing Ti(C,N particles in the EN AW-AlCu4Mg1(A aluminium alloy on the mechanical properties, wear resistance.Design/methodology/approach: some of the composite materials were hyperquenched for 0.5 h at the temperature of 495ºC with the subsequent cooling in water, and were quench aged next for 6 h at 200°C. Hardness tests were made on HAUSER hardness tester with the Vickers method at 10 N. Abrasion resistance wear tests were carried out with the constant number of cycles of 5000 (120 m at various loads: 4, 5, 6, 7, and 8 N. Test pieces were rinsed in the ultrasonic washer to clean them and next were weighed on the analytical balance with the accuracy of 0.0001 g to check the mass loss.Findings: Besides visible improvement of mechanical properties and wear resistance there were also observed the influence of heat treatment.Practical implications: Tested composite materials can be applied among others in automotive industry but it requires additional researches.Originality/value: It was demonstrated that the mechanical properties, as well as the wear resistance of the investigated composite materials with the EN AW-Al Cu4Mg1(A alloy matrix may be formed by the dispersion hardening with the Ti(C,N particles in various portions and by the precipitation hardening of the matrix.

  18. Combined effects of cold work and chemical polishing on the absorption and release of hydrogen from SRF cavities inferred from resistance measurements of cavity-grade niobium bars

    Science.gov (United States)

    Dzyuba, A.; Cooley, L. D.

    2014-03-01

    A series of small fine-grained and single-crystal bars, with strain from 0% (recrystallized) to 50%, were given different amounts of chemical polishing. Four-point resistivity (ρ) data was used to characterize the electron scattering from dislocations, hydrogen, and any other trace contaminants. As noted by previous studies, annealed Nb displayed a weak linear increase of ρ (11 K) with polishing time due to hydrogen absorption, and bulk hydrogen concentration did not exceed 15% for 200 μm metal removed. Cold-worked samples displayed steeper slopes with polishing time (after subtracting resistivity due to strain alone), suggesting that dislocations assist the absorption of hydrogen during polishing. Absorption accelerated above 30% strain and 100 μm material removal, with room-temperature hydrogen concentration rising rapidly from 2% up to 5%. This threshold is significant, since superconducting radio-frequency (SRF) cavities are usually polished as-formed, with >35% strain, and polishing removes >150 μm of metal. Resistance jumps between 40 and 150 K, which signal the formation of hydride precipitates, were stronger in cold-worked samples, suggesting that dislocations also assist precipitate nucleation. High-vacuum anneals at 800 °C for 2 h, which are known to fully recrystallize cavity-grade niobium and de-gas hydrogen, removed the 40-150 K jumps and recovered the resistivity increase due to chemical polishing entirely. But, about 30% of the resistivity increase due to cold work remained, possibly due to residual dislocation clusters. Continued annealing only facilitated the diffusion of surface impurities into the bulk and did not recover the initial 0% state. Strain, polishing, and annealing thus appear to combine as irreversible paths that change the material. Bearing this in mind, the significant difference in hydrogen uptake between annealed and cold-worked samples suggests that annealing SRF cavities prior to chemical polishing could greatly reduce

  19. Germanium-on-Silicon Strain Engineered Materials for Improved Device Performance Grown by Chemical Vapor Deposition

    Science.gov (United States)

    Bharathan, Jayesh Moorkoth

    The primary goal of this research is to develop a chemical vapor deposition process for growing epitaxial films of germanium on silicon (001) substrates with two-dimensional (2-D) morphology, and a low density of threading dislocations. Growth was carried out in a reduced-pressure chemical vapor deposition (RPCVD) system by a two-step growth technique. An accurate knowledge of elastic constants of thin films is important in understanding the effect of strain on material properties. Residual thermal strain was used to measure the Poisson ratio of Ge films grown on Si(001) substrates, by the sin2Psi method and highresolution x-ray diffraction. The Poisson ratio of the Ge films was measured to be 0.25, compared to the bulk value of 0.27. The result was found to be independent of film thickness and defect density, which confirmed that the strain is associated with the elastic response of the film. The study showed that the use of Poisson ratio instead of bulk compliance values yields a more accurate description of the state of in-plane strain present in the film. The experimentally measured in-plane strain in Ge films was found to be lower than the theoretical calculations based on the differential thermal expansion coefficients of Si and Ge. The mechanism of thermal misfit strain relaxation in epitaxial Ge films grown on Si(001) substrates was investigated by x-ray diffraction, and transmission electron microscopy. Lattice misfit strain associated with Ge/(001)Si mismatched epitaxy is relieved by a network of Lomer edge misfit dislocations during the first step of the growth technique. However, thermal misfit strain energy during growth is relieved by interdiffusion mechanism at the heterointerface. Two SiGe compositions containing 0.5 and 6.0 atomic percent Si were detected that relieve the thermal mismatch strain associated with the two steps of the growth process. This study discusses the importance of interdiffusion mechanism in relieving small misfit strains

  20. Dissolution behavior of chemically amplified resist for advanced mask- and NIL mold-making as studied by dissolution rate monitor

    Science.gov (United States)

    Takeshi, Kazumasa; Oono, Kazuto; Negishi, Yoshiyuki; Inokuchi, Daisuke; Tanaka, Keishi; Tamura, Akira

    2006-05-01

    The dissolution behaviors of chemically amplified resists for electron beam lithography (EB CARs) have been investigated using the technique of quartz crystal microbalance (QCM) method. We report the first direct measurement of the dissolution rate of EB CARs and the comparison with CAR of using KrF exposure in wafer fabrication. The EB CAR for nano-imprint lithography mold making was also evaluated by this technique, and then resolved 50 nm line and space patterns using conventional 50 KV variable shape beam writing system. The understanding of dissolution kinetics of EB CARs is capable of designing high performance resists in near future.

  1. Soft x-ray spectroscopy for probing electronic and chemical states of battery materials

    Science.gov (United States)

    Wanli, Yang; Ruimin, Qiao

    2016-01-01

    The formidable challenge of developing high-performance battery system stems from the complication of battery operations, both mechanically and electronically. In the electrodes and at the electrode-electrolyte interfaces, chemical reactions take place with evolving electron states. In addition to the extensive studies of material synthesis, electrochemical, structural, and mechanical properties, soft x-ray spectroscopy provides unique opportunities for revealing the critical electron states in batteries. This review discusses some of the recent soft x-ray spectroscopic results on battery binder, transition-metal based positive electrodes, and the solid-electrolyte-interphase. By virtue of soft x-ray’s sensitivity to electron states, the electronic property, the redox during electrochemical operations, and the chemical species of the interphases could be fingerprinted by soft x-ray spectroscopy. Understanding and innovating battery technologies need a multimodal approach, and soft x-ray spectroscopy is one of the incisive tools to probe the chemical and physical evolutions in batteries.

  2. The testing of materials within the purview of the laws concerning the control of chemical substances

    International Nuclear Information System (INIS)

    The main approach adopted for this book is the question of whether and to what extent the commercially available chemical products (ranging from foodstuffs and drugs to pesticides and similar pollutants) have been assessed for environmental and health safety prior to release. The relevant existing laws concerning the testing and characterisation of substances are analysed and compared with a view to the major environmental principle, to prevent chemicals-induced hazards to health and the environment. The book reviews the following laws (and their implementing provisions): law on chemical substances, pesticides, fertilisers, drugs, detergents, leaded petrol, food and feedstuffs, explosives, and transport of hazardous materials. Environmentally significant laws reviewed include the waste management act, the atomic energy act (non-recycable wastes, plutonium, tritium), the water management act, and the act for protection against harmful effects on the environment. (orig./HP)

  3. Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system

    Directory of Open Access Journals (Sweden)

    Penna Thereza CV

    2006-08-01

    Full Text Available Abstract Background Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value necessary to inactivate 90% of the initial bioburden (decimal reduction time was experimentally determined. Methods Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were called in house (wild bacteria. Pseudomonas diminuta ATCC 11568, Pseudomonas alcaligenes INCQS , Pseudomonas aeruginosa ATCC 15442, Pseudomonas fluorescens ATCC 3178, Pseudomonas picketti ATCC 5031, Bacillus subtilis ATCC 937 and Escherichia coli ATCC 25922 were used as 'standard' bacteria to evaluate resistance at 25°C against either 0.5% citric acid, 0.5% hydrochloric acid, 70% ethanol, 0.5% sodium bisulfite, 0.4% sodium hydroxide, 0.5% sodium hypochlorite, or a mixture of 2.2% hydrogen peroxide (H2O2 and 0.45% peracetic acid. Results The efficacy of the sanitizers varied with concentration and contact time to reduce decimal logarithmic (log10 population (n cycles. To kill 90% of the initial population (or one log10 cycle, the necessary time (D-value was for P. aeruginosa into: (i 0.5% citric acid, D = 3.8 min; (ii 0.5% hydrochloric acid, D = 6.9 min; (iii 70% ethanol, D = 9.7 min; (iv 0.5% sodium bisulfite, D = 5.3 min; (v 0.4% sodium hydroxide, D = 14.2 min; (vi 0.5% sodium

  4. A Damage Resistance Comparison Between Candidate Polymer Matrix Composite Feedline Materials

    Science.gov (United States)

    Nettles, A. T

    2000-01-01

    As part of NASAs focused technology programs for future reusable launch vehicles, a task is underway to study the feasibility of using the polymer matrix composite feedlines instead of metal ones on propulsion systems. This is desirable to reduce weight and manufacturing costs. The task consists of comparing several prototype composite feedlines made by various methods. These methods are electron-beam curing, standard hand lay-up and autoclave cure, solvent assisted resin transfer molding, and thermoplastic tape laying. One of the critical technology drivers for composite components is resistance to foreign objects damage. This paper presents results of an experimental study of the damage resistance of the candidate materials that the prototype feedlines are manufactured from. The materials examined all have a 5-harness weave of IM7 as the fiber constituent (except for the thermoplastic, which is unidirectional tape laid up in a bidirectional configuration). The resin tested were 977-6, PR 520, SE-SA-1, RS-E3 (e-beam curable), Cycom 823 and PEEK. The results showed that the 977-6 and PEEK were the most damage resistant in all tested cases.

  5. Preparation and wear resistance of Ti-Zr-Ni quasicrystal and polyamide composite materials

    Science.gov (United States)

    Wang, Xinlu; Li, Xuesong; Zhang, Zhenjiang; Zhang, Shanshan; Liu, Wanqiang; Wang, Limin

    2011-07-01

    Ti-Zr-Ni icosahedral quasicrystal powders (Ti-QC), prepared by mechanical alloying and then annealing in a vacuum furnace, were used as a novel filler material in polyamide 12 (PA12). The melt processability of the composite was studied using a Haake torque rheometer. This indicates that PA12/Ti-QC composites can be melt-processed into a wear-resistant material. Further, these composites, fabricated by compression molding, were tested in sliding wear against a polished bearing steel counterface. The results from wear testing show that the addition of Ti-QC filler to PA12 enhances wear resistance and reduces volume loss by half compared with neat PA12. Furthermore, it is found that the hardness of the composite increases with increasing content of Ti-QC filler. In addition, PA12/Ti-QC composites exhibit a slightly higher crystallization temperature and better thermal stability than PA12. These combined results demonstrate that Ti-QC filler may be a desirable alternative when attempting to increase the wear resistance of PA12.

  6. Fracture resistance of endodontically treated teeth restored with a bulkfill flowable material and a resin composite

    Science.gov (United States)

    Isufi, Almira; Plotino, Gianluca; Grande, Nicola Maria; Ioppolo, Pietro; Testarelli, Luca; Bedini, Rossella; Al-Sudani, Dina; Gambarini, Gianluca

    2016-01-01

    Summary Aim To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Methods Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (Pendodontically treated teeth restored with a traditional resin composite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. Conclusions No significant difference was observed in the mechanical fracture resistance of endodontically treated molars restored with traditional resin composite restorations compared to bulk fill flowable composite restorations. PMID:27486505

  7. Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher; Dai, Sheng

    2016-06-07

    An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted in liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.

  8. Safety Issues of HG and PB as IFE Target Materials: Radiological Versus Chemical Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, S; Latkowski, J F; Cadwallader, L C; Moir, R W; Rio, G. D; Sanz, J

    2002-11-11

    We have performed a safety assessment of mercury and lead as possible hohlraum materials for Inertial Fusion Energy (IFE) targets, including for the first time a comparative analysis of the radiological and toxicological consequences of an accidental release. In order to calculate accident doses to the public, we have distinguished between accidents at the target fabrication facility and accidents at other areas of the power plant. Regarding the chemical toxicity assessment, we have used the USDOE regulations to determine the maximum allowable release in order to protect the public from adverse health effects. Opposite to common belief, it has been found that the chemical safety requirements for these materials appear to be more stringent than the concentrations that would result in an acceptable radiological dose.

  9. Diffusion, Thermal Properties and Chemical Compatibilities of Select MAX Phases with Materials For Advanced Nuclear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Barsoum, Michel [Drexel Univ., Philadelphia, PA (United States); Bentzel, Grady [Drexel Univ., Philadelphia, PA (United States); Tallman, Darin J. [Drexel Univ., Philadelphia, PA (United States); Sindelar, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcia-Diaz, Brenda [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hoffman, Elizabeth [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-04

    The demands of Gen IV nuclear power plants for long service life under neutron irradiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ ºC) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the chemical compatibility of select MAX with potential materials that are important for nuclear energy, as well as to measure the thermal transport properties as a function of neutron irradiation. The chemical counterparts chosen for this work are: pyrolytic carbon, SiC, U, Pd, FLiBe, Pb-Bi and Na, the latter 3 in the molten state. The thermal conductivities and heat capacities of non-irradiated MAX phases will be measured.

  10. Chemical States of Lanthanum in Carbonized La2O3-Mo Thermionic Cathode Materials

    Institute of Scientific and Technical Information of China (English)

    王金淑; 周美玲; 王亦曼; 张久兴; 聂祚仁; 左铁镛

    2003-01-01

    The chemical reaction between lanthanum oxide and molybdenum carbide was studied by thermodynamic calculation, thermal analysis and in-situ X-ray Photoelectron Spectroscopy. The theoretical results show that at the environment allowing for the evaporation of lanthanum, such as in high vacuum, La2O3 in the La2O3-Mo materials can be reduced to metallic lanthanum by molybdenum carbide (Mo2C). To confirm the conclusion, many analysis methods such as XRD, SPS, and TG-DTA were taken. The experimental results show that the chemical state of lanthanum changes during heating. It was proved, for the first time, that reacted metallic lanthanum appears at the surface of this kind of material at high temperature.

  11. Numerical Simulation for Thermal Shock Resistance of Thermal Protection Materials Considering Different Operating Environments

    Directory of Open Access Journals (Sweden)

    Weiguo Li

    2013-01-01

    Full Text Available Based on the sensitivities of material properties to temperature and the complexity of service environment of thermal protection system on the spacecraft, ultrahigh-temperature ceramics (UHTCs, which are used as thermal protection materials, cannot simply consider thermal shock resistance (TSR of the material its own but need to take the external constraint conditions and the thermal environment into full account. With the thermal shock numerical simulation on hafnium diboride (HfB2, a detailed study of the effects of the different external constraints and thermal environments on the TSR of UHTCs had been made. The influences of different initial temperatures, constraint strengths, and temperature change rates on the TSR of UHTCs are discussed. This study can provide a more intuitively visual understanding of the evolution of the TSR of UHTCs during actual operation conditions.

  12. Mesoporous acid catalysts for renewable raw-material conversion into chemicals and fuel

    OpenAIRE

    Castanheiro, J; Caiado, M; Farinha, J

    2015-01-01

    Mesoporous catalysts, such as silica (PMOs, MCM-41, SBA-15) and activated carbons, have been used in heterogeneous catalysis, due to a combination of high surface areas and controlled pore sizes. These mesoporous materials have been used as catalyst in a wide range of chemical reactions. Due to environmental pressure and a decrease in fossil fuel sources, alternative fuel sources, such as biomass or renewable feedstock sources, have become increasingly popular. Traditional...

  13. Escalation of terrorism? On the risk of attacks with chemical, biological, radiological and nuclear weapons or materials

    International Nuclear Information System (INIS)

    The report on the risk of attacks with chemical, biological, radiological and nuclear weapons or materials covers the following topics: the variety of terrorism: ethnic-nationalistic, politically motivated, social revolutionary, political extremism, religious fanaticism, governmental terrorism; CBRN (chemical, biological, radiological, nuclear) weapons and materials: their availability and effectiveness in case of use; potential actor groups; prevention and counter measures, emergency and mitigating measures.

  14. Study on dry friction and wear resistance of a WC-Co particle reinforced iron matrix composite material

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2013-05-01

    Full Text Available In order to select a suitable material for the rolling mill guide application, the dry sliding friction and wear resistance of a tungsten carbide combining cobalt (WC-Co particle reinforced chromium cast iron composite material were studied. In particular, the wear resistance was discussed in detail. The results showed that the composite material demonstrates 25 times the wear resistance of high Cr cast iron, and 9 times the wear resistance of heat resistant steel. However, the average friction factor in the stable friction stage showed a relationship of μComposites/45 # steel > μHigh chromium cast iron/45 # steel > μHeat resistant steel/45 # steel. The wear resistance mechanism of the composite material was associated with the reinforcing particles, which protruded from the worn surface to bear the friction load when the matrix material surface was worn, thereby reducing the abrasive and adhesive wear. In addition, the matrix material possessed suitable hardness and toughness, providing a support to the reinforcements.

  15. Preliminary Investigation of Candidate Materials for Use in Accident Resistant Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Jason M. Harp; Paul A. Lessing; Blair H. Park; Jakeob Maupin

    2013-09-01

    As part of a Collaborative Research and Development Agreement (CRADA) with industry, Idaho National Laboratory (INL) is investigating several options for accident resistant uranium compounds including silicides, and nitrides for use in future light water reactor (LWR) fuels. This work is part of a larger effort to create accident tolerant fuel forms where changes to the fuel pellets, cladding, and cladding treatment are considered. The goal fuel form should have a resistance to water corrosion comparable to UO2, have an equal to or larger thermal conductivity than uranium dioxide, a melting temperature that allows the material to stay solid under power reactor conditions, and a uranium loading that maintains or improves current LWR power densities. During the course of this research, fuel fabricated at INL will be characterized, irradiated at the INL Advanced Test Reactor, and examined after irradiation at INL facilities to help inform industrial partners on candidate technologies.

  16. Chemical Emissions of Residential Materials and Products: Review of Available Information

    Energy Technology Data Exchange (ETDEWEB)

    Willem, Henry; Singer, Brett

    2010-09-15

    This report is prepared in the context of a larger program whose mission is to advance understanding of ventilation and indoor air quality in U.S. homes. A specific objective of this program is to develop the scientific basis ? through controlled experiments, monitoring and analysis ? for health risk-based ventilation standards. Appropriate and adequate ventilation is a basic element of a healthy home. Ventilation provides outdoor air and in the process removes indoor odors and contaminants including potentially unhealthful chemicals emitted by indoor materials, products and activities. Ventilation traditionally was assured to occur via infiltration of outdoor air through cracks and other leakage pathways in the residential building envelope. As building air tightness is improved for energy efficiency, infiltration can be reduced to inadequate levels. This has lead to the development of standards requiring mechanical ventilation. Though nominally intended to ensure acceptable indoor air quality, the standards are not explicitly tied to health risk or pollutant exposure targets. LBNL is currently designing analyses to assess the impact of varying ventilation standards on pollutant concentrations, health risks and energy use. These analyses require information on sources of chemical pollutant emissions, ideally including emission rates and the impact of ventilation on emissions. Some information can be obtained from recent studies that report measurements of various air contaminants and their concentrations in U.S. residences. Another way to obtain this information is the bottom-up approach of collecting and evaluating emissions data from construction and interior materials and common household products. This review contributes to the latter approach by summarizing available information on chemical emissions from new residential products and materials. We review information from the scientific literature and public sources to identify and discuss the databases that

  17. Silver nanoparticle-based thermal interface materials with ultra-low thermal resistance for power electronics applications

    International Nuclear Information System (INIS)

    We studied the thermal conduction of thermal interface materials (TIM) using silver nanoparticles (AgNP) and achieved ultra-low thermal resistance. The experimental data show that silver nanoparticles are very good candidates for TIM in power electronics applications in terms of the reduction in thermal resistance. The ultra-low thermal resistance of the AgNP-based TIM originates from the thinness, high thermal conductivity of silver and low temperature sintering properties of AgNP.

  18. Biological and chemical-physical properties of root-end filling materials: A comparative study

    Directory of Open Access Journals (Sweden)

    Matteo Ceci

    2015-01-01

    Full Text Available Aim: The purpose of the study is to evaluate and compare the biological and chemical-physical properties of four different root-end filling materials. Materials and Methods: Cytotoxicity towards murine odontoblasts cells (MDPC-23 was evaluated using the Transwell insert methodology by Alamar blue test. Streptococcus salivarius, S. sanguis, and S. mutans strains were selected to evaluate the antimicrobial activity by agar disc diffusion test. Solubility was determined after 24 h and 2 months. pH values were measured after 3 and 24 h. To evaluate radiopacity, all materials were scanned on a GE Healthcare Lunar Prodigy. Results: Excellent percentage of vitality were obtained by mineral trioxide aggregate (MTA-based materials and Biodentine. MTA-Angelus, ProRoot MTA, and Intermediate Restorative Material (IRM showed the highest values for the inhibition zones when tested for S. mutans, while Biodentine showed the largest inhibition zone when tested for S. sanguis. All the materials fulfilled the requirements of the International Standard 6876, demonstrating low solubility with a weight loss of less than 3%. No significant reduction in pH value was demonstrated after 24 h. ProRoot MTA and MTA-Angelus showed the highest values of radiographic density. Conclusions: The differences showed by the root-end filling materials tested do not cover completely the ideal clinical requests.

  19. Chipping fracture resistance of dental CAD/CAM restorative materials: Part 2. Phenomenological model and the effect of indenter type

    OpenAIRE

    Quinn, G. D.; Giuseppetti, A. A.; Hoffman, K. H.

    2014-01-01

    The edge chipping resistances of six CAD/CAM dental restoration materials are analyzed and correlated to other mechanical properties. A new quadratic relationship that is based on a phenomenological model is presented.

  20. Organic Contaminant Content and Physico-Chemical Characteristics of Waste Materials Recycled in Agriculture

    Directory of Open Access Journals (Sweden)

    Hannah Rigby

    2015-12-01

    Full Text Available A range of wastes representative of materials currently applied, or with future potential to be applied, to agricultural land in the UK as fertilisers and soil improvers or used as animal bedding in livestock production, were investigated. In addition to full physico-chemical characterization, the materials were analysed for a suite of priority organic contaminants. In general, contaminants were present at relatively low concentrations. For example, for biosolids and compost-like-output (CLO, concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs and polychlorinated biphenyls (PCBs were approximately 1−10 and 5–50 times lower, respectively, than various proposed or implemented European limit values for these contaminants in biosolids or composts applied to agricultural land. However, the technical basis for these limits may require re-evaluation in some cases. Polybrominated, and mixed halogenated, dibenzo-p-dioxins/dibenzofurans are not currently considered in risk assessments of dioxins and dioxin-like chemicals, but were detected at relatively high concentrations compared with PCDD/Fs in the biosolids and CLOs and their potential contribution to the overall toxic equivalency is assessed. Other ‘emerging’ contaminants, such as organophosphate flame retardants, were detected in several of the waste materials, and their potential significance is discussed. The study is part of a wider research programme that will provide evidence that is expected to improve confidence in the use of waste-derived materials in agriculture and to establish guidelines to protect the food chain where necessary.

  1. Chemical modeling of acid-base properties of soluble biopolymers derived from municipal waste treatment materials.

    Science.gov (United States)

    Tabasso, Silvia; Berto, Silvia; Rosato, Roberta; Marinos, Janeth Alicia Tafur; Ginepro, Marco; Zelano, Vincenzo; Daniele, Pier Giuseppe; Montoneri, Enzo

    2015-01-01

    This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials. PMID:25658795

  2. Chemical Modeling of Acid-Base Properties of Soluble Biopolymers Derived from Municipal Waste Treatment Materials

    Directory of Open Access Journals (Sweden)

    Silvia Tabasso

    2015-02-01

    Full Text Available This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials.

  3. Development of radiation resistant structural materials utilizing fission research reactors in Japan (Role of research reactors)

    International Nuclear Information System (INIS)

    Structural materials for next-generation nuclear power systems should have a good radiation resistance, where the expected accumulation dose will largely exceed 10 dpa. Among several candidate materials, materials of five categories, 1. Austenitic steels, including high nickel alloys, 2. Low activation ferritic martensitic steels, 3. ODS steels (austenitic and ferritic), 4. Vanadium based alloys, 5. Silicon carbide composites (SiC/SiCf). All have been most extensively studied in Japan, in collaboration among industries, national institutes such as Japan Atomic Energy Agency (JAEA), National Institute for Fusion Science (NIFS) and National Institute for Materials Science (NIMS), and universities. The high nickel base alloys were studied for their low swelling behaviors mainly by the NIMS and the austenitic steels are studied for their reliable engineering data base and their reliable performance in irradiation environments mainly by the JAEA, mainly for their application in the near-term projects such as the ITER and the Sodium Cooled Fast Reactors. The most extensive studies are now concentrated on the Low Activation Ferritic Marsensitic steels and ODS steels, for their application in a demonstration fusion reactor and prototype sodium cooled fast reactors. Fundamental studies on radiation effects are carried out, mainly utilizing Japan Materials Testing Rector (JMTR) with its flexible irradiation ability, up to a few dpa. For higher dpa irradiation, a fast test reactor, JOYO is utilized up to several 10s dpa. Some international collaborations such as Japan/USA and Japan/France are effective to utilize reactors abroad, such as High Flux Isotope Reactor (HFIR) of Oak Ridge National Laboratory, and sodium cooled high flux fast reactors in France. Silicon carbide based composites are extensively studied by university groups led by Kyoto University and the JAEA. For their performance in heavy irradiation environments, the Japan/USA collaboration plays an important role

  4. Chemical densification of plasma sprayed yttria stabilized zirconia (YSZ) coatings for high temperature wear and corrosion resistance

    International Nuclear Information System (INIS)

    Highlights: ► Plasma-sprayed YSZ coatings were modified by a novel chemical densification process. ► A lower porosity and a higher microhardness were achieved by the post treatment. ► The enhanced adhesive strength of the ceramic top coat was evaluated by shear tests. ► Mechanisms of this processing were proposed. - Abstract: Plasma-sprayed yttria stabilized zirconia (YSZ) ceramic coatings have been widely used as wear- and corrosion-resistant coatings in high temperature applications and an aggressive environment due to their high hardness, wear resistance, heat and chemical resistance, and low thermal conductivity. The highly porous structure of plasma-sprayed ceramic coatings and their poor adhesion to the substrate usually lead to the coating degradation and failure. In this study, a two-layer system consisting of atmospheric plasma-sprayed 8 wt.% yttria-stabilized zirconia (8YSZ) and Ni-based alloy coatings was post-treated by means of a novel chemical sealing process at moderate temperatures of 600–800 °C. Microstructure characteristics of the YSZ coatings were studied using an electron probe micro-analyzer (EPMA). Results revealed that the ceramic top coat was densified by the precipitated zirconia in the open pores. Therefore, the sealed YSZ coatings exhibit reduced porosity, higher hardness and a better adhesion onto the bond coat. The mechanisms for the sealing process were also proposed.

  5. Influence of heat treatment on corrosion resistance of PM composite materials

    OpenAIRE

    A. Włodarczyk-Fligier; L.A. Dobrzański; M. Adamiak

    2007-01-01

    Purpose: of the project was evaluation of the effect of heat treatment and of the reinforcing Al2O3, Ti(C,N) and BN particles in the EN AW-AlCu4Mg1(A) aluminium alloy on the corrosion resistance in the NaCl water solution environment.Design/methodology/approach: some of the composite materials were hyperquenched for 0.5 h at the temperature of 495ºC with the subsequent cooling in water, and were quench aged next for 6 h at 200°C. Corrosion tests were made in 5%...

  6. A chemical activity evaluation of two dental calcium silicate-based materials

    Directory of Open Access Journals (Sweden)

    Chalas Renata

    2015-06-01

    Full Text Available Calcium silicate-based materials are interesting products widely used in dentistry. The study was designed to compare the chemical reaction between analyzed two preparates and dentin during cavity lining. In our work, dentinal discs were prepared from human extracted teeth filled with Biodentine and MTA+. The samples were then analyzed by way of SEM, EDS and Raman spectroscopy. The obtained results revealed differences in elemental composition between both materials. Biodentine showed higher activity in contact with dentine. Moreover, the interfacial layer in the tooth filled by Biodentine was wider than that in the tooth filled with MTA+. The applied methods of analysis confirmed that both materials have a bioactive potential which is a promising ability.

  7. Thermodynamic analysis of chemical stability of ceramic materials in hydrogen-containing atmospheres at high temperatures

    Science.gov (United States)

    Misra, Ajay K.

    1990-01-01

    The chemical stability of several ceramic materials in hydrogen-containing environments was analyzed with thermodynamic considerations in mind. Equilibrium calculations were made as a function of temperature, moisture content, and total system pressure. The following ceramic materials were considered in this study: SiC, Si3N4, SiO2, Al2O3, mullite, ZrO2, Y2O3, CaO, MgO, BeO, TiB2, TiC, HfC, and ZrC. On the basis of purely thermodynamic arguments, upper temperature limits are suggested for each material for long-term use in H2-containing atmospheres.

  8. A J integral based method to measure fracture resistance and cohesive laws in materials exhibiting large scale plasticity

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Goutianos, Stergios

    2014-01-01

    A method is developed to extract the fracture resistance and mode I cohesive law of nonlinear elastic-plastic materials using a Double Cantilever Beam (DCB) sandwich specimen loaded with pure bending moments. The method is based on the J integral which is valid for materials having a non-linear s......A method is developed to extract the fracture resistance and mode I cohesive law of nonlinear elastic-plastic materials using a Double Cantilever Beam (DCB) sandwich specimen loaded with pure bending moments. The method is based on the J integral which is valid for materials having a non...

  9. Using biological and physico-chemical test methods to assess the role of concrete mixture design in resistance to microbially induced corrosion

    Science.gov (United States)

    House, Mitchell Wayne

    Concrete is the most widely used material for construction of wastewater collection, storage, and treatment infrastructure. The chemical and physical characteristics of hydrated portland cement make it susceptible to degradation under highly acidic conditions. As a result, some concrete wastewater infrastructure may be susceptible to a multi-stage degradation process known as microbially induced corrosion, or MIC. MIC begins with the production of aqueous hydrogen sulfide (H2S(aq)) by anaerobic sulfate reducing bacteria present below the waterline. H2S(aq) partitions to the gas phase where it is oxidized to sulfuric acid by the aerobic sulfur oxidizing bacteria Thiobacillus that resides on concrete surfaces above the waterline. Sulfuric acid then attacks the cement paste portion of the concrete matrix through decalcification of calcium hydroxide and calcium silica hydrate coupled with the formation of expansive corrosion products. The attack proceeds inward resulting in reduced service life and potential failure of the concrete structure. There are several challenges associated with assessing a concrete's susceptibility to MIC. First, no standard laboratory tests exist to assess concrete resistance to MIC. Straightforward reproduction of MIC in the laboratory is complicated by the use of microorganisms and hydrogen sulfide gas. Physico-chemical tests simulating MIC by immersing concrete specimens in sulfuric acid offer a convenient alternative, but do not accurately capture the damage mechanisms associated with biological corrosion. Comparison of results between research studies is difficult due to discrepancies that can arise in experimental methods even if current ASTM standards are followed. This thesis presents two experimental methods to evaluate concrete resistance to MIC: one biological and one physico-chemical. Efforts are made to address the critical aspects of each testing method currently absent in the literature. The first method presented is a new test

  10. Effect of electric pulse processing on physical and chemical properties of inorganic materials

    Science.gov (United States)

    Sakipova, S. E.; Nussupbekov, B. R.; Ospanova, D.; Khassenov, A.; Sakipova, Sh E.

    2015-04-01

    This article analyzes various aspects of the practical application of electric pulse technology of industrial raw materials processing as a result of a spark electric discharge in a liquid solution of the raw material under processing. The object of the study are samples of technogenic materials from a deposit in Central Kazakhstan, which are crushed and ground to particles with a preset degree of fragmentation. The electric pulse processing is performed by using different numbers of discharges. The effect of electric pulse processing with different electrical parameters is carried out on the basis of comparison of the properties and structure of metal-containing and industrial raw materials after machining and electric pulse processing. The X-ray spectral microanalysis was performed using a scanning microscope. The researchers obtained data on changes in the microstructure and elemental composition of inorganic material samples as a result of electric pulse processing. It was established that the technology of electric pulse crushing and grinding of inorganic materials makes it possible to obtain not only a final product with desired size of dispersed particles, but also to change their physical and chemical properties.

  11. Chemical compatibility study of melilite-type gallate solid electrolyte with different cathode materials

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Alessandro [INSTM R.U. and Department of Chemistry–Physical Chemistry Division, University of Pavia, Pavia I-27100 (Italy); Felice, Valeria; Natali Sora, Isabella [INSTM R.U. and Department of Engineering, University of Bergamo, Dalmine, Bergamo I-24044 (Italy); Malavasi, Lorenzo [INSTM R.U. and Department of Chemistry–Physical Chemistry Division, University of Pavia, Pavia I-27100 (Italy); Tealdi, Cristina, E-mail: cristina.tealdi@unipv.it [INSTM R.U. and Department of Chemistry–Physical Chemistry Division, University of Pavia, Pavia I-27100 (Italy)

    2014-05-01

    Chemical reactivity between cathodes and electrolytes is a crucial issue for long term SOFCs stability and performances. In this study, chemical reactivity between selected cathodic materials and the ionic conducting melilite La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25} has been extensively investigated by X-ray powder diffraction in a wide temperature range (up to 1573 K). Perovskite-type La{sub 0.8}Sr{sub 0.2}MnO{sub 3−d} and La{sub 0.8}Sr{sub 0.2}Fe{sub 0.8}Cu{sub 0.2}O{sub 3−d} and K{sub 2}NiF{sub 4}-type La{sub 2}NiO{sub 4+d} were selected as cathode materials. The results of this study allow identifying the most suitable electrode material to be used in combination with the melilite-type gallate electrolyte and set the basis for future work on this novel system. - Graphical abstract: Chemical reactivity between cathodes and electrolytes is a crucial issue for long term SOFCs stability and performances. In this study, chemical reactivity between selected cathodic materials and the ionic conducting melilite La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25} has been extensively investigated by means of X-ray powder diffraction. - Highlights: • Chemical compatibility between melilite-type gallate and cathodes for SOFCs up to 1573 K. • No reactivity observed between La{sub 0.8}Sr{sub 0.2}Fe{sub 0.8}Cu{sub 0.2}O{sub 3−d} and La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25}. • Reactivity observed between La{sub 0.80}Sr{sub 0.20}MnO{sub 3−d} and La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25}. • Significant reactivity observed between La{sub 2}NiO{sub 4+d} and La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25}.

  12. Chemical compatibility study of melilite-type gallate solid electrolyte with different cathode materials

    International Nuclear Information System (INIS)

    Chemical reactivity between cathodes and electrolytes is a crucial issue for long term SOFCs stability and performances. In this study, chemical reactivity between selected cathodic materials and the ionic conducting melilite La1.50Sr0.50Ga3O7.25 has been extensively investigated by X-ray powder diffraction in a wide temperature range (up to 1573 K). Perovskite-type La0.8Sr0.2MnO3−d and La0.8Sr0.2Fe0.8Cu0.2O3−d and K2NiF4-type La2NiO4+d were selected as cathode materials. The results of this study allow identifying the most suitable electrode material to be used in combination with the melilite-type gallate electrolyte and set the basis for future work on this novel system. - Graphical abstract: Chemical reactivity between cathodes and electrolytes is a crucial issue for long term SOFCs stability and performances. In this study, chemical reactivity between selected cathodic materials and the ionic conducting melilite La1.50Sr0.50Ga3O7.25 has been extensively investigated by means of X-ray powder diffraction. - Highlights: • Chemical compatibility between melilite-type gallate and cathodes for SOFCs up to 1573 K. • No reactivity observed between La0.8Sr0.2Fe0.8Cu0.2O3−d and La1.50Sr0.50Ga3O7.25. • Reactivity observed between La0.80Sr0.20MnO3−d and La1.50Sr0.50Ga3O7.25. • Significant reactivity observed between La2NiO4+d and La1.50Sr0.50Ga3O7.25

  13. Chemical and physical analysis of core materials for advanced high temperature reactors with process heat applications

    International Nuclear Information System (INIS)

    Various chemical and physical methods for the analysis of structural materials have been developed in the research programmes for advanced high temperature reactors. These methods are discussed using as examples the structural materials of the reactor core - the fuel elements consisting of coated particles in a graphite matrix and the structural graphite. Emphasis is given to the methods of chemical analysis. The composition of fuel kernels is investigated using chemical analysis methods to determine the heavy metals content (uranium, plutonium, thorium and metallic impurity elements) and the amount of non-metallic constituents. The properties of the pyrocarbon and silicon carbide coatings of fuel elements are investigated using specially developed physiochemical methods. Regarding the irradiation behaviour of coated particles and fuel elements, methods have been developed for examining specimens in hot cells following exposures under reactor operating conditions, to supplement the measurements of in-reactor performance. For the structural graphite, the determination of impurities is important because certain impurities may cause pitting corrosion during irradiation. The localized analysis of very low impurity concentrations is carried out using spectrochemical d.c. arc excitation, local laser and inductively coupled plasma methods. (orig.)

  14. NVENTIONS IN THE NANOTECHNOLOGICAL AREA PROVIDE INCREASED RESISTANCE OF CONSTRUCTION MATERIALS AND PRODUCTS TO OPERATIONAL LOAD

    Directory of Open Access Journals (Sweden)

    VLASOV Vladimir Alexeevich

    2013-12-01

    Full Text Available The invention «Dispersion of Carbon Nanotubes (RU 2494961» can be used in production of modifying additives for construction materials. Dispersion of carbon nanotubes contains, mass %: carbon nanotubes 1–20; surface active agent – sodium chloride of sulfonated derived naphthalene 1–20; fumed silica 5–15; water – the rest. Dispersion can additionally contain ethylene glycol as antifreeze. Dispersion is steady in storage, it is soluble in water, provides increased strength of construction materials. Invention «Building Structures Reinforcement Composition (RU 2493337» can beused in construction to reinforce concrete, brick and masonry structures. Composition contains glass or basalt roving taken in quantity 90÷100 parts by weight, soaked in polymer binder based on epoxy taken in quantity 0,001÷1,5 parts by weight. This invention provides high resistance to operational load.

  15. INCREASING THE FRACTURE TOUGHNESS OF EROSION-RESISTANT LAYERED MATERIALS PRODUCED BY EXPLOSION WELDING

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevski

    2015-05-01

    Full Text Available It is proposed to use the J-integral criterion that takes into account the plastic deformation at the crack tip for layered materials based on high-strength steel 38HN3MFA alloys and erosion resistant cobalt alloy ЭП 131, molybdenum alloy MT, which are destroyed according to the laws of elastic-plastic mechanics. The experimental technique for determining and numerical calculation of energetic J-integral has been described. Numerical modeling of the destruction process has shown good convergence with experimental researches. There was shown that the high-velocity deformation at explosive processing of steel forms structure with high parameters of strain crack toughness and significant increase of yield strength of a material.

  16. Improvement on corrosion resistance of NiTi orthopedic materials by carbon plasma immersion ion implantation

    Science.gov (United States)

    Poon, Ray W. Y.; Ho, Joan P. Y.; Luk, Camille M. Y.; Liu, Xuanyong; Chung, Jonathan C. Y.; Chu, Paul K.; Yeung, Kelvin W. K.; Lu, William W.; Cheung, Kenneth M. C.

    2006-01-01

    Nickel-titanium shape memory alloys (NiTi) have potential applications as orthopedic implants because of their unique super-elastic properties and shape memory effects. However, the problem of out-diffusion of harmful Ni ions from the alloys during prolonged use inside a human body must be overcome before they can be widely used in orthopedic implants. In this work, we enhance the corrosion resistance of NiTi using carbon plasma immersion ion implantation and deposition (PIII&D). Our corrosion and simulated body fluid tests indicate that either an ion-mixed amorphous carbon coating fabricated by PIII&D or direct carbon PIII can drastically improve the corrosion resistance and block the out-diffusion of Ni from the materials. Results of atomic force microscopy (AFM) indicate that both C2H2-PIII&D and C2H2-PIII do not roughen the original flat surface to an extent that can lead to degradation in corrosion resistance.

  17. Characterization of organic materials in civil engineering by chemical and physicochemical methods, chapter 25 In : Yves Mouton (Eds), Organic Materials for Sustainable Construction

    OpenAIRE

    FARCAS, Fabienne

    2013-01-01

    From the domain of roads to the domain of construction, the organic materials used are very diverse (bitumens, paints, cements, etc), but studying their chemical structure and their composition generally uses the same analysis techniques. Without claiming to be exhaustive, this chapter completes and brings up to date the presentation of chemical, physicochemical, physicomechanical and thermomechanical properties previously offered through research studying the chemical structure of basic orga...

  18. Features of the vacuum activated thermo-chemical treatment of materials

    International Nuclear Information System (INIS)

    In this study the option of a heat-resistant layer is approved for protecting products from niobium was tested and based on silicides of molybdenum and niobium. Coating was formed by method of vacuum diffusion saturation in presence vapors of sodium chloride. As the saturating environment was used mixture, consisting of powders disilicide of molybdenum, silicon and alloying additions. The thermodynamics calculation of possible chemical reactions was executed for determination of components saturation environment of gas and terms transfer of molybdenum in niobium. Niobium samples were siliconized at the temperature of T = 1250 oN within 7 hours and stream activator 1 g/hour. The coating consisted of two layers, thickness upper layer - 90 mkm, adjoining to basis - 10 mkm. Also the process of vacuum- activated boriding of steel 45 was investigated.

  19. Long-term behaviour of heat-resistant steels and high-temperature materials

    International Nuclear Information System (INIS)

    This book contains 10 lectures with the following subjects: On the effect of thermal pretreatment on the structure and creep behaviour of the alloy 800 H (V. Guttmann, J. Timm); Material properties of heat resistant ferritic and austenitic steels after cold forming (W. Bendick, H. Weber); Investigations for judging the working behaviour of components made of alloy 800 and alloy 617 under creep stress (H.J. Penkalla, F. Schubert); Creep behaviour of gas turbine materials in hot gas (K.H. Kloos et al.); Effect of small cold forming on the creep beahviour of gas turbine blades made of Nimonic 90 (K.H. Keienburg et al.); Investigations on creep fatigue alternating load strength of nickel alloys (G. Raule); Change of structure, creep fatigue behaviour and life of X20 Cr Mo V 12 1 (by G. Eggeler et al.); Investigations on thermal fatigue behaviour (K.H. Mayer et al.); Creep behaviour of similar welds of the steels 13 Cr Mo 4 4, 14 MoV 6 3, 10 Cr Mo 910 and GS-17 Cr Mo V 5 11 (K. Niel et al.); Determining the creep crack behaviour of heat resistant steels with samples of different geometry (K. Maile, R. Tscheuschner). (orig.,/MM)

  20. ICONEL 690: a material with improved corrosion resistance for PWR steam generator tubes

    International Nuclear Information System (INIS)

    This paper reviews the major aspects of the joint program carried out by the Commissariat a l'Energie Atomique, Electricite de France, Framatome and Westinghouse on the investigation of Inconel 690 (I.690) for use as PWR Steam Generator Tubing. The program was conceived as a further step in the long-term development of improvements in S.G. tube material corrosion resistance. Although the major emphasis of the work was on the corrosion resistance it was also necessary, in preparing for the commercial use of I.690 for S.G. tubing, to verify other aspects of behaviour in respect of physical and mechanical properties and for steam generator fabrication purposes. A key activity in the preparation for commercial use was the pre-production fabrication by a tube supplier of about 200 full-length tubes from each of three different heats. These tubes not only served the need to fully characterize the tubing (a requirement of the French specifications) but also provided a source of additional fully representative material for confirmatory corrosion and fabrication evaluation

  1. Effect of Fly Ash on TSA Resistance of Cement-based Material

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fengchen; MA Baoguo; WU Shengxing; ZHOU Jikai

    2011-01-01

    Thaumasite form of sulfate attack (TSA) is a major concern in evaluating durability of concrete structures subjected to sulfate and carbonate ions. By means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM),and energy dispersive spectrum (EDS)as well as Raman spectra of erosion substances, effect of fly ash on TSA resistance of Portland cement-based material were investigated. Immersed in magnesium sulfate solution with 33 800 ppm mass concentration of SO42- at 5±2 ℃ for 15 weeks, ratio of compressive strength loss decreased as binder replacement ratio of fly ash increased. Furthermore, when binder replacement of fly ash was 60%, compressive strength increased. When thaumasite came into being in samples with 0, 15% binder replacement ratio of fly ash, ettringite and gypsum appeared in those with 30%, 45%, 60% binder replacement ratio of fly ash. Results mentioned above showed that fly ash can restrain formation of thaumasite and improve TSA resistance of Portland cement-based material sufficiently.

  2. Effect of Cr, Ni and Mo on corrosion resistance of highly alloyed materials in sour well environments

    International Nuclear Information System (INIS)

    The effect of Cr, Ni and Mo on the corrosion behaviours of highly alloyed materials was investigated in simulated sour well environments. The increases of all of Cr, Ni and Mo contents increase the resistance to general and pitting corrosion. Increasing Ni content also improves the resistance to stress corrosion cracking (SCC). From the standpoint of those resistances, high Ni content as well as high Cr and Mo contents is essential to maintain the corrosion resistance in sour well environments. Surface film analysis shows there are two types of film structure, that is: Cr oxide single layer, and double layer with outer Ni sulfide and inner Cr oxide. Corrosion resistance is basically determined by the presence of surface Cr oxide film. Increasing Ni and Mo contents is considered to increase the stability of the surface film. In addition, electrochemical measurements were carried out with high alloy materials and pure metals to clarify the behaviours of Cr, Ni and Mo

  3. Effects of ionizing radiation on plastic food packaging materials: a review. 1. Chemical and physical changes

    International Nuclear Information System (INIS)

    Irradiation of prepackaged food causes chemical and physical changes in plastic packaging materials. The effects of ionizing radiation on these materials have been studied for almost 40 years; the respective literature is reviewed to provide the basis for a safety evaluation of plastics for use in food irradiation. Permeability of plastic films is generally not affected; deterioration of mechanical properties, that may occur with certain polymers, can usually be controlled with adequate stabilizers; and changes in infrared and UV/VIS spectra are slight at food irradiation doses. Gaseous radiolysis products include hydrogen, methane, CO2, CO, hydrocarbons, and for chlorine-containing polymers, hydrogen chloride. A range of volatile products, mainly hydrocarbons, alcohols, aldehydes, ketones, and carboxylic acids, has been characterized for low density polyethylene and polypropylene, other important materials, e.g., polystyrene and poly(vinyl chloride), are less well-investigated. Comparatively little is known on the effect of irradiation on multilayer structures. Radiation-induced changes are shown to depend on the chemical structure of the polymer, on the composition (additives) and processing history of the plastic, and on the irradiation conditions

  4. The use of sugarcane bagasse ash as an alternative local pozzolanic material: study of chemical composition

    International Nuclear Information System (INIS)

    The sugarcane bagasse ash is used as fuel in the boilers of the Kinana sugar factory in Sudan. The field observation and qualitative study of the ash revealed that it consisted of major amounts of carbon and organic materials; this is due to the incomplete combustion of bagasse fibers in boilers. Therefore, it became necessary to recondition the samples for use as pozzolana by re-ashing it. The study of chemical composition of the ash revealed that such byproducts are likely to be pozzolanic. Comparison between chemical compositions of Kinana sugarcane bagasse ash and the pulverized coal fly ashes (ASTM C 618 1999) shows that the composition of bagasse resembles that of Class F Coal Fly Ash, as the total of alumina, silica, and ferric oxide content is about 72 %. It may, behave like Class F Fly Ash, in its engineering properties. (author)

  5. Effects of coal rank on the chemical composition and toxicological activity of coal liquefaction materials

    Energy Technology Data Exchange (ETDEWEB)

    Wright, C.W.; Dauble, D.D.

    1986-05-01

    This report presents data from the chemical analysis and toxicological testing of coal liquefaction materials from the EDS and H-Coal processes operated using different ranks of coal. Samples of recycle solvent from the bottoms recycle mode of the EDS direct coal liquefaction process derived from bituminous, sub-bituminous, and lignite coals were analyzed. In addition, the H-Coal heavy fuel oils derived from bituminous and sub-bituminous coals were analyzed. Chemical methods of analysis included adsoprtion column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, and low-voltage probe-inlet mass spectrometry. The toxicological activity of selected samples was evaluated using the standard microbial mutagenicity assay, an initiation/promotion assay for mouse-skin tumorigenicity, and a static bioassy with Daphnia magna for aquatic toxicity of the water-soluble fractions. 22 refs., 16 figs., 14 tabs.

  6. Pyrolysis of triglyceride materials for the production of renewable fuels and chemicals.

    Science.gov (United States)

    Maher, K D; Bressler, D C

    2007-09-01

    Conversion of vegetable oils and animal fats composed predominantly of triglycerides using pyrolysis type reactions represents a promising option for the production of renewable fuels and chemicals. The purpose of this article was to collect and review literature on the thermo-chemical conversion of triglyceride based materials. The literature was divided and discussed as (1) direct thermal cracking and (2) combination of thermal and catalytic cracking. Typically, four main catalyst types are used including transition metal catalysts, molecular sieve type catalysts, activated alumina, and sodium carbonate. Reaction products are heavily dependant on the catalyst type and reaction conditions and can range from diesel like fractions to gasoline like fractions. Research in this area is not as advanced as bio-oil and bio-diesel research and there is opportunity for further study in the areas of reaction optimization, detailed characterization of products and properties, and scale-up. PMID:17166713

  7. Chemically modified and nanostructured porous silicon as a drug delivery material and device

    Science.gov (United States)

    Anglin, Emily Jessica

    This thesis describes the fabrication, chemical modification, drug release, and toxicity studies of nanostructured porous silicon for the purposes of developing a smart drug delivery device. The first chapter is an introductory chapter, presenting the chemical and physical properties of porous silicon, the concepts and issues of current drug delivery devices and materials, and how porous silicon can address the issues regarding localized and controlled drug therapies. The second chapter discusses chemical modifications of nanostructured porous Si for stabilizing the material in biologically relevant media while providing an extended release of a therapeutic in vitro. This chapter also demonstrates the utility of the porous silicon optical signatures for effectively monitoring drug release from the system and its applications for development of a self-reporting drug delivery device. In chapter three, the concept of providing a triggered release of a therapeutic from porous silicon microparticles through initiation by an external stimulus is demonstrated. The microparticles are chemically modified, and the release is enhanced by a short application of ultrasound to the particulate system. The effect of ultrasound on the drug release and particle size is discussed. Chapter four presents a new method for sustaining the release of a monoclonal antibody from the porous matrix of porous SiO2. The therapeutic is incorporated into the films through electrostatic adsorption and a slow release is observed in vitro. A new method of quantifying the extent of drug loading is monitored with interferometry. The last chapter of the thesis provides a basic in vivo toxicity study of various porous Si microparticles for intraocular applications. Three types of porous Si particles are fabricated and studied in a rabbit eye model. The toxicity studies were conducted by collaborators at the Shiley Eye Center, La Jolla, CA. This work, demonstrates the feasibility of developing a self

  8. Entrapping quercetin in silica/polyethylene glycol hybrid materials: Chemical characterization and biocompatibility.

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Nocera, Paola; Piccolella, Simona; Pacifico, Severina

    2016-11-01

    Sol-gel synthesis was exploited to entrap quercetin, a natural occurring antioxidant polyphenol, in silica-based hybrid materials, which differed in their polyethylene glycol (PEG) content (6, 12, 24 and 50wt%). The materials obtained, whose nano-composite nature was ascertained by Scanning Electron Microscopy (SEM), were chemically characterized by Fourier Transform InfraRed (FT-IR) and UV-Vis spectroscopies. The results prove that a reaction between the polymer and the drug occurred. Bioactivity tests showed their ability to induce hydroxyapatite nucleation on the sample surfaces. The direct contact method was applied to screen the cytotoxicity of the synthetized materials towards fibroblast NIH 3T3 cells, commonly used for in vitro biocompatibility studies, and three nervous system cell lines (neuroblastoma SH-SY5Y, glioma U251, and pheochromocytoma PC12 cell lines), adopted as models in oxidative stress related studies. Using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay NIH 3T3 proliferation was assessed and the morphology was not compromised by direct exposure to the materials. Analogously, PC-12, and U-251 cell lines were not affected by new materials. SH-SY5Y appeared to be the most sensitive cell line with cytotoxic effects of 20-35%. PMID:27524014

  9. Inedible cellulose-based biomass resist material amenable to water-based processing for use in electron beam lithography

    International Nuclear Information System (INIS)

    An electron beam (EB) lithography method using inedible cellulose-based resist material derived from woody biomass has been successfully developed. This method allows the use of pure water in the development process instead of the conventionally used tetramethylammonium hydroxide and anisole. The inedible cellulose-based biomass resist material, as an alternative to alpha-linked disaccharides in sugar derivatives that compete with food supplies, was developed by replacing the hydroxyl groups in the beta-linked disaccharides with EB-sensitive 2-methacryloyloxyethyl groups. A 75 nm line and space pattern at an exposure dose of 19 μC/cm2, a resist thickness uniformity of less than 0.4 nm on a 200 mm wafer, and low film thickness shrinkage under EB irradiation were achieved with this inedible cellulose-based biomass resist material using a water-based development process

  10. Chemical solver to compute molecule and grain abundances and non-ideal MHD resistivities in prestellar core-collapse calculations

    Science.gov (United States)

    Marchand, P.; Masson, J.; Chabrier, G.; Hennebelle, P.; Commerçon, B.; Vaytet, N.

    2016-07-01

    We develop a detailed chemical network relevant to calculate the conditions that are characteristic of prestellar core collapse. We solve the system of time-dependent differential equations to calculate the equilibrium abundances of molecules and dust grains, with a size distribution given by size-bins for these latter. These abundances are used to compute the different non-ideal magneto-hydrodynamics resistivities (ambipolar, Ohmic and Hall), needed to carry out simulations of protostellar collapse. For the first time in this context, we take into account the evaporation of the grains, the thermal ionisation of potassium, sodium, and hydrogen at high temperature, and the thermionic emission of grains in the chemical network, and we explore the impact of various cosmic ray ionisation rates. All these processes significantly affect the non-ideal magneto-hydrodynamics resistivities, which will modify the dynamics of the collapse. Ambipolar diffusion and Hall effect dominate at low densities, up to nH = 1012 cm-3, after which Ohmic diffusion takes over. We find that the time-scale needed to reach chemical equilibrium is always shorter than the typical dynamical (free fall) one. This allows us to build a large, multi-dimensional multi-species equilibrium abundance table over a large temperature, density and ionisation rate ranges. This table, which we make accessible to the community, is used during first and second prestellar core collapse calculations to compute the non-ideal magneto-hydrodynamics resistivities, yielding a consistent dynamical-chemical description of this process. The multi-dimensional multi-species equilibrium abundance table and a copy of the code are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A18

  11. Effect of chemical surface treatments and repair material on transverse strength of repaired acrylic denture resin

    Directory of Open Access Journals (Sweden)

    Vojdani Mahroo

    2008-01-01

    Full Text Available Purpose: This study was performed to evaluate the transverse strength of a denture base resin (H, repaired with an autopolymerizing acrylic resin (A or a visible light-curing (VLC resin (T following the use of three chemical solvents: methyl methacrylate monomer, aceton or chloroform. Materials and Methods: Eighty specimens (65.0 x 10.0 x 3.3 mm of H were fabricated and stored in distilled water at 37°C for seven days. Specimens were divided into eight equal groups of 10. In each group, specimens were sectioned in the middle to create a 10 mm gap. Two groups served as controls and had no surface treatment. They were repaired with A or T materials. In the remaining six experimental groups, specimen surfaces were treated with ac for 30 sec or mma for 180 sec or ch for 5 sec. Then A or T material was placed on the treated surfaces, using the same preparation molds. After seven days′ storage at 37°C, the transverse bond strength (MPa of the specimens was measured using a three-point bending test. A two-way ANOVA and a Tukey HSD were performed to identify significant differences ( P < 0.05. The nature of the failures was noted as adhesive, cohesive or mixed. Results: Significant differences were found between the controls and experimental groups ( P < 0.05. In the control groups, repair with A showed significantly higher strength (60.3 MPa than those repaired with T (51.3 MPa. Mean transverse strength of experimental specimens repaired with A was (75.06 MPa which was significantly greater than those repaired with T (67.9 MPa. Although surface treatment increased repair strength, no significant differences were detected between the effects of the chemical etchants. Conclusions: The autopolymerizing resin exhibited significantly higher repair strength than VLC resin. The transverse strength of the repaired specimens was increased significantly after chemical treatments.

  12. Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J.; Reboul, S. H.; Wiersma, B. J.; Coleman, C. J.

    2013-11-08

    A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt % or 2 wt %) were used at 55 �C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results.

  13. Impacts on health and safety from transfer/consolidation of nuclear materials and hazardous chemicals

    International Nuclear Information System (INIS)

    Environmental restoration plans at the US Department of Energy (USDOE) Hanford Site calls for transfer/consolidation of ''targets/threats,'' namely nuclear materials and hazardous chemicals. Reductions in the health and safety hazards will depend on the plans implemented. Pacific Northwest Laboratory (PNL) estimated these potential impacts, assuming implementation of the current reference plan and employing ongoing risk and safety analyses. The results indicated the potential for ''significant'' reductions in health and safety hazards in the long term (> 25 years) and a potentially ''noteworthy'' reduction in health hazard in the short term (≤ 25 years)

  14. Modelling of Physical, Chemical, and Material Properties of Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jakub Kupecki

    2015-01-01

    Full Text Available This paper provides a review of modelling techniques applicable for system-level studies to account for physical, chemical, and material properties of solid oxide fuel cells. Functionality of 0D to 3D models is discussed and selected examples are given. Author provides information on typical length scales in evaluation of power systems with solid oxide fuel cells. In each section, proper examples of previous studies done in the field of 0D–3D modelling are recalled and discussed.

  15. Sanitary Assessment of Hazardous Materials Exposed To Highly Toxic Chemical Compounds

    International Nuclear Information System (INIS)

    Industrial or terroristic accidents in which toxic chemicals (TC) are the main or attendant damaging factors should be regarded as a new challenge for experts, because of little knowledge on the methodology to estimating the long-term risk for humans due to contamination of the building materials and environment. In the Russian Federation, there appeared to be a kind of model systems for developing an algorithm for solving these or similar problems. Under dismantling and liquidation of the former facilities for chemical weapon production (FCWP) the building materials are regarded as potential waste products the fate of which (processing, warehousing, utilization, and destruction) is dependent on their possible hazard for human population and environment. The standard approaches for hazard assessment of waste products of the FCWP turned out to be insufficient. When conducting the present work, the following problems have been solved: 1. Selection of representative samples taking into consideration a diversity of construction materials, great quantities of potentially toxic waste materials, information on the production conditions, breakdowns in the process of production, accidents, composition of the decontaminators used, decontamination frequency, etc. 2. Analysis of TC in composite matrixes complicated by the following problems: extraction, masking effects of concomitant components during indirect analysis, lack of certified methods of direct analysis of TC, discrepancy of results of GC and direct GCMS analysis, low sensitivity of GCMS analysis, big volume of samples (more than 0.5 kg), heterogeneity of physical-chemical properties of different matrixes influencing the process of degradation of TC. 3. Hazard assessment of the wastes in toxic-and-sanitary experiment relying on non-specific signs of intoxication due to relatively low percentage of TC and masking effects of various matrix components. Application of the integral toxicity tests with soil

  16. Chemically programmed ink-jet printed resistive WORM memory array and readout circuit

    International Nuclear Information System (INIS)

    In this paper an ink-jet printed write once read many (WORM) resistive memory fabricated on paper substrate is presented. The memory elements are programmed for different resistance states by printing triethylene glycol monoethyl ether on the substrate before the actual memory element is printed using silver nano particle ink. The resistance is thus able to be set to a broad range of values without changing the geometry of the elements. A memory card consisting of 16 elements is manufactured for which the elements are each programmed to one of four defined logic levels, providing a total of 4294 967 296 unique possible combinations. Using a readout circuit, originally developed for resistive sensors to avoid crosstalk between elements, a memory card reader is manufactured that is able to read the values of the memory card and transfer the data to a PC. Such printed memory cards can be used in various applications. (paper)

  17. Chemically programmed ink-jet printed resistive WORM memory array and readout circuit

    Science.gov (United States)

    Andersson, H.; Manuilskiy, A.; Sidén, J.; Gao, J.; Hummelgård, M.; Kunninmel, G. V.; Nilsson, H.-E.

    2014-09-01

    In this paper an ink-jet printed write once read many (WORM) resistive memory fabricated on paper substrate is presented. The memory elements are programmed for different resistance states by printing triethylene glycol monoethyl ether on the substrate before the actual memory element is printed using silver nano particle ink. The resistance is thus able to be set to a broad range of values without changing the geometry of the elements. A memory card consisting of 16 elements is manufactured for which the elements are each programmed to one of four defined logic levels, providing a total of 4294 967 296 unique possible combinations. Using a readout circuit, originally developed for resistive sensors to avoid crosstalk between elements, a memory card reader is manufactured that is able to read the values of the memory card and transfer the data to a PC. Such printed memory cards can be used in various applications.

  18. Corrosion resistance of welded joints of OX18H10T and 20K steels under multiple chemical decontamination conditions

    Energy Technology Data Exchange (ETDEWEB)

    Olschewski, M. (VEB Dampfkesselbau Hohenthurm bei Halle (German Democratic Republic))

    1985-07-01

    Some results of studies on the corrosion behaviour of welded joints of materials typical for nuclear power plants under multiple chemical decontamination conditions are presented and interpreted. The studies were restricted to clean unirradiated samples. Objective of this work was to specify frequency criteria for decontaminating primary circuit equipment.

  19. Contribution to the study of physico-chemical properties of surfaces modified by laser treatment. Application to the enhancement of localized corrosion resistance of stainless steels

    International Nuclear Information System (INIS)

    Metallic materials are more and more used in severe conditions with particularly strong request for improving their behavior in aggressive environment and especially over long periods. The objective of this PhD work is to estimate the potentiality of a laser surface melting treatment on the improvement of the stainless steel 304L corrosion resistance, surface treatments by laser can be revisited on the basis of a recent change in the laser technology. In the frame of this work, a nano-pulsed laser fiber was chosen: it allows the treated surface to be melted for few microns in depth, followed by an ultra-fast solidification occurring with cooling rates up to 1011 K/s. The combination of these processes leads to the elimination of the surface defects, the formation (trapping) of metastable phases, the segregation of chemical elements and the growth of a new oxide layer which properties are governed by the laser parameters. To correlate these latter to the electrochemical reactivity of the surface, the influence of two laser parameters on the physico-chemical properties of the surface was studied: the laser power and the overlap of the laser impacts. To support this approach, the pitting corrosion resistance of the samples was determined by standard electrochemical tests. For specific laser parameters, the pitting potential of a 304L stainless steel was increased by more than 500 mV corresponding to an important enhancement in localized corrosion resistance in chloride environment. The interdependence of the different phenomena resulting from the laser treatment lead to a quite complex prioritization of their role on the sensibility of the 304L. However, it was demonstrated that the nature of the thermal oxide formed during the laser surface melting and the induced defects are first-order parameters for the initiation of pits. (author)

  20. 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.

    Science.gov (United States)

    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

  1. Challenge toward breakage of RLS trade-off for EUV lithography by Photosensitized Chemically Amplified Resist (PSCAR) with flood exposure

    Science.gov (United States)

    Nagahara, Seiji; Carcasi, Michael; Nakagawa, Hisashi; Buitrago, Elizabeth; Yildirim, Oktay; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Tomono, Masaru; Mizoguchi, Hironori; Estrella, Joel; Nagai, Tomoki; Naruoka, Takehiko; Dei, Satoshi; Hori, Masafumi; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin; Meeuwissen, Marieke; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Maas, Raymond; Nakashima, Hideo; Tagawa, Seiichi

    2016-03-01

    This paper proposes a promising approach to break the resolution (R), line-edge-roughness (LER), and sensitivity (S) trade-off (RLS trade-off) relationships that limit the ultimate lithographic performance of standard chemically amplified resists (CAR). This is accomplished in a process that uses a Photosensitized Chemically Amplified Resist (PSCAR) in combination with a flood-exposure in an in-line track connected to a pattern exposure tool. PSCAR is a modified CAR which contains a photosensitizer precursor (PP) in addition to other standard CAR components such as a protected polymer, a photo acid generator (PAG) and a quencher. In this paper, the PSCAR concept and the required conditions in resist formulation are carefully explained. In the PSCAR process, the sensitivity improvement is accomplished by PAG decomposition to selectively generate more acid at the pattern exposed areas during the flood exposure. The selective photosensitization happens through the excitation of the photosensitizer (PS) generated by the deprotection of the PP at the pattern exposed areas. A higher resist chemical gradient which leads to an improved resolution and lower LER values is also predicted using the PSCAR simulator. In the PSCAR process, the improved chemical gradient can be realized by dual acid quenching steps with the help of increased quencher concentration. Acid quenching first happens simultaneously with acid catalytic PP to PS reactions. As a result, a sharpened PS latent image is created in the PSCAR. This image is subsequently excited by the flood exposure creating additional acid products at the pattern exposed areas only. Much the same as in the standard CAR system, unnecessary acid present in the non-pattern exposed areas can be neutralized by the remaining quencher to therefore produce sharper acid latent images. EUV exposure results down to 15 nm half pitch (HP) line/space (L/S) patterns using a PSCAR resist indicate that the use of PSCAR has the potential to

  2. Corrosion resistance of structural material AlMg-2 in water following heat treatment and cooling

    International Nuclear Information System (INIS)

    Corrosion tests of structural material AlMg-2 in water were carried out using autoclave in order to study the effects of heat treatment on the corrosion resistance of the material. Prior to the tests, the samples were heat-treated at temperatures of 90, 200, 300 and 500 °C and cooled in air, sand and water. The corrosion tests were conducted in water at temperature of 150 °C for 250 hours. The results showed that AlMg-2 samples were corroded although the increase of mass gain was relatively small. Heat treatment from 90 to 500 °C in sand cooling media resulted in an increase of mass gain despite that at 300 °C the increase was less than those at 200 °C and 500 °C. For water cooling media in the temperature range of 90 to 200 °C, the mass gain increased from 0.1854 g/cm2 to 2.1204 g/cm2 although after 200 °C it decreased to 1.8207 g/cm2 and 1.6779 g/cm2 respectively. For air cooling media, the mass gain was relatively constant. Based on the experiment results, it can be concluded that heat treatment and cooling did not significantly influence the corrosion resistance of material AlMg-2. The passive film Al2O3 on the surface was able to protect the inner surface from further corrosion. Water media with pH range from 4 – 9 did not cause damage to passive layer formed. (author)

  3. Measurement of the high-temperature strain of UHTC materials using chemical composition gratings

    Science.gov (United States)

    Xie, Weihua; Meng, Songhe; Jin, Hua; Du, Chong; Wang, Libin; Peng, Tao; Scarpa, F.; Huo, Shiyu

    2016-05-01

    This paper proposes a simple bonding and measuring technique to realise silica-based chemical composition gratings’ (CCGs) high temperature applications on hot structures. We describe a series of experiments on CCGs to measure the thermal and mechanical response characteristics of ultra-high temperature ceramic (UHTC) materials when the maximum temperature is above 1000 °C. Response characteristics are obtained at the heating and cooling stages. Results show that the wavelength response of the CCGs bonded on the UHTC plate increases non-linearly with increasing temperatures, but decreases almost linearly with decreasing temperatures. The temperature-dependent strain transfer coefficients are calculated theoretically and experimentally; results show that the values of strain transfer coefficients below 1000 °C are significantly affected by the thermal expansion coefficient of the substrate material and the interface. The strain transfer coefficient value tends to vary slowly between 0.616 and 0.626 above 700 °C.

  4. Research on the molecular scale material removal mechanism in chemical mechanical polishing

    Institute of Scientific and Technical Information of China (English)

    WANG YongGuang; ZHAO YongWu

    2008-01-01

    This paper investigates a novel molecular scale material removal mechanism in chemical mechanical polishing (CMP) by incorporating the order-of-magnitude calculations,particle adhesion force,defect of wafer,thickness of newly formed oxidizedlayer,and large deformation of pad/particle not discussed by previous analysis.The theoretical analysis and experimental data show that the indentation depth,scratching depth and polishing surface roughness are on the order of molecular scale or less.There.fore,this novel mechanism has gained the support from wide order-of- magnitude calculations and experimental data.In addition,with the decrease in the particle size,the molecular scale removal mechanism is plausibly one of the most promising removal mechanisms to clarify the CMP polishing process.The results are useful to substantiating the molecular-scale mechanism of the CMP material removal in addition to its underlying theoretical foundation.

  5. Experiments of the selection of a method evaluating the fire resistance of some materials based on macromolecular compounds

    Science.gov (United States)

    Stoica, Steln; Sebe, Mircea Octavian

    1987-01-01

    A comparative experimental study on the application of various tests for the evaluation of the fire-resistant properties of plastic materials is presented. On the basis of the results obtained conclusions are drawn on the advantages and disadvantages of the methods used, and a preferred test method is picked, i.e., the introduction of fire retardant materials into the polymers.

  6. Immediate impact on the rim zone of cement based materials due to chemical attack

    Energy Technology Data Exchange (ETDEWEB)

    Schwotzer, M., E-mail: matthias.schwotzer@kit.edu [Karlsruhe Institute of Technology (KIT), Institute of Functional Interfaces (IFG), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Scherer, T. [Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Gerdes, A. [Karlsruhe Institute of Technology (KIT), Institute of Functional Interfaces (IFG), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); University of Applied Sciences Karlsruhe, Institute for Prevention in Construction, Moltkestr. 30, D-76133 Karlsruhe (Germany)

    2015-01-15

    Cement based materials are in their widespread application fields exposed to various aqueous environments. This can lead to serious chemical changes affecting the durability of the materials. In particular in the context of service life prediction a detailed knowledge of the reaction mechanisms is a necessary base for the evaluation of the aggressivity of an aqueous medium and this is deduced commonly from long term investigations. However, these processes start immediately at the material/water-interface, when a cementitious system comes into contact with an aqueous solution, altering here the chemical composition and microstructure. This rim zone represents the first hurdle that has to be overcome by an attacking aqueous solution. Therefore, the properties of the surface near area should be closely associated with the further course of deterioration processes by reactive transport. In this context short term exposure experiments with hardened cement paste over 4 and 48 h have been carried out with demineralized water, hard tap water and different sulfate solutions. In order to investigate immediate changes in the near-surface region, depth profile cuts have been performed on the cement paste samples by means of focused ion beam preparation techniques. A scanning beam of Gallium ions is applied to cut a sharp edge in the cement paste surface, providing insights into the composition and microstructure of the upper ten to hundred microns. Electron microscopic investigations on such a section of the rim zone, together with surface sensitive X-ray diffraction accompanied by a detailed characterization of the bulk composition confirm that the properties of the material/water interface are of relevance for the durability of cement based systems in contact with aqueous solutions. In this manner, focused ion beam investigations constitute auspicious tools to contribute to a more sophisticated understanding of the reaction mechanisms. - Highlights: • The chemical

  7. Immediate impact on the rim zone of cement based materials due to chemical attack

    International Nuclear Information System (INIS)

    Cement based materials are in their widespread application fields exposed to various aqueous environments. This can lead to serious chemical changes affecting the durability of the materials. In particular in the context of service life prediction a detailed knowledge of the reaction mechanisms is a necessary base for the evaluation of the aggressivity of an aqueous medium and this is deduced commonly from long term investigations. However, these processes start immediately at the material/water-interface, when a cementitious system comes into contact with an aqueous solution, altering here the chemical composition and microstructure. This rim zone represents the first hurdle that has to be overcome by an attacking aqueous solution. Therefore, the properties of the surface near area should be closely associated with the further course of deterioration processes by reactive transport. In this context short term exposure experiments with hardened cement paste over 4 and 48 h have been carried out with demineralized water, hard tap water and different sulfate solutions. In order to investigate immediate changes in the near-surface region, depth profile cuts have been performed on the cement paste samples by means of focused ion beam preparation techniques. A scanning beam of Gallium ions is applied to cut a sharp edge in the cement paste surface, providing insights into the composition and microstructure of the upper ten to hundred microns. Electron microscopic investigations on such a section of the rim zone, together with surface sensitive X-ray diffraction accompanied by a detailed characterization of the bulk composition confirm that the properties of the material/water interface are of relevance for the durability of cement based systems in contact with aqueous solutions. In this manner, focused ion beam investigations constitute auspicious tools to contribute to a more sophisticated understanding of the reaction mechanisms. - Highlights: • The chemical

  8. Year 1 Progress Report Computational Materials and Chemical Sciences Network Administration

    Energy Technology Data Exchange (ETDEWEB)

    Rehr, John J.

    2012-08-02

    This document reports progress on the project “Computational Materials and Chemical Sciences Network Administration,” which is supported by DOE BES Grant DE-FG02-02ER45990 MOD 08. As stated in the original proposal, the primary goal of this project is to carry out the scientific administrative responsibilities for the Computational Materials and Chemical Sciences Network (CMCSN) of the U.S. Department of Energy, Office of Basic Energy Sciences. These responsibilities include organizing meetings, publishing and maintaining CMCSN’s website, publishing a periodic newsletter, writing original material for both the website and the newsletter, maintaining CMCSN documentation, editing scientific documents, as needed, serving as liaison for the entire Network, facilitating information exchange across the network, communicating CMCSN’s success stories to the larger community and numerous other tasks outside the purview of the scientists in the CMCSN. Given the dramatic increase in computational power, advances in computational materials science can have an enormous impact in science and technology. For many of the questions that can be addressed by computation there is a choice of theoretical techniques available, yet often there is no accepted understanding of the relative strengths and effectiveness of the competing approaches. The CMCSN fosters progress in this understanding by providing modest additional funding to research groups which engage in collaborative activities to develop, compare, and test novel computational techniques. Thus, the CMCSN provides the “glue” money which enables different groups to work together, building on their existing programs and expertise while avoiding unnecessary duplication of effort. This includes travel funding, partial postdoc salaries, and funding for periodic scientific meetings. The activities supported by this grant are briefly summarized below.

  9. Combined oxides as oxygen-carrier material for chemical-looping with oxygen uncoupling

    International Nuclear Information System (INIS)

    Highlights: • Manganese-based combined oxides are examined for chemical-looping combustion applications. • Promising compositions includes (MnyFe1−y)Ox, (MnySi1−y)Ox and CaMnO3−δ. • Study includes thermodynamic analysis and overview of current experimental experiences. - Abstract: Oxygen-carrier materials for chemical-looping with oxygen uncoupling (CLOU) must be capable of taking up and releasing gas-phase O2 at conditions relevant for generation of heat and power. In principle, the capability of a certain material to do so is determined by its thermodynamic properties. This paper provides an overview of the possibility to design feasible oxygen carrier materials from combined oxides, i.e. oxides with crystal structures that include several different cations. Relevant literature is reviewed and the thermodynamic properties and key characteristics of a few selected combined oxide systems are calculated and compared to experimental data. The general challenges and opportunities of the combined oxide concept are discussed. The focus is on materials with manganese as one of its components and the following families of compounds and solid solutions have been considered: (MnyFe1−y)Ox, (MnySi1−y)Ox, CaMnO3−δ, (NiyMn1−y)Ox, (MnyCu1−y)Ox and (MnyMg1−y)Ox. In addition to showing promise from a thermodynamic point of view, reactivity data from experimental investigations suggests that the rate of O2 release can be high for all systems. Thus these combined oxides could also be very suitable for practical application

  10. Data on post irradiation experiments of heat resistant ceramic composite materials. PIE for 97M-13A

    International Nuclear Information System (INIS)

    The research on the radiation damage mechanism of heat resistant ceramic composite materials is one of the research subjects of the innovative basic research in the field of high temperature engineering, using the High Temperature engineering Test Reactor (HTTR). Three series of irradiation tests on the heat resistant ceramic composite materials, first to third irradiation test program, were carried out using the Japan Material Testing Reactor (JMTR). This is a summary report on the first irradiation test program; irradiation induced dimensional change, thermal expansion coefficient, X-ray diffraction and γ-ray spectrum are reported. (author)

  11. Data on post irradiation experiments of heat resistant ceramic composite materials. PIE for 97M-13A

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Shin-ichi; Ishihara, Masahiro; Souzawa, Shizuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sekino, Hajime [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The research on the radiation damage mechanism of heat resistant ceramic composite materials is one of the research subjects of the innovative basic research in the field of high temperature engineering, using the High Temperature engineering Test Reactor (HTTR). Three series of irradiation tests on the heat resistant ceramic composite materials, first to third irradiation test program, were carried out using the Japan Material Testing Reactor (JMTR). This is a summary report on the first irradiation test program; irradiation induced dimensional change, thermal expansion coefficient, X-ray diffraction and {gamma}-ray spectrum are reported. (author)

  12. Material Characterization in the Electro-Analytic Approach for Applications in Chemical Mechanical Planarization and Electrochemical Energy Systems

    Science.gov (United States)

    Rock, Simon E.

    the generation of ion-incorporated tantalum pentoxide. DBSA strongly affects the CMP chemistry of Cu, but exhibits relatively weaker effects on the surface activity of Ta, and thus plays a vital role in dictating the selectivity of Ta:Cu polish rates. CMP of tantalum nitride is also an essential step of material processing in the fabrication of integrated circuits, which is looked separately in this thesis. The present work investigates certain chemical aspects of this strategy of TaN-CMP by also using guanidine carbonate (GC) as a surface complexing agent, and employing electrochemical experiments. The experiments are designed to study the chemical and electrochemical origins of the CMP-specific surface complex films formed on a TaN wafer in acidic solutions of GC and hydrogen peroxide. Open circuit potential, polarization resistance, and electrochemical impedance measurements are employed to probe the surface effects that facilitate material removal in chemically prevailing CMP of TaN. The results are discussed in view of designing slurry variables to support barrier layer planarization with reduced roles of mechanical abrasion. Nonvolatile and nonflammable ionic liquids (ILs) have distinct thermal advantages over the traditional organic solvent electrolytes of lithium ion batteries. However, this beneficial feature of ILs is often counterbalanced by their high viscosity (a limiting factor for ionic conductivity) and, sometimes, by their unsuitable electrochemistry for generating protective layers on electrode surfaces. In an effort to alleviate these limiting Aspects of ILs, we have synthesized a PEGylated imidazolium bis(triflouromethylsulfonyl)amide (bistriflamide) IL that exhibited better thermal and electrochemical stability than a conventional electrolyte based on a blend of ethylene carbonate and diethyl carbonate. The electrochemical performance of this IL has been demonstrated using a cathode consisting of ball-milled LiMn2O4 particles. A direct comparison

  13. Organic Chemical Attribution Signatures for the Sourcing of a Mustard Agent and Its Starting Materials.

    Science.gov (United States)

    Fraga, Carlos G; Bronk, Krys; Dockendorff, Brian P; Heredia-Langner, Alejandro

    2016-05-17

    Chemical attribution signatures (CAS) are being investigated for the sourcing of chemical warfare (CW) agents and their starting materials that may be implicated in chemical attacks or CW proliferation. The work reported here demonstrates for the first time trace impurities from the synthesis of tris(2-chloroethyl)amine (HN3) that point to the reagent and the specific reagent stocks used in the synthesis of this CW agent. Thirty batches of HN3 were synthesized using different combinations of commercial stocks of triethanolamine (TEA), thionyl chloride, chloroform, and acetone. The HN3 batches and reagent stocks were then analyzed for impurities by gas chromatography/mass spectrometry. All the reagent stocks had impurity profiles that differentiated them from one another. This was demonstrated by building classification models with partial least-squares discriminant analysis (PLSDA) and obtaining average stock classification errors of 2.4, 2.8, 2.8, and 11% by cross-validation for chloroform (7 stocks), thionyl chloride (3 stocks), acetone (7 stocks), and TEA (3 stocks), respectively, and 0% for a validation set of chloroform samples. In addition, some reagent impurities indicative of reagent type were found in the HN3 batches that were originally present in the reagent stocks and presumably not altered during synthesis. More intriguing, impurities in HN3 batches that were apparently produced by side reactions of impurities unique to specific TEA and chloroform stocks, and thus indicative of their use, were observed. PMID:27116337

  14. Organic Chemical Attribution Signatures for the Sourcing of a Mustard Agent and Its Starting Materials

    Energy Technology Data Exchange (ETDEWEB)

    Fraga, Carlos G.; Bronk, Krys; Dockendorff, Brian P.; Heredia-Langner, Alejandro

    2016-05-17

    Chemical attribution signatures (CAS) are being investigated for the sourcing of chemical warfare (CW) agents and their starting materials that may be implicated in chemical attacks or CW proliferation. The work reported here demonstrates for the first time trace impurities produced during the synthesis of tris(2-chloroethyl)amine (HN3) that point to specific reagent stocks used in the synthesis of this CW agent. Thirty batches of HN3 were synthesized using different combinations of commercial stocks of triethanolamine (TEA), thionyl chloride, chloroform, and acetone. The HN3 batches and reagent stocks were then analyzed for impurities by gas chromatography/mass spectrometry. Reaction-produced impurities indicative of specific TEA and chloroform stocks were exclusively discovered in HN3 batches made with those reagent stocks. In addition, some reagent impurities were found in the HN3 batches that were presumably not altered during synthesis and believed to be indicative of reagent type regardless of stock. Supervised classification using partial least squares discriminant analysis (PLSDA) on the impurity profiles of chloroform samples from seven stocks resulted in an average classification error by cross-validation of 2.4%. A classification error of zero was obtained using the seven-stock PLSDA model on a validation set of samples from an arbitrarily selected chloroform stock. In a separate analysis, all samples from two of seven chloroform stocks that were purposely not modeled had their samples matched to a chloroform stock rather than assigned a “no class” classification.

  15. Ni(II immobilization by bio-apatite materials: Appraisal of chemical, thermal and combined treatments

    Directory of Open Access Journals (Sweden)

    Šljivić-Ivanović Marija

    2016-01-01

    Full Text Available Animal bones are natural and rich source of calcium hydroxyapatite (HAP, which was found to be a good sorbent material for heavy metals and radionuclides. Various treatments can reduce the content of bone organic phase and improve sorption properties. In this study, sorption capacities of raw bovine bones (B and samples obtained by chemical treatment with NaOH (BNaOH, by heating at 400 oC (B400 and by combined chemical and thermal treatment (BNaOH+400, were compared, using Ni(II ions as sorbates. Maximum sorption capacities increased in the order Bmaterial with low organic content and high efficiency for Ni(II sorption, it is also a good candidate for in-situ soil remediation, particularly at lower contamination levels. [Projekat Ministarstva nauke Republike Srbije, br. III 43009

  16. The radiometric analysis of non-radioactive materials by chemical exchange

    International Nuclear Information System (INIS)

    The use of radioisotopes to measure the composition of different materials via chemical exchange within an instrument is described. The product of the reaction is a radioactive gas which is counted and serves as the indicator of measurement. This method has been applied to a number of different liquids and gases for their specific and sensitive determination. The chief limiting condition on sensitivity is imposed by the specific activity of the radiochemical component. Where high specific activities are available, sensitivity in terms of chemical quantity will be very great. The recent development of quinol- Kr85 clathrate compounds has provided a basic radiochemical source which not only provides high specific activities at low cost but also excellent half-life and energy characteristics. These clathrate compounds can be oxidized only by very strong oxidizing agents, such as ozone to release Kr85. When coupled with a salt, such as sodium chlorite, the sensing of reducing materials such as SO2 may be accomplished. Two applications of the radiometric technique employing clathrates are described. The first is the development of a balloon-borne sonde for the meteorological analysis of ozone in the upper atmosphere. The other is its use in air pollution and process control work in the form of a portable analyser. Different gases may be analysed by this device by merely changing the radiochemical reaction cell. (author)

  17. Surface reconstruction and chemical evolution of stoichiometric layered cathode materials for lithium-ion batteries.

    Science.gov (United States)

    Lin, Feng; Markus, Isaac M; Nordlund, Dennis; Weng, Tsu-Chien; Asta, Mark D; Xin, Huolin L; Doeff, Marca M

    2014-01-01

    The present study sheds light on the long-standing challenges associated with high-voltage operation of LiNi(x)Mn(x)Co(1-2x)O2 cathode materials for lithium-ion batteries. Using correlated ensemble-averaged high-throughput X-ray absorption spectroscopy and spatially resolved electron microscopy and spectroscopy, here we report structural reconstruction (formation of a surface reduced layer, to transition) and chemical evolution (formation of a surface reaction layer) at the surface of LiNi(x)Mn(x)Co(1-2x)O2 particles. These are primarily responsible for the prevailing capacity fading and impedance buildup under high-voltage cycling conditions, as well as the first-cycle coulombic inefficiency. It was found that the surface reconstruction exhibits a strong anisotropic characteristic, which predominantly occurs along lithium diffusion channels. Furthermore, the surface reaction layer is composed of lithium fluoride embedded in a complex organic matrix. This work sets a refined example for the study of surface reconstruction and chemical evolution in battery materials using combined diagnostic tools at complementary length scales. PMID:24670975

  18. The effect of blood contamination on dislocation resistance of different endodontic reparative materials.

    Science.gov (United States)

    Üstün, Yakup; Topçuoğlu, Hüseyin S; Akpek, Firdevs; Aslan, Tuğrul

    2015-09-01

    This study evaluated the retention characteristics of ProRoot mineral trioxide aggregate (MTA), RetroMTA, Supra MTA, and Biodentine biomaterials used to repair furcation perforations contaminated with blood. Furcal perforations measuring 1.3 mm in diameter and 2 mm in height were created in 96 mandibular first molar teeth, which were then randomly divided into the following two groups (n = 48): contaminated (+) or non-contaminated (-) with blood. The groups were subdivided into four groups (n = 12) according to the material used (ProRoot MTA, RetroMTA, Supra MTA, and Biodentine) to seal the perforations. The samples were allowed to set for 14 days and were then subjected to push-out testing. The results were analyzed using ANOVA, and the failure modes were examined using a surgical microscope. ProRoot MTA (+/-) and RetroMTA (+/-) exhibited superior bond strength values; in addition, there were no significant differences among these groups (P > 0.05). Biodentine (+) showed intermediate values that were sometimes statistically similar to the ProRoot MTA (+/-) and RetroMTA (+/-) groups (P > 0.05) and, at other times, the Biodentine (-) and Supra MTA (+/-) groups (P > 0.05). The lowest bond strength values were shown by the Biodentine (-) and Supra MTA groups (P > 0.05). "Adhesive failure mode" was the most frequently observed type for all tested materials. Blood contamination did not affect the dislocation resistance of materials. PMID:26369481

  19. Dose of irradiation and residual voltage in radiation resistant polymer insulation materials

    International Nuclear Information System (INIS)

    For the various cables used for nuclear power stations, the high reliability so as to be able to maintain their functions even if a loss of coolant accident occurs at the end of 40 year plant life is demanded. For further increasing the reliability, in addition to the material design of insulators, it is effective also to diagnose the degree of deterioration of cable by nondestructive method for maintenance management. Various methods have been used for judging the degree of deterioration of insulation materials, but those are not suitable to nondestructive method. The authors paid attention to residual voltage, and examined to apply it to the diagnosis of insulation deterioration. It was found that the degree of oxidation, which is closely related with the mechanical and insulation properties, can be examined by the results of residual voltage measurement. In this study, on the polymer insulation materials having high radiation resistance and more practicality, the relation of residual voltage, leak current and discharged charges with irradiation dose was compared, and the possibility of applying the residual voltage due to gamma-ray irradiation to the diagnosis of insulation deterioration was investigated. (K.I.)

  20. Sheet Resistance and Gas-Sensing Properties of Tin Oxide Thin Films by Plasma Enhanced Chemical Vapor Deposition

    Institute of Scientific and Technical Information of China (English)

    刘彭义; 陈俊芳; 孙汪典

    2004-01-01

    Tin oxide (SnO2) thin films are prepared at different temperatures by plasmaenhanced chemical vapor deposition (PECVD). The structural characterizations of the films are investigated by various analysis techniques. X-ray diffraction patterns (XRD) show that the phase of SnO2 films are different at different deposition temperatures. The sheet resistance of the films decreases with increase of deposition temperature. X-ray photoelectron spectroscopy (XPS) shows that the SnO2 thin film is non-stoichiometric. The sheet resistance increases with increase in oxygen flow. Sb-doped SnO2 thin films are more sensitive to alcohol than carbon monoxide, and its maximum sensitivity is about 220%.