WorldWideScience

Sample records for candidate structural materials

  1. Compatibility of ITER candidate structural materials with static gallium

    International Nuclear Information System (INIS)

    Tests were conducted on the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor, e.g., Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy, as well as Armco iron, Nickel 270, and pure chromium. Type 316 stainless steel is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400 degrees C, corrosion rates are ∼4.0, 0.5, and 0.03 mm/yr for type 316 SS, Inconel 625, and Nb-5 Mo- 1 Zr alloy, respectively. The pure metals react rapidly with gallium. In contrast to findings in earlier studies, pure iron shows greater corrosion than nickel. The corrosion rates at 400 degrees C are ≥88 and 18 mm/yr, respectively, for Armco iron and Nickel 270. The results indicate that at temperatures up to 400 degrees C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The solubility data for pure metals and oxygen in gallium are reviewed. The physical, chemical, and radioactive properties of gallium are also presented. The supply and availability of gallium, as well as price predictions through the year 2020, are summarized

  2. Irradiation creep experiments on fusion reactor candidate structural materials

    International Nuclear Information System (INIS)

    Irradiation creep rates were determined for annealed and cold-worked AMCR- and 316-type steel alloys in the high flux reactor at Petten, for various irradiation temperatures, stresses and for neutron doses up to 4 dpa. Primary creep elongations were found in all annealed materials. A negative creep elongation was found in cold-worked materials for stresses equal to or below about 100 MPa. An increase of the negative creep elongation is found for decreasing irradiation temperatures and decreasing applied stresses. The stress exponent of the irradiation creep rate in annealed and cold-worked AMCR alloys is n = 1.85 and n = 1.1, respectively. The creep rates of cold-worked AMCR alloys are almost temperature independent over the range investigated (573-693 K). The results obtained in the HFR at Petten are compared with those obtained in ORR and EBR II. The smallest creep rates are found for cold-worked materials of AMCR- and US-PCA-type at Petten which are about a factor two smaller than the creep rates obtained of US-316 at Petten or for US-PCA at ORR or for 316L at EBR II. The scatter band factor for US-PCA, 316L, US-316 irradiated in ORR and EBR II is about 1.5 after a temperature and damage rate normalization

  3. Fracture toughness of irradiated candidate materials for ITER first wall/blanket structures: Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, D.J.; Pawel, J.E.; Grossbeck, M.L.; Rowcliffe, A.F. [Oak Ridge National Lab., TN (United States)] [and others

    1996-04-01

    Disk compact specimens of candidate materials for first wall/blanket structures in ITER have been irradiated to damage levels of about 3 dpa at nominal irradiation temperatures of either 90 250{degrees}C. These specimens have been tested over a temperature range from 20 to 250{degrees}C to determine J-integral values and tearing moduli. The results show that irradiation at these temperatures reduces the fracture toughness of austenic stainless steels, but the toughness remains quite high. The toughness decreases as the temperature increases. Irradiation at 250{degrees}C is more damaging that at 90{degrees}C, causing larger decreases in the fracture toughness. The ferritic-martensitic steels HT-9 and F82H show significantly greater reductions in fracture toughness that the austenitic stainless steels.

  4. Stress corrosion cracking susceptibility of candidate structural materials in supercritical pressurized water

    Energy Technology Data Exchange (ETDEWEB)

    Je, Hwanil, E-mail: hwanil.je@gmail.com; Kimura, Akihiko

    2014-12-15

    The stress corrosion cracking (SCC) susceptibility in supercritical pressurized water (SCPW) was investigated for the candidate structural steels of advanced fusion and fission nuclear system, which are SUS316L austenitic steel, F82H ferritic–martensitic steel and SOC-16 oxide dispersion strengthened (ODS) ferritic steel. In order to evaluate the susceptibility to SCC with those materials, slow strain rate test (SSRT) was carried out at 773 K, under a pressure of 25 MPa of SCPW with deaerated condition. High temperature tensile test in vacuum at 773 K was also performed to compare the deformation and fracture behavior between corrosive environment of SCPW and non-corrosive environment. Although SUS316L showed a change in the fracture mode in the deaerated SCPW from an entire ductile fracture at higher strain rate to a mixed mode of ductile and brittle fracture at lower one, the fracture mode of ODS steel and F82H was not changed in the tested strain rate range. Both the IGSCC and TGSCC were observed in SUS316L. And F82H steel suffered from much severer oxidation than SUS316L and SOC-16.

  5. Stress corrosion cracking susceptibility of candidate structural materials in supercritical pressurized water

    International Nuclear Information System (INIS)

    The stress corrosion cracking (SCC) susceptibility in supercritical pressurized water (SCPW) was investigated for the candidate structural steels of advanced fusion and fission nuclear system, which are SUS316L austenitic steel, F82H ferritic–martensitic steel and SOC-16 oxide dispersion strengthened (ODS) ferritic steel. In order to evaluate the susceptibility to SCC with those materials, slow strain rate test (SSRT) was carried out at 773 K, under a pressure of 25 MPa of SCPW with deaerated condition. High temperature tensile test in vacuum at 773 K was also performed to compare the deformation and fracture behavior between corrosive environment of SCPW and non-corrosive environment. Although SUS316L showed a change in the fracture mode in the deaerated SCPW from an entire ductile fracture at higher strain rate to a mixed mode of ductile and brittle fracture at lower one, the fracture mode of ODS steel and F82H was not changed in the tested strain rate range. Both the IGSCC and TGSCC were observed in SUS316L. And F82H steel suffered from much severer oxidation than SUS316L and SOC-16

  6. Corrosion tests of candidate fuel cladding and reactor internal structural materials

    International Nuclear Information System (INIS)

    Corrosion screening tests were conducted on candidate materials for nuclear fuel cladding and reactor internals of supercritical water reactor (SCWR) in static and flowing supercritical water (SCW) autoclave at the temperatures of 550, 600 and 650°C, pressure of about 25MPa, deaerated or saturated dissolved hydrogen (STP). Samples are nickel base alloy type Hastelloy C276, austenitic stainless steels type 304NG and AL-6XN, ferritic/martensitic (F/M) steel type P92, and oxide dispersion strengthened steel MA 956. This paper focuses on the formation and breakdown of corrosion oxide scales, and proposes the future trend for the development of SCWR fuel cladding materials. (author)

  7. Corrosion tests of candidate fuel cladding and reactor internal structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.; Zhu, F.; Bao, Y. [Shanghai Jiao Tong Univ., School of Nuclear Science and Engineering, Shanghai (China); Tang, R. [Nuclear Power Inst. of China, National Key Lab. for Nuclear Fuel and Materials, Chengdu, Sichuan (China)

    2010-07-01

    Corrosion screening tests were conducted on candidate materials for nuclear fuel cladding and reactor internals of supercritical water reactor (SCWR) in static and flowing supercritical water (SCW) autoclave at the temperatures of 550, 600 and 650°C, pressure of about 25MPa, deaerated or saturated dissolved hydrogen (STP). Samples are nickel base alloy type Hastelloy C276, austenitic stainless steels type 304NG and AL-6XN, ferritic/martensitic (F/M) steel type P92, and oxide dispersion strengthened steel MA 956. This paper focuses on the formation and breakdown of corrosion oxide scales, and proposes the future trend for the development of SCWR fuel cladding materials. (author)

  8. Effects of surface condition on the corrosion of candidate structural materials in a simulated HTGR-GT environment

    International Nuclear Information System (INIS)

    A simulated high-temperature gas-cooled reactor (HTGR) helium environment was used to study the effects of surface finish conditions on the subsequent elevated-temperature corrosion behavior of key candidate structural materials. The environment contained helium with 500 μatm H2/50 μatm CO/50 μatm CH4/2O at 9000C with total test exposure durations of 3000 hours. Specimens with lapped, grit-blasted, pickled, and preoxidized surface conditions were studied. Materials tested included two cast superalloys, IN 100 and IN 713LC; one centrifugally cast high-temperature alloy, HK 40 one oxice-dispersion-strengthened alloy, Inconel MA 754; and three wrought high-temperature alloys, Hastelloy Alloy X, Inconel Alloy 617, and Alloy 800H

  9. An annotated history of container candidate material selection

    International Nuclear Information System (INIS)

    This paper documents events in the Nevada Nuclear Waste Storage Investigations (NNWSI) Project that have influenced the selection of metals and alloys proposed for fabrication of waste package containers for permanent disposal of high-level nuclear waste in a repository at Yucca Mountain, Nevada. The time period from 1981 to 1988 is covered in this annotated history. The history traces the candidate materials that have been considered at different stages of site characterization planning activities. At present, six candidate materials are considered and described in the 1988 Consultation Draft of the NNWSI Site Characterization Plan (SCP). The six materials are grouped into two alloy families, copper-base materials and iron to nickel-base materials with an austenitic structure. The three austenitic candidates resulted from a 1983 survey of a longer list of candidate materials; the other three candidates resulted from a special request from DOE in 1984 to evaluate copper and copper-base alloys. 24 refs., 2 tabs

  10. Scattering Properties of Candidate Planetary Regolith Materials

    Science.gov (United States)

    Nelson, R. M.; Smythe, W. D.; Hapke, B. W.; Hale, A. S.; Piatek, J. A.

    2001-01-01

    The laboratory investigation of the scattering properties of candidate planetary regolith materials is an important technique for understanding the physical properties of a planetary regolith. Additional information is contained in the original extended abstract.

  11. Characterization of nanoparticles as candidate reference materials

    International Nuclear Information System (INIS)

    We report the characterization of three different nanoparticles (silica, silver and multi-walled carbon nanotubes) as candidate reference material. We focus our analysis on the size distribution of those particles as measured by different microscopy techniques. (author)

  12. Characterization of nanoparticles as candidate reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Martins Ferreira, E.H.; Robertis, E. de; Landi, S.M.; Gouvea, C.P.; Archanjo, B.S.; Almeida, C.A.; Araujo, J.R. de; Kuznetsov, O.; Achete, C.A., E-mail: smlandi@inmetro.gov.br [Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    We report the characterization of three different nanoparticles (silica, silver and multi-walled carbon nanotubes) as candidate reference material. We focus our analysis on the size distribution of those particles as measured by different microscopy techniques. (author)

  13. 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.

  14. Experimental studies on interactions of molten LiF-NaF salt with some candidate structural materials for components of advanced nuclear reactors

    International Nuclear Information System (INIS)

    Interaction of molten 60 LiF - 40 NaF (% mol) salt with candidate structural materials for components of advanced nuclear reactors has been studied using electron probe microanalysis (EPMA) and inductively coupled plasma atomic emission spectrometry (ICP-OES). The corrosion of structural materials (stainless steel, Ni base alloy, nickel), which was induced by the molten salt melt, has been examined in dependence on the time of exposure at operating temperature of 680 deg C. The above choice of the two analytical techniques made it possible to assess on the whole the extent of corrosion. The corrosion phenomena in structural materials were investigated using EPMA. Corrosion-released elements dissolved in solidified molten salt were determined after salt dissolution by means of ICP-OES. The LiF-NaF melt produced corrosion, which proved as a surficial modification of a structural material and a trace contamination of the melt itself. The X-ray maps by EPMA with its 1-μm lateral resolution revealed compositional changes in structural materials, such as, e. g. regular depletion of Cr in alloy A686 to the depth of 10 - 25 μm. While the lateral resolution of LA-ICP-MS with the applied laser spot diameter of 25 μm was not exactly adequate to mapping of the corroded material section and, consequently, yielded less information in comparison with EPMA, this technique was quite sufficient for the mapping of elemental content changes in solidified salt profile. Finally, nickel was proved to be the most resistant material. It was concluded that: (i) EPMA study, involving semi-quantitative elemental mapping / content profiling and detailed spot quantitative analyses makes it possible to obtain quantitative assessment of the corrosion process; (ii) qualitative profiles are provided by LA-ICP-MS, which needs further development on quantification procedure based on matched calibration samples. (author)

  15. 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

  16. Effects of a range of machined and ground surface finishes on the simulated reactor helium corrosion of several candidate structural materials

    International Nuclear Information System (INIS)

    This report discusses the corrosion behavior of several candidate reactor structural alloys in a simulated advanced high-temperature gas-cooled reactor (HTGR) environment over a range of lathe-machined and centerless-ground surface finishes. The helium environment contained 50 Pa H2/5 Pa CO/5 Pa CH4/2O (500 μatm H2/50 μatm CO/50 μatm CH4/2O) at 9000C for a total exposure of 3000 h. The test alloys included two vacuum-cast superalloys (IN 100 and IN 713LC); a centrifugally cast austenitic alloy (HK 40); three wrought high-temperature alloys (Alloy 800H, Hastelloy X, and Inconel 617); and a nickel-base oxide-dispersion-strengthened alloy (Inconel MA 754). Surface finish variations did not affect the simulated advanced-HTGR corrosion behavior of these materials. Under these conditions, the availability of reactant gaseous impurities controls the kinetics of the observed gas-metal interactions. Variations in the near-surface activities and mobilities of reactive solute elements, such as chromium, which might be expected to be affected by changes in surface finish, do not seem to greatly influence corrosion in this simulated advanced HTGR environment. 18 figures, 4 tables

  17. Canister filling materials -- Design requirements and evaluation of candidate materials

    International Nuclear Information System (INIS)

    SKB has been evaluating a copper/steel canister for use in the disposal of spent nuclear reactor fuel. Once the canister is breached by corrosion, it is possible that the void volume inside the canister might fill with water. Water inside the canister would moderate the energy of the neutrons emitted by spontaneous fission in the fuel. It the space in the canister between and around the fuel pins is occupied by canister filling materials, the potential for criticality is avoided. The authors have developed a set of design requirements for canister filling material for the case where it is to be used alone, with no credit for burnup of the fuel or other measures, such as the use of neutron absorbers. Requirements were divided into three classes: essential requirements, desirable features, and undesirable features. The essential requirements are that the material fill at least 60% of the original void space, that the solubility of the filling material be less than 100 mg/l in pure water or expected repository waters at 50 C, and that the material not compact under its own weight by more than 10%. In this paper they review the reasons for these requirements, the desirable and undesirable features, and evaluate 11 candidate materials with respect to the design requirements and features. The candidate materials are glass beads, lead shot, copper spheres, sand, olivine, hematite, magnetite, crushed rock, bentonite, other clays, and concrete. Emphasis is placed on the determination of whether further work is needed to eliminate uncertainties in the evaluation of the ability of a particular filling material to be successfully used under actual conditions, and on the ability to predict the long-term performance of the material under the repository conditions

  18. Candidate materials to prevent brittle fracture - (186)

    International Nuclear Information System (INIS)

    For heavy transport or dual purpose casks, selecting the appropriate materials for the body is a key decision. To get a Type B(U) approval, it is necessary to demonstrate that the mechanical strength of the material is good enough at temperature as low as -40 C so as to prevent the cask from any risk of brittle fracture in regulatory accident conditions. Different methods are available to provide such a demonstration and can lead to different choices. It should be noted also that the material compositions given by national or international standards display relatively wide tolerances and therefore are not necessarily sufficient to guarantee a required toughness. It is therefore necessary to specify to the fabricator the minimum value for toughness, and to verify it. This paper gives an overview of the different methods and materials that are used in several countries. Although the safety is strongly linked to the choice of the material, it is shown that many other parameters are important, such as the design, the fabrication process (multi layer, cast or forged body), the welding material and process, the ability to detect flaws, and the measured and/or calculated stress level, including stress concentration, in particular when bolts are used. The paper will show that relying exclusively on high toughness at low temperature does not necessarily deliver the maximum safety as compared with other choices. It follows that differences in approaches to licensing by different competent authorities may bias the choice of material depending on the country of application, even though B(U) licenses are meant to guarantee unilaterally a uniform minimum level of safety

  19. CASE via MS: Ranking Structure Candidates by Mass Spectra

    OpenAIRE

    Kerber, Adalbert; Meringer, Markus; Rücker, Christoph

    2006-01-01

    Two important tasks in computer-aided structure elucidation (CASE) are the generation of candidate structures from a given molecular formula, and the ranking of structure candidates according to compatibility with an experimental spectrum. Candidate ranking with respect to electron impact mass spectra is based on virtual fragmentation of a candidate structure and comparison of the fragments’ isotope distributions against the spectrum of the unknown compound, whence a structure–spectrum compat...

  20. Recent production of candidate reference materials at IRMM

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, G.N.; Pauwels, J.; Le Guern, L.; Schimmel, H.; Trapmann, S. [Commission of the European Communities, Geel (Belgium). Joint Research Centre

    2001-06-01

    In the execution of its mission to promote a common European measurement system in support of EU policies, IRMM's Reference Materials Unit is currently involved in preparation of proficiency-testing samples and candidate reference materials. Recent work related to bovine spongiform encephalopathy in cows, genetically modified organisms, and a variety of environmental materials is described. (orig.)

  1. Surface segregation in binary alloy first wall candidate materials

    International Nuclear Information System (INIS)

    We have been studying the conditions necessary to produce a self-sustaining stable lithium monolayer on a metal substrate as a means of creating a low-Z film which sputters primarily as secondary ions. It is expected that because of the toroidal field, secondary ions originating at the first wall will be returned and contribute little to the plasma impurity influx. Aluminum and copper have, because of their high thermal conductivity and low induced radioactivity, been proposed as first wall candidate materials. The mechanical properties of the pure metals are very poorly suited to structural applications and an alloy must be used to obtain adequate hardness and tensile strength. In the case of aluminum, mechanical properties suitable for aircraft manufacture are obtained by the addition of a few at% Li. In order to investigate alloys of a similar nature as candidate structural materials for fusion machines we have prepared samples of Li-doped aluminum using both a pyro-metallurgical and a vapor-diffusion technique. The sputtering properties and surface composition have been studied as a function of sample temperature and heating time, and ion beam mass. The erosion rate and secondary ion yield of both the sputtered Al and Li have been monitored by secondary ion mass spectroscopy and Auger analysis providing information on surface segregation, depth composition profiles, and diffusion rates. The surface composition ahd lithium depth profiles are compared with previously obtained computational results based on a regular solution model of segregation, while the partial sputtering yields of Al and Li are compared with results obtained with a modified version of the TRIM computer program. (orig.)

  2. Tests of candidate materials for particle bed reactors

    International Nuclear Information System (INIS)

    Rhenium metal hot frits and zirconium carbide-coated fuel particles appear suitable for use in flowing hydrogen to at least 2000 K, based on previous tests. Recent tests on alternate candidate cooled particle and frit materials are described. Silicon carbide-coated particles began to react with rhenium frit material at 1600 K, forming a molten silicide at 2000 K. Silicon carbide was extensively attacked by hydrogen at 2066 K for 30 minutes, losing 3.25% of its weight. Vitrous carbon was also rapidly attacked by hydrogen at 2123 K, losing 10% of its weight in two minutes. Long term material tests on candidate materials for closed cycle helium cooled particle bed fuel elements are also described. Surface imperfections were found on the surface of pyrocarbon-coated fuel particles after ninety days exposure to flowing (∼500 ppM) impure helium at 1143 K. The imperfections were superficial and did not affect particle strength

  3. Compatibility of ITER candidate materials with static gallium

    International Nuclear Information System (INIS)

    Corrosion tests have been conducted to determine the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor (ITER) first wall/blanket systems, e.g., Type 316 stainless steel (SS), Inconel 625, and Nb-5 Mo-1 Zr. The results indicate that Type 316 SS is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400 C, corrosion rates for Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy are ∼ 4.0, 0.5, and 0.03 mm/yr, respectively. Iron, nickel, and chromium react rapidly with gallium. Iron shows greater corrosion than nickel at 400 C (≥ 88 and 18 mm/yr, respectively). The present study indicates that at temperatures up to 400 C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The growth of intermetallic compounds may control the overall rate of corrosion

  4. Degradation mode surveys of high performance candidate container materials

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; McCright, R.D.

    1990-12-01

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project`s high-level radioactive waste disposal containers. Nickel-chromium-molybdenum alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion and of how various parameters affect it will be necessary for adequate performance assessment of candidate container materials. Examples of some of the concerns involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition, concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250{degree}C) are presented. Also some mechanistic considerations of localized corrosion are given. 45 refs., 1 tab.

  5. Degradation mode surveys of high performance candidate container materials

    International Nuclear Information System (INIS)

    Corrosion resistant materials are being considered for the metallic barrier of the Yucca Mountain Project's high-level radioactive waste disposal containers. Nickel-chromium-molybdenum alloys and titanium alloys have good corrosion resistance properties and are considered good candidates for the metallic barrier. The localized corrosion phenomena, pitting and crevice corrosion, are considered as potentially limiting for the barrier lifetime. An understanding of the mechanisms of localized corrosion and of how various parameters affect it will be necessary for adequate performance assessment of candidate container materials. Examples of some of the concerns involving localized corrosion are discussed. The effects of various parameters, such as temperature and concentration of halide species, on localized corrosion are given. In addition, concerns about aging of the protective oxide layer in the expected service temperature range (50 to 250 degree C) are presented. Also some mechanistic considerations of localized corrosion are given. 45 refs., 1 tab

  6. Oxygen-Diffused Titanium as a Candidate Brake Rotor Material

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

    2009-01-01

    Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

  7. Homogeneity study of candidate reference material in fish matrix

    International Nuclear Information System (INIS)

    A material is perfectly homogeneous with respect to a given characteristic, or composition, if there is no difference between the values obtained from one part to another. Homogeneity is usually evaluated using analysis of variance (ANOVA). However, the requirement that populations of data to be processed must have a normal distribution and equal variances greatly limits the use of this statistical tool. A more suitable test for assessing the homogeneity of RMs, known as sufficient homogeneity, was proposed by Fearn and Thompson. In this work, we evaluate the performance of the two statistical treatments for assessing homogeneity of methylmercury (MeHg) in candidate reference material of fish tissue

  8. Stress corrosion cracking of candidate waste container materials

    International Nuclear Information System (INIS)

    Six alloys have been selected as candidate container materials for the storage of high-level nuclear waste at the proposed Yucca Mountain site in Nevada. These materials are Type 304L stainless steel (SS), Type 316L SS, Incology 825, P-deoxidized Cu, Cu-30%Ni, and Cu-7% Al. The present program has been initiated to determine whether any of these materials can survive for 300 years in the site environment without developing through-wall stress corrosion cracks, and to assess the relative resistance of these materials to stress corrosion cracking (SCC). A series of slow-strain-rate tests (SSRTs) in simulated Well J-13 water which is representative of the groundwater present at the Yucca Mountain site has been completed, and crack-growth-rate (CGR) tests are also being conducted under the same environmental conditions. 13 refs., 60 figs., 22 tabs

  9. Candidate Materials Evaluation for Supercritical Water-Cooled Reactor

    International Nuclear Information System (INIS)

    Final technical report on the corrosion, stress corrosion cracking, and radiation response of candidate materials for the supercritical water-cooled reactor concept. The objective of the proposed research was to investigate degradation of materials in the supercritical water environment (SCW). First, representative alloys from the important classes of candidate materials were studied for their corrosion and stress-corrosion cracking (SCC) resistance in supercritical water. These included ferritic/martensitic (F/M) steels, austenitic stainless steels, and Ni-base alloys. Corrosion and SCC tests were conducted at various temperatures and exposure times, as well as in various water chemistries. Second, emerging plasma surface modification and grain boundary engineering technologies were applied to modify the near surface chemistry, microstructure, and stress-state of the alloys prior to corrosion testing. Third, the effect of irradiation on corrosion and SCC of alloys in the as-received and modified/engineered conditions were examined by irradiating samples using high-energy protons and then exposing them to SCW

  10. Material Properties of Three Candidate Elastomers for Space Seals Applications

    Science.gov (United States)

    Bastrzyk, Marta B.; Daniels, Christopher C.; Oswald, Jay J.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.

    2010-01-01

    A next-generation docking system is being developed by the National Aeronautics and Space Administration (NASA) to support Constellation Space Exploration Missions to low Earth orbit (LEO), to the Moon, and to Mars. A number of investigations were carried out to quantify the properties of candidate elastomer materials for use in the main interface seal of the Low Impact Docking System (LIDS). This seal forms the gas pressure seal between two mating spacecraft. Three candidate silicone elastomer compounds were examined: Esterline ELA-SA-401, Parker Hannifin S0383-70, and Parker Hannifin S0899-50. All three materials were characterized as low-outgassing compounds, per ASTM E595, so as to minimize the contamination of optical and solar array systems. Important seal properties such as outgas levels, durometer, tensile strength, elongation to failure, glass transition temperature, permeability, compression set, Yeoh strain energy coefficients, coefficients of friction, coefficients of thermal expansion, thermal conductivity and diffusivity were measured and are reported herein.

  11. Phosphate bonded ceramics as candidate final-waste-form materials

    International Nuclear Information System (INIS)

    Room-temperature setting phosphate-bonded ceramics were studied as candidate materials for stabilization of DOE low-level problem mixed wastes which cannot be treated by other established stabilization techniques. Phosphates of Mg, Mg-Na, Al and Zr were studied to stabilize ash surrogate waste containing RCRA metals as nitrates and RCRA organics. We show that for a typical loading of 35 wt.% of the ash waste, the phosphate ceramics pass the TCLP test. The waste forms have high compression strength exceeding ASTM recommendations for final waste forms. Detailed X-ray diffraction studies and differential thermal analyses of the waste forms show evidence of chemical reaction of the waste with phosphoric acid and the host matrix. The SEM studies show evidence of physical bonding. The excellent performance in the leaching tests is attributed to a chemical solidification and physical as well as chemical bonding of ash wastes in these phosphate ceramics

  12. Corrosion of candidate container materials by Yucca Mountain bacteria

    International Nuclear Information System (INIS)

    Several candidate container materials have been studied in modified Yucca Mountain (YM) ground water in the presence or absence of YM bacteria. YM bacteria increased corrosion rates by 5-6 fold in UNS G10200 carbon steel, and nearly 100-fold in UNS NO4400 Ni-Cu alloy. YM bacteria caused microbiologically influenced corrosion (MIC) through de-alloying or Ni-depletion of Ni-Cu alloy as evidenced by scanning electronic microscopy (SEM) and inductively coupled plasma spectroscopy (ICP) analysis. MIC rates of more corrosion-resistant alloys such as UNS NO6022 Ni-Cr- MO-W alloy, UN's NO6625 Ni-Cr-Mo alloy, and UNS S30400 stainless steel were measured below 0.05 umyr, however YM bacteria affected depletion of Cr and Fe relative to Ni in these materials. The chemical change on the metal surface caused by depletion was characterized in anodic polarization behavior. The anodic polarization behavior of depleted Ni-based alloys was similar to that of pure Ni. Key words: MIC, container materials, YM bacteria, de-alloying, Ni-depletion, Cr-depletion, polarization resistance, anodic polarization,

  13. Stress corrosion cracking of candidate waste container materials; Final report

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.Y.; Maiya, P.S.; Soppet, W.K.; Diercks, D.R.; Shack, W.J.; Kassner, T.F. [Argonne National Lab., IL (United States)

    1992-06-01

    Six alloys have been selected as candidate container materials for the storage of high-level nuclear waste at the proposed Yucca mountain site in Nevada. These materials are Type 304L stainless steel (SS). Type 316L SS, Incoloy 825, phosphorus-deoxidized Cu, Cu-30%Ni, and Cu-7%Al. The present program has been initiated to determine whether any of these materials can survive for 300 years in the site environment without developing through-wall stress corrosion cracks. and to assess the relative resistance of these materials to stress corrosion cracking (SCC)- A series of slow-strain-rate tests (SSRTs) and fracture-mechanics crack-growth-rate (CGR) tests was performed at 93{degree}C and 1 atm of pressure in simulated J-13 well water. This water is representative, prior to the widespread availability of unsaturated-zone water, of the groundwater present at the Yucca Mountain site. Slow-strain-rate tests were conducted on 6.35-mm-diameter cylindrical specimens at strain rates of 10-{sup {minus}7} and 10{sup {minus}8} s{sup {minus}1} under crevice and noncrevice conditions. All tests were interrupted after nominal elongation strain of 1--4%. Scanning electron microscopy revealed some crack initiation in virtually all the materials, as well as weldments made from these materials. A stress- or strain-ratio cracking index ranks these materials, in order of increasing resistance to SCC, as follows: Type 304 SS < Type 316L SS < Incoloy 825 < Cu-30%Ni < Cu and Cu-7%Al. Fracture-mechanics CGR tests were conducted on 25.4-mm-thick compact tension specimens of Types 304L and 316L stainless steel (SS) and Incoloy 825. Crack-growth rates were measured under various load conditions: load ratios M of 0.5--1.0, frequencies of 10{sup {minus}3}-1 Hz, rise nines of 1--1000s, and peak stress intensities of 25--40 MPa{center_dot}m {sup l/2}.

  14. Corrosion of candidate container materials by Yucca Mountain bacteria

    International Nuclear Information System (INIS)

    Several candidate container materials have been studied in modified Yucca Mountain (YM) ground water in the presence or absence of YM bacteria. YM bacteria increased corrosion rates by 5--6 fold in UNS G10200 carbon steel, and nearly 100-fold in UNS N04400 Ni-Cu alloy. YM bacteria caused microbiologically influenced corrosion (MIC) through de-alloying or Ni-depletion of Ni-Cu alloy as evidenced by scanning electronic microscopy (SEM) and inductively coupled plasma spectroscopy (ICP) analysis. MIC rates of more corrosion-resistant alloys such as UNS N06022 Ni-Cr-Mo- W alloy, UNS N06625 Ni-Cr-Mo alloy, and UNS S30430 stainless steel were measured below 0.05 microm/yr, however YM bacteria affected depletion of Cr and Fe relative to Ni in these materials. The chemical change on the metal surface caused by depletion was characterized in anodic polarization behavior. The anodic polarization behavior of depleted Ni-based alloys was similar to that of pure Ni

  15. Stress corrosion cracking of candidate materials for nuclear waste containers

    International Nuclear Information System (INIS)

    Types 304L and 316L stainless steel (SS), Incoloy 825, Cu, Cu-30%Ni, and Cu-7%Al have been selected as candidate materials for the containment of high-level nuclear waste at the proposed Yucca Mountain Site in Nevada. The susceptibility of these materials to stress corrosion cracking has been investigated by slow-strain-rate tests (SSRTs) in water which simulates that from well J-13 (J-13 water) and is representative of the groundwater present at the Yucca Mountain site. The SSRTs were performed on specimens exposed to simulated J-13 water at 93 degree C and at a strain rate 10-7 s-1 under crevice conditions and at a strain rate of 10-8 s-1 under both crevice and noncrevice conditions. All the tests were interrupted after nominal elongation strains of 1--4%. Examination by scanning electron microscopy showed some crack initiation in virtually all specimens. Optical microscopy of metallographically prepared transverse sections of Type 304L SS suggests that the crack depths are small (<10 μm). Preliminary results suggest that a lower strain rate increases the severity of cracking of Types 304L and 316L SS, Incoloy 825, and Cu but has virtually no effect on Cu-30%Ni and Cu-7%Al. Differences in susceptibility to cracking were evaluated in terms of a stress ratio, which is defined as the ratio of the increase in stress after local yielding in the environment to the corresponding stress increase in an identical test in air, both computed at the same strain. On the basis of this stress ratio, the ranking of materials in order of increasing resistance to cracking is: Types 304L SS < 316L SS < Incoloy 825 congruent Cu-30%Ni < Cu congruent Cu-7%Al. 9 refs., 12 figs., 7 tabs

  16. Humid air corrosion of YMP waste package candidate material

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.

    1998-01-01

    The Yucca Mountain Site Characterization Project is evaluating candidate materials for high level nuclear waste containers (Waste Packages) for a potential deep geologic repository at Yucca Mountain, Nevada. The potential repository is located above the water table in the unsaturated zone. The rock contains nominally 10% by volume water and gas pressure in the emplacement drifts of the repository is expected to remain near the ambient atmospheric pressure. The heat generated by the radioactive decay of the waste will raise the temperature of the waste packages and the surrounding rock. Waste Package temperatures above the ambient boiling point of water are anticipated for the waste emplacement scenarios. Because the repository emplacement drifts are expected to remain at the ambient atmospheric pressure, the maximum relative humidity obtainable decreases above the boiling point of water. Temperatures of the Waste Packages and the surrounding rock are expected to reach maximum temperature within 100`s of years and then gradually decrease with time. Episodic liquid water contact with the WPs is also expected; this will result in the deposition of salts and mineral scale.

  17. Auxetic materials and structures

    CERN Document Server

    Lim, Teik-Cheng

    2015-01-01

    This book describes the fundamentals of the mechanics and design of auxetic solids and structures, which possess a negative Poisson’s ratio. It will benefit two groups of readers: (a) industry practitioners, such as product and structural designers, who need to control mechanical stress distributions using auxetic materials, and (b) academic researchers and students who intend to produce structures with unique mechanical and other physical properties using auxetic materials.

  18. Evaluation of C/C-SiC Composites as Potential Candidate Materials for High Performance Braking Systems

    Science.gov (United States)

    Saptono Duryat, Rahmat

    2016-05-01

    This paper is aimed at evaluating the characteristic and performance of C/C-SiC composites as potential candidate materials for high performance braking system. A set of material specifications had been derived from specific engineering design requirements. Analysis was performed by formulating the function(s), constraint(s), and objective(s) of design and materials selection. Function of a friction material is chiefly to provide friction, absorb and dissipate energy. It is done while withstanding load and maintaining the structural adequacy and characteristic of tribology at high temperature. Objective of the material selection and design is to maximize the absorption and dissipation of energy and to minimize weight and cost. Candidate materials were evaluated based on their friction and wear, thermal capacity and conductivity, structural properties, manufacturing properties, and densities. The present paper provides a state of the art example on how materials - function - geometry - design, are all interrelated.

  19. Behaviour of Structural Materials: India

    International Nuclear Information System (INIS)

    Two buoyancy driven LBE loops have been set up in BARC to study corrosion effects of LBE on candidate structural materials for spallation target module; like SS-316 L, 316 LN, SS-304 L, 9Cr-1Mo etc. The larger loops getting ready would be ~ 7 metre high and its riser and downcomer legs would operate at 5500°C and 4500°C respectively. The buoyancy head is estimated to provide a LBE mass flow rate of 1.7kg/s. The flow velocity around the sample is ~0.6 m/s. Material samples exposed in an already operational smaller corrosion loop were being evaluated by Charpy and Tensile tests after exposing the samples for 2000 hours in the flow with oxygen control. Provision is also being made in this loop to enhance the LBE flow by gas injection

  20. Structural and Material Instability

    DEFF Research Database (Denmark)

    Cifuentes, Gustavo Cifuentes

    This work is a small contribution to the general problem of structural and material instability. In this work, the main subject is the analysis of cracking and failure of structural elements made from quasi-brittle materials like concrete. The analysis is made using the finite element method. Three...... program based on the finite element method for the analysis of cracks in structural elements is presented; in this program the interface and elements with embedded discontinuities are implemented....... use of interface elements) is used successfully to model cases where the path of the discontinuity is known in advance, as is the case of the analysis of pull-out of fibers embedded in a concrete matrix. This method is applied to the case of non-straight fibers and fibers with forces that have...

  1. Structural materials for fusion reactors

    International Nuclear Information System (INIS)

    Full text: A long term solution to problems of energy production, green house gas generation, and pollution control may rest with controlled nuclear fusion reactors. Candidate structural materials for such reactors include low activation ferritic steels. Understanding and eliminating deleterious irradiation effects in these materials is the goal of these experiments in this collaboration using the ANL facility. In recent experiments on ferritic alloys we have recently found a significant difference with alloy composition in the microstructural response to irradiation, which corresponds to a bulk mechanical property change at a similar composition. In a collaboration between the Department of Materials at the University of Oxford and the Materials Science Division at Argonne National Laboratory, experiments which employ the unique transmission electron microscope and in situ ion irradiation user facility at ANL were performed on a series of Fe-Cr alloys. Enhanced nanometer-sized defect formation with Cr concentrations up to 11 % have been found and correlated with a decrease in mechanical hardening and embrittlement in similar alloys. (author)

  2. LEO effects on candidate solar-cell cover materials

    International Nuclear Information System (INIS)

    The Long Duration Exposure Facility (LDEF) test samples discussed within are part of the Solar Array Materials Passive (SAMPLE) LDEF experiment, which included contributions from NASA and Jet Propulsion Lab (JPL). Only the JPL portion is described in this paper. The JPL test plate contains 30 individual thin silicon solar cell/cover samples. It was the intent of the experiment to evaluate the stability and protective capability of various cover materials such as conventional fused silica and potential alternative materials such as Teflon, silicone RTV's, glass resins, polyimides, and a copolymer encapsulate. Examination of the recovered experiment shows extensive physical changes have occurred. Approximately 150 micrometeoroid/debris impact were noted, some directly on the solar cells. Of particular interest are the results of ultraviolet and atomic oxygen interactions with the various cover materials. Initial results show that the fused silica cover is the most stable and protective, with performance of other materials varying widely. Electrical measurements of the cell/cover samples are presented as part of the evaluation of cover materials to protect cells in low earth orbit environments

  3. Characterization of Candidate Materials for Remote Recession Measurements of Ablative Heat Shield Materials

    Science.gov (United States)

    Butler, Bradley D.; Winter, Michael; Panerai, Francesco; Martin, Alexandre; Bailey, Sean C. C.; Stackpoole, Margaret; Danehy, Paul M.; Splinter, Scott

    2016-01-01

    A method of remotely measuring surface recession of a material sample in a plasma flow through emission spectroscopy of the post shock layer was characterized through experiments in the NASA Langley HYMETS arc jet facility. Different methods for delivering the seed products into the Phenolic Impregnated Carbon Ablator (PICA) material samples were investigated. Three samples were produced by seeding the PICA material with combinations of Al, Si, HfO2, VB2, Al2O3, SiO2, TiC, HfC, NaCl, and MgCl2 through infusing seed materials into a core of PICA, or through encapsulating seed material in an epoxy disk, mechanically bonding the disk to a PICA sample. The PICA samples seeded with the candidate tracers were then tested at surface temperatures near 2400 K under low pressure air plasma. The emission of Al, Ti, V, Na, and Mg in the post-shock layer was observed in the UV with a high resolution imaging spectrometer viewing the whole stagnation line from the side, and from UV to NIR with a fiber-coupled miniaturized spectrometer observing the sample surface in the wavelength range from 200 nm to 1,100 nm from the front through a collimator. Al, Na, and Mg were found to be emitting in the post-shock spectra even before the recession reached the seeding depth - therefore possibly characterizing the pyrolysis process rather than the recession itself. The appearance of Ti and V emission in the spectra was well correlated with the actual recession which was monitored through a video of the front surface of the sample. The applicability of a seed material as an indicator for recession appears to be related to the melting temperature of the seed material. Future parametric studies will be carried out in low power plasma facilities at the University of Kentucky.

  4. Structural materials assessment

    International Nuclear Information System (INIS)

    The selection of first wall and structural materials is strongly dependent on the proposed design of breeding blanket components and the targets for a fusion reactor development. An envelope of parameters which have to be covered in future R and D activities and which have been adapted in different proposals has been compiled. A short description of interesting material groups like ferritic-martensitic steels, vanadium alloys and ceramic composites, major criteria for their selection and a survey on existing irradiation data is given. This is followed by a comparative assessment of relevant properties and an identification of major issues for each material group. A more detailed proposal for the future R and D activities is then developed for the ferritic-martensitic steels, the present reference material for the European Breeding Blankets. It describes different phases of development necessary for the qualification of this material for DEMO and gives time schedules which are compatible with parallel component developments. A more selective strategy is proposed for the development of vanadium alloys and the ceramic composite material SiC/SiC. For these alternatives work should be concentrated on identified high-risk issues, before a comprehensive development programme is started. The necessity of efficient irradiation facilities to study the irradiation behaviour of the materials under simulation - and realistic fusion conditions is discussed. The availability of high flux fission reactors and necessary extensions of irradiation rigs for the next decade is stressed. Finally it is shown that for the qualification of materials under realistic fusion conditions a high-energetic, high-flux neutron source is mandatory. An accelerator-driven d-Li neutron source (IFMIF) can fulfil essential users requirements as test bed for materials and can technically be made available in due time. In combination with ITER and DEMO, where a concept verification and full scale

  5. Structure and evolution of barley powdery mildew effector candidates

    Directory of Open Access Journals (Sweden)

    Pedersen Carsten

    2012-12-01

    Full Text Available Abstract Background Protein effectors of pathogenicity are instrumental in modulating host immunity and disease resistance. The powdery mildew pathogen of grasses Blumeria graminis causes one of the most important diseases of cereal crops. B. graminis is an obligate biotrophic pathogen and as such has an absolute requirement to suppress or avoid host immunity if it is to survive and cause disease. Results Here we characterise a superfamily predicted to be the full complement of Candidates for Secreted Effector Proteins (CSEPs in the fungal barley powdery mildew parasite B. graminis f.sp. hordei. The 491 genes encoding these proteins constitute over 7% of this pathogen’s annotated genes and most were grouped into 72 families of up to 59 members. They were predominantly expressed in the intracellular feeding structures called haustoria, and proteins specifically associated with the haustoria were identified by large-scale mass spectrometry-based proteomics. There are two major types of effector families: one comprises shorter proteins (100–150 amino acids, with a high relative expression level in the haustoria and evidence of extensive diversifying selection between paralogs; the second type consists of longer proteins (300–400 amino acids, with lower levels of differential expression and evidence of purifying selection between paralogs. An analysis of the predicted protein structures underscores their overall similarity to known fungal effectors, but also highlights unexpected structural affinities to ribonucleases throughout the entire effector super-family. Candidate effector genes belonging to the same family are loosely clustered in the genome and are associated with repetitive DNA derived from retro-transposons. Conclusions We employed the full complement of genomic, transcriptomic and proteomic analyses as well as structural prediction methods to identify and characterize the members of the CSEPs superfamily in B. graminis f

  6. Neutron irradiation of candidate ceramic breeder materials of fusion reactors

    International Nuclear Information System (INIS)

    In the context of the European programs for the future fusion reactors, the Process Chemistry Department of ENEA, Casaccia Center (Rome), has been involved in preparing ceramic blanket materials as tritium breeders; a special consideration has been addressed to the nuclear characterization of LiAlO2 and Li2ZrO3. In this paper are reported neutron irradiation of ceramic specimens in TRIGA reactor and γ-spectrometric measurements for INAA purposes; and isothermal annealing of the irradiated samples and tritium extraction, by using an 'out of pile' system. (author) 3 refs.; 4 figs.; 4 tabs

  7. Graphene oxide as an optimal candidate material for methane storage

    Science.gov (United States)

    Chouhan, Rajiv K.; Ulman, Kanchan; Narasimhan, Shobhana

    2015-07-01

    Methane, the primary constituent of natural gas, binds too weakly to nanostructured carbons to meet the targets set for on-board vehicular storage to be viable. We show, using density functional theory calculations, that replacing graphene by graphene oxide increases the adsorption energy of methane by 50%. This enhancement is sufficient to achieve the optimal binding strength. In order to gain insight into the sources of this increased binding, that could also be used to formulate design principles for novel storage materials, we consider a sequence of model systems that progressively take us from graphene to graphene oxide. A careful analysis of the various contributions to the weak binding between the methane molecule and the graphene oxide shows that the enhancement has important contributions from London dispersion interactions as well as electrostatic interactions such as Debye interactions, aided by geometric curvature induced primarily by the presence of epoxy groups.

  8. High temperature indentation tests on fusion reactor candidate materials

    International Nuclear Information System (INIS)

    Flat-top cylinder indenter for mechanical characterization (FIMEC) is an indentation technique employing cylindrical punches with diameters ranging from 0.5 to 2 mm. The test gives pressure-penetration curves from which the yield stress can be determined. The FIMEC apparatus was developed to test materials in the temperature range from -180 to +200 oC. Recently, the heating system of FIMEC apparatus has been modified to operate up to 500 oC. So, in addition to providing yield stress over a more extended temperature range, it is possible to perform stress-relaxation tests at temperatures of great interest for several nuclear fusion reactor (NFR) alloys. Data on MANET-II, F82H mod., Eurofer-97, EM-10, AISI 316 L, Ti6Al4V and CuCrZr are presented and compared with those obtained by mechanical tests with standard methods

  9. Nano structured Magnetic Materials

    International Nuclear Information System (INIS)

    The saga of nanostructured magnetic materials (NMMs) has prevailed since the discovery of the first giant magnetoresistance (GMR) effect in metals in 1988. NMMs represent a unique system that incorporates the interplay between the properties associated with spin degrees of freedom and the nanoscaled structures, which provide a very strong platform for exploring both basic science and technical applications in the fields of solid-state physics, chemistry, materials science, and engineering. In fact, an active research field called “spintronics,” which has a big overlap with NMMs, has emerged and prevailed very recently. Through manipulation of spin of electrons in solids, a wide variety of NMMs and devices have been playing a prominent role in information processing and transport in our modern life. A rich variety of materials, such as transition metals, manganite, wide bandgap semiconductors, and nanocomposites, have already been developed for generating well-controlled nanostructures with new functionalities. Many scientists believe that the 21st century will be a “Century of Spin.” Nanomaterials and nanotechnologies have provided historical opportunities for research and development of novel spintronics materials and devices. NMSs manifest fascinating properties compared to the bulks because of size effect and quantum effect. Nanotechnologies have been proven to be an effective way to fabricate devices with fine nanostructures. The combination of spintronics and nanomaterials will undisputedly open new pathways in solid-state physics. The present special issue focuses on the recent development in the understanding of the synthesis, the studies on magnetic properties of nanostructures, and their potential applications based on the multiple functionalities.

  10. Advanced Gas Cooled Nuclear Reactor Materials Evaluation and Development Program: Topical report I, selection of candidate alloys. Volume 3. Selection of surface coating/substrate systems for screening creep and structural stability studies

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-20

    Considering the high temperature, low O/sub 2/, high C environment of operation in the Very High Temperature Reactor (VHTR) Systems, the utilization of coatings is envisaged to hold potential for extending component lifetimes through the formation of stable and continuous oxide films with enhanced resistance to C diffusion. A survey of the current state of technology for high temperature coatings has been performed. The usefulness of these coatings on the Mo, Ni, and Fe base alloys is discussed. Specifically, no coating substitute was identified for TZM other than the well known W-3 (pack silicide) and Al/sub 2/O/sub 3/ forming coatings were recommended for the Fe and Ni base structural materials. Recommendations as to coating types and processng have been made based on the predicted VHTR component size, shape, base metal and operational environment. Four tests designed to evaluate the effects of selected combinations of coatings and substrate matrices are recommended for consideration.

  11. Preliminary cleaning tests on candidate materials for APS beamline and front end UHV components

    International Nuclear Information System (INIS)

    Comparative cleaning tests have been done on four candidate materials for use in APS beamline and front-end vacuum components. These materials are 304 SS, 304L SS, OFHC copper, and Glidcop* (Cu-Al2O3)- Samples of each material were prepared and cleaned using two different methods. After cleaning, the sample surfaces were analyzed using ESCA (Electron Spectography for Chemical Analysis). Uncleaned samples were used as a reference. The cleaning methods and surface analysis results are further discussed

  12. Mechanical Properties of Candidate Materials for Hot Gas Duct of VHTR

    International Nuclear Information System (INIS)

    Hot gas duct of VHTR is operated at 950 .deg.. Ni based superalloys, such as Hastelloy XR, Alloy 617, Haynes 230, for hot gas duct have been candidate material because of good strength and corrosion properties at high temperature. Mechanical properties of these alloys are tested at high temperature to apply to hot gas duct of VHTR

  13. Characteristics study of bentonite as candidate of buffer materials for radioactive waste disposal system

    International Nuclear Information System (INIS)

    Literature studies on bentonite characteristic of, as candidate for radioactive waste disposal system, have been conducted. Several information have been obtained from references, which would be contributed on performance assessment of engineered barrier. The functions bentonite includes the buffering of chemical and physical behavior, i.e. swelling property, self sealing, hydraulic conductivities and gas permeability. This paper also presented long-term stability of bentonite in natural condition related to the illitisazation, which could change its buffering capacities. These information, showed that bentonite was satisfied to be used for candidate of buffer materials in radioactive waste disposal system. (author)

  14. Analysis of candidate micro-reference materials of lichen and algae by SRXRF and PIXE

    International Nuclear Information System (INIS)

    The two micro-analysis techniques, synchrotron radiation X-ray fluorescence and macro-proton induced X-ray emission (macro-PIXE), were used in a homogeneity test of two candidate reference materials (RMs), lichen IAEA-338 and algae IAEA-413 (International Atomic Energy Agency, IAEA), in the present work. The two candidate RMs had good homogeneity with the minimum sampling mass of 10 mg required for micro-analytical nuclear techniques. The elemental content in the RMs was also determined by macro-PIXE. The relative homogeneity factors HE of elements in the RMs were estimated on the base of our macro-PIXE results

  15. Element content and particle size characterization of a mussel candidate reference material

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Edson G.; Vasconcellos, Marina B.A., E-mail: emoreira@ipen.b, E-mail: mbvascon@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro do Reator de Pesquisas; Santos, Rafaela G. dos; Martinelli, Jose R., E-mail: jroberto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais

    2011-07-01

    The use of certified reference materials is an important tool in the quality assurance of analytical measurements. To assure reliability on recently prepared powder reference materials, not only the characterization of the property values of interest and their corresponding uncertainties, but also physical properties such as the particle size distribution must be well evaluated. Narrow particle size distributions are preferable than larger ones; as different size particles may have different analyte content. Due to this fact, the segregation of the coarse and the fine particles in a bottle may lead to inhomogeneity of the reference material, which should be avoided. In this study the element content as well as the particle size distribution of a mussel candidate reference material produced at IPEN-CNEN/SP was investigated. Instrumental Neutron Activation Analysis was applied to the determination of 15 elements in seven fractions of the material with different particle size distributions. Subsamples of the materials were irradiated simultaneously with elemental standards at the IEA-R1 research nuclear reactor and the induced gamma ray energies were measured in a hyperpure germanium detector. Three vials of the candidate reference material and three coarser fractions, collected during the preparation, were analyzed by Laser Diffraction Particle Analysis to determine the particle size distribution. Differences on element content were detected for fractions with different particle size distribution, indicating the importance of particle size control for biological reference materials. From the particle size analysis, Gaussian particle size distribution was observed for the candidate reference material with mean particle size {mu} = 94.6 {+-} 0.8 {mu}m. (author)

  16. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three iron- to nickel-based austenitic alloys and three copper-based alloys are being considered as candidate materials for the fabrication of high-level radioactive-waste disposal containers. The austenitic alloys are Types 304L and 316L stainless steels and the high-nickel material Alloy 825. The copper-based alloys are CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). Waste in the forms of both spent fuel assemblies from reactors and borosilicate glass will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides will result in the generation of substantial heat and gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including undesirable phase transformations due to a lack of phase stability; atmospheric oxidation; general aqueous corrosion; pitting; crevice corrosion; intergranular stress corrosion cracking; and transgranular stress corrosion cracking. Problems specific to welds, such as hot cracking, may also occur. A survey of the literature has been prepared as part of the process of selecting, from among the candidates, a material that is adequate for repository conditions. The modes of degradation are discussed in detail in the survey to determine which apply to the candidate alloys and the extent to which they may actually occur. The eight volumes of the survey are summarized in Sections 1 through 8 of this overview. The conclusions drawn from the survey are also given in this overview

  17. Infra-red material structures

    International Nuclear Information System (INIS)

    A process for modifying properties of infra-red materials in or for use in infra-red windows and other structures, in which the infra-red material is subjected to ion implantation whereby ions of an elemental dopant are implanted into the infra-red material under vacuum conditions. Heat diffusion may improve the depth of ion penetration. Specified materials are germanium, zinc sulphide, cadmium mercury telluride, calcium lanthanum sulphide and zinc selenide; specified dopants are boron, carbon and silicon. (author)

  18. Hypersonic Materials and Structures

    Science.gov (United States)

    Glass, David E.

    2016-01-01

    Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this presentation is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components.

  19. Ti{sub 3}SiC{sub 2} as a candidate material for lead cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Utili, M., E-mail: marco.utili@enea.i [Universita degli studi di Bologna, Facolta di Ingegneria, Via Risorgimento, 2 DIENCA, Bologna (Italy); Agostini, M.; Coccoluto, G. [ENEA CR Brasimone, Fis Ing, Camugnano (Italy); Lorenzini, E. [Universita degli studi di Bologna, Facolta di Ingegneria, Via Risorgimento, 2 DIENCA, Bologna (Italy)

    2011-05-15

    One of the main issues regarding the design of LFR is the corrosion-erosion behaviour of materials in contact with high temperature and high velocity lead, such as pump impeller and bearing materials. Those materials will worked in lead at about 480 {sup o}C with a velocity relative to impeller blade in the magnitude of 10 m/s. Ti{sub 3}SiC{sub 2}, a ternary compound was selected as one of the most promising candidate material, the most significant aspect of Ti{sub 3}SiC{sub 2} is that it combines some of the most attractive proprieties of ceramics with those of metals. This material was already applied in industry but more effort is needed to qualify its performance when compared with candidate structural stainless steel available in Europe. With the purpose of evaluating the corrosion resistance of Ti{sub 3}SiC{sub 2}, a preliminary screening test was carried out at ENEA Brasimone in fluent lead under oxidation conditions (oxygen concentration of about 10{sup -6} wt% in the melt), with an average temperature of 500 {sup o}C and a stream velocity of about 1 m/s.

  20. Application of a passive electrochemical noise technique to localized corrosion of candidate radioactive waste container materials

    International Nuclear Information System (INIS)

    One of the key engineered barriers in the design of the proposed Yucca Mountain repository is the waste canister that encapsulates the spent fuel elements. Current candidate metals for the canisters to be emplaced at Yucca Mountain include cast iron, carbon steel, Incoloy 825 and titanium code-12. This project was designed to evaluate passive electrochemical noise techniques for measuring pitting and corrosion characteristics of candidate materials under prototypical repository conditions. Experimental techniques were also developed and optimized for measurements in a radiation environment. These techniques provide a new method for understanding material response to environmental effects (i.e., gamma radiation, temperature, solution chemistry) through the measurement of electrochemical noise generated during the corrosion of the metal surface. In addition, because of the passive nature of the measurement the technique could offer a means of in-situ monitoring of barrier performance

  1. Fusible heat sink materials - Evaluation of alternate candidates. [for PLSS cooling systems

    Science.gov (United States)

    Selvaduray, Guna S.; Lomax, W. C.

    1992-01-01

    Fusible heat sinks are a possible source for thermal regulation of space suited astronauts. Materials with greater thermal storage capability than water could enable both an extension of time between recharging and/or a reduction in size and/or mass. An extensive literature search identified 1,215 candidates with a solid-liquid transformation within the temperature range of -13 C to 5 C. Based on data available in the literature, several candidates with a cooling capacity significantly greater than water were identified. Measurements of the transformation temperature and enthalpy of transformation were then undertaken with a differential scanning calorimeter in order to confirm the accuracy of the literature. Laboratory measurements have thus far not been able to corroborate the extremely high values found from the literature. This paper presents the approach for materials selection utilized in this study, the experimental procedure, and the results of the measurements thus far undertaken.

  2. Structural evaluation of candidate space shuttle thermal protection systems

    Science.gov (United States)

    Burns, A. B.

    1972-01-01

    The characteristics and development of a lightweight reusable thermal protection system for the space shuttle are discussed. The test articles consisted of metallic substrates with upper surfaces covered with all-silica, reusable, surface insulation material. The material is processed in the form of tiles. The external surfaces of the tiles are provided with a coating system which consists of a borosilicate coating with a silicon carbide emittance agent and impregnation with a hydrophobic agent. The finished tiles are attached to the metal substrate by adhesive bonding. Charts and graphs of the properties of the material are provided.

  3. Preliminary corrosion studies of candidate materials for supercritical water oxidation reactor systems

    OpenAIRE

    Orzalli, John Clarke

    1994-01-01

    An experimental test facility has been designed and constructed for investigation of the corrosion behavior of candidate materials in a supercritical water oxidation environment. The high temperatures (500 deg C) and high pressures (300 atm) required in this process, made the experimental apparatus construction and control a complex engineering problem. The facility consists of two systems. The first is an exposure autoclave internal volume 850 ml, with associated monitoring and control syste...

  4. Inner material requirements and candidates screening for spent fuel disposal canister

    International Nuclear Information System (INIS)

    In the context of the present Spanish 'once-through' nuclear fuel cycle, the need arises to complete the geological repository reference concept with a spent fuel canister final design. One of the main issues in its design is selecting the inner material to be placed inside the canister, between the steel walls and the spent fuel assemblies. The primary purpose of this material will be to avoid the possibility of a criticality event once the canister walls have been finally breached by corrosion and the spent fuel is flooded with groundwater. That is an important role because the increase in heat generation from such an event would act against spent fuel stability and compromise bentonite barrier functions, negatively affecting overall repository performance. To prevent this possibility a detailed set of requirements for a material to fulfil this role in the repository environment have been devised and presented in this paper. With these requirements in view, eight potentially interesting candidates were selected and evaluated: cast iron or steel, borosilicate glass, spinel, depleted uranium, dehydrated zeolites, haematite, phosphates, and olivine. Among these, the first four materials or material families are found promising for this application. In addition, other relevant non-performance-related aspects of candidate materials, which could help on decision making, are also considered and evaluated. (authors)

  5. High-Temperature Phase Change Materials (PCM) Candidates for Thermal Energy Storage (TES) Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J. C.

    2011-09-01

    It is clearly understood that lower overall costs are a key factor to make renewable energy technologies competitive with traditional energy sources. Energy storage technology is one path to increase the value and reduce the cost of all renewable energy supplies. Concentrating solar power (CSP) technologies have the ability to dispatch electrical output to match peak demand periods by employing thermal energy storage (TES). Energy storage technologies require efficient materials with high energy density. Latent heat TES systems using phase change material (PCM) are useful because of their ability to charge and discharge a large amount of heat from a small mass at constant temperature during a phase transformation like melting-solidification. PCM technology relies on the energy absorption/liberation of the latent heat during a physical transformation. The main objective of this report is to provide an assessment of molten salts and metallic alloys proposed as candidate PCMs for TES applications, particularly in solar parabolic trough electrical power plants at a temperature range from 300..deg..C to 500..deg.. C. The physical properties most relevant for PCMs service were reviewed from the candidate selection list. Some of the PCM candidates were characterized for: chemical stability with some container materials; phase change transformation temperatures; and latent heats.

  6. Structural materials for fusion reactors

    International Nuclear Information System (INIS)

    In order to preserve the condition of an environmentally safe machine, present selection of materials for structural components of a fusion reactor is made not only on the basis of adequate mechanical properties, behavior under irradiation and compatibility with other materials and cooling media, but also on their radiological properties, i.e. activity, decay heat, radiotoxicity. These conditions strongly limit the number of materials available to a few families of alloys, generically known as low activation materials. We discuss the criteria for deciding on such materials, the alloys resulting from the application of the concept and the main issues and problems of their use in a fusion environment. (author)

  7. Structure and kinematics of candidate double-barred galaxies

    CERN Document Server

    Moiseev, A V; Chavushyan, V H

    2003-01-01

    Results of optical and NIR spectral and photometric observations of a sample of candidate double-barred galaxies are presented. Velocity fields and velocity dispersion maps of stars and ionized gas, continuum and emission-line images were constructed from integral-field spectroscopy observations carried out at the 6m telescope (BTA) of SAO RAS, with the MPFS spectrograph and the scanning Fabry-Perot Interferometer. NGC2681 was also observed with long-slit spectrograph of the BTA. Optical and NIR images were obtained at the BTA and at the 2.1m telescope (OAN, M\\'exico). High-resolution images were retrieved from the HST data archive. Morphological and kinematic features of all 13 sample objects are described in detail. Attention is focused on the interpretation of observed non-circular motions of gas and stars in circumnuclear (one kiloparsec- scale) regions. We have shown first of all that these motions are caused by a gravitational potential of large-scale bar. NGC3368 and NGC3786 have nuclear bars only, the...

  8. Behaviour of Structural Materials: China

    International Nuclear Information System (INIS)

    Since accelerator driven system (ADS) will be used as the facility for long life radioactive waste transmutation, some issues in structure materials of ADS are being paid attention, such as the compatibility of the materials and coolant, the development and selection of materials which are irradiation resistance to neutron and high energy proton, and corrosion resistance to Pb-Bi. In China, ADS material programme was proposed in 2000, started in 2001, and the compatibility project is focused on three topics: – The compatibility studies of tungsten with sodium and with water; – The development and investigation of the structure materials; – The primary tests of the complex technologies for W–S.S. and W–Zr cladding. Some primary results from these researches have been obtained, and some investigations are being performed. Since our investigation is in an early step, a lot of issues on materials have to be studied further in the near future

  9. Value determination of ZrO2 in-house reference material (RM) candidate

    International Nuclear Information System (INIS)

    The value determination of zirconium oxide in-house reference materials (RM) candidate has been done by referring to ISO:35-2006 standard. The raw material of RM was 4 kg of ZrO2, Merck, that was dried at 90°C for 2×6 hours in a closed room. The samples were crushed with stainless steel (SS) pestle to pass ≤ 200 mesh sieve, homogenized in a homogenizer for 3×6 hours to obtain the powdered, dried and homogenous samples. The gravimetric method was performed to test the moisture content, while XRF and AAS methods were used to test the homogeneity and stability of samples candidates. Reference material (RM) candidates of ZrO2 powder were put into polyethylene bottles, each weighing 100 g. Samples were distributed to 10 testing laboratories that have been accredited for testing the composition of the oxide contents and loss of ignition (LOI) using variety of analytical methods that have been validated such as AAS, XRF, NAA, and UV-Vis. The testing results of oxide content and loss of ignition parameters from various laboratories were analyzed using statistical methods. The testing data of oxide concentration in zirconium oxide RM candidates obtained from various laboratories were ZrO2: 97.7334 ± 0.0016%, HfO2: 1.7329 ± 0.0024%, SiO2: 30.1224 ± 0.0053%, Al2O3: 0.0245 ± 0.0015%, TiO2: 0.0153 ± 0.0006%, Fe2O3: 0.0068 ± 0.0005%, CdO: 3.1798 ± 0.00006 ppm, and the LOI results was = 0.0217 ± 0.00022%. (author)

  10. Pyrochlores and perovskites: candidates for exploring structure functionality relationships

    International Nuclear Information System (INIS)

    Pyrochlores (A2B2O7) and perovskites (ABO3) are two widely studied classes of compounds which exhibit myriad properties like ionic conductivity, magnetism, dielectric behaviour, catalysis, optical properties etc. The stability of these structures is highly dependent upon the radius ratio of the cations occupying A- and B-sites. The intriguing crystal chemistry that originates from varying this radius ratio forms the basis for interesting structural studies. Further, the elemental versatility allows possibility of introducing a variety of guest ions in its lattice which makes it possible to fine tune the structure in order to obtain desirable properties. Some of the recent studies in our group have shown that in rare earth based mixed-pyrochlore oxides like Sm2-xDyxZr2O7, Gd1-xNdxZr2O7(0.0 ≤ x ≤ 2.0) etc., fine tuning of structure could be obtained by varying A-site cation which had a profound bearing on ionic conductivity of the resultant system. Similarly, the ABO3 systems like GdSc1-xInxO3, Gd1-xYxInO3 (0.0 ≤ x ≤ 1.0) etc. showed interesting structural and dielectric behavior due to fine control of BO5, polyhedra in these indates. The careful tuning of A and B-site occupants and the choice of synthesis route lead to stabilization of metastable structures in these classes with tunable electrical behavior. The present talk will thus concentrate upon elucidating the relation between structure and the electrical behavior by taking specific examples in these two classes of compounds. (author)

  11. A feasibility study for producing an egg matrix candidate reference material for the polyether ionophore salinomycin.

    Science.gov (United States)

    Ferreira, Rosana Gomes; Monteiro, Mychelle Alves; Pereira, Mararlene Ulberg; da Costa, Rafaela Pinto; Spisso, Bernardete Ferraz; Calado, Veronica

    2016-08-01

    The aim of this work was to study the feasibility of producing an egg matrix candidate reference material for salinomycin. Preservation techniques investigated were freeze-drying and spray drying dehydration. Homogeneity and stability studies of the produced batches were conducted according to ISO Guides 34 and 35. The results showed that all produced batches were homogeneous and both freeze-drying and spray drying techniques were suitable for matrix dehydrating, ensuring the material stability. In order to preserve the material integrity, it must be transported within the temperature range of -20 up to 25°C. The results constitute an important step towards the development of an egg matrix reference material for salinomycin is possible. PMID:27216677

  12. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys, CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni), are being considered along with three austenitic candidates as possible materials for fabrication of containers for disposal of high-level radioactive waste. The waste will include spent fuel assemblies from reactors as well as high-level reprocessing wastes in borosilicate glass and will be sent to the prospective repository at Yucca Mountain, Nevada, for disposal. The containers must maintain mechanical integrity for 50 yr after emplacement to allow for retrieval of waste during the preclosure phase of repository operation. Containment is required to be substantially complete for up to 300 to 1000 yr. During the early period, the containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. The final closure joint will be critical to the integrity of the containers. This volume surveys the available data on the metallurgy of the copper-based candidate alloys and the welding techniques employed to join these materials. The focus of this volume is on the methods applicable to remote-handling procedures in a hot-cell environment with limited possibility of postweld heat treatment. The three copper-based candidates are ranked on the basis of the various closure techniques. On the basis of considerations regarding welding, the following ranking is proposed for the copper-based alloys: CDA 715 (best) > CDA 102 > CDA 613 (worst). 49 refs., 15 figs., 1 tab

  13. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Bullen, D.B.; Gdowski, G.E. (Science and Engineering Associates, Inc., Pleasanton, CA (USA)); Weiss, H. (Lawrence Livermore National Lab., CA (USA))

    1988-06-01

    Three copper-based alloys, CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni), are being considered along with three austenitic candidates as possible materials for fabrication of containers for disposal of high-level radioactive waste. The waste will include spent fuel assemblies from reactors as well as high-level reprocessing wastes in borosilicate glass and will be sent to the prospective repository at Yucca Mountain, Nevada, for disposal. The containers must maintain mechanical integrity for 50 yr after emplacement to allow for retrieval of waste during the preclosure phase of repository operation. Containment is required to be substantially complete for up to 300 to 1000 yr. During the early period, the containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. The final closure joint will be critical to the integrity of the containers. This volume surveys the available data on the metallurgy of the copper-based candidate alloys and the welding techniques employed to join these materials. The focus of this volume is on the methods applicable to remote-handling procedures in a hot-cell environment with limited possibility of postweld heat treatment. The three copper-based candidates are ranked on the basis of the various closure techniques. On the basis of considerations regarding welding, the following ranking is proposed for the copper-based alloys: CDA 715 (best) > CDA 102 > CDA 613 (worst). 49 refs., 15 figs., 1 tab.

  14. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the...... properties of lime mortar....

  15. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1997-01-01

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the...

  16. Structural Chemistry of Functional Materials

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ This innovative research group on structural chemistry of functional materials was approved by NSFC in 2005.Headed by Prof.HONG Maochun, the team consists of several young research scientists from the CAS Fujian Institute of Research on the Structures of Matter, including Profs CAO Rong, LU Canzhong, GUO Guocong, CHEN Zhongning, MAO Jianggao Mao and CHEN Ling.

  17. Biologically-Induced Micropitting of Alloy 22, a Candidate Nuclear Waste Packaging Material

    International Nuclear Information System (INIS)

    The effects of potential microbiologically influenced corrosion (MIC) on candidate packaging materials for nuclear waste containment are being assessed. Coupons of Alloy 22, the outer barrier candidate for waste packaging, were exposed to a simulated, saturated repository environment (or microcosm) consisting of crushed rock (tuff) from the Yucca Mountain repository site and a continual flow of simulated groundwater for periods up to five years at room temperature and 30 C. Coupons were incubated with YM tuff under both sterile and non-sterile conditions. Surfacial analysis by scanning electron microscopy of the biotically-incubated coupons show development of both submicron-sized pinholes and pores; these features were not present on either sterile or untreated control coupons. Room temperature, biotically-incubated coupons show a wide distribution of pores covering the coupon surface, while coupons incubated at 30 C show the pores restricted to polishing ridges

  18. Structural materials for fusion magnets

    International Nuclear Information System (INIS)

    Of major technical and cost impact to Magnetic Fusion Energy development are the materials for the magnet structure. Likened to gas pressure, the magnetic field lines try to expand the structure with equivalent pressures up to 1000 atm. Not only are large tensile forces produced, but significant bending forces may also be present. To withstand these forces in the restricted spaces available, materials of exceptional strength and toughness are required. In this regard, the low-temperature environment of superconducting magnets can be an advantage because many materials exhibit enhanced properties at reduced temperatures. Those materials and fabrication techniques that are attractive to fusion magnets are discussed and relative comparisons made. Considerations such as strength, toughness, and joining techniques are balanced agains recommended design criteria to reach an optimum design. Several examples of material selection are cited for large fusion magnets such as Baseball II, the Mirror Fusion Test Facility, the Toroidal Fusion Test Facility, and the Large Coil Project. (orig.)

  19. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. (Lawrence Livermore National Lab., CA (USA)); Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-04-01

    Three iron- to nickel-based austenitic alloys (Types 304L and 316L stainless steels and Alloy 825) are being considered as candidate materials for the fabrication of high-level radioactive-waste containers. Waste will include fuel assemblies from reactors as well as high-level waste in borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides in the repository will result in the generation of substantial heat and in fluences of gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including atmospheric oxidation; uniform aqueous phase corrosion; pitting; crevice corrosion; sensitization and intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This report is an analysis of data relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of the three austenitic candidate alloys. The candidates are compared in terms of their susceptibilities to these forms of corrosion. Although all three candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these types of localized corrosion (LC); such resistance is important because pits can penetrate the metal and serve as crack initiation sites. Both Types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented in Alloy 825 under comparable conditions. Gamma radiation has been found to enhance SCC in Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while the effects of microbiologically induced corrosion have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. 211 refs., 49 figs., 10 tabs.

  20. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three iron- to nickel-based austenitic alloys (Types 304L and 316L stainless steels and Alloy 825) are being considered as candidate materials for the fabrication of high-level radioactive-waste containers. Waste will include fuel assemblies from reactors as well as high-level waste in borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides in the repository will result in the generation of substantial heat and in fluences of gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including atmospheric oxidation; uniform aqueous phase corrosion; pitting; crevice corrosion; sensitization and intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This report is an analysis of data relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of the three austenitic candidate alloys. The candidates are compared in terms of their susceptibilities to these forms of corrosion. Although all three candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these types of localized corrosion (LC); such resistance is important because pits can penetrate the metal and serve as crack initiation sites. Both Types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented in Alloy 825 under comparable conditions. Gamma radiation has been found to enhance SCC in Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while the effects of microbiologically induced corrosion have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. 211 refs., 49 figs., 10 tabs

  1. Provisional Assessment of Candidate High-Temperature Thermal Conductivity Reference Materials in the EMRP “Thermo” Project

    OpenAIRE

    Wu, J.; Morrell, R; T. Fry; Gnaniah, S.; Gohil, D.; Dawson, A.; Hameury, J.; Koenen, Alain; Hammerschmidt, U.; Turzó-András, E.; Strnad, R.; Blahut, A.

    2015-01-01

    This article describes the provisional assessment of a short list of four candidate high-temperature thermal conductivity reference materials in a European research project, “Thermo.” These four candidate materials are low-density calcium silicate, amorphous silica, high-density calcium silicate, and exfoliated vermiculite. Based on initial tests on material composition and microstructure changes, dimensional stability, mechanical stability, chemical stability and uniformity, the best two can...

  2. A study on homogeneity of the IAEA candidate reference materials for microanalysis and analytical support in the certification of these materials

    International Nuclear Information System (INIS)

    In this paper a study on homogeneity of new IAEA candidate reference materials: IAEA 338 Lichen and IAEA 413 Algae in small (ca.10 mg) samples as well as some data contributing to certification of these materials are presented. (author)

  3. Fissile material disposition program: Screening of alternate immobilization candidates for disposition of surplus fissile materials

    International Nuclear Information System (INIS)

    With the end of the Cold War, the world faces for the first time the need to dismantle vast numbers of ''excess'' nuclear weapons and dispose of the fissile materials they contain, together with fissile residues in the weapons production complex left over from the production of these weapons. If recently agreed US and Russian reductions are fully implemented, tens of thousands of nuclear weapons, containing a hundred tons or more of plutonium and hundreds of tonnes* of highly enriched uranium (HEU), will no longer be needed worldwide for military purposes. These two materials are the essential ingredients of nuclear weapons, and limits on access to them are the primary technical barrier to prospective proliferants who might desire to acquire a nuclear weapons capability. Theoretically, several kilograms of plutonium, or several times that amount of HEU, is sufficient to make a nuclear explosive device. Therefore, these materials will continue to be a potential threat to humanity for as long as they exist

  4. Fissile material disposition program: Screening of alternate immobilization candidates for disposition of surplus fissile materials

    Energy Technology Data Exchange (ETDEWEB)

    Gray, L.W.

    1996-01-08

    With the end of the Cold War, the world faces for the first time the need to dismantle vast numbers of ``excess`` nuclear weapons and dispose of the fissile materials they contain, together with fissile residues in the weapons production complex left over from the production of these weapons. If recently agreed US and Russian reductions are fully implemented, tens of thousands of nuclear weapons, containing a hundred tons or more of plutonium and hundreds of tonnes* of highly enriched uranium (HEU), will no longer be needed worldwide for military purposes. These two materials are the essential ingredients of nuclear weapons, and limits on access to them are the primary technical barrier to prospective proliferants who might desire to acquire a nuclear weapons capability. Theoretically, several kilograms of plutonium, or several times that amount of HEU, is sufficient to make a nuclear explosive device. Therefore, these materials will continue to be a potential threat to humanity for as long as they exist.

  5. Screening of candidate corrosion resistant materials for coal combustion environments -- Volume 4. Final report, January 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Boss, D.E.

    1997-12-31

    The development of a silicon carbide heat exchanger is a critical step in the development of the Externally-Fired Combined Cycle (EFCC) power system. SiC is the only material that provides the necessary combination of resistance to creep, thermal shock, and oxidation. While the SiC structural materials provide the thermomechanical and thermophysical properties needed for an efficient system, the mechanical properties of the SiC tubes are severely degraded through corrosion by the coal combustion products. To obtain the necessary service life of thousands of hours at temperature, a protective coating is needed that is stable with both the SiC tube and the coal combustion products, resists erosion from the particle laden gas stream, is thermal-shock resistant, adheres to SiC during repeated thermal shocks (start-up, process upsets, shut-down), and allows the EFCC system to be cost competitive. The candidate protective materials identified in a previous effort were screened for their stability to the EFCC combustion environment. Bulk samples of each of the eleven candidate materials were prepared, and exposed to coal slag for 100 hours at 1,370 C under flowing air. After exposure the samples were mounted, polished, and examined via x-ray diffraction, energy dispersive spectroscopy, and scanning electron microscopy. In general, the alumina-based materials behaved well, with comparable corrosion depths in all five samples. Magnesium chromite formed a series of reaction products with the slag, which included an alumina-rich region. These reaction products may act as a diffusion barrier to slow further reaction between the magnesium chromite and the slag and prove to be a protective coating. As for the other materials; calcium titanate failed catastrophically, the CS-50 exhibited extension microstructural and compositional changes, and zirconium titanate, barium zironate, and yttrium chromite all showed evidence of dissolution with the slag.

  6. A quantitative assessment of microbiological contributions to corrosion of candidate nuclear waste package materials

    International Nuclear Information System (INIS)

    The US Department of Energy is contributing to the design of a potential nuclear waste repository at Yucca Mountain, Nevada. A system to predict the contribution of Yucca Mountain (YM) bacteria to overall corrosion rates of candidate waste package (WP) materials was designed and implemented. DC linear polarization resistance techniques were applied to candidate material coupons that had been inoculated with a mixture of YM-derived bacteria with potentially corrosive activities, or left sterile. Inoculated bacteria caused a 5- to 6-fold increase in corrosion rate of carbon steel C1020 (to approximately 7--8 microm/yr), and an almost 100-fold increase in corrosion rate of Alloy 400 (to approximately 1 microm/yr) was observed due to microbiological activities. Microbiologically Influenced Corrosion (MIC) rates on more resistant materials (CRMs: Alloy 625, Type 304 Stainless Steel, and Alloy C22) were on the order of hundredths of micrometers per year (microm/yr). Bulk chemical and surfacial endpoint analyses of spent media and coupon surfaces showed preferential dissolution of nickel from Alloy 400 coupons and depletion of chromium from CRMs after incubation with YM bacteria. Scanning electron microscopy also showed greater damage to the Alloy 400 surface than that indicated by electrochemical detection methods

  7. Corrosion Assessment of Candidate Materials for the SHINE Subcritical Assembly Vessel and Components FY15 Report

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-01

    In the previous report of this series, a literature review was performed to assess the potential for substantial corrosion issues associated with the proposed SHINE process conditions to produce 99Mo. Following the initial review, substantial laboratory corrosion testing was performed emphasizing immersion and vapor-phase exposure of candidate alloys in a wide variety of solution chemistries and temperatures representative of potential exposure conditions. Stress corrosion cracking was not identified in any of the exposures up to 10 days at 80°C and 10 additional days at 93°C. Mechanical properties and specimen fracture face features resulting from slow-strain rate tests further supported a lack of sensitivity of these alloys to stress corrosion cracking. Fluid velocity was found not to be an important variable (0 to ~3 m/s) in the corrosion of candidate alloys at room temperature and 50°C. Uranium in solution was not found to adversely influence potential erosion-corrosion. Potentially intense radiolysis conditions slightly accelerated the general corrosion of candidate alloys, but no materials were observed to exhibit an annualized rate above 10 μm/y.

  8. Corrosion Assessment of Candidate Materials for the SHINE Subcritical Assembly Vessel and Components FY15 Report

    International Nuclear Information System (INIS)

    In the previous report of this series, a literature review was performed to assess the potential for substantial corrosion issues associated with the proposed SHINE process conditions to produce 99Mo. Following the initial review, substantial laboratory corrosion testing was performed emphasizing immersion and vapor-phase exposure of candidate alloys in a wide variety of solution chemistries and temperatures representative of potential exposure conditions. Stress corrosion cracking was not identified in any of the exposures up to 10 days at 80°C and 10 additional days at 93°C. Mechanical properties and specimen fracture face features resulting from slow-strain rate tests further supported a lack of sensitivity of these alloys to stress corrosion cracking. Fluid velocity was found not to be an important variable (0 to ∼3 m/s) in the corrosion of candidate alloys at room temperature and 50°C. Uranium in solution was not found to adversely influence potential erosion-corrosion. Potentially intense radiolysis conditions slightly accelerated the general corrosion of candidate alloys, but no materials were observed to exhibit an annualized rate above 10 μm/y.

  9. Scoping corrosion tests on candidate waste package basket materials for the Yucca Mountain project

    International Nuclear Information System (INIS)

    A scoping corrosion test was performed on candidate waste package basket materials. The corrosion medium was a pH-buffered solution of chemical species expected to be produced by radiolysis. The test was conducted at 90 C for 96 hours. Samples included aluminum-, copper-, stainless steel- and zirconium-based metallic materials and several ceramics, incorporating neutron-absorbing elements. Sample weight losses and solution chemical changes were measured. Both corrosion of the host materials and dissolution of the neutron-absorbing elements were studied. The ceramics and the zirconium-based materials underwent only minor corrosion. The stainless steel-based materials performed well except for a welded sample. The aluminum- and copper-based materials exhibited the highest corrosion rates. Boron dissolution depends on its chemical form. Boron oxide and many metal borides dissolve readily in acidic solutions while high-chromium borides and boron carbide, though thermodynamically unstable, exhibit little dissolution in short times. The results of solution chemical analyses were consistent with this. Gadolinium did not dissolve significantly from monazite, and hafnium showed little dissolution from a variety of host materials, in keeping with its low solubility

  10. Experimental results of angular neutron flux spectra leaking from slabs of fusion reactor candidate materials, (1)

    International Nuclear Information System (INIS)

    This report summarizes experimental data of angular neutron flux spectra measured on the slab assemblies of fusion reactor candidate materials using the neutron time-of-flight (TOF) method. These experiments have been performed for graphite (carbon), beryllium and lithium-oxide. The obtained data are very suitable for the benchmark tests to check the nuclear data and calculational code systems. For use of that purpose, the experimental conditions, definitions of key terms and results obtained are compiled in figures and numerical tables. (author)

  11. Evaluations of Structural Failure Probabilities and Candidate Inservice Inspection Programs

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, Mohammad A.; Simonen, Fredric A.

    2009-05-01

    The work described in this report applies probabilistic structural mechanics models to predict the reliability of nuclear pressure boundary components. These same models are then applied to evaluate the effectiveness of alternative programs for inservice inspection to reduce these failure probabilities. Results of the calculations support the development and implementation of risk-informed inservice inspection of piping and vessels. Studies have specifically addressed the potential benefits of ultrasonic inspections to reduce failure probabilities associated with fatigue crack growth and stress-corrosion cracking. Parametric calculations were performed with the computer code pc-PRAISE to generate an extensive set of plots to cover a wide range of pipe wall thicknesses, cyclic operating stresses, and inspection strategies. The studies have also addressed critical inputs to fracture mechanics calculations such as the parameters that characterize the number and sizes of fabrication flaws in piping welds. Other calculations quantify uncertainties associated with the inputs calculations, the uncertainties in the fracture mechanics models, and the uncertainties in the resulting calculated failure probabilities. A final set of calculations address the effects of flaw sizing errors on the effectiveness of inservice inspection programs.

  12. Evaluations of Structural Failure Probabilities and Candidate Inservice Inspection Programs

    International Nuclear Information System (INIS)

    The work described in this report applies probabilistic structural mechanics models to predict the reliability of nuclear pressure boundary components. These same models are then applied to evaluate the effectiveness of alternative programs for inservice inspection to reduce these failure probabilities. Results of the calculations support the development and implementation of risk-informed inservice inspection of piping and vessels. Studies have specifically addressed the potential benefits of ultrasonic inspections to reduce failure probabilities associated with fatigue crack growth and stress-corrosion cracking. Parametric calculations were performed with the computer code pc-PRAISE to generate an extensive set of plots to cover a wide range of pipe wall thicknesses, cyclic operating stresses, and inspection strategies. The studies have also addressed critical inputs to fracture mechanics calculations such as the parameters that characterize the number and sizes of fabrication flaws in piping welds. Other calculations quantify uncertainties associated with the inputs calculations, the uncertainties in the fracture mechanics models, and the uncertainties in the resulting calculated failure probabilities. A final set of calculations address the effects of flaw sizing errors on the effectiveness of inservice inspection programs.

  13. Structural materials for fusion magnets

    International Nuclear Information System (INIS)

    Of major technical and cost impact to Magnetic Fusion Energy development are the materials for the magnet structure. Those materials and fabrication techniques that are attractive to fusion magnets are discussed and relative comparisons made. Considerations such as strength, toughness, and joining techniques are balanced against recommended design criteria to reach an optimum design. Several examples of material selection are cited for large fusion magnets such as Base II, the Mirror Fusion Test Facility, the Toroidal Fusion Test Facility, and the Large Coil Project

  14. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys, CDA 102 (oxygen-free, high-purity copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni), are candidates for the fabrication of high-level radioactive-waste disposal containers. Waste will include spent fuel assemblies from reactors as well as borosilicate glass, and will be sent to the prospective repository site at Yucca Mountain in Nye County, Nevada. The decay of radionuclides will result in the generation of substantial heat and in fluxes of gamma radiation outside the containers. In this environment, container materials might degrade by atmospheric oxidation, general aqueous phase corrosion, localized corrosion (LC), and stress corrosion cracking (SCC). This volume is a critical survey of available data on pitting and crevice corrosion of the copper-based candidates. Pitting and crevice corrosion are two of the most common forms of LC of these materials. Data on the SCC of these alloys is surveyed in Volume 4. Pitting usually occurs in water that contains low concentrations of bicarbonate and chloride anions, such as water from Well J-13 at the Nevada Test Site. Consequently, this mode of degradation might occur in the repository environment. Though few quantitative data on LC were found, a tentative ranking based on pitting corrosion, local dealloying, crevice corrosion, and biofouling is presented. CDA 102 performs well in the categories of pitting corrosion, local dealloying, and biofouling, but susceptibility to crevice corrosion diminishes its attractiveness as a candidate. The cupronickel alloy, CDA 715, probably has the best overall resistance to such localized forms of attack. 123 refs., 11 figs., 3 tabs

  15. Behaviour of Structural Materials: Belgium

    International Nuclear Information System (INIS)

    For the development and qualification of structural materials for advanced and sustainable nuclear systems, the efforts are concentrated on the systems which are considered as priority for the Institute for Advanced Nuclear Systems. These are: accelerator driven systems where both the spallation source and the cooling medium is the liquid lead-bismuth eutecticum, lead cooled fast reactor (LFR) as a serious option for GEN IV systems. The material development and qualification activities are primarily concerned with the chemical and physical integrity of the selected materials when subjected to the expected but new harsh conditions. The issues that are being addressed and will be pursued in the future are: 1) the effects of irradiation on the material performance including spectrum, temperature and flux variations, 2) the specific compatibility issues related to application of these materials in the foreseen reactor environment especially under the synergetic effect of irradiation and 3) the modeling of these effects in order to be able to extrapolate the validity of the data to cover relevant operation conditions as no irradiation facility exist now a days that is able to reproduce the expected environment. The definition of these priority reactor systems focusses the research efforts on the high chromium ferritic–martensitic steels, austenitic stainless steels and oxide dispersion strengthened steels and alloys with emphasis on their fabricability, weldability and performance. This goal relies on the expertise, available from the activities along the research into radiation and ageing effects on structural materials for the currently operating nuclear power plants. This expertise covers databases on the behaviour of irradiated materials, validated test methods for evaluation of mechanical properties and environmental assisted cracking and models for prediction of radiation damage effects on the microstructure of the material and its effect on the material

  16. Study on corrosion behavior of candidate materials in 650℃ supercritical water

    International Nuclear Information System (INIS)

    The general corrosion behavior of three candidate materials (347, HR3C and In-718) was investigated in 650 ℃/25 MPa deionized water. Morphology and composition of the surface oxide film with different exposure time were observed through FEG-SEM and EDS. The phase constitute was analyzed by GIXRD. For all the test materials, the weight loss follows typical parabolic law and the weight loss of 347 shows more than 40 times higher than that of HR3C and In-718. The oxide film of three alloys mainly consists of Ni(Cr, Fe)2O4. In-718 shows severe pitting and the oxide film of 347 appears significant spalling, while HR3C has compact oxide film. In the high temperature supercritical water, the high Cr content may enhance the general corrosion property of the alloys, while addition of Nb may be detrimental to the pitting resistance of alloys. (authors)

  17. Creep rupture behavior of candidate materials for nuclear process heat applications

    International Nuclear Information System (INIS)

    Creep and stress rupture properties are determined for the candidate materials to be used in hightemperature gas-cooled reactor (HTGR) components. The materials and test methods are briefly described based on experimental results of test durations of about20000 h. The medium creep strengths of the alloys Inconel-617, Hastelloy-X, Nimonic-86, Hastelloy-S, Manaurite-36X, IN-519, and Incoloy-800H are compared showing that Inconel-617 has the best creep rupture properties in the temperature range above 8000C. The rupture time of welded joints is in the lower range of the scatterband of the parent metal. The properties determined in different simulated HTGR atmospheres are within the scatterband of the properties obtained in air. Extrapolation methods are discussed and a modified minimum commitment method is favored

  18. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Six alloys are being considered as possible materials for the fabrication of containers for the disposal of high-level radioactive waste. Three of these candidate materials are copper-based alloys: CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The other three are iron- to nickel-based austenitic materials: Types 304L and 316L stainless steels and Alloy 825. Radioactive waste will include spent-fuel assemblies from reactors as well as waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The waste-package containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, the containers must be retrievable from the disposal site. Shortly after emplacement of the containers in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This radiation will promote the radiolytic decomposition of moist air to hydrogen. This volume surveys the available data on the effects of hydrogen on the six candidate alloys for fabrication of the containers. For copper, the mechanism of hydrogen embrittlement is discussed, and the effects of hydrogen on the mechanical properties of the copper-based alloys are reviewed. The solubilities and diffusivities of hydrogen are documented for these alloys. For the austenitic materials, the degradation of mechanical properties by hydrogen is documented. The diffusivity and solubility of hydrogen in these alloys are also presented. For the copper-based alloys, the ranking according to resistance to detrimental effects of hydrogen is: CDA 715 (best) > CDA 613 > CDA 102 (worst). For the austenitic alloys, the ranking is: Type 316L stainless steel ∼ Alloy 825 > Type 304L stainless steel (worst). 87 refs., 19 figs., 8 tabs

  19. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers

    International Nuclear Information System (INIS)

    Oxidation and atmospheric corrosion data suggest that addition of Cr provides the greatest improvement in oxidation resistance. Cr-bearing cast irons are resistant to chloride environments and solutions containing strongly oxidizing constituents. Weathering steels, including high content and at least 0.04% Cu, appear to provide adequate resistance to oxidation under temperate conditions. However, data from long-term, high-temperature oxidation studies on weathering steels were not available. From the literature, it appears that the low alloy steels, plain carbon steels, cast steels, and cast irons con-ode at similar rates in an aqueous environment. Alloys containing more than 12% Cr or 36% Ni corrode at a lower rate than plain carbon steels, but pitting may be worse. Short term tests indicate that an alloy of 9Cr-1Mo may result in increased corrosion resistance, however long term data are not available. Austenitic cast irons show the best corrosion resistance. A ranking of total corrosion performance of the materials from most corrosion resistant to least corrosion resistant is: Austenitic Cast Iron; 12% Cr = 36% Ni = 9Cr-1Mo; Carbon Steel = Low Alloy Steels; and Cast Iron. Since the materials to be employed in the Advanced Conceptual Design (ACD) waste package are considered to be corrosion allowance materials, the austenitic cast irons, high Cr steels, high Ni steels and the high Cr-Mo steels should not be considered as candidates for the outer containment barrier. Based upon the oxidation and corrosion data available for carbon steels, low alloy steels, and cast irons, a suitable list of candidate materials for a corrosion allowance outer barrier for an ACD waste package could include, A516, 2.25%Cr -- 1%Mo Steel, and A27

  20. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Vinson, D.W.; Nutt, W.M.; Bullen, D.B. [Iowa State Univ. of Science and Technology, Ames, IA (United States)

    1995-06-01

    Oxidation and atmospheric corrosion data suggest that addition of Cr provides the greatest improvement in oxidation resistance. Cr-bearing cast irons are resistant to chloride environments and solutions containing strongly oxidizing constituents. Weathering steels, including high content and at least 0.04% Cu, appear to provide adequate resistance to oxidation under temperate conditions. However, data from long-term, high-temperature oxidation studies on weathering steels were not available. From the literature, it appears that the low alloy steels, plain carbon steels, cast steels, and cast irons con-ode at similar rates in an aqueous environment. Alloys containing more than 12% Cr or 36% Ni corrode at a lower rate than plain carbon steels, but pitting may be worse. Short term tests indicate that an alloy of 9Cr-1Mo may result in increased corrosion resistance, however long term data are not available. Austenitic cast irons show the best corrosion resistance. A ranking of total corrosion performance of the materials from most corrosion resistant to least corrosion resistant is: Austenitic Cast Iron; 12% Cr = 36% Ni = 9Cr-1Mo; Carbon Steel = Low Alloy Steels; and Cast Iron. Since the materials to be employed in the Advanced Conceptual Design (ACD) waste package are considered to be corrosion allowance materials, the austenitic cast irons, high Cr steels, high Ni steels and the high Cr-Mo steels should not be considered as candidates for the outer containment barrier. Based upon the oxidation and corrosion data available for carbon steels, low alloy steels, and cast irons, a suitable list of candidate materials for a corrosion allowance outer barrier for an ACD waste package could include, A516, 2.25%Cr -- 1%Mo Steel, and A27.

  1. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-08-01

    Six alloys are being considered as possible materials for the fabrication of containers for the disposal of high-level radioactive waste. Three of these candidate materials are copper-based alloys: CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The other three are iron- to nickel-based austenitic materials: Types 304L and 316L stainless steels and Alloy 825. Radioactive waste will include spent-fuel assemblies from reactors as well as waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The waste-package containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, the containers must be retrievable from the disposal site. Shortly after emplacement of the containers in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This radiation will promote the radiolytic decomposition of moist air to hydrogen. This volume surveys the available data on the effects of hydrogen on the six candidate alloys for fabrication of the containers. For copper, the mechanism of hydrogen embrittlement is discussed, and the effects of hydrogen on the mechanical properties of the copper-based alloys are reviewed. The solubilities and diffusivities of hydrogen are documented for these alloys. For the austenitic materials, the degradation of mechanical properties by hydrogen is documented. The diffusivity and solubility of hydrogen in these alloys are also presented. For the copper-based alloys, the ranking according to resistance to detrimental effects of hydrogen is: CDA 715 (best) > CDA 613 > CDA 102 (worst). For the austenitic alloys, the ranking is: Type 316L stainless steel {approx} Alloy 825 > Type 304L stainless steel (worst). 87 refs., 19 figs., 8 tabs.

  2. Charge, spin and orbital order in the candidate multiferroic material LuFe2O4

    International Nuclear Information System (INIS)

    This thesis is a detailed study of the magnetic, structural and orbital order parameters of the candidate multiferroic material LuFe2O4. Multiferroic oxides with a strong magnetoelectric coupling are of high interest for potential information technology applications, but they are rare because the traditional mechanism of ferroelectricity is incompatible with magnetism. Consequently, much attention is focused on various unconventional mechanisms of ferroelectricity. Of these, ferroelectricity originating from charge ordering (CO) is particularly intriguing because it potentially combines large electric polarizations with strong magneto-electric coupling. However, examples of oxides where this mechanism occurs are exceedingly rare and none is really well understood. LuFe2O4 is often cited as the prototypical example of CO-based ferroelectricity. In this material, the order of Fe valences has been proposed to render the triangular Fe/O bilayers polar by making one of the two layers rich in Fe2+ and the other rich in Fe3+, allowing for a possible ferroelectric stacking of the individual bilayers. Because of this new mechanism for ferroelectricity, and also because of the high transition temperatures of charge order (TCO ∝320K) and ferro magnetism (TN∝240 K) LuFe2O4 has recently attracted increasing attention. Although these polar bilayers are generally accepted in the literature for LuFe2O4, direct proof is lacking. An assumption-free experimental determination of whether or not the CO in the Fe/O bilayers is polar would be crucial, given the dependence of the proposed mechanism of ferroelectricity from CO in LuFe2O4 on polar bilayers. This thesis starts with a detailed characterization of the macroscopic magnetic properties, where growing ferrimagnetic contributions observed in magnetization could be ascribed to increasing oxygen off-stoichiometry. The main focus is on samples exhibiting a sharp magnetic transition to long-range spin order at TN∝240 K

  3. Candidate BCR reference materials for arsenic and selenium determinations in human serum and urine

    International Nuclear Information System (INIS)

    The pilot production of candidate reference materials for the quality assurance and statistical control of methods to determine toxic trace elements in biological samples is described. In the initial phase the project concerns a lyophilized human blood material containing Cd and Pb, a lyophilized human urine material containing As, Cd, Co and Cr, and a liquid human serum material with Al, Se and Zn at three different levels, representative of environmental and occupational exposure. The homogeneity and stability of the pilot batches were investigated by determining Al and Zn in serum, As in urine, Cd and Pb in blood at the medium level. The pilot batches produced were deemed to be homogeneous with respect to all the trace elements tested, and there was no indication of thermal instability except that the arsenic levels decreased significantly with time at 200 deg., 370 deg. and 450 deg. C. Thirty-two laboratories from 12 different countries participated in an intercomparison round organized to test the suitability of the reference material and validate the methodological approaches for certification purposes. Focusing on the neutron activation results, the outcome of this first intercomparison exercise demonstrates that the comparability of the calibration standards needs improvement. Therefore, for the certification round stronger efforts will be undertaken to document the spiked concentrations and to reduce their uncertainties, and the laboratories will be required to meet defined quality criteria for the checking and documentation of traceability. (author)

  4. Radiation damage of structural materials

    CERN Document Server

    Koutsky, Jaroslav

    1994-01-01

    Maintaining the integrity of nuclear power plants is critical in the prevention or control of severe accidents. This monograph deals with both basic groups of structural materials used in the design of light-water nuclear reactors, making the primary safety barriers of NPPs. Emphasis is placed on materials used in VVER-type nuclear reactors: Cr-Mo-V and Cr-Ni-Mo-V steel for RPV and Zr-Nb alloys for fuel element cladding. The book is divided into 7 main chapters, with the exception of the opening one and the chapter providing a phenomenological background for the subject of radiation damage. Ch

  5. Structural materials challenges for advanced reactor systems

    Science.gov (United States)

    Yvon, P.; Carré, F.

    2009-03-01

    Key technologies for advanced nuclear systems encompass high temperature structural materials, fast neutron resistant core materials, and specific reactor and power conversion technologies (intermediate heat exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes, etc.). The main requirements for the materials to be used in these reactor systems are dimensional stability under irradiation, whether under stress (irradiation creep or relaxation) or without stress (swelling, growth), an acceptable evolution under ageing of the mechanical properties (tensile strength, ductility, creep resistance, fracture toughness, resilience) and a good behavior in corrosive environments (reactor coolant or process fluid). Other criteria for the materials are their cost to fabricate and to assemble, and their composition could be optimized in order for instance to present low-activation (or rapid desactivation) features which facilitate maintenance and disposal. These requirements have to be met under normal operating conditions, as well as in incidental and accidental conditions. These challenging requirements imply that in most cases, the use of conventional nuclear materials is excluded, even after optimization and a new range of materials has to be developed and qualified for nuclear use. This paper gives a brief overview of various materials that are essential to establish advanced systems feasibility and performance for in pile and out of pile applications, such as ferritic/martensitic steels (9-12% Cr), nickel based alloys (Haynes 230, Inconel 617, etc.), oxide dispersion strengthened ferritic/martensitic steels, and ceramics (SiC, TiC, etc.). This article gives also an insight into the various natures of R&D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, lab-scale tests to characterize candidate materials

  6. Application of INAA complementary gamma ray photopeaks to homogeneity study of candidate reference materials

    International Nuclear Information System (INIS)

    Characterization and certification of reference materials, RMs, is a complex task involving many steps. One of them is the homogeneity testing to assure that key property values will not present variation among RM bottles. Good precision is the most important figure of merit of an analytical technique to allow it to be used in the homogeneity testing of candidate RMs. Due to its inherent characteristics, Instrumental Neutron Activation Analysis, INAA, is an analytical technique of choice for homogeneity testing. Problems with sample digestion and contamination from reagents are not an issue in INAA, as solid samples are analyzed directly. For element determination via INAA, the activity of a suitable gamma ray decay photopeak for an element is chosen and it is compared to the activity of a standard of the element. An interesting possibility is the use of complementary gamma ray photopeaks (for the elements that present them) to confirm the homogeneity test results for an element. In this study, an investigation of the use of the complementary gamma ray photopeaks of 110mAg, 82Br, 60Co, 134Cs, 152Eu, 59Fe, 140La, 233Pa (for Th determination), 46Sc and 75Se radionuclides was undertaken in the between bottle homogeneity study of a mussel candidate RM under preparation at IPEN - CNEN/SP. Although some photopeaks led to biased element content results, the use of complementary gamma ray photopeaks proved to be helpful in supporting homogeneity study conclusions of new RMs. (author)

  7. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-08-01

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of containers for disposal of high-level radioactive waste. This waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, they must be retrievable from the disposal site. Shortly after the containers are emplaced in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of the high-level waste. This volume surveys the available data on oxidation and corrosion of the iron- to nickel-based austenitic materials (Types 304L and 316L stainless steels and Alloy 825) and the copper-based alloy materials (CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni)), which are the present candidates for fabrication of the containers. Studies that provided a large amount of data are highlighted, and those areas in which little data exists are identified. Examples of successful applications of these materials are given. On the basis of resistance to oxidation and general corrosion, the austenitic materials are ranked as follows: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is as follows: CDA 715 and CDA 613 (both best), and CDA 102 (worst). 110 refs., 30 figs., 13 tabs.

  8. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of containers for disposal of high-level radioactive waste. This waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, they must be retrievable from the disposal site. Shortly after the containers are emplaced in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of the high-level waste. This volume surveys the available data on oxidation and corrosion of the iron- to nickel-based austenitic materials (Types 304L and 316L stainless steels and Alloy 825) and the copper-based alloy materials [CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni)], which are the present candidates for fabrication of the containers. Studies that provided a large amount of data are highlighted, and those areas in which little data exists are identified. Examples of successful applications of these materials are given. On the basis of resistance to oxidation and general corrosion, the austenitic materials are ranked as follows: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is as follows: CDA 715 and CDA 613 (both best), and CDA 102 (worst). 110 refs., 30 figs., 13 tabs

  9. Preparation and evaluation of the homogeneity of milk as a candidate reference material for carbon-14

    International Nuclear Information System (INIS)

    A pilot project was initiated to study the feasibility of preparing milk as a candidate reference material for 14C near environmental levels. Two materials, MK-B at natural level of 14C and MK-C4 at an elevated level, have been prepared from pasteurized 2% dairy milk. MK-C4 was spiked with an appropriate amount of 14C-methylated casein tracer to achieve the elevated level. Several samples from MK-B and MK-C4 have been analyzed to test the homogeneity of these materials for the distribution of 14C. The samples were combusted in oxygen under 20 atmospheres pressure using a Parr bomb. The 14C concentrations were determined by liquid scintillation counting using Carbo-Sorb/Permafluor E+ cocktail. The results indicate that these materials are homogeneous with respect to 14C concentration even in sub-sample sizes of 0.25 g of the freeze-dried material. The precision of our 14C measurements, as expressed by the % relative standard deviation, is within 5%. The accuracy has been tested by analyzing replicate samples of the IAEA 14C quality assurance materials, C-3 (cellulose) and C-6 (ANU sucrose) and found to be within 3%. The lower limits of detection are 0.08, 0.05 and 0.02 Bq.g-1 of carbon for 20 ml of liquid scintillation mixture (Carbo-Sorb/Permafluor E+ = ∼0.67) loaded with up to 0.4g of carbon from the sample and counted for 3 cycles of 60, 180 and 1000 min each, respectively. Our measurements of 14C specific activities of MK-B and MK-C4 are 0.26 ± 0.01 and 15.3 ± 0.4 Bq.g-1 of carbon, respectively. (author)

  10. New π-Conjugated Materials Based on Furylenevinylene Candidate for Organic Solar Cells Application: A DFT Study

    Directory of Open Access Journals (Sweden)

    El Alamy Aziz

    2015-12-01

    Full Text Available The specific properties of organic-conjugated molecules and polymers are of great importance since they have become the most promising materials for the optoelectronic device technology such as solar cells. The use of low band gap materials is a viable method for better harvesting of the solar spectrum and increasing its efficiency. The control of the parameters of these materials is a research issue of ongoing interest. In this work, a quantum chemical investigation was performed to explore the optical and electronic properties of a series of different compounds based on furylenevinylene. Different electron side groups were introduced to investigate their effects on the electronic structure. The theoretical knowledge of the highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO energy levels of the components is basic in studying organic solar cells; so the HOMO, LUMO, Gap energy and open circuit voltage (Voc of the studied compounds have been calculated and reported. These properties suggest that these materials behave as good candidate for organic solar cells. DOI: http://dx.doi.org/10.17807/orbital.v7i4.763 

  11. IDMS studies on sodalite - a candidate material for nuclear waste containment

    International Nuclear Information System (INIS)

    Nuclear waste management is one of the important aspects of nuclear fuel cycle from environmental and safety considerations. Different forms of waste storage matrices are known to be applicable for different kinds of nuclear wastes. Glass bonded sodalite (GBS) (Na8(AISiO4)6Cl2), a glass-ceramic, is a promising candidate for the immobilization of the chloride waste resulting from pyrometallurgical reprocessing of nuclear fuels. Characterization of individual components is essential for the development of this waste storage material which is expected to encounter different physicochemical conditions. For this purpose, we have undertaken studies to determine the concentrations of individual components in GBS employing Isotope Dilution Mass Spectrometry (IDMS) owing to its capability to ensure precise and accurate data for multi element analysis in a matrix

  12. Thermo-Optical and Mechanical Property Testing of Candidate Solar Sail Materials

    Science.gov (United States)

    Hollerman, WIlliam A.; Stanaland, T. L.; Womack, F.; Edwards, David; Hubbs, Whitney; Semmel, Charles

    2003-01-01

    Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions, enabling new concepts that are difficult by conventional means. The National Aeronautics and Space Administration's Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra-lightweight materials for spacecraft propulsion. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate sails to evaluate the thermo-optical and mechanical properties after exposure to electrons. This poster will discuss the preliminary results of this research.

  13. Global blending optimization of laminated composites with discrete material candidate selection and thickness variation

    DEFF Research Database (Denmark)

    Sørensen, Søren N.; Stolpe, Mathias

    2015-01-01

    distinct choice among predefined numbers of candidates. The laminate thickness is variable but the number of plies must be integer. We solve the convex mixed binary non-linear programming problem by an outer approximation cutting-plane method augmented with a few heuristics to accelerate the convergence...... but is, however, convex in the original mixed binary nested form. Convexity is the foremost important property of optimization problems, and the proposed method can guarantee the global or near-global optimal solution; unlike most topology optimization methods. The material selection is limited to a...... rate. The capabilities of the method and the effect of active versus inactive manufacturing constraints are demonstrated on several numerical examples of limited size, involving at most 320 binary variables. Most examples are solved to guaranteed global optimality and may constitute benchmark examples...

  14. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Strum, M.J.; Weiss, H.; Farmer, J.C. (Lawrence Livermore National Lab., CA (USA)); Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-06-01

    This volume surveys the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825. These materials are candidates for the fabrication of containers for the long-term storage of high-level nuclear waste. The metallurgical characteristics of fusion welds are reviewed here and related to potential degradation modes of the containers. Three specific areas are discussed in depth: (1) decreased resistance to corrosion in the forms of preferential corrosion, sensitization, and susceptibility to stress corrosion cracking, (2) hot cracking in the heat-affected zone and the weld zone, and (3) formation of intermetallic phases. The austenitic alloys are ranked as follows in terms of overall weldability: Alloy 825 (best) > Type 316L stainless steel > Type 304L stainless steel (worst). 108 refs., 31 figs., 7 tabs.

  15. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    This volume surveys the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825. These materials are candidates for the fabrication of containers for the long-term storage of high-level nuclear waste. The metallurgical characteristics of fusion welds are reviewed here and related to potential degradation modes of the containers. Three specific areas are discussed in depth: (1) decreased resistance to corrosion in the forms of preferential corrosion, sensitization, and susceptibility to stress corrosion cracking, (2) hot cracking in the heat-affected zone and the weld zone, and (3) formation of intermetallic phases. The austenitic alloys are ranked as follows in terms of overall weldability: Alloy 825 (best) > Type 316L stainless steel > Type 304L stainless steel (worst). 108 refs., 31 figs., 7 tabs

  16. 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.

  17. A three-dimensional measurement method based on mesh candidates assisted with structured light

    Science.gov (United States)

    Xu, Gang; Zhang, Wenming; Li, Haibin; Liu, Bin

    2009-07-01

    Rendering three-dimensional information of a scene from optical measurement is very important for a wide variety of applications such as robot navigation, rapid prototyping, medical imaging, industrial inspection, etc. In this paper, a new 3D measurement method based on mesh candidate with structured light illuminating is proposed. The vision sensor consists of two CCD cameras and a DLP projector. The measurement system combines the technology of binocular stereo vision and structured light, so as to simplify the process of acquiring depth information using mesh candidates. The measurement method is based on mesh candidates which represent the potential depth in the three dimensional scene. First the mesh grid was created along the direction of axes in world coordinate system, and the nodes were considered as depth candidates on the surface of object. Then each group of the mesh nodes varying along z axis were mapped to the captured image planes of both cameras. At last, according to the similarity measure of the corresponding pixel pairs, the depth of the object surface can be obtained. The matching process is between the pixels in both camera planes corresponding to the spatial mesh candidates. Aided by the structured light pattern, the accuracy of measurement system improved. Appending the periodic sawtooth pattern on the scene by structured light made measurement easier, while the computational cost did not increased since the projector had no need to be calibrated. The 3DS MAX and Matlab software were used to simulate measurement system and reconstruct the surface of the object. After the positioned cameras have been calibrated using Matlab calibration toolbox, the projector is used to project structured light pattern on the scene. Indicated by experimental results, the mesh-candidate-based method is obviously superior in computation and accuracy. Compared with traditional methods based on image matching, our method has several advantages: (1) the complex

  18. Emissivity of Candidate Materials for VHTR Applicationbs: Role of Oxidation and Surface Modification Treatments

    International Nuclear Information System (INIS)

    The Generation IV (GEN IV) Nuclear Energy Systems Initiative was instituted by the Department of Energy (DOE) with the goal of researching and developing technologies and materials necessary for various types of future reactors. These GEN IV reactors will employ advanced fuel cycles, passive safety systems, and other innovative systems, leading to significant differences between these future reactors and current water-cooled reactors. The leading candidate for the Next Generation Nuclear Plant (NGNP) to be built at Idaho National Lab (INL) in the United States is the Very High Temperature Reactor (VHTR). Due to the high operating temperatures of the VHTR, the Reactor Pressure Vessel (RPV) will partially rely on heat transfer by radiation for cooling. Heat expulsion by radiation will become all the more important during high temperature excursions during off-normal accident scenarios. Radiant power is dictated by emissivity, a material property. The NGNP Materials Research and Development Program Plan (1) has identified emissivity and the effects of high temperature oxide formation on emissivity as an area of research towards the development of the VHTR.

  19. Short-term stability test for thorium soil candidate a reference material

    Energy Technology Data Exchange (ETDEWEB)

    Clain, Almir F.; Fonseca, Adelaide M.G.; Dantas, Vanessa V.D.B.; Braganca, Maura J.C.; Souza, Poliana S., E-mail: almir@ird.gov.br, E-mail: adelaide@ird.gov.br, E-mail: vanessa@ird.gov.br, E-mail: maura@ird.gov.br, E-mail: poliana@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This work describes a methodology to determine the soil short-term stability after the steps of production in laboratory. The short-term stability of the soil is an essential property to be determined in order to producing a reference material. The soil is a candidate of reference material for chemical analysis of thorium with metrological traceability to be used in environmental analysis, equipment calibration, validation methods, and quality control. A material is considered stable in a certain temperature if the property of interest does not change with time, considering the analytical random fluctuations. Due to this, the angular coefficient from the graphic of Th concentration versus elapsed time must be near to zero. The analytical determinations of thorium concentration were performed by Instrumental Neutron activation Analysis. The slopes and their uncertainties were obtained from the regression lines at temperatures of 20 deg C and 60 deg C, with control temperature of -20 deg C. From the obtained data a t-test was applied. In both temperatures the calculated t-value was lower than the critical value, so we can conclude with 95% confidence level that no significant changes happened during the period studied concerning thorium concentration in soil at temperatures of 20 deg C and 60 deg C, showing stability at these temperatures. (author)

  20. LONG-TERM CORROSION TESTING OF CANDIDATE MATERIALS FOR HIGH-LEVEL RADIOACTIVE WASTE CONTAINMENT

    International Nuclear Information System (INIS)

    Preliminary results are presented from the long-term corrosion test program of candidate materials for the high-level radioactive waste packages that would be emplaced in the potential repository at Yucca Mountain, Nevada. The present waste package design is based on a multi-barrier concept having an inner container of a corrosion resistant material and an outer container of a corrosion allowance material. Test specimens have been exposed to simulated bounding environments that may credibly develop in the vicinity of the waste packages. Corrosion rates have been calculated for weight loss and crevice specimens, and U-bend specimens have been examined for evidence of stress corrosion cracking (SCC). Galvanic testing has been started recently and initial results are forthcoming. Pitting characterization of test specimens will be conducted in the coming year. This test program is expected to continue for a minimum of five years so that long-term corrosion data can be determined to support corrosion model development, performance assessment, and waste package design

  1. Emissivity of Candidate Materials for VHTR Applicationbs: Role of Oxidation and Surface Modification Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Anderson, Mark; Cao, Guoping; Kulcinski, Gerald

    2011-07-25

    The Generation IV (GEN IV) Nuclear Energy Systems Initiative was instituted by the Department of Energy (DOE) with the goal of researching and developing technologies and materials necessary for various types of future reactors. These GEN IV reactors will employ advanced fuel cycles, passive safety systems, and other innovative systems, leading to significant differences between these future reactors and current water-cooled reactors. The leading candidate for the Next Generation Nuclear Plant (NGNP) to be built at Idaho National Lab (INL) in the United States is the Very High Temperature Reactor (VHTR). Due to the high operating temperatures of the VHTR, the Reactor Pressure Vessel (RPV) will partially rely on heat transfer by radiation for cooling. Heat expulsion by radiation will become all the more important during high temperature excursions during off-normal accident scenarios. Radiant power is dictated by emissivity, a material property. The NGNP Materials Research and Development Program Plan [1] has identified emissivity and the effects of high temperature oxide formation on emissivity as an area of research towards the development of the VHTR.

  2. Short-term stability test for thorium soil candidate a reference material

    International Nuclear Information System (INIS)

    This work describes a methodology to determine the soil short-term stability after the steps of production in laboratory. The short-term stability of the soil is an essential property to be determined in order to producing a reference material. The soil is a candidate of reference material for chemical analysis of thorium with metrological traceability to be used in environmental analysis, equipment calibration, validation methods, and quality control. A material is considered stable in a certain temperature if the property of interest does not change with time, considering the analytical random fluctuations. Due to this, the angular coefficient from the graphic of Th concentration versus elapsed time must be near to zero. The analytical determinations of thorium concentration were performed by Instrumental Neutron activation Analysis. The slopes and their uncertainties were obtained from the regression lines at temperatures of 20 deg C and 60 deg C, with control temperature of -20 deg C. From the obtained data a t-test was applied. In both temperatures the calculated t-value was lower than the critical value, so we can conclude with 95% confidence level that no significant changes happened during the period studied concerning thorium concentration in soil at temperatures of 20 deg C and 60 deg C, showing stability at these temperatures. (author)

  3. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of high-level radioactive-waste disposal containers. The waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The copper-based alloy materials are CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The austenitic materials are Types 304L and 316L stainless steels and Alloy 825. The waste-package containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr, and they must be retrievable from the disposal site during the first 50 yr after emplacement. The containers will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This volume surveys the available data on the phase stability of both groups of candidate alloys. The austenitic alloys are reviewed in terms of the physical metallurgy of the iron-chromium-nickel system, martensite transformations, carbide formation, and intermetallic-phase precipitation. The copper-based alloys are reviewed in terms of their phase equilibria and the possibility of precipitation of the minor alloying constituents. For the austenitic materials, the ranking based on phase stability is: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is: CDA 102 (oxygen-free copper) (best), and then both CDA 715 and CDA 613. 75 refs., 24 figs., 6 tabs

  4. Pelamis WEC - main body structural design and materials selection

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, C.

    2003-07-01

    This report summarises the results of a study evaluating the potential use of rolled steel, glass reinforced plastic, wood-epoxy laminate, and different forms of concrete as primary structural materials for the Pelamis Wave Energy Converter (WEC) as part of a strategy to refine the design by highlighting cost savings for long-term manufacture. Details are given of the drawing up of a load spectrum in order to assess the candidate structures, the choice of glass reinforced plastic, concrete, and steel for further evaluation based on preliminary screening, the assessment of the material requirements for each candidate structure, and cost estimates. The advantages of the use of concrete are discussed and recommendations are presented.

  5. Physical oceanographic processes at candidate dredged-material disposal sites B1B and 1M offshore San Francisco

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, C.R.; Denbo, D.W.; Downing, J.P. (Pacific Northwest Lab., Richland, WA (USA)); Coats, D.A. (Marine Research Specialists, Ventura, CA (USA))

    1990-10-01

    The US Army Corps of Engineers (USACE), San Francisco District, has identified two candidate sites for ocean disposal of material from several dredging projects in San Francisco Bay. The disposal site is to be designated under Section 103 of the Ocean Dumping Act. One of the specific criteria in the Ocean Dumping Act is that the physical environments of the candidate sites be considered. Toward this goal, the USACE requested that the Pacific Northwest Laboratory conduct a study of physical oceanographic and sediment transport processes at the candidate sites, B1B and 1M. The results of that study are presented in this report. 40 refs., 27 figs., 10 tabs.

  6. Assessment of commutability for candidate certified reference material ERM-BB130 "chloramphenicol in pork".

    Science.gov (United States)

    Zeleny, Reinhard; Emteborg, Håkan; Schimmel, Heinz

    2010-10-01

    Chloramphenicol (CAP), an effective antibiotic against many microorganisms, is meanwhile banned in the EU for treatment of food-producing animals due to adverse health effects. The Institute for Reference Materials and Measurements (IRMM) is currently developing a certified reference material (CRM) for CAP in pork, intended for validation and method performance verifications of analytical methods. The material will be certified using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) methods and has a target CAP level around the minimum required performance limit (MRPL) of 0.3 microg/kg. To prove that the material can be applied as a quality control tool for screening methods, a commutability study was conducted, involving five commercially available enzyme-linked immunosorbent assay kits and one biosensor assay (BiaCore kit). Meat homogenates (cryo-milled wet tissue) with CAP concentrations around the MRPL and the candidate CRM (lyophilised powder) were measured by LC-MS/MS and GC-MS as well as the six screening methods. Pairwise method comparisons of results obtained for the two sample types showed that the CRM can successfully be applied as quality control (QC) sample to all six screening methods. The study suggests that ERM-BB130 is sufficiently commutable with the investigated assays and that laboratories applying one of the investigated kits therefore benefit from using ERM-BB130 to demonstrate the correctness of their results. However, differences among the assays were observed, either in the abundance of bias between screening and confirmatory LC and GC methods, the repeatability of test results, or goodness of fit between the methods. PMID:20665007

  7. Transient Scuffing of Candidate Diesel Engine Materials at Temperatures up to 600oC

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.

    2003-06-20

    This milestone report summarizes the general characteristics of scuffing damage to solid surfaces, then describes transient effects on scuffing observed during oscillating sliding wear tests of candidate material pairs for high-temperature diesel engine applications, like waste-gate bushings in exhaust gas recirculation (EGR) systems. It is shown that oxidation and the formation of wear particle layers influence the friction of such components. In the case of metallic materials in cylindrical contacts where there is a generous clearance, debris layers can form which reduce the torque over time. For ceramic combinations, the opposite effect is observed. Here, the accumulation of wear debris leads to an increase in the turning torque. High-temperature transient scuffing behavior is considered in terms of a series of stages in which the composition and morphology of the contact is changing. These changes are used to explain the behavior of 11 material pairs consisting of stainless steels, Ni-based alloys, Co-based alloys, and structural ceramics.

  8. Investigation on candidates of principal facilities for exposure dose to public for the facilities using nuclear material

    International Nuclear Information System (INIS)

    HTTR holds the nuclear fuel material use facilities in its reactor facilities, for the purpose of study on the fracture behavior of fuel and release behavior of fission products, development of high-performance fuel, and measurement of neutron flux. Due to the revision of the 'Act on the regulation of nuclear source material, nuclear fuel material and reactor', the facilities having the 'Important safety-related facilities' among the facilities applicable to the Enforcement Ordinance Article 41 (Article 41 facilities) has come to need to conform to the 'Regulations concerning standards for the location, structure, and equipment of used facilities and others'. In this case, actions such as modification by all possible means are required. The nuclear fuel substance use facilities of HTTR correspond to Article 41 facilities. So, whether it is a candidate for the 'Important safety-related facilities' has been examined. As a result, it is confirmed that the facilities are not correspond to the 'Important safety-related facilities', and it has been concluded that modification measures for the purpose of conforming to this approval standard rule are not necessary as of the present. (A.O.)

  9. 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.

  10. Superconducting Gamma/Neutron Spectrometer Task 1 Completion Report Evaluation of Candidate Neutron-Sensitive Materials

    CERN Document Server

    Bell, Z W

    2002-01-01

    A review of the scientific literature regarding boron- and lithium-containing compounds was completed. Information such as Debye temperature, heat capacity, superconductivity properties, physical and chemical characteristics, commercial availability, and recipes for synthesis was accumulated and evaluated to develop a list of neutron-sensitive materials likely to perform properly in the spectrometer. The best candidate borides appear to be MgB sub 2 (a superconductor with T sub c = 39 K), B sub 6 Si, B sub 4 C, and elemental boron; all are commercially available. Among the lithium compounds are LiH, LiAl, Li sub 1 sub 2 Si sub 7 , and Li sub 7 Sn sub 2. These materials have or are expected to have high Debye temperatures and sufficiently low heat capacities at 100 mK to produce a useful signal. The responses of sup 1 sup 0 B and sup 6 Li to a fission neutron spectrum were also estimated. These demonstrated that the contribution of scattering events is no more than 3% in a boron-based system and 1.5% in a lith...

  11. The rheology of structured materials

    Science.gov (United States)

    Sun, Ning

    2000-10-01

    In this work, the rheological properties of structured materials are studied via both theoretical (continuum mechanics and molecular theory) and experimental approaches. Through continuum mechanics, a structural model, involving shear-induced structural breakdown and buildup, is extended to model biofluids. In particular, we study the cases of steady shear flow, hysteresis, yield stress, small amplitude oscillatory flow as well as non-linear viscoelasticity. Model predictions are successfully compared with experimental data on complex materials such as blood and a penicillin suspension. Next, modifications are introduced into the network model. A new formulation involving non-affine motion is proposed and its applications are presented. The major improvement is that a finite elongational viscosity is predicted for finite elongational rate, contrary to infinite elongational viscosities existing at some elongational rates predicted by most previous network models. Comparisons with experimental data on shear viscosity, primary normal stress coefficient and elongational viscosity are given, in terms of the same set of model parameters. Model predictions for the stress growth are also shown. The model is successfully tested with data on a polyisobutylene solution (S1), on a polystyrene solution and on a poly-alpha-methylstyrene solution. A further extension of the network model is related to the prediction of the stress jump phenomenon which is defined as the instantaneous gain or loss of stress on startup or cessation of a deformation. It is not predicted by most existing models. In this work, the internal viscosity idea used in the dumbbell model is incorporated into the transient network model. Via appropriate approximations, a closed form constitutive equation, which predicts a stress jump, is obtained. Successful comparisons with the available stress jump measurements are given. In addition, the model yields good quantitative predictions of the standard steady

  12. Biocompatibility and characterisation of a candidate microelectrode material for biosensor applications

    International Nuclear Information System (INIS)

    Recent advances in microcircuit technology have enabled the fabrication of Multiple Microelectrode Arrays (MEAs) for investigating the characteristics of networks of neuronal cells either in vivo or in vitro. When producing a MEA materials used must be corrosion resistant, have low electrical impedance and the materials must be biocompatible. Existing MEA's have limited life spans, relatively high impedance values and limited uses. Thus creating a requirement for new MEA technology. TiN thin films have become increasingly useful in a wide variety of applications, due to their nature, which includes chemical stability, high hardness, excellent wear and electrical properties and also biocompatibility. The favourable electrical and biocompatibility characteristics of thin films of TiN make them a possible candidate for use in a MEA. TiN thin films can be deposited by a number of methods including evaporation, ion plating and sputtering. The method of deposition, along with process parameters used can have a marked effect on the characteristics of TiN films, including changes in preferred orientation, hardness and wear and also biocompatibility. TiN thin films were deposited onto glass substrates by pulsed DC reactive sputtering of a Ti target, with Argon and nitrogen gas mixtures and labelled Type I TiN films. Also industrial TIN films deposited by Arc Ion plating were carefully selected for comparison and labelled Type II TiN films. The microstructure, composition, surface chemistry, surface topography and roughness were studied using X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Atomic Force Microscopy (AFM) and Profilometry. Type I TIN films showed a surface topography similar to Zone I and Type II TiN films showed a surface topography similar to Zone 2 of the Movchan and Dernchishin structure zone model for sputtered films. XPS showed that the surface composition of all TiN films was predominantly TiO2, TiN and TiNxOy. Significant differences in

  13. Detecting protein candidate fragments using a structural alphabet profile comparison approach.

    Science.gov (United States)

    Shen, Yimin; Picord, Géraldine; Guyon, Frédéric; Tuffery, Pierre

    2013-01-01

    Predicting accurate fragments from sequence has recently become a critical step for protein structure modeling, as protein fragment assembly techniques are presently among the most efficient approaches for de novo prediction. A key step in these approaches is, given the sequence of a protein to model, the identification of relevant fragments - candidate fragments - from a collection of the available 3D structures. These fragments can then be assembled to produce a model of the complete structure of the protein of interest. The search for candidate fragments is classically achieved by considering local sequence similarity using profile comparison, or threading approaches. In the present study, we introduce a new profile comparison approach that, instead of using amino acid profiles, is based on the use of predicted structural alphabet profiles, where structural alphabet profiles contain information related to the 3D local shapes associated with the sequences. We show that structural alphabet profile-profile comparison can be used efficiently to retrieve accurate structural fragments, and we introduce a fully new protocol for the detection of candidate fragments. It identifies fragments specific of each position of the sequence and of size varying between 6 and 27 amino-acids. We find it outperforms present state of the art approaches in terms (i) of the accuracy of the fragments identified, (ii) the rate of true positives identified, while having a high coverage score. We illustrate the relevance of the approach on complete target sets of the two previous Critical Assessment of Techniques for Protein Structure Prediction (CASP) rounds 9 and 10. A web server for the approach is freely available at http://bioserv.rpbs.univ-paris-diderot.fr/SAFrag. PMID:24303019

  14. Surface states and bulk electronic structure in the candidate type-II Weyl semimetal WTe2

    OpenAIRE

    Bruno, F. Y.; Tamai, A.; Wu, Q. S.; Cucchi, I.; Barreteau, C.; A. de la Torre; Walker, S. McKeown; Riccò, S; Wang, Z.; Kim, T K; Hoesch, M.; Shi, M. (Mimi); Plumb, N. C.; Giannini, E; Soluyanov, A. A.

    2016-01-01

    We report angle-resolved photoemission experiments identifying an arc-like surface state connecting the bulk electron and hole pockets of the candidate type-II Weyl semimetal WTe2. This surface state can be isolated clearly on one of two distinct surface terminations observed experimentally, which we associate with the in-equivalent top and bottom surfaces of the non-centrosymmetric crystal structure. We further use the identification of the two different surfaces to clarify the number of bul...

  15. Laboratory corrosion tests on candidate high-level waste container materials: Results from the Belgian programme

    International Nuclear Information System (INIS)

    The Belgian SAFIR-2 concept foresees the geological disposal of conditioned high-level radioactive waste in stainless steel containers and overpacks placed in a concrete gallery backfilled with Boom clay or a bentonite-type backfill. In addition to earlier in situ experiments, we used a laboratory approach to investigate the corrosion properties of selected stainless steels in Boom clay and bentonite environments. In the SAFIR-2 concept, AISI 316L hMo is the main candidate overpack material. As an alternative, we also investigated the higher alloyed stainless steel UHB 904L. Our study focused on localised corrosion and in particular pitting. We used cyclic potentiodynamic polarisation measurements to determine the pit nucleation potential ENP and the protection potential EPP. The evolution of the corrosion potential with time was determined by monitoring the open circuit potential in synthetic clay-water over extended periods. In this paper we present and discuss some results from our laboratory programme, focusing on long-term interactions between the stainless steel overpack and the backfill materials. We describe in particular the influence of chloride and thio-sulphate ions on the pitting corrosion behaviour. The results show that, under geochemical conditions typical for geological disposal, i.e. [Cl-] ∼ 30 mg/L for a Boom clay backfill and [Cl-] ∼ 90 mg/L for a bentonite backfill, neither AISI 316L hMo nor UHB 904L is expected to present pitting problems. An important factor in the long-term prediction of the corrosion behaviour however, is the robustness of the model for the evolution of the geochemistry of the backfill. Indeed, at chloride levels higher than 1000 mg/L, we predict pitting corrosion for AISI 316L hMo. (authors)

  16. Development of a candidate certified reference material of cypermethrin in green tea

    International Nuclear Information System (INIS)

    Highlights: ► A cypermethrin CRM in green tea was developed. ► Using two isotope dilution mass spectrometry techniques for characterization. ► Certified value of 148 μg kg−1 with expanded uncertainty of ±9.2%. ► Support quality assurance of pesticide residue analysis in tea to testing. - Abstract: This paper presents the preparation of a candidate certified reference material (CRM) of cypermethrin in green tea, GLHK-11-01a according to the requirements of ISO Guide 34 and 35. Certification of the material was performed using a newly developed isotope dilution mass spectrometry (IDMS) approach, with gas chromatography high resolution mass spectrometry (GC–HRMS) and gas chromatography–tandem mass spectrometry (GC–MS/MS). Statistical analysis (one-way ANOVA) showed excellent agreement of the analytical data sets generated from the two mass spectrometric detections. The characterization methods have also been satisfactorily applied in an Asia-Pacific Metrology Program (APMP) interlaboratory comparison study. Both the GC–HRIDMS and GC–IDMS/MS methods proved to be sufficiently reliable and accurate for certification purpose. The certified value of cypermethrin in dry mass fraction was 148 μg kg−1 and the associated expanded uncertainty was 14 μg kg−1. The uncertainty budget was evaluated from sample in homogeneity, long-term and short-term stability and variability in the characterization procedure. GLHK-11-01a is primarily developed to support the local and wider testing community on need basis in quality assurance work and in seeking accreditation.

  17. Certification of a new biological reference material - Virginia Tobacco Leaves (CTA-VTL-2) and homogeneity study by NAA on this and other candidate reference materials

    International Nuclear Information System (INIS)

    This report describes the laboratory's participation in the interlaboratory comparison run where the laboratory applied neutron activation analysis aimed at certification of the candidate reference material. Data evaluation and statistical treatment steps are discussed. The report also describes homogeneity study on the reference material and provides details of the analytical procedures

  18. Characterization of a backfill candidate material, IBECO-RWC-BF Baclo Project - Phase 3 Laboratory tests

    International Nuclear Information System (INIS)

    A backfill candidate material, IBECO-RWC-BF, which origin from Milos, Greece, has been investigated. The material was delivered both as granules and as pellets. The investigation described in this report aimed to characterize the material and evaluate if it can be used in a future repository. The following investigations have been done and are presented in this report: 1. Standard laboratory tests. Water content, liquid limit and swelling potential are examples on standard tests that have been performed. 2. Block manufacturing. The block compaction properties of the material have been determined. A first test was performed in laboratory but also tests in large scale have been performed. After finishing the test phase, 60 tons of blocks were manufactured at Hoeganaes Bjuf AB. The blocks will be used in large scale laboratory tests at Aespoe HRL. 3. Mechanical parameters. The compressibility of the material was investigated with oedometer tests (four tests) where the load was applied in steps after saturation. The evaluated oedometer modulus varied between 34.50 MPa. Tests were made to evaluate the elastic parameters of the material (E, ν). Altogether three tests were made on specimens with dry densities of about 1,710 kg/m3. The evaluated E-modulus and Poisson's ratio varied between 231-263 MPa and 0.16-0.19 respectively. The strength of the material, both the compressive strength and the tensile strength were measured on specimens compacted to different dry densities. The test results yielded a relation between density and the two types of strength. Furthermore, tests have been made in order to determine the compressibility of the unsaturated filling of pellets. Two tests were made where the pellets were loosely filled in a Proctor cylinder and then compressed at a constant rate of strain during continuously measurement of the applied load. 4. Swelling pressure and hydraulic conductivity. There is, as expected, a very clear influence of the dry density on the

  19. Reversible Hydrogen Storage MaterialsStructure, Chemistry, and Electronic Structure

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Ian M. [University of Wisconsin-Madison; Johnson, Duane D. [Ames Lab., Iowa

    2014-06-21

    To understand the processes involved in the uptake and release of hydrogen from candidate light-weight metal hydride storage systems, a combination of materials characterization techniques and first principle calculation methods have been employed. In addition to conventional microstructural characterization in the transmission electron microscope, which provides projected information about the through thickness microstructure, electron tomography methods were employed to determine the three-dimensional spatial distribution of catalyst species for select systems both before and after dehydrogenation. Catalyst species identification as well as compositional analysis of the storage material before and after hydrogen charging and discharging was performed using a combination of energy dispersive spectroscopy, EDS, and electron energy loss spectroscopy, EELS. The characterization effort was coupled with first-principles, electronic-structure and thermodynamic techniques to predict and assess meta-stable and stable phases, reaction pathways, and thermodynamic and kinetic barriers. Systems studied included:NaAlH4, CaH2/CaB6 and Ca(BH4)2, MgH2/MgB2, Ni-Catalyzed Magnesium Hydride, TiH2-Catalyzed Magnesium Hydride, LiBH4, Aluminum-based systems and Aluminum

  20. Material Properties Analysis of Structural Members in Pumpkin Balloons

    Science.gov (United States)

    Sterling, W. J.

    2003-01-01

    The efficient design, service-life qualification, and reliability predictions for lightweight aerospace structures require careful mechanical properties analysis of candidate structural materials. The demand for high-quality laboratory data is particularly acute when the candidate material or the structural design has little history. The pumpkin-shaped super-pressure balloon presents both challenges. Its design utilizes load members (tendons) extending from apex to base around the gas envelope to achieve a lightweight structure. The candidate tendon material is highly weight-efficient braided HM cord. Previous mechanical properties studies of Zylon have focused on fiber and yarn, and industrial use of the material in tensile applications is limited. For high-performance polymers, a carefully plamed and executed properties analysis scheme is required to ensure the data are relevant to the desired application. Because no directly-applicable testing standard was available, a protocol was developed based on guidelines fiom professional and industry organizations. Due to the liquid-crystalline nature of the polymer, the cord is very stiff, creeps very little, and does not yield. Therefore, the key material property for this application is the breaking strength. The pretension load and gauge length were found to have negligible effect on the measured breaking strength over the ranges investigated. Strain rate was found to have no effect on breaking strength, within the range of rates suggested by the standards organizations. However, at the lower rate more similar to ULDB operations, the strength was reduced. The breaking strength increased when the experiment temperature was decreased from ambient to 183K which is the lowest temperature ULDB is expected to experience. The measured strength under all test conditions was well below that resulting from direct scale-up of fiber strength based on the manufacturers data. This expected result is due to the effects of the

  1. Cryogenic structural materials for superconducting magnets

    International Nuclear Information System (INIS)

    This paper reviews research in the United States and Japan on structural materials for high-field superconducting magnets. Superconducting magnets are used for magnetic fusion energy devices and for accelerators that are used in particle-physics research. The cryogenic structural materials that we review are used for magnet cases and support structures. We expect increased materials requirements in the future

  2. Detailed mechanical/structural test and analysis on the spacer grid candidates for the advanced LWR fuel

    International Nuclear Information System (INIS)

    The spacer grid is one of the structural components of the nuclear fuel assemblies for the pressurized light water reactors. Based on the nuclear fuel assembly mechanical/ thermal-hydraulic design experience and scrutinizing the design features on the foreign advanced nuclear fuel and the foreign patents of the spacer grid, 14 kinds of spacer grid candidates have been conceptually derived and applied for the patents since 1997. Through the screening test on the 5 candidates of the spacer grids 2 leading candidates have been selected for detailed test from the mechanical/structural point of view. In this paper detailed test and analysis results on the leading candidates are discussed

  3. Spectral emissivity measurements of candidate materials for very high temperature reactors

    Energy Technology Data Exchange (ETDEWEB)

    Cao, G.; Weber, S.J.; Martin, S.O.; Anderson, M.H. [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Drive, Madison, WI (United States); Sridharan, K., E-mail: kumars@cae.wisc.edu [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Drive, Madison, WI (United States); Allen, T.R. [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Drive, Madison, WI (United States)

    2012-10-15

    Heat dissipation by radiation is an important consideration in VHTR components, particularly the reactor pressure vessel (RPV), because of the fourth power temperature dependence of radiated heat. Since emissivity is the material property that dictates the ability to radiate heat, measurements of emissivities of materials that are being specifically considered for the construction of VHTR become important. Emissivity is a surface phenomenon and therefore compositional, structural, and topographical changes that occur at the surfaces of these materials as a result of their interactions with the environment at high temperatures will alter their emissivities. With this background, an experimental system for the measurement of spectral emissivity has been designed and constructed. The system has been calibrated in conformance with U.S. DoE quality assurance standards using inert ceramic materials, boron nitride, silicon carbide, and aluminum oxide. The results of high temperature emissivity measurements of potential VHTR materials such as ferritic steels SA 508, T22, T91 and austenitic alloys IN 800H, Haynes 230, IN 617, and 316 stainless steel have been presented.

  4. Spectral emissivity measurements of candidate materials for very high temperature reactors

    International Nuclear Information System (INIS)

    Heat dissipation by radiation is an important consideration in VHTR components, particularly the reactor pressure vessel (RPV), because of the fourth power temperature dependence of radiated heat. Since emissivity is the material property that dictates the ability to radiate heat, measurements of emissivities of materials that are being specifically considered for the construction of VHTR become important. Emissivity is a surface phenomenon and therefore compositional, structural, and topographical changes that occur at the surfaces of these materials as a result of their interactions with the environment at high temperatures will alter their emissivities. With this background, an experimental system for the measurement of spectral emissivity has been designed and constructed. The system has been calibrated in conformance with U.S. DoE quality assurance standards using inert ceramic materials, boron nitride, silicon carbide, and aluminum oxide. The results of high temperature emissivity measurements of potential VHTR materials such as ferritic steels SA 508, T22, T91 and austenitic alloys IN 800H, Haynes 230, IN 617, and 316 stainless steel have been presented.

  5. Behaviour of Structural Materials: Japan

    International Nuclear Information System (INIS)

    One of main problems to use lead alloys for nuclear systems such as ADS (Accelerator Driven Dystem) and FBR (Fast Breeder Reactors) is compatibility of steels with lead alloys. Mainly approaches from the following two directions have been made: 1) basic investigation on effects of various parameters to corrosion behaviour in liquid LBE (lead bismuth eutectic) investigation on applicability of candidate steels developed for FBR to LBE environment. Effects of temperature, oxygen concentration in LBE and contents of alloying elements, Cr, Ni, Si and Al in steels on corrosion behaviour are investigated in static liquid LBE. Drawing up the corrosion map in liquid LBE is the main goal in this study. In order to examine the applicability of candidate steels to LBE environment, some steels developed for FBR are used for corrosion tests in LBE. Furthermore, estimation of the predicted curves of the corrosion depth is the main goal

  6. Preparation of candidate reference materials for the determination of phosphorus containing flame retardants in styrene-based polymers.

    Science.gov (United States)

    Roth, Thomas; Urpi Bertran, Raquel; Latza, Andreas; Andörfer-Lang, Katrin; Hügelschäffer, Claudia; Pöhlein, Manfred; Puchta, Ralph; Placht, Christian; Maid, Harald; Bauer, Walter; van Eldik, Rudi

    2015-04-01

    Candidate reference materials (RM) for the analysis of phosphorus-based flame retardants in styrene-based polymers were prepared using a self-made mini-extruder. Due to legal requirements of the current restriction for the use of certain hazardous substances in electrical and electronic equipment, focus now is placed on phosphorus-based flame retardants instead of the brominated kind. Newly developed analytical methods for the first-mentioned substances also require RMs similar to industrial samples for validation and verification purposes. Hence, the prepared candidate RMs contained resorcinol-bis-(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), triphenyl phosphate and triphenyl phosphine oxide as phosphorus-based flame retardants. Blends of polycarbonate and acrylonitrile-co-butadiene-co-styrene as well as blends of high-impact polystyrene and polyphenylene oxide were chosen as carrier polymers. Homogeneity and thermal stability of the candidate RMs were investigated. Results showed that the candidate RMs were comparable to the available industrial materials. Measurements by ICP/OES, FTIR and NMR confirmed the expected concentrations of the flame retardants and proved that analyte loss and degradation, respectively, was below the uncertainty of measurement during the extrusion process. Thus, the candidate RMs were found to be suitable for laboratory use. PMID:25410641

  7. Determination of butoxyacetic acid (biomarker of ethylene glycol monobutyl ether exposure) in human urine candidate reference material

    Czech Academy of Sciences Publication Activity Database

    Sperlingova, I.; Dabrowská, L.; Stránský, V.; Duskova, S.; Kučera, Jan; Tvrdíková, M.; Tichý, M.

    2010-01-01

    Roč. 397, č. 2 (2010), s. 433-438. ISSN 1618-2642. [12th International Symposium on Biological and Environmental Reference Materials Keble Coll. Oxford, 07.07.2009-10.07.2009] Institutional research plan: CEZ:AV0Z10480505 Keywords : Candidate reference material * Ethylene glycol monobutyl ether * Metabolite Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.841, year: 2010

  8. A review of candidate ceramic materials for use as heat shield tiles in a supercritical-water-cooled-reactor

    International Nuclear Information System (INIS)

    The proposed Canadian supercritical-water-cooled reactor (SCWR) utilizes a reactor shell made of a zirconium alloy insulated with a ceramic tile heat shield. The main consideration in the selection of a tile material will be resistance to corrosion in supercritical water and long term microstructure stability, in addition to thermal conductivity. This paper provides a review of the literature on corrosion behaviours of ceramic materials in supercritical water and ranks candidate ceramic materials accordingly. Materials reviewed include alumina, zirconia, silica glasses, silicon carbide, silicon nitride, sialon, mullite, and aluminum nitride. (author)

  9. A new candidate as the cathode material for intermediate and low temperature SOFCs

    Institute of Scientific and Technical Information of China (English)

    LI Song; SUN Xueli; WEN Zhongsheng; SUN Juncai

    2006-01-01

    In order to develop the new cathode materials suitable for intermediate and low temperature solid oxide fuel cells (IT/LTSOFCs), LaNi1-xFexO3(x=0.4-0.8) (LNF) materials were synthesized using coprecipitation method. Their structures and morphologies were investigated by XRD and SEM, and their electronic conductivities at different temperatures were measured by dc four terminal method. Fuel cells were fabricated to evaluate the electrochemical properties of the LNF materials as cathodes at different temperatures. The performance of 450-497 mW·cm-2 was obtained in the temperature region of 580-650 ℃ for the LaNi0.2Fe0.8O3 cathode, and of 209-227 mW·cm-2 at 400-500 ℃ for the LaNi0.4Fe0.6O3. The excellent fuel cell performances indicate that the LNF materials are good cathodes for IT/LTSOFCs.

  10. Phase stability effects on the corrosion behavior of the metal barrier candidate materials for the nuclear waste management program

    International Nuclear Information System (INIS)

    Six candidate materials are currently under consideration by the Nuclear Waste Management Program (NWMP) at Lawrence Livermore National Laboratory as potential metal barrier materials for high-level nuclear waste storage. The waste package, which must meet the Nuclear Regulatory Commission licensing requirements for the Nevada Nuclear Waste Storage Investigations Project (NNWSI), will contain spent fuel from civilian nuclear power plants PWR and BWR fuel assemblies, commercial high level waste (CHLW) in the form of borosilicate glass containing commercial spent fuel reprocessing wastes and defense high level waste (DHLW) contained in borosilicate glass. The waste package is being designed for emplacement in the unsaturated zone above the water table at the Yucca Mountain site in Nevada. This location should result in a slightly oxidizing repository environment. The Metal Barrier Selection and Testing Task is responsible for the selection of the materials to be employed in the waste package container. The candidate materials include three iron to nickel-based austenitic materials and three copper-based alloy materials. The austenitic materials are AISI 304L stainless steel, AISI 316L stainless steel and alloy 825. The copper-based alloy materials are CDA 102 (OFHC copper), CDA 613 (Cu-7Al) and CDA 715 (Cu-30Ni). The selection of the final metal barrier material is dependent upon the expected behavior of these materials in the repository environment

  11. Glass: a candidate engineered material for management of high level nuclear waste

    International Nuclear Information System (INIS)

    While the commercial importance of glass is generally recognized, a few people are aware of extremely wide range of glass formulations that can be made and of the versatility of this engineered material. Some of the recent developments in the field of glass leading to various technological applications include glass fiber reinforcement of cement to give new building materials, substrates for microelectronics circuitry in form of semiconducting glasses, nuclear waste immobilization and specific medical applications. The present paper covers fundamental understanding of glass structure and its application for immobilization of high level radioactive liquid waste. High level radioactive liquid waste (HLW) arising during reprocessing of spent fuel are immobilized in sodium borosilicate glass matrix developed indigenously. Glass compositions are modified according to the composition of HLW to meet the criteria of desirable properties in terms. These glass matrices have been characterized for different properties like homogeneity, chemical durability, thermal stability and radiation stability. (author)

  12. Erosion and redeposition behavior of selected net-candidate materials under high-flux hydrogen, deuterium plasma bombardment in PISCES

    International Nuclear Information System (INIS)

    Plasma erosion and redeposition behavior of selected candidate materials for plasma-facing components in the NET-machine have been investigated using the PISCES-A facility. Materials studied include SiC-impregnated graphite, 2D graphite weaves with and without CVD- SiC coatings, and isotropic graphite. These specimens were exposed to continuous hydrogen or deuterium plasmas under the following conditions: electron temperature range from 5 to 35eV; plasma density range from 5 x 1011 to 1 x 1012 cm-3; flux range from 5 x 1017 to 2 x 1018 ions cm-2 s-1; fluence of the order from 1021 to 1022 ions/cm2; bombarding energies of 50 and 100eV; target temperature range from 300 to 1000/degree/C. The erosion yield of SiC-impregnated graphite due to deuterium plasma bombardment is found to be a factor of 2 to 3 less than that of isotropic graphite materials. A further factor of 2-3 reduction in the erosion yield is observed in when redeposition associated with reionization of sputtered particle becomes significant. From postbombardment surface analysis with AES, the surface composition in terms of the Si/C of SiC-impregnated graphite ratio is found to increase from 0.15 to 0.7 after hydrogen plasma bombardment to a fluence around 4 x 1021 ions/cm2 at 350/degree/C. However, the final surface composition appears to remain unchanged up to 4 x 1022 ions/cm2, the highest fluence in the present study. Significant surface morphological modifications of SiC-impregnated graphite are observed after the high-fluence plasma exposure. Several structural problems such as coating-substrate adhesion have been pointed out for SiC-coated 2D graphite weave. 11 refs., 6 figs., 1 tab

  13. Radiation effects on structural materials

    International Nuclear Information System (INIS)

    This report discusses the following topics on the effect radiation has on thermonuclear reactor materials: Atomic Displacements; Microstructure Evolution; Materials Engineering, Mechanics, and Design; Research on Low-Activation Steels; and Research Motivated by Grant Support

  14. Hot carrier solar cell absorbers: investigation of carrier cooling properties of candidate materials

    Science.gov (United States)

    Conibeer, G.; Shrestha, Santosh; Huang, Shujuan; Patterson, Robert; Xia, Hongze; Feng, Yu; Zhang, Pengfei; Gupta, Neeti; Smyth, Suntrana; Liao, Yuanxun; Lin, Shu; Wang, Pei; Dai, Xi; Chung, Simon; Yang, Jianfeng; Zhang, Yi

    2015-09-01

    The hot carrier cell aims to extract the electrical energy from photo-generated carriers before they thermalize to the band edges. Hence it can potentially achieve a high current and a high voltage and hence very high efficiencies up to 65% under 1 sun and 86% under maximum concentration. To slow the rate of carrier thermalisation is very challenging, but modification of the phonon energies and the use of nanostructures are both promising ways to achieve some of the required slowing of carrier cooling. A number of materials and structures are being investigated with these properties and test structures are being fabricated. Initial measurements indicate slowed carrier cooling in III-Vs with large phonon band gaps and in multiple quantum wells. It is expected that soon proof of concept of hot carrier devices will pave the way for their development to fully functioning high efficiency solar cells.

  15. Comparison of lithium and the eutectic lead-lithium alloy, two candidate liquid metal breeder materials for self-cooled blankets

    International Nuclear Information System (INIS)

    Liquid metals are attractive candidates for both near-term and long-term fusion applications. The subjects of this comparison are the differences between the two candidate liquid metal breeder materials Li and LiPb for use in breeding blankets in the areas of neutronics, magnetohydrodynamics, tritium control, compatibility with structural materials, heat extraction system, safety and required research and development program. Both candidates appear to be promising for use in self-cooled breeding blankets which have inherent simplicity with the liquid metal serving as both breeder and coolant. Each liquid metal breeder has advantages and concerns associated with it, and further development is needed to resolve these concerns. The remaining feasibility question for both breeder materials is the electrical insulation between the liquid metal and the duct walls. Different ceramic coatings are required for the two breeders, and their crucial issues, namely self-healing of insulator cracks and tolerance to radiation-induced electrical degradation, have not yet been demonstrated. (orig.)

  16. Materials research at Stanford University. [composite materials, crystal structure, acoustics

    Science.gov (United States)

    1975-01-01

    Research activity related to the science of materials is described. The following areas are included: elastic and thermal properties of composite materials, acoustic waves and devices, amorphous materials, crystal structure, synthesis of metal-metal bonds, interactions of solids with solutions, electrochemistry, fatigue damage, superconductivity and molecular physics and phase transition kinetics.

  17. In-situ tube burst testing and high-temperature deformation behavior of candidate materials for accident tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Gussev, Maxim N.; Byun, Thak Sang; Yamamoto, Yukinori; Maloy, Stuart A.; Terrani, Kurt A.

    2015-11-01

    The high resistance of cladding to plastic deformation and burst failure is one of the most essential properties of accident tolerant fuel (ATF) for maintaining structural integrity during a loss-of-coolant accident (LOCA) since the deformation and burst behavior governs the cooling efficiency of flow channels and process of fission product release. To simulate and evaluate such deformation and burst process of thin-walled cladding, an in-situ testing and evaluation method has been developed on the basis of visual imaging and image analysis techniques. The method uses a specialized optics system consisted of a high-resolution video camera, light filtering unit, and monochromatic light sources, and the in-situ testing is performed using a 50 mm long pressurized thin-walled tubular specimen set in a programmable furnace. In this study eleven (11) candidate cladding materials for ATF, i.e., 6 FeCrAl alloys and 5 nanostructured steels, were tested using the newly developed method, and the time-dependent images were analyzed to produce detailed deformation and burst data such as true hoop stress, strain (creep) rate, and failure stress. Relatively soft FeCrAl alloys deformed and burst below 800°C while negligible strain rates were measured for higher strength alloys and/or for relatively thick wall specimens.

  18. Building Investigation: Material or Structural Performance

    OpenAIRE

    Yusof M.Z.

    2014-01-01

    Structures such as roof trusses will not suddenly collapse without ample warning such as significant deflection, tilting etc. if the designer manages to avoid the cause of structural failure at the material level and the structural level. This paper outlines some principles and procedures of PDCA circle and QC tools which can show some clues of structural problems in terms of material or structural performance

  19. Building Investigation: Material or Structural Performance

    Directory of Open Access Journals (Sweden)

    Yusof M.Z.

    2014-03-01

    Full Text Available Structures such as roof trusses will not suddenly collapse without ample warning such as significant deflection, tilting etc. if the designer manages to avoid the cause of structural failure at the material level and the structural level. This paper outlines some principles and procedures of PDCA circle and QC tools which can show some clues of structural problems in terms of material or structural performance

  20. Identification of candidate structured RNAs in the marine organism 'Candidatus Pelagibacter ubique'

    Directory of Open Access Journals (Sweden)

    Schwalbach Michael S

    2009-06-01

    Full Text Available Abstract Background Metagenomic sequence data are proving to be a vast resource for the discovery of biological components. Yet analysis of this data to identify functional RNAs lags behind efforts to characterize protein diversity. The genome of 'Candidatus Pelagibacter ubique' HTCC 1062 is the closest match for approximately 20% of marine metagenomic sequence reads. It is also small, contains little non-coding DNA, and has strikingly low GC content. Results To aid the discovery of RNA motifs within the marine metagenome we exploited the genomic properties of 'Cand. P. ubique' by targeting our search to long intergenic regions (IGRs with relatively high GC content. Analysis of known RNAs (rRNA, tRNA, riboswitches etc. shows that structured RNAs are significantly enriched in such IGRs. To identify additional candidate structured RNAs, we examined other IGRs with similar characteristics from 'Cand. P. ubique' using comparative genomics approaches in conjunction with marine metagenomic data. Employing this strategy, we discovered four candidate structured RNAs including a new riboswitch class as well as three additional likely cis-regulatory elements that precede genes encoding ribosomal proteins S2 and S12, and the cytoplasmic protein component of the signal recognition particle. We also describe four additional potential RNA motifs with few or no examples occurring outside the metagenomic data. Conclusion This work begins the process of identifying functional RNA motifs present in the metagenomic data and illustrates how existing completed genomes may be used to aid in this task.

  1. Oxidation behavior of austenitic stainless steels as fuel cladding candidate materials for SCWR in superheated steam

    International Nuclear Information System (INIS)

    Highlights: • Effect of cold work on oxidation kinetics was clearly observed for 15Cr–20Ni SS. • The tube-shaped 15Cr–20Ni SS showed very good oxidation resistance. • The machined layer by cold drawing has a significant role to mitigate oxidation. - Abstract: Oxidation behavior of austenitic stainless steels as fuel cladding candidate materials for supercritical-water-cooled reactor (SCWR), including three types of 15Cr–20Ni stainless steels (1520 SSs), in the temperature range of 700–780 °C superheated steam have been investigated. Effect of temperature, dissolved oxygen (DO), degree of cold work (CW), and machined layer by cold drawing process on the oxidation kinetics assuming power-law kinetics are discussed. Characteristics of oxide layers and its relation to oxidation behaviors are also discussed. The effect of DO on the weight gain behavior in superheated steam at 700 °C was minor for all specimens at least up to 200 ppb DO. The tube-shaped specimens of 1520 SSs showed very good oxidation resistance at 700–780 °C. There was no clear difference in the oxidation kinetics among the three investigated types of 1520 SSs. The machined layer formed at the tube surface has a significant role to mitigate oxidation in superheated steam. A fine-grained microstructure near the surface due to recrystallization by cold drawing process is effective to form the protective Cr2O3 layer. It has been suggested that since Cr diffusion in the outside surface of tubes is accelerated as a result of an increased dislocation density and/or grain refinement by cold drawing, tube specimens show very slow oxidation kinetics. Breakdown of the protective Cr2O3 layer and nodule oxide formation were partly observed on the tube-shaped specimens of 15Cr–20Ni SSs. The reliability of Cr2O3 layer has to be carefully examined to predict the oxidation kinetics after long-term exposure

  2. Challenges of structural materials for innovative nuclear systems in Europe

    International Nuclear Information System (INIS)

    New fusion and fission reactors for generation IV are envisaged to operate at conditions well above the actual ones for commercial fission reactors. This type of reactor combined a high operation temperature with a high neutron dose and an aggressive coolant, which imply new challenges for structural materials. One of the key issues to assure the safety and feasibility of these new nuclear systems is the selection of the structural materials, especially for in core components. Beside the differences between them, especially the amount of transmutation He in fusion reactors, similar structural materials have been selected. Some of the selected materials are well characterized at least at medium temperatures, as conventional ferritic/martensitic steels, but the qualification for higher temperatures is needed. For other materials, as ODS steels, there is a need for a complete characterization and qualification. In this paper a review of the operating conditions and selected structural materials for generation IV and fusion reactors within Europe is made. The needs for a complete characterization of these candidate materials are identified in terms of high temperature behaviour, radiation damage and coolant compatibility. (author)

  3. Structure and interactions of a malarial vaccine candidate, AMA1, form the parasite plasmodium falciparum

    International Nuclear Information System (INIS)

    Full text: Apical membrane antigen 1 (AMA1), a merozoite surface protein found in all species of Plasmodium and other apicomplexan parasites, is a strong candidate for inclusion in a malarial vaccine. Recombinant AMA1 protected against P. fragile in monkeys and P. chabaudi adami in mice. P. falciparum AMA1 which has a 62-kDa ectodomain consisting of three disulphide-stabilised domains, is a target of antibodies that inhibit merozoite invasion in vitro. Here we describe the solution structure of domain III (14 kDa), determined by NMR on 15N- and 13C/15N-labelled samples. It has a well-defined disulphide-stabilised core interrupted by a disordered loop, and both the N- and C-terminal regions of the molecule are unstructured. The structured region includes all three disulphide bonds. Naturally-occurring mutations across 11 different P falciparum strains that are located far apart in the sequence cluster around the disulphide core in the 3D structure of domain III, suggesting that this region contains the major epitopes recognised by neutralising antibodies. Consistent with this, the disulphide-bond stabilised conformation of the ectodomain was essential for protection, as the antigen was not an effective vaccine after reduction and alkylation. Peptides have been found by phage display that bind to AMA1 and block merozoite invasion of erythrocytes. We have investigated their solution structures and interaction with full-length AMA1 ectodomain in an effort to understand the structure-function relationships of this important vaccine candidate

  4. Surface Catalytic Efficiency of Advanced Carbon Carbon Candidate Thermal Protection Materials for SSTO Vehicles

    Science.gov (United States)

    Stewart, David A.

    1996-01-01

    The catalytic efficiency (atom recombination coefficients) for advanced ceramic thermal protection systems was calculated using arc-jet data. Coefficients for both oxygen and nitrogen atom recombination on the surfaces of these systems were obtained to temperatures of 1650 K. Optical and chemical stability of the candidate systems to the high energy hypersonic flow was also demonstrated during these tests.

  5. A nuclear structure study of the proposed gamma-ray laser candidate nucleus 186Re

    International Nuclear Information System (INIS)

    We present results of theoretical nuclear structure model calculations for the gamma-ray laser candidate nucleus 186Re proposed by Collins. Our calculations of this odd-odd transitional nucleus are based on an axially-asymmetric (particle plus triaxial rotor) model for constructing the orbitals of the odd nucleons that couple under the influence of the residual neutron-proton interaction. We include pairing correlations in the determination of these orbitals by using the BCS approximation with newly determined pairing strengths. The matrix elements of the residual neutron-proton interaction are obtained using phenomenological spin-dependent δ function potentials of both surface and volume forms. We examine the sensitivity of the calculated low-excitation level structure of 186Re to the strength of these potentials. Calculated energy levels of 186Re will be presented and compared with experiment. The impact of our results on the proposed use of 186Re as a gamma-ray laser will be discussed. In addition, based upon these and other model calculations to be described, we assess the level of effort necessary in a full-scale theoretical search for a viable candidate nucleus for a gamma-ray laser. 17 refs., 1 fig., 3 tabs

  6. Materials analogue of zero-stiffness structures

    Science.gov (United States)

    Kumar, Arun; Subramaniam, Anandh

    2011-04-01

    Anglepoise lamps and certain tensegrities are examples of zero-stiffness structures. These structures are in a state of neutral equilibrium with respect to changes in configuration of the system. Using Eshelby's example of an edge dislocation in a thin plate that can bend, we report the discovery of a non-trivial new class of material structures as an analogue to zero-stiffness structures. For extended positions of the edge dislocation in these structures, the dislocation experiences a zero image force. Salient features of these material structures along with the key differences from conventional zero-stiffness structures are pointed out.

  7. Structural evaluation of candidate designs for the large space telescope primary mirror

    Science.gov (United States)

    Soosaar, K.; Grin, R.; Furey, M.; Hamilton, J.

    1975-01-01

    Structural performance analyses were conducted on two candidate designs (Itek and Perkin-Elmer designs) for the large space telescope three-meter mirror. The mirror designs and the finite-element models used in the analyses evaluation are described. The results of the structural analyses for several different types of loading are presented in tabular and graphic forms. Several additional analyses are also reported: the evaluation of a mirror design concept proposed by the Boeing Co., a study of the global effects of local cell plate deflections, and an investigation of the fracture mechanics problems likely to occur with Cervit and ULE. Flexibility matrices were obtained for the Itek and Perkin-Elmer mirrors to be used in active figure control studies. Summary, conclusions, and recommendations are included.

  8. A New Light Weight Structural Material for Nuclear Structures

    Energy Technology Data Exchange (ETDEWEB)

    Rabiei, Afsaneh [North Carolina State Univ., Raleigh, NC (United States)

    2016-01-14

    Radiation shielding materials are commonly used in nuclear facilities to attenuate the background ionization radiations to a minimum level for creating a safer workplace, meeting regulatory requirements and maintaining high quality performance. The conventional radiation shielding materials have a number of drawbacks: heavy concrete contains a high amount of elements that are not desirable for an effective shielding such as oxygen, silicon, and calcium; a well known limitation of lead is its low machinability and toxicity, which is causing a major environmental concern. Therefore, an effective and environmentally friendly shielding material with increased attenuation and low mass density is desirable. Close-cell composite metal foams (CMFs) and open-cell Al foam with fillers are light-weight candidate materials that we have studied in this project. Close-cell CMFs possess several suitable properties that are unattainable by conventional radiation shielding materials such as low density and high strength for structural applications, high surface area to volume ratio for excellent thermal isolation with an extraordinary energy absorption capability. Open-cell foam is made up of a network of interconnected solid struts, which allows gas or fluid media to pass through it. This unique structure provided a further motive to investigate its application as radiation shields by infiltrating original empty pores with high hydrogen or boron compounds, which are well known for their excellent neutron shielding capability. The resulting open-cell foam with fillers will not only exhibit light weight and high specific surface area, but also possess excellent radiation shielding capability and good processability. In this study, all the foams were investigated for their radiation shielding efficiency in terms of X-ray, gamma ray and neutron. X-ray transmission measurements were carried out on a high-resolution microcomputed tomography (microCT) system. Gamma-emitting sources: 3.0m

  9. A New Light Weight Structural Material for Nuclear Structures

    International Nuclear Information System (INIS)

    Radiation shielding materials are commonly used in nuclear facilities to attenuate the background ionization radiations to a minimum level for creating a safer workplace, meeting regulatory requirements and maintaining high quality performance. The conventional radiation shielding materials have a number of drawbacks: heavy concrete contains a high amount of elements that are not desirable for an effective shielding such as oxygen, silicon, and calcium; a well known limitation of lead is its low machinability and toxicity, which is causing a major environmental concern. Therefore, an effective and environmentally friendly shielding material with increased attenuation and low mass density is desirable. Close-cell composite metal foams (CMFs) and open-cell Al foam with fillers are light-weight candidate materials that we have studied in this project. Close-cell CMFs possess several suitable properties that are unattainable by conventional radiation shielding materials such as low density and high strength for structural applications, high surface area to volume ratio for excellent thermal isolation with an extraordinary energy absorption capability. Open-cell foam is made up of a network of interconnected solid struts, which allows gas or fluid media to pass through it. This unique structure provided a further motive to investigate its application as radiation shields by infiltrating original empty pores with high hydrogen or boron compounds, which are well known for their excellent neutron shielding capability. The resulting open-cell foam with fillers will not only exhibit light weight and high specific surface area, but also possess excellent radiation shielding capability and good processability. In this study, all the foams were investigated for their radiation shielding efficiency in terms of X-ray, gamma ray and neutron. X-ray transmission measurements were carried out on a high-resolution microcomputed tomography (microCT) system. Gamma-emitting sources: 3.0m

  10. Production of candidate natural matrix reference materials for micro-analytical techniques

    International Nuclear Information System (INIS)

    Homogeneity is considered to be the most vital prerequisite for a certified reference material (CRM); more stringent requirements exist for the analysis of small subsamples. Many of the natural matrix CRMs are prepared from bulk samples by grinding and milling them to a certain particle size, which is expected to provide a more homogenous material; however recommended sample sizes for biological and environmental reference materials are found to be more than 100 mg. Since the milling of materials is costly and has some drawbacks, natural materials that already occur as small particles such as air particulate matter, certain sediments, and cellular biological materials may form the basis of the required reference materials. The nature of these materials, i.e. naturally occurring particles, may provide ideal model reference material. We describe here the production of the materials and preliminary tests, the evaluation for the micro-analytical techniques

  11. Development of miniaturized specimens for the study of neutron irradiation/plasma exposure synergistic effects on candidate fusion reactor materials

    International Nuclear Information System (INIS)

    The aim of this work is to choose a miniaturized specimen version relevant for testing candidate fusion reactor materials including mechanical testing after combined neutron irradiation/plasma exposure in a fission reactor. The material examined was reactor pressure vessel type steel in irradiated and aged (unirradiated) conditions. Comparative standard impact, three point bend and small punch tests were conducted. It is established that there is a possibility of miniaturization of irradiated steel experimental specimens by means of proper specimens type choice with mass reducing from ∼40 (Charpy) to 0.4 g (small plates). (orig.)

  12. Euro hybrid materials and structures. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hausmann, Joachim M.; Siebert, Marc (eds.)

    2016-08-01

    In order to use the materials as best as possible, several different materials are usually mixed in one component, especially in the field of lightweight design. If these combinations of materials are joined inherently, they are called multi material design products or hybrid structures. These place special requirements on joining technology, design methods and manufacturing and are challenging in other aspects, too. The eight chapters with manuscripts of the presentations are: Chapter 1- Interface: What happens in the interface between the two materials? Chapter 2 - Corrosion and Residual Stresses: How about galvanic corrosion and thermal residual stresses in the contact zone of different materials? Chapter 3 - Characterization: How to characterize and test hybrid materials? Chapter 4 - Design: What is a suitable design and dimensioning method for hybrid structures? Chapter 5 - Machining and Processing: How to machine and process hybrid structures and materials? Chapter 6 - Component Manufacturing: What is a suitable manufacturing route for hybrid structures? Chapter 7 - Non-Destructive Testing and Quality Assurance: How to assure the quality of material and structures? Chapter 8 - Joining: How to join components of different materials?.

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

    Science.gov (United States)

    Riccio, Joe; Milhoan, Jim D.

    2010-01-01

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

  14. Two spruce shoot candidate reference materials from the German environmental specimen bank

    International Nuclear Information System (INIS)

    Two new materials are introduced that might serve as useful aids for the harmonisation of analytical results. Spruce shoots, cryogenically homogenized and characterized for 50 elements from two sampling sites of the German Environmental Specimen Bank (ESB) are presented as possible third generation reference materials that might also act as calibrating materials in speciation analysis. (author)

  15. Haynes 230 Mini-Can Welding to Support Planned irradiation Testing of Candidate Space Fuel Materials

    International Nuclear Information System (INIS)

    The objective of the Space MICE-3B irradiation testing was to test uranium dioxide (UO2) and uranium nitride (UN) fuel pellets under conditions anticipated in a prototypic space reactor application. One goal of the test program was to optimize the accuracy of UN and UO2 fuel sample temperature measurement during testing. The fuel samples were required to be canned to (1) prevent sample dissociation, (2) prevent release of fission products in excess of test reactor emission thresholds, and (3) prevent chemical interaction with impurities in the helium-neon gas stream [A]. Haynes 230, a nickel-chromium-tungsten (Ni-Cr-W) high creep strength structural alloy was selected as the encapsulation material that could be easily hermetically sealed and meet material property requirements at 1550 F (1116 K), the maximum design temperature of the mini-can. Laser welding was pursued to minimize weld distortion and meet ASME Boiler and Pressure Vessel code weld qualification standards [2]. The mini-can design contained a 0.050 inch (1.3 mm) thick can lid that was to be welded to a 0.050 inch thick lip on the base can such that the lid overlapped the base lip as a lap joint (Figure la). The circumferential flat lap joint weld required a minimum depth of penetration of 0.050 inches (1.3 mm). Initially, a maximum diametrical distortion of 0.002-0.003 inches (50-75 microns) of the outside diameter of the can after welding was specified to allow for close proximity of a thermocouple near the external wall of the mini-can containing UN samples and result in improved fuel sample temperature measurement accuracy during testing. For the encapsulation of UO2 specimens a 0.01 0 inch (250 micron) diametrical distortion was allowed due to lower heat generation expected within the capsule and greater flexibility on thermocouple location. Manual gas tungsten arc welding was then developed with a V-groove weld lap joint design (Figures 1b). All welding was done in a high purity helium cover gas

  16. Simulated Solar Flare X-Ray and Thermal Cycling Durability Evaluation of Hubble Space Telescope Thermal Control Candidate Replacement Materials

    Science.gov (United States)

    deGroh, Kim K.; Banks, Bruce A.; Sechkar, Edward A.; Scheiman, David A.

    1998-01-01

    During the Hubble Space Telescope (HST) second servicing mission (SM2), astronauts noticed that the multilayer insulation (MLI) covering the telescope was damaged. Large pieces of the outer layer of MLI (aluminized Teflon fluorinated ethylene propylene (Al-FEP)) were torn in several locations around the telescope. A piece of curled up Al-FEP was retrieved by the astronauts and was found to be severely embrittled, as witnessed by ground testing. Goddard Space Flight Center (GSFC) organized a HST MLI Failure Review Board (FRB) to determine the damage mechanism of FEP in the HST environment, and to recommend replacement insulation material to be installed on HST during the third servicing mission (SM3) in 1999. Candidate thermal control replacement materials were chosen by the FRB and tested for environmental durability under various exposures and durations. This paper describes durability testing of candidate materials which were exposed to charged particle radiation, simulated solar flare x-ray radiation and thermal cycling under load. Samples were evaluated for changes in solar absorptance and tear resistance. Descriptions of environmental exposures and durability evaluations of these materials are presented.

  17. Magnetism and Structure in Functional Materials

    CERN Document Server

    Planes, Antoni; Saxena, Avadh

    2005-01-01

    Magnetism and Structure in Functional Materials addresses three distinct but related topics: (i) magnetoelastic materials such as magnetic martensites and magnetic shape memory alloys, (ii) the magnetocaloric effect related to magnetostructural transitions, and (iii) colossal magnetoresistance (CMR) and related magnanites. The goal is to identify common underlying principles in these classes of materials that are relevant for optimizing various functionalities. The emergence of apparently different magnetic/structural phenomena in disparate classes of materials clearly points to a need for common concepts in order to achieve a broader understanding of the interplay between magnetism and structure in this general class of new functional materials exhibiting ever more complex microstructure and function. The topic is interdisciplinary in nature and the contributors correspondingly include physicists, materials scientists and engineers. Likewise the book will appeal to scientists from all these areas.

  18. Radiation Effects on Spacecraft Structural Materials

    International Nuclear Information System (INIS)

    Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

  19. Multi-Material Design Optimization of Composite Structures

    DEFF Research Database (Denmark)

    Hvejsel, Christian Frier

    design of laminated composite structures is studied including the problem of orienting orthotropic material optimally. The approach taken in this work is to consider this multi-material design problem as a generalized topology optimization problem including multiple candidate materials with known...... or random search techniques. Thus, a main issue is the question of how to parametrize the originally discrete optimization problem in a manner making it suitable for solution using gradient-based algorithms. This is a central theme throughout the thesis and in particular two gradient-based approaches...... consists of a relaxation-based search heuristic that accelerates a Generalized Benders' Decomposition technique for global optimization and enables the solution of medium-scale problems to global optimality. Improvements in the ability to solve larger problems to global optimality are found and potentially...

  20. Evaluation of Landfill Site Candidate for Naturally Occurring Radioactive Materials (Norm) and Hazardous Waste

    International Nuclear Information System (INIS)

    Refers to co-location concept, Kabil site, where located at the southeast end of low hills in Batam Island, will be sited as an integrated industrial waste management center including landfill. So that, it is necessary an evaluation of the landfill site candidate for NORM and hazardous waste. The evaluation includes geological and non-geological aspects, to determine the suitability or capability in supporting the function as landfill facility. The site candidate was evaluated by serial sreps as follows: 1) criteria formulation; 2) selecting the parameter for evaluation; 3) Positive screening or evaluation of the land having potentiality for landfill site by descriptive method: and 4) determine the land suitability or capability for landfill site. The evaluation of geological and non- geological aspects include topography, litology, seismicity, groundwater and surface water, climate, hydro-oceanography, flora and fauna, spatial pattern and transportation system. The most of the parameters evaluated show the fulfilling to the site criteria, and can be mentioned that the land is suitable for landfill site. Some parameters are not so suitable for that purpose, especially on permeability and homogeneity of the rocks/soils, distance to surface water body, depth of groundwater, the flow rate of groundwater, precipitation, and humidity of the air. The lack of suitability showed by some parameters can be compensated by improving the appropriate engineered barrier in order to fulfill the landfill performance in providing the supporting capacity, long live stability and waste containment. (author)

  1. Global patterns of abundance, diversity and community structure of the Aminicenantes (candidate phylum OP8.

    Directory of Open Access Journals (Sweden)

    Ibrahim F Farag

    Full Text Available We investigated the global patterns of abundance, diversity, and community structure of members of the Aminicenantes (candidate phylum OP8. Our aim was to identify the putative ecological role(s played by members of this poorly characterized bacterial lineages in various ecosystems. Analysis of near full-length 16S rRNA genes identified four classes and eight orders within the Aminicenantes. Within 3,134 datasets comprising ∼1.8 billion high throughput-generated partial 16S rRNA genes, 47,351 Aminicenantes-affiliated sequences were identified in 913 datasets. The Aminicenantes exhibited the highest relative abundance in hydrocarbon-impacted environments, followed by marine habitats (especially hydrothermal vents and coral-associated microbiome samples, and aquatic, non-marine habitats (especially in terrestrial springs and groundwater samples. While the overall abundance of the Aminicenantes was higher in low oxygen tension as well as non-saline and low salinity habitats, it was encountered in a wide range of oxygen tension, salinities, and temperatures. Analysis of the community structure of the Aminicenantes showed distinct patterns across various datasets that appear to be, mostly, driven by habitat variations rather than prevalent environmental parameters. We argue that the detection of the Aminicenantes across environmental extremes and the observed distinct community structure patterns reflect a high level of intraphylum metabolic diversity and adaptive capabilities that enable its survival and growth in a wide range of habitats and environmental conditions.

  2. Assessment of Commutability for Candidate Certified Reference Material ERM-BB130 "Chloramphenicol in Pork"

    OpenAIRE

    Zeleny, Reinhard; EMTEBORG Per; Schimmel, Heinz

    2010-01-01

    Chloramphenicol (CAP), an effective antibiotic against many microorganisms, is meanwhile banned in the EU for treatment of food-producing animals due to adverse health effects. The Institute for Reference Materials and Measurements (IRMM) is currently developing a certified reference material (CRM) for CAP in pork, intended for validation and method performance verifications of analytical methods. The material will be certified using liquid chromatography tandem mass spectrometry (LC-MS/MS) a...

  3. Corrosion Assessment of Candidate Materials for the SHINE Subcritical Assembly Vessel and Components FY14 Report

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-10-01

    Laboratory corrosion testing of candidate alloys—including Zr-4 and Zr-2.5Nb representing the target solution vessel, and 316L, 2304, 304L, and 17-4 PH stainless steels representing process piping and balance-of-plant components—was performed in support of the proposed SHINE process to produce 99Mo from low-enriched uranium. The test solutions used depleted uranyl sulfate in various concentrations and incorporated a range of temperatures, excess sulfuric acid concentrations, nitric acid additions (to simulate radiolysis product generation), and iodine additions. Testing involved static immersion of coupons in solution and in the vapor above the solution, and was extended to include planned-interval tests to examine details associated with stainless steel corrosion in environments containing iodine species. A large number of galvanic tests featuring couples between a stainless steel and a zirconium-based alloy were performed, and limited vibratory horn testing was incorporated to explore potential erosion/corrosion features of compatibility. In all cases, corrosion of the zirconium alloys was observed to be minimal, with corrosion rates based on weight loss calculated to be less than 0.1 mil/year with no change in surface roughness. The resulting passive film appeared to be ZrO2 with variations in thickness that influence apparent coloration (toward light brown for thicker films). Galvanic coupling with various stainless steels in selected exposures had no discernable effect on appearance, surface roughness, or corrosion rate. Erosion/corrosion behavior was the same for zirconium alloys in uranyl sulfate solutions and in sodium sulfate solutions adjusted to a similar pH, suggesting there was no negative effect of uranium resulting from fluid dynamic conditions aggressive to the passive film. Corrosion of the candidate stainless steels was similarly modest across the entire range of exposures. However, some sensitivity to corrosion of the stainless steels was

  4. Collection of radiation irradiation study reports for the candidate materials and instruments in the J-PARC

    International Nuclear Information System (INIS)

    This document presents the collected reports of radiation irradiation study for the candidate materials and instruments to be used in the High Intensity Proton Accelerator Facility, J-PARC. The examinations were executed at the gamma-ray irradiation facility in JAEA Takasaki Institute. 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. This report shows the subject of the instruments or the materials in the J-PARC facility, the theme of the irradiation study, the results of examination and the selected decision of the policy for usage. (author)

  5. Science-Driven Candidate Search for New Scintillator Materials FY 2013 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Fei; Kerisit, Sebastien N.; Xie, YuLong; Wu, Dangxin; Prange, Micah P.; Van Ginhoven, Renee M.; Campbell, Luke W.; Wang, Zhiguo

    2013-10-01

    This annual report presents work carried out during Fiscal Year (FY) 2013 at Pacific Northwest National Laboratory (PNNL) under the project entitled “Science-Driven Candidate Search for New Scintillator Materials” (Project number: PL13-SciDriScintMat-PD05) and led by Dr. Fei Gao. This project is divided into three tasks, namely (1) Ab initio calculations of electronic properties, electronic response functions and secondary particle spectra; (2) Intrinsic response properties, theoretical light yield, and microscopic description of ionization tracks; and (3) Kinetics and efficiency of scintillation: nonlinearity, intrinsic energy resolution, and pulse shape discrimination. Detailed information on the findings and insights obtained in each of these three tasks are provided in this report. Additionally, papers published this fiscal year or currently in review are included in Appendix together with presentations given this fiscal year.

  6. In situ corrosion studies on candidate container materials for the underground disposal of high level radioactive waste in Boom Clay

    International Nuclear Information System (INIS)

    SCK·CEN has developed in the early 1980's, with the support of NIRAS/ONDRAF and EC, an extensive in situ corrosion program to evaluate the long-term corrosion behavior of various candidate container materials for the disposal of conditioned high-level radioactive waste and spent fuel. The in situ corrosion experiments were performed in the underground research facility, HADES, situated in the Boom Clay formation at a depth of 225 meters below ground level. These experiments place the samples either in direct contact with clay (type I), in a humid clay atmosphere (type 2), or in a concrete saturated clay atmosphere (type 3). During the period 1985--1994, twelve in situ corrosion experiments were installed in the underground laboratory. The exploitation of these experiments ended in 1996. All samples were recuperated and analyzed. The purpose of this paper is to summarize and discuss the results from the type 1 corrosion experiments (samples in direct contact with Boom Clay). Surface analyses tend to indicate that the so-called corrosion-resistant materials, e.g. stainless steels, Ni- and Ti-alloys, remain intact after exposure to Boom Clay between 16 and 170 C, whereas carbon steel presents significant pitting corrosion. Carbon steel seems to be unsuitable for the Belgian repository concept (pits up to 240microm deep are detected after direct exposure to the argillaceous environment for 2 years at 90 C). The stainless steels look very promising candidate container materials

  7. Search for a circum-planetary material and orbital period variations of short-period Kepler exoplanet candidates

    CERN Document Server

    Garai, Z; Budaj, J; Stellingwerf, R F

    2014-01-01

    A unique short-period Mercury-size Kepler exoplanet candidate KIC012557548b has been discovered recently by Rappaport et al. (2012). This object is a transiting disintegrating exoplanet with a circum-planetary material - comet-like tail. Close-in exoplanets, like KIC012557548b, are subjected to the greatest planet-star interactions. This interaction may have various forms. In certain cases it may cause formation of the comet-like tail. Strong interaction with the host star, and/or presence of an additional planet may lead to variations in the orbital period of the planet. Our main aim is to search for comet-like tails similar to KIC012557548b and for long-term orbital period variations. We are curious about frequency of comet-like tail formation among short-period Kepler exoplanet candidates. We concentrate on a sample of 20 close-in candidates with a period similar to KIC012557548b from the Kepler mission.

  8. Thermal characteristics of non-edible oils as phase change materials candidate to application of air conditioning chilled water system

    Science.gov (United States)

    Irsyad, M.; Indartono, Y. S.; Suwono, A.; Pasek, A. D.

    2015-09-01

    The addition of phase change material in the secondary refrigerant has been able to reduce the energy consumption of air conditioning systems in chilled water system. This material has a high thermal density because its energy is stored as latent heat. Based on material melting and freezing point, there are several non-edible oils that can be studied as a phase change material candidate for the application of chilled water systems. Forests and plantations in Indonesia have great potential to produce non-edible oil derived from the seeds of the plant, such as; Calophyllum inophyllum, Jatropha curcas L, and Hevea braziliensis. Based on the melting temperature, these oils can further studied to be used as material mixing in the secondary refrigerant. Thermal characteristics are obtained from the testing of T-history, Differential Scanning Calorimetric (DSC) and thermal conductivity materials. Test results showed an increase in the value of the latent heat when mixed with water with the addition of surfactant. Thermal characteristics of each material of the test results are shown completely in discussion section of this article.

  9. Steels from materials science to structural engineering

    CERN Document Server

    Sha, Wei

    2013-01-01

    Steels and computer-based modelling are fast growing fields in materials science as well as structural engineering, demonstrated by the large amount of recent literature. Steels: From Materials Science to Structural Engineering combines steels research and model development, including the application of modelling techniques in steels.  The latest research includes structural engineering modelling, and novel, prototype alloy steels such as heat-resistant steel, nitride-strengthened ferritic/martensitic steel and low nickel maraging steel.  Researchers studying steels will find the topics vital to their work.  Materials experts will be able to learn about steels used in structural engineering as well as modelling and apply this increasingly important technique in their steel materials research and development. 

  10. Development of the structural materials information center

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where data and information on the time variation of concrete and other structural material properties under the influence of pertinent environmental stressors and aging factors are being collected and assembled into a data base. This data base will be used to assist in the prediction of potential long-term deterioration of critical structural components in nuclear power plants and to establish limits on hostile environmental exposure for these structures and materials. Two complementary data base formats have been developed. The Structural Materials Handbook is an expandable, hard-copy reference document that contains complete sets of data and information for selected portland cement concrete, metallic reinforcement prestressing tendon, and structural steel materials. Baseline data, reference properties and environmental information are presented in the hand book as tables, notes and graphs. The handbook, which will be published inn four volumes, serves as the information source for the electronic data base. The Structural Materials Electronic Data Base is accessible by an IBM-compatible personal computer and provides an efficient means for searching the various data base files to locate materials with similar properties. Properties are reported in the International System of Units (SI) and in customary units whenever possible

  11. Development of the Structural Materials Information Center

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where data and information on the time variation of concrete and other structural material properties under the influence of pertinent environmental stressors and aging factors are being collected and assembled into a data base. This data base will be used to assist in the prediction of potential long-term deterioration of critical structural components in nuclear power plants and to establish limits on hostile environmental exposure for these structures and materials. Two complementary data base formats have been developed. The Structural Materials Handbook is an expandable, hard-copy reference document that contains complete sets of data and information for selected portland cement concrete, metallic reinforcement, prestressing tendon, and structural steel materials. Baseline data, reference properties and environmental information are presented in the handbook as tables, notes and graphs. The handbook, which will be published in four volumes, serves as the information source for the electronic data base. The Structural Materials Electronic Data Base is accessible by an IBM-compatible personal computer and provides an efficient means for searching the various data base files to locate materials with similar properties. Properties will be reported in the International System of Units (SI) and in customary units whenever possible. 7 refs., 3 figs., 4 tabs

  12. Data base on structural materials aging properties

    Energy Technology Data Exchange (ETDEWEB)

    Oland, C.B.

    1992-03-01

    The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where long-term and environment-dependent properties of concretes and other structural materials are being collected and assembled into a data base. These properties will be used to evaluate the current condition of critical structural components in nuclear power plants and to estimate the future performance of these materials during the continued service period.

  13. Report on Reactor Physics Assessment of Candidate Accident Tolerant Fuel Cladding Materials in LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Jeffrey J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan [Univ. of Tennessee, Knoxville, TN (United States); Maldonado, G. Ivan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Worrall, Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-28

    This work focuses on ATF concepts being researched at Oak Ridge National Laboratory (ORNL), expanding on previous studies of using alternate cladding materials in pressurized water reactors (PWRs). The neutronic performance of two leading alternate cladding materials were assessed in boiling water reactors (BWRs): iron-chromium-aluminum (FeCrAl) cladding, and silicon carbide (SiC)-based composite cladding. This report fulfills ORNL Milestone M3FT-15OR0202332 within the fiscal year 2015 (FY15)

  14. Crevice Corrosion Behavior of Candidate Nuclear Waste Container Materials in Repository Environment

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua; J. Sarver; W. Mohn

    2001-11-08

    Alloy 22 (UNS N06022) and Ti Grade 7 (UNS R52400) have been proposed as the corrosion resistant materials for fabricating the waste package outer barrier and the drip shield, respectively for the proposed nuclear waste repository Yucca Mountain Project. In this work, the susceptibility of welded and annealed Alloy 22 (N06022) and Ti Grade 7 (UNS R52400) to crevice corrosion was studied by the Multiple Crevice Assembly (ASTM G78) method combined with surface morphological observation after four and eight weeks of exposure to the Basic Saturated Water (BSW-12) in a temperature range from 60 to 105 C. The susceptibility of the materials to crevice corrosion was evaluated based on the appearance of crevice attack underneath the crevice formers and the weight loss data. The results showed that, after exposed to BSW-12 for four and eight weeks, no obvious crevice attack was observed on these materials. The descaled weight loss increased with the increase in temperature for all materials. The weight loss, however, is believed to be caused by general corrosion, rather than crevice corrosion. There was no significant difference between the annealed and welded materials either. On the other hand, to conclude that these materials are immune to crevice corrosion in BSW-12 will require longer term testing.

  15. Characterisation of bentonites from Kutch, India and Milos, Greece - some candidate tunnel back-fill materials?

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Siv; Karnland, Ola (Clay Technology AB, Lund (Sweden))

    2009-12-15

    During the past decades comprehensive investigations have been made on bentonite clays in order to find optimal components of the multi-barrier system of repositories for radioactive waste. The present study gives a mineralogical characterisation of some selected bentonites, in order to supply some of the necessary background data on the bentonites for evaluating their potential as tunnel back-fill materials. Two bentonites from the island of Milos, Greece (Milos BF 04 and BF 08), and two bentonites from Kutch, India (Kutch BF 04 and BF 08) were analysed for their grain size distribution, cation exchange properties and chemical composition. The mineralogical composition was determined by X-ray diffraction analysis and evaluated quantitatively by use of the Siroquant software. Both the bulk bentonite and the <1mum fraction were analyzed when relevant. Prior to the chemical analyses the <1 mum fractions were converted to homo-ionic clays and purified by dialysis. The chemical data were used for calculating the structural formula of the smectites. Milos BF 04 contains ca. 10% particles >63 mum. The bentonite is distinguished by a high content of dolomite and calcite, which make up almost 25% of the bulk sample. The major accessory minerals are K-feldspars and plagioclase, whereas the content of sulphur-bearing minerals is very low (0.06% total S). Smectite makes up around 60% of the bulk sample, which has a CEC value of 73 meq/100 g. The pool of interlayer cations has a composition Mg>Ca>>Na>>K. The X-ray diffraction characteristics and the high potassium content (1.03% K{sub 2}O) of the <1 mum fraction suggest that the smectite is interstratified with ca. 10% illitic layers. Based on the charge distribution the smectite should be classified as montmorillonite and according to the structural formula, Mg predominates over Fe in the octahedral sheet. However, remnants of Mg-carbonates, if present, may be a source of error in the formula calculation. Milos BF 08 has a

  16. Smart materials and structures: what are they?

    Science.gov (United States)

    Spillman, W. B., Jr.; Sirkis, J. S.; Gardiner, P. T.

    1996-06-01

    There has been considerable discussion in the technical community on a number of questions concerned with smart materials and structures, such as what they are, whether smart materials can be considered a subset of smart structures, whether a smart structure and an intelligent structure are the same thing, etc. This discussion is both fueled and confused by the technical community due to the truly multidisciplinary nature of this new field. Smart materials and structures research involves so many technically diverse fields that it is quite common for one field to completely misunderstand the terminology and start of the art in other fields. In order to ascertain whether a consensus is emerging on a number of questions, the technical community was surveyed in a variety of ways including via the internet and by direct contact. The purpose of this survey was to better define the smart materials and structures field, its current status and its potential benefits. Results of the survey are presented and discussed. Finally, a formal definition of the field of smart materials and structures is proposed.

  17. Progress in the US program to develop low-activation structural materials for fusion

    International Nuclear Information System (INIS)

    It has long been recognized that attainment of the safety and environmental potential of fusion energy requires the successful development of low-activation materials for the first wall, blanket and other high heat flux structural components. Only a limited number of materials potentially possess the physical, mechanical and low-activation characteristics required for this application. The current US structural materials research effort is focused on three candidate materials: advanced ferritic steels, vanadium alloys, and silicon carbide composites. Recent progress has been made in understanding the response of these materials to neutron irradiation. (author)

  18. Progress in the U.S. program to develop low-activation structural materials for fusion

    International Nuclear Information System (INIS)

    It has long been recognized that attainment of the safety and environmental potential of fusion energy requires the successful development of low-activation materials for the first wall, blanket and other high heat flux structural components. Only a limited number of materials potentially possess the physical, mechanical and low-activation characteristics required for this application. The current U.S. structural materials research effort is focused on three candidate materials: advanced ferritic steels, vanadium alloys, and silicon carbide composites. Recent progress has been made in understanding the response of these materials to neutron irradiation. (author)

  19. Characterisation of bentonites from Kutch, India and Milos, Greece - some candidate tunnel back-fill materials?

    International Nuclear Information System (INIS)

    During the past decades comprehensive investigations have been made on bentonite clays in order to find optimal components of the multi-barrier system of repositories for radioactive waste. The present study gives a mineralogical characterisation of some selected bentonites, in order to supply some of the necessary background data on the bentonites for evaluating their potential as tunnel back-fill materials. Two bentonites from the island of Milos, Greece (Milos BF 04 and BF 08), and two bentonites from Kutch, India (Kutch BF 04 and BF 08) were analysed for their grain size distribution, cation exchange properties and chemical composition. The mineralogical composition was determined by X-ray diffraction analysis and evaluated quantitatively by use of the Siroquant software. Both the bulk bentonite and the 63 μm. The bentonite is distinguished by a high content of dolomite and calcite, which make up almost 25% of the bulk sample. The major accessory minerals are K-feldspars and plagioclase, whereas the content of sulphur-bearing minerals is very low (0.06% total S). Smectite makes up around 60% of the bulk sample, which has a CEC value of 73 meq/100 g. The pool of interlayer cations has a composition Mg>Ca>>Na>>K. The X-ray diffraction characteristics and the high potassium content (1.03% K2O) of the Na>Mg>>K. The 2O) which indicates that also this smectite may be interstratified with a few percent illitic layers. Based on the charge distribution the smectite should be classified as montmorillonite but in this case Fe predominates over Mg in the octahedral sheet. The structural formula suggests that this smectite has the lowest total layer charge of the smectites examined. Kutch BF 04 contains essentially no particles >63 μm. The bentonite has a high content of titanium and iron-rich accessory minerals, such as anatase, magnetite, hematite and goethite. Other accessory minerals of significance are feldspars and quartz, whereas the content of sulphur

  20. Science-Driven Candidate Search for New Scintillator Materials: FY 2014 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Kerisit, Sebastien N.; Gao, Fei; Xie, YuLong; Campbell, Luke W.; Wu, Dangxin; Prange, Micah P.

    2014-10-01

    This annual reports presents work carried out during Fiscal Year (FY) 2014 at Pacific Northwest National Laboratory (PNNL) under the project entitled “Science-Driven Candidate Search for New Scintillator Materials” (Project number: PL13-SciDriScintMat-PD05) and led by Drs. Fei Gao and Sebastien N. Kerisit. This project is divided into three tasks: 1) Ab initio calculations of electronic properties, electronic response functions and secondary particle spectra; 2) Intrinsic response properties, theoretical light yield, and microscopic description of ionization tracks; and 3) Kinetics and efficiency of scintillation: nonproportionality, intrinsic energy resolution, and pulse shape discrimination. Detailed information on the results obtained in each of the three tasks is provided in this Annual Report. Furthermore, peer-reviewed articles published this FY or currently under review and presentations given this FY are included in Appendix. This work was supported by the National Nuclear Security Administration, Office of Nuclear Nonproliferation Research and Development (DNN R&D/NA-22), of the U.S. Department of Energy (DOE).

  1. Localized corrosion of a candidate container material for high-level nuclear waste disposal

    International Nuclear Information System (INIS)

    Localized corrosion is one of the important considerations in the design of metallic containers used for the geologic disposal of high-level nuclear waste. This paper addresses the effect of environmental factors on the localized corrosion behavior of alloy 825, one of the candidate alloys for containers in the Yucca Mountain repository site. A two-level, full factorial experimental design was used to examine the main effects and interactions of chloride, sulfate, nitrate, fluoride, and temperature. This was augmented by additional experiments involving chloride and temperature at several levels. Cyclic, potentiodynamic polarization tests were used to determine the relative susceptibility of the alloy to localized corrosion. Crevice corrosion was detected at chloride levels as low as 20 ppm, and both pitting and crevice corrosion were observed at higher chloride levels. Among the environmental factors, chloride and sulfate were found to be promoters of localized corrosion, while nitrate and fluoride were inhibitors of localized corrosion. The experiments indicated that the electrochemical parameters (e.g., pitting potential, repassivation potential, or the difference between them) were not sufficient indicators of localized corrosion. Instead, the visual observation and electrochemical parameters were combined into an index, termed localized corrosion index (LCI), to quantify the extent of localized corrosion

  2. Relativistic electron gas: A candidate for nature's left-handed materials

    Science.gov (United States)

    de Carvalho, C. A. A.

    2016-05-01

    The electric permittivities and magnetic permeabilities for a relativistic electron gas are calculated from quantum electrodynamics at finite temperature and density as functions of temperature, chemical potential, frequency, and wave vector. The polarization and the magnetization depend linearly on both electric and magnetic fields, and are the sum of a zero-temperature and zero-density vacuum part with a temperature- and chemical-potential-dependent medium part. Analytic calculations lead to generalized expressions that depend on three scalar functions. In the nonrelativistic limit, results reproduce the Lindhard formula. In the relativistic case, and in the long wavelength limit, we obtain the following: (i) for ω =0 , generalized susceptibilities that reduce to known nonrelativistic limits; (ii) for ω ≠0 , Drude-type responses at zero temperature. The latter implies that both the electric permittivity ɛ and the magnetic permeability μ may be simultaneously negative, a behavior characteristic of metamaterials. This unambiguously indicates that the relativistic electron gas is one of nature's candidates for the realization of a negative index of refraction system. Moreover, Maxwell's equations in the medium yield the dispersion relation and the index of refraction of the electron gas. Present results should be relevant for plasma physics, astrophysical observations, synchrotrons, and other environments with fast-moving electrons.

  3. Candidate coffee reference material for element content: production and certification schemes adopted at CENA/USP

    International Nuclear Information System (INIS)

    Certified reference materials (CRMs) play a fundamental role in analytical chemistry establishing the traceability of measurement results and assuring accuracy and reliability. In spite of the huge importance of measurements in the food sector, Brazil does not produce CRMs to supply the demand. Consequently the acquisition of CRMs depends on imports at high costs. The coffee sector needs CRMs, however there is no material that represents the coffee composition. Since 1998, the Laboratorio de Radioisotopos (LRi) of CENA/USP has been involved in analysis of coffee. During this period, knowledge has been accumulated about several aspects of coffee, such as system of cultivation, elemental composition, homogeneity of the material, possible contaminants and physical properties of beans. Concomitantly, LRi has concentrated efforts in the field of metrology in chemistry, and now all this expertise is being used as the basis for the production of a coffee certified reference material (CRM) for inorganic element content. The scheme developed for the preparation and certification of coffee RM relies on the ISO Guides 34 and 35. The approaches for selection, collection and preparation of the material, moisture determination method, homogeneity testing, certification and long-term stability testing are discussed and a time frame for the expected accomplishments is provided. (author)

  4. Candidate coffee reference material for element content: production and certification schemes adopted at CENA/USP

    Energy Technology Data Exchange (ETDEWEB)

    Tagliaferro, Fabio Sileno; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio Arruda; Franca, Elvis Joacir de [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radioisotopos], e-mail: fabiotag@cena.usp.br, e-mail: lis@cena.usp.br, e-mail: mabacchi@cena.usp.br, e-mail: ejfranca@cena.usp.br; Bode, Peter; Bacchi, Marcio Arruda; Franca, Elvis Joacir de [Delft University of Technology, Delft (Netherlands). Interfaculty Reactor Inst.], e-mail: P.Bode@iri.tudelft.nl

    2003-07-01

    Certified reference materials (CRMs) play a fundamental role in analytical chemistry establishing the traceability of measurement results and assuring accuracy and reliability. In spite of the huge importance of measurements in the food sector, Brazil does not produce CRMs to supply the demand. Consequently the acquisition of CRMs depends on imports at high costs. The coffee sector needs CRMs, however there is no material that represents the coffee composition. Since 1998, the Laboratorio de Radioisotopos (LRi) of CENA/USP has been involved in analysis of coffee. During this period, knowledge has been accumulated about several aspects of coffee, such as system of cultivation, elemental composition, homogeneity of the material, possible contaminants and physical properties of beans. Concomitantly, LRi has concentrated efforts in the field of metrology in chemistry, and now all this expertise is being used as the basis for the production of a coffee certified reference material (CRM) for inorganic element content. The scheme developed for the preparation and certification of coffee RM relies on the ISO Guides 34 and 35. The approaches for selection, collection and preparation of the material, moisture determination method, homogeneity testing, certification and long-term stability testing are discussed and a time frame for the expected accomplishments is provided. (author)

  5. Understanding structural conservation through materials science:

    DEFF Research Database (Denmark)

    Fuster-López, Laura; Krarup Andersen, Cecil

    2014-01-01

    Mechanical properties and the structure of materials are key elements in understanding how structural interventions in conservation treatments affect cultural heritage objects. In this context, engineering mechanics can help determine the strength and stability found in art objects as it can prov...

  6. Testing the homogeneity of candidate reference materials by solid sampling - AAS and INAA

    International Nuclear Information System (INIS)

    The necessity to quantify a natural material's homogeneity with respect to its elemental distribution prior to chemical analysis of a given aliquot is emphasised. Available instruments and methods to obtain the relevant information are described. Additionally the calculation of element specific, relative homogeneity factors, HE, and of a minimum sample mass M5% to achieve 5% precision on a 95% confidence level is given. Especially, in the production and certification of Certified Reference Materials (CRMs) this characteristic information should be determined in order to provide the user with additional inherent properties of the CRM to enable more economical use of the expensive material and to evaluate further systematic bias of the applied analytical technique. (author)

  7. Quality assessment of organic coffee beans for the preparation of a candidate reference material

    International Nuclear Information System (INIS)

    A random sampling was carried out in the coffee beans collected for the preparation of the organic green coffee reference material in view of assessing the homogeneity and the presence of soil as impurity. Fifteen samples were taken for the between-sample homogeneity evaluation. One of the samples was selected and 10 test portions withdrawn for the within-sample homogeneity evaluation. Br, Ca, Co, Cs, Fe, K, Na, Rb, Sc and Zn were determined by instrumental neutron activation analysis (INAA). The F-test demonstrated that the material is homogeneous for Ca, Co, Cs, K and Sc, but not homogeneous for Br, Fe, Na, Rb and Zn. Results of terrigenous elements suggested negligible soil contamination in the raw material. (author)

  8. Fe-Au and Fe-Ag composites as candidates for biodegradable stent materials.

    Science.gov (United States)

    Huang, Tao; Cheng, Jian; Bian, Dong; Zheng, Yufeng

    2016-02-01

    In this study, Fe-Ag and Fe-Au composites were fabricated by powder metallurgy using spark plasma sintering. Their microstructures, mechanical properties, and biocorrosion behavior were investigated by using optical microscopy, X-ray diffraction, environment scanning electronic microscopy, compressive test, electrochemical measurements, and immersion tests. Microstructure characterization indicated that the as-sintered iron-based materials obtained much finer grains than that of as-cast pure iron. Phase analysis showed that the Fe-Ag composites were composed of α-Fe and pure Ag phases, and Fe-Au composites consisted of α-Fe and Au phases. Compressive test showed that the improved mechanical strengths were obtained in as-sintered iron-based materials, among which the Fe-5 wt %Ag exhibited the best mechanical properties. The electrochemical and immersion tests revealed that the addition of Ag and Au could increase the corrosion rate of the iron matrix and change the corrosion mode into more uniform one. Based on the results of cytotoxicity evaluation, it was found that all the experimental material extracts performed no significant toxicity on the L-929 cells and EA. hy-926 cells, whereas a considerable inhibition on the proliferation of vascular smooth muscle cells was observed. The hemocompatibility tests showed that the hemolysis of all the experimental materials was within the range of 5%, which is the criteria value of biomaterials with good hemocomaptibility. The amount of platelet adhered on the surface of as-sintered iron-based materials was lower than that of as-cast pure iron, and the morphology of platelets kept smoothly spherical on the surface of all the experimental materials. PMID:25727071

  9. Structural materials for fission & fusion energy

    Directory of Open Access Journals (Sweden)

    Steven J. Zinkle

    2009-11-01

    Full Text Available Structural materials represent the key for containment of nuclear fuel and fission products as well as reliable and thermodynamically efficient production of electrical energy from nuclear reactors. Similarly, high-performance structural materials will be critical for the future success of proposed fusion energy reactors, which will subject the structures to unprecedented fluxes of high-energy neutrons along with intense thermomechanical stresses. Advanced materials can enable improved reactor performance via increased safety margins and design flexibility, in particular by providing increased strength, thermal creep resistance and superior corrosion and neutron radiation damage resistance. In many cases, a key strategy for designing high-performance radiation-resistant materials is based on the introduction of a high, uniform density of nanoscale particles that simultaneously provide good high temperature strength and neutron radiation damage resistance.

  10. Preparation of Nickel Materials with Fractal Structure

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A way of manufacturing nickel material with fractal structure has been studied. Some algae with natural fractalstructure were used as the basic substrates. The nickel was coated on the substrates by both electroless depositionand electrodeposition. After elimination of the foundational algae by erosion, dissolution etc, the pure nickel materialswith fractal structure were obtained. At last, the specific surface area was analyzed by BET analyses and the fractaldimension of the nickel material was calculated by means of box-counting technique. The comparison of fractaldimension between Ni structure and natural algae was also given.

  11. Structure and thermal stability of nanocrystalline materials

    Indian Academy of Sciences (India)

    B S Murty; M K Datta; S K Pabi

    2003-02-01

    Nanocrystalline materials, which are expected to play a key role in the next generation of human civilization, are assembled with nanometre-sized “building blocks” consisting of the crystalline and large volume fractions of intercrystalline components. In order to predict the unique properties of nanocrystalline materials, which are a combination of the properties of the crystalline and intercrystalline regions, it is essential to understand precisely how the structures of crystalline and intercrystalline regions vary with decrease in crystallite size. In addition, study of the thermal stability of nanocrystalline materials against significant grain growth is both scientific and technological interest. A sharp increase in grain size (to micron levels) during consolidation of nanocrystalline powders to obtain fully dense materials may consequently result in the loss of some unique properties of nanocrystalline materials. Therefore, extensive interest has been generated in exploring the size effects on the structure of crystalline and intercrystalline region of nanocrystalline materials, and the thermal stability of nanocrystalline materials against significant grain growth. The present article is aimed at understanding the structure and stability of nanocrystalline materials.

  12. Determination of cadmium, lead and zinc in a candidate reference materials using isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    The growing demands placed on analytical laboratories to ensure the reliability of their results, due to the introduction of systems of quality and to the increasing use of metrology in chemical measurements has led most laboratories to validate their methodologies and to control them statistically. One of the techniques used most often for these purposes is based on the use of reference materials. The proper use of these materials means that laboratory results may be traced to the International System of Units, analytical methodologies can be validated, instruments calibrated and chemical measurements harmonized. One of the biggest challenges in developing reference materials is that of certifying their properties, a process that has been defined as assigning a concentration value that is as close as possible to the true value together with its uncertainty. Organizations that produce reference materials use several options for their certification process, and among these is the use of a primary method. Among the primary methods recognized by the International Office of Weights and Measures is the Isotope Dilution Mass Spectrometry technique. The Chilean Nuclear Energy Commission, through its Reference Materials Program, has prepared a reference material of clam tissue, which has been chemically defined by different analytical methodologies applied in different national and international laboratories. This work describes the methodology developed with the CIEMAT for determining the elements lead, cadmium and zinc in the clam tissue reference material using the primary technique of Isotope Dilution Mass Spectrometry. The calculation is described for obtaining the spike amounts to be added to the sample and the procedure is explained for carrying out the isotopic exchange. The isotopic relationships 204Pb/205Pb, 111Cd/114Cd and 66Zn/67Zn were determined in an atomic emission spectrometer with a plasma source with the following characteristics: plasma ionization

  13. Charge, spin and orbital order in the candidate multiferroic material LuFe{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Groot, Joost de

    2012-06-28

    This thesis is a detailed study of the magnetic, structural and orbital order parameters of the candidate multiferroic material LuFe{sub 2}O{sub 4}. Multiferroic oxides with a strong magnetoelectric coupling are of high interest for potential information technology applications, but they are rare because the traditional mechanism of ferroelectricity is incompatible with magnetism. Consequently, much attention is focused on various unconventional mechanisms of ferroelectricity. Of these, ferroelectricity originating from charge ordering (CO) is particularly intriguing because it potentially combines large electric polarizations with strong magneto-electric coupling. However, examples of oxides where this mechanism occurs are exceedingly rare and none is really well understood. LuFe{sub 2}O{sub 4} is often cited as the prototypical example of CO-based ferroelectricity. In this material, the order of Fe valences has been proposed to render the triangular Fe/O bilayers polar by making one of the two layers rich in Fe{sup 2+} and the other rich in Fe{sup 3+}, allowing for a possible ferroelectric stacking of the individual bilayers. Because of this new mechanism for ferroelectricity, and also because of the high transition temperatures of charge order (T{sub CO} {proportional_to}320K) and ferro magnetism (T{sub N}{proportional_to}240 K) LuFe{sub 2}O{sub 4} has recently attracted increasing attention. Although these polar bilayers are generally accepted in the literature for LuFe{sub 2}O{sub 4}, direct proof is lacking. An assumption-free experimental determination of whether or not the CO in the Fe/O bilayers is polar would be crucial, given the dependence of the proposed mechanism of ferroelectricity from CO in LuFe{sub 2}O{sub 4} on polar bilayers. This thesis starts with a detailed characterization of the macroscopic magnetic properties, where growing ferrimagnetic contributions observed in magnetization could be ascribed to increasing oxygen off-stoichiometry. The

  14. Engineered materials characterization report for the Yucca Mountain Site Characterization Project. Volume 1, Introduction, history, and current candidates

    International Nuclear Information System (INIS)

    The purpose of the Yucca Mountain Site Characterization Project is to evaluate Yucca Mountain for its suitability as a potential site for the nation's first high-level nuclear waste repository. As part of this effort, Lawrence Livermore National Laboratory (LLNL) has been occupied for a number of years with developing and evaluating the performance of waste packages for the potential repository. In recent years this work has been carried out under the guidance of and in collaboration with the Management and Operating contractor for the Civilian Radioactive Waste Management System, TRW Environmental Safety Systems, Inc., which in turn reports to the Office of Civilian Radioactive Waste Management of the US Department of Energy. This report summarizes the history of the selection and characterization of materials to be used in the engineered barrier system for the potential repository at Yucca Mountain, describes the current candidate materials, presents a compilation of their properties, and summarizes available corrosion data and modeling. The term ''engineered materials'' is intended to distinguish those materials that are used as part of the engineered barrier system from the natural, geologic materials of the site

  15. Structural characterization of the mechanosensitive channel candidate MCA2 from Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Hideki Shigematsu

    Full Text Available Mechanosensing in plants is thought to be governed by sensory complexes containing a Ca²⁺-permeable, mechanosensitive channel. The plasma membrane protein MCA1 and its paralog MCA2 from Arabidopsis thaliana are involved in mechanical stress-induced Ca²⁺ influx and are thus considered as candidates for such channels or their regulators. Both MCA1 and MCA2 were functionally expressed in Sf9 cells using a baculovirus system in order to elucidate their molecular natures. Because of the abundance of protein in these cells, MCA2 was chosen for purification. Purified MCA2 in a detergent-solubilized state formed a tetramer, which was confirmed by chemical cross-linking. Single-particle analysis of cryo-electron microscope images was performed to depict the overall shape of the purified protein. The three-dimensional structure of MCA2 was reconstructed at a resolution of 26 Å from 5,500 particles and appears to comprise a small transmembrane region and large cytoplasmic region.

  16. Structural Materials and Fuels for Space Power Plants

    Science.gov (United States)

    Bowman, Cheryl; Busby, Jeremy; Porter, Douglas

    2008-01-01

    A fission reactor combined with Stirling convertor power generation is one promising candidate in on-going Fission Surface Power (FSP) studies for future lunar and Martian bases. There are many challenges for designing and qualifying space-rated nuclear power plants. In order to have an affordable and sustainable program, NASA and DOE designers want to build upon the extensive foundation in nuclear fuels and structural materials. This talk will outline the current Fission Surface Power program and outline baseline design options for a lunar power plant with an emphasis on materials challenges. NASA first organized an Affordable Fission Surface Power System Study Team to establish a reference design that could be scrutinized for technical and fiscal feasibility. Previous papers and presentations have discussed this study process in detail. Considerations for the reference design included that no significant nuclear technology, fuels, or material development were required for near term use. The desire was to build upon terrestrial-derived reactor technology including conventional fuels and materials. Here we will present an overview of the reference design, Figure 1, and examine the materials choices. The system definition included analysis and recommendations for power level and life, plant configuration, shielding approach, reactor type, and power conversion type. It is important to note that this is just one concept undergoing refinement. The design team, however, understands that materials selection and improvement must be an integral part of the system development.

  17. Homogeneity study on biological candidate reference materials: the role of neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Daniel P.; Moreira, Edson G., E-mail: dsilva.pereira@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Instrumental Neutron activation Analysis (INAA) is a mature nuclear analytical technique able to accurately determine chemical elements without the need of sample digestion and, hence, without the associated problems of analyte loss or contamination. This feature, along with its potentiality use as a primary method of analysis, makes it an important tool for the characterization of new references materials and in the assessment of their homogeneity status. In this study, the ability of the comparative method of INAA for the within-bottle homogeneity of K, Mg, Mn and V in a mussel reference material was investigated. Method parameters, such as irradiation time, sample decay time and distance from sample to the detector were varied in order to allow element determination in subsamples of different sample masses in duplicate. Sample masses were in the range of 1 to 250 mg and the limitations of the detection limit for small sample masses and dead time distortions for large sample masses were investigated. (author)

  18. Homogeneity study on biological candidate reference materials: the role of neutron activation analysis

    International Nuclear Information System (INIS)

    Instrumental Neutron activation Analysis (INAA) is a mature nuclear analytical technique able to accurately determine chemical elements without the need of sample digestion and, hence, without the associated problems of analyte loss or contamination. This feature, along with its potentiality use as a primary method of analysis, makes it an important tool for the characterization of new references materials and in the assessment of their homogeneity status. In this study, the ability of the comparative method of INAA for the within-bottle homogeneity of K, Mg, Mn and V in a mussel reference material was investigated. Method parameters, such as irradiation time, sample decay time and distance from sample to the detector were varied in order to allow element determination in subsamples of different sample masses in duplicate. Sample masses were in the range of 1 to 250 mg and the limitations of the detection limit for small sample masses and dead time distortions for large sample masses were investigated. (author)

  19. Testing of candidate waste-package backfill and canister materials for basalt

    International Nuclear Information System (INIS)

    The Basalt Waste Isolation Project (BWIP) is developing a multiple-barrier waste package to contain high-level nuclear waste as part of an overall system (e.g., waste package, repository sealing system, and host rock) designed to isolate the waste in a repository located in basalt beneath the Hanford Site, Richland, Washington. The three basic components of the waste package are the waste form, the canister, and the backfill. An extensive testing program is under way to determine the chemical, physical, and mechanical properties of potential canister and backfill materials. The data derived from this testing program will be used to recommend those materials that most adequately perform the functions assigned to the canister and backfill

  20. Composition and long-term safety of salt deposits as candidate sites for toxic material dumping

    International Nuclear Information System (INIS)

    For the evaluation of the long-term safety of toxic material dumps in salt bodies, it is necessary to understand also the potential processes in the rock and to evaluate their effects on the dump. The scientific fundamentals are observations on the geological situation as well as the mineralogical and chemical composition of the rock in which the dump is planned to be constructed. Knowledge on the existing geological, mineralogical and physico-chemical conditions of formation and transformation of evaporite allow a quantitative interpretation of mineral reactions and material transfers, which have taken place in the geological past. This working principle is independent of location. It is exemplarily applied to the Gorleben salt dome. (orig./DG)

  1. Inorganic material candidates to replace a metallic or non-metallic concrete containment liner

    International Nuclear Information System (INIS)

    Internal liners for concrete containments are generally organic or metals. They have to be able to inhibit radioactive leakage into the environment, but both types have shortcomings. The results of research to develop a better liner are published in this paper. The best material found was fibre-reinforced mortar. Of the fibres considered, steel, kevlar and glass were the best, each showing advantages and disadvantages. 1 ref., 9 tabs., 12 figs

  2. Systematic Study of Trace Radioactive Impurities in Candidate Construction Materials for EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, D.S.; Grinberg, P.; Weber, P.; Baussan, E.; Djurcic, Z.; Keefer, G.; Piepke, A.; Pocar, A.; Vuilleumier, J.-L.; Vuilleumier, J.-M.; Akimov, D.; Bellerive, A.; Bowcock, M.; Breidenbach, M.; Burenkov, A.; Conley, R.; Craddock, W.; Danilov, M.; DeVoe, R.; Dixit, M.; Dolgolenko, A.; /Alabama U. /NRC-INMS /Neuchatel U. /Stanford U., Phys. Dept. /SLAC /Colorado State U. /Laurentian U. /Maryland U. /UC, Irvine

    2007-10-24

    The Enriched Xenon Observatory (EXO) will search for double beta decays of 136Xe. We report the results of a systematic study of trace concentrations of radioactive impurities in a wide range of raw materials and finished parts considered for use in the construction of EXO-200, the first stage of the EXO experimental program. Analysis techniques employed, and described here, include direct gamma counting, alpha counting, neutron activation analysis, and high-sensitivity mass spectrometry.

  3. Study of Clay Materials as Host Rock for Candidate of Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    Generally some rock types such as crystalline, volcanic and clay materials have been using as host rock for radwaste disposal site. Objective of the paper is to completing the clays study for radwaste disposal through literature study which has related to information of clay. The characteristic of clay rocks, both physically and chemically has good potential for radwaste disposal site, due to this reason the clay rocks has been used for radwaste disposal in another countries. (author)

  4. A Straightforward and Automated Open Database Analysis as a First Sweep for Candidate Materials

    OpenAIRE

    Joachim Breternitz; Gregory, Duncan H.

    2015-01-01

    The storage of hydrogen is considered as the bottleneck in the implementation of portable fuel cell power generating systems. The necessary experimental studies to discover and develop appropriate storage materials are always time-limited. We discuss herein the approach of an uncomplicated and accessible computationally based analysis of database knowledge towards the identification of promising storage systems. The open access policy of the Crystallography Open Database (COD) invites researc...

  5. Systematic study of trace radioactive impurities in candidate construction materials for EXO-200

    CERN Document Server

    Leonard, D S; Weber, P; Baussan, E; Djurcic, Z; Keefer, G; Piepke, A; Pocar, A; Vuilleumier, J -L; Vuilleumier, J -M; Akimov, D; Bellerive, A; Bowcock, M; Breidenbach, M; Burenkov, A; Conley, R; Craddock, W; Danilov, M; DeVoe, R; Dixit, M; Dolgolenko, A; Ekchtout, I; Fairbank, W; Farine, J; Fierlinger, P; Flatt, B; Gratta, G; Green, M; Hall, C; Hall, K; Hallman, D; Hargrove, C; Herbst, R; Hodgson, J; Jeng, S; Kolkowitz, S; Kovalenko, A; Kovalenko, D; LePort, F; Mackay, D; Moe, M; Díez, M Montero; Neilson, R; Odian, A; O'Sullivan, K; Ounalli, L; Prescott, C Y; Rowson, P C; Schenker, D; Sinclair, D; Skarpaas, K; Smirnov, G; Stekhanov, V; Strickland, V; Virtue, C; Wamba, K; Wodin, J

    2007-01-01

    The Enriched Xenon Observatory (EXO) will search for double beta decays of 136Xe. We report the results of a systematic study of trace concentrations of radioactive impurities in a wide range of raw materials and finished parts considered for use in the construction of EXO-200, the first stage of the EXO experimental program. Analysis techniques employed, and described here, include direct gamma counting, alpha counting, neutron activation analysis, and high-sensitivity mass spectrometry.

  6. Tritium retention in candidate next-step protection materials: Engineering key issues and research requirements

    International Nuclear Information System (INIS)

    Although a considerable volume of valuable data on the behavior of tritium in beryllium and carbon-based armors exposed to hydrogenic fusion plasmas has been compiled over the past years both from operation of present-day tokamaks and from laboratory simulations, knowledge is far from being complete and tritium inventory predictions for these materials remain highly uncertain. In this paper the authors elucidate the main mechanisms responsible for tritium trapping and release in next step D-T tokamaks, as well as the applicability of some of the presently known database for design purposes. Due to their strong anticipated implications on the design, attention is focused mainly on codeposition and neutron damage effects. Some preliminary quantitative estimates are presented based on most recent experimental findings and latest modeling developments as well. The influence of important working conditions such as target temperature, loading particle fluxes, erosion and redeposition rates, as well as material characteristics such as the type of morphology of the protection material (i.e., amorphous plasma-sprayed beryllium vs. solid forms), and design dependent parameters are discussed in this paper. Remaining issues which require additional effort are identified

  7. Tritium retention in candidate next-step protection materials: engineering key issues and research requirements

    International Nuclear Information System (INIS)

    Although a considerable volume of valuable data on the behaviour of tritium in beryllium and carbon-based armours exposed to hydrogenic fusion plasmas has been compiled over the past years both from operation of present-day tokamaks and from laboratory simulations, knowledge is far from complete and tritium inventory predictions for these materials remain highly uncertain. In this paper we elucidate the main mechanisms responsible for tritium trapping and release in next-step D-T tokamaks, as well as the applicability of some of the presently known data bases for design purposes. Owing to their strong anticipated implications on tritium uptake and release, attention is focused mainly on the interaction of tritium with neutron damage induced defects, on tritium codeposition with eroded carbon and on the effects of oxide and surface contaminants. Some preliminary quantitative estimates are presented based on most recent experimental findings and latest modelling developments as well. The influence of important working conditions such as target temperature, loading particle fluxes, erosion and redeposition rates, as well as material characteristics such as the type of morphology of the protection material (i.e. amorphous plasma-sprayed beryllium vs. solid forms), and design dependent parameters are discussed in this paper. Remaining issues which require additional effort are identified. (orig.)

  8. Albedo calculations for candidate fusion reactor materials used in the inboard side of a compact tokamak reactor and the effects of using such materials on the tritium breeding

    International Nuclear Information System (INIS)

    In this paper the total neutron albedo and associated energy distributions for 10 candidate fusion reactor materials have been calculated. The angular distributions of reflected neutrons for monodirectional 14.1 MeV neutrons incident on slabs of Pb, Be, and W are presented and the dependence of albedo on neutron energy and incident angle has been investigated. Finally, the impact on the tritium breeding of the outboard blanket of the choice of material used in the inboard side of the reactor has been assessed. Tritium breeding ratio (TBR) calculations have shown the inadequacy of the neutron albedo concept in predicting the impact of inboard materials on the TBR of the reactor. (author)

  9. Structural materials challenges for fusion power systems

    International Nuclear Information System (INIS)

    Full text: Structural materials in a fusion power system must function in an extraordinarily demanding environment that includes various combinations of high temperatures, reactive chemicals, time-dependent thermal and mechanical stresses, and intense damaging radiation. The fusion neutron environment produces displacement damage equivalent to displacing every atom in the material about 150 times during its expected service life, and changes in chemical composition by transmutation reactions, which includes creation of reactive and insoluble gases. Fundamental materials challenges that must be resolved to effectively harness fusion power include (1) understanding the relationships between material strength, ductility and resistance to cracking, (2) development of materials with extraordinary phase stability, high-temperature strength and resistance to radiation damage, (3) establishment of the means to control corrosion of materials exposed to aggressive environments, (4) development of technologies for large-scale fabrication and joining, and (5) design of structural materials that provide for an economically attractive fusion power system while simultaneously achieving safety and environmental acceptability goals. The most effective approach to solve these challenges is a science-based effort that couples development of physics-based, predictive models of materials behavior with key experiments to validate the models. The U.S. Fusion Materials Sciences program is engaged in an integrated effort of theory, modeling and experiments to develop structural materials that will enable fusion to reach its safety, environmental and economic competitiveness goals. In this presentation, an overview of recent progress on reduced activation ferritic/martensitic steels, nanocomposited ferritic alloys, and silicon carbide fiber reinforced composites for fusion applications will be given

  10. Structure-activity relationship analysis of cytotoxic cyanoguanidines: selection of CHS 828 as candidate drug

    Directory of Open Access Journals (Sweden)

    Gullbo Joachim

    2009-06-01

    Full Text Available Abstract Background N-(6-(4-chlorophenoxyhexyl-N'-cyano-N''-4-pyridyl guanidine (CHS 828 is the first candidate drug from a novel group of anti-tumour agents – the pyridyl cyanoguanidines, shown to be potent compounds interfering with cellular metabolism (inhibition of nicotinamide phosphoribosyl transferase and NF-κB signalling. Substituted cyanoguanidines are also found in anti-hypertensive agents such as the potassium channel opener pinacidil (N-cyano-N'-(4-pyridyl-N''-(1,2,2-trimethylpropylguanidine and histamine-II receptor antagonists (e.g. cimetidine, N-cyano-N'-methyl-N''-[2-[[(5-methylimidazol-4-yl]methyl]thio]ethylguanidine. In animal studies, CHS 828 has shown very promising activity, and phase I and II studies resulted in further development of a with a water soluble prodrug. Findings To study the structural requirements for cyanoguanidine cytotoxicity a set of 19 analogues were synthesized. The cytotoxic effects were then studied in ten cell lines selected for different origins and mechanisms of resistance, using the fluorometric microculture cytotoxicity assay (FMCA. The compounds showed varying cytotoxic activity even though the dose-response curves for some analogues were very shallow. Pinacidil and cimetidine were found to be non-toxic in all ten cell lines. Starting with cyanoguanidine as the crucial core it was shown that 4-pyridyl substitution was more efficient than was 3-pyridyl substitution. The 4-pyridyl cyanoguanidine moiety should be linked by an alkyl chain, optimally a hexyl, heptyl or octyl chain, to a bulky end group. The exact composition of this end group did not seem to be of crucial importance; when the end group was a mono-substituted phenyl ring it was shown that the preferred position was 4-substitution, followed by 3- and, finally, 2-substitution as the least active. Whether the substituent was a chloro, nitro or methoxy substituent seemed to be of minor importance. Finally, the activity patterns in the

  11. Optimization on electrochemical synthesis of HKUST-1 as candidate catalytic material for Green diesel production

    Science.gov (United States)

    Lestari, W. W.; Nugraha, R. E.; Winarni, I. D.; Adreane, M.; Rahmawati, F.

    2016-04-01

    In the effort to support the discovery of new renewable energy sources in Indonesia, biofuel is one of promising options. The conversion of vegetable oil into ready-biofuel, especially green diesel, needs several steps, one of which is a hydrogenation or hydro-deoxygenation reaction. In this case, the catalyst plays a very important role regarding to its activity and selectivity, and Metal-Organic Frameworks (MOFs) becoming a new generation of heterogeneous catalyst in this area. In this research, a preliminary study to optimize electrochemical synthesis of the catalytic material based on MOFs, namely HKUST-1 [Cu3(BTC)2], has been conducted. Some electrochemical reaction parameters were tested, for example by modifying the electrochemical synthetic conditions, i.e. by performing variation of voltages (12, 13, 14, and 15 Volt), temperatures (RT, 40, 60, and 80 °C) and solvents (ethanol, water, methanol and dimethyl-formamide (DMF)). Material characterization was carried out by XRD, SEM, FTIR, DTA/TG and SAA. The results showed that the optimum synthetic conditions of HKUST-1 are performed at room temperature in a solvent combination of water: ethanol (1: 1) and a voltage of 15 Volt for 2 hours. The XRD-analysis revealed that the resulted peaks are identical to the simulated powder pattern generated from single crystal data and comparable to the peaks of solvothermal method. However, the porosity of the resulting material through electrochemical method is still in the range of micro-pore according to IUPAC and 50% smaller than the porosity resulted from solvothermal synthesis. The corresponding compounds are thermally stable until 300 °C according to TG/DTA.

  12. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    International Nuclear Information System (INIS)

    Three copper-based alloys --- CDA 102 (OFHC copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni) --- are being considered as possible materials for the fabrication of high-level radioactive-waste disposal containers. Waste will include fuel assemblies from reactors as well as borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada, for emplacement. The three copper-based alloys discussed here are being considered in addition to the iron- to nickel-based austenitic materials discussed in Volume 3. The decay of radionuclides will result in substantial heat generation and in fluxes of gamma radiation. In this environment, container materials may degrade by atmospheric oxidation, uniform aqueous phase corrosion, pitting, crevice corrosion, transgranular stress corrosion cracking (TGSCC) in tarnishing environments, or intergranular stress corrosion cracking (IGSCC) in nontarnishing environments. This report is a critical survey of available data on the stress corrosion cracking (SCC) of the three copper-based alloys. The requisite conditions for TGSCC and IGSCC include combinations of stress, oxygen, ammonia or nitrite, and water. Note that nitrite is generated by gamma radiolysis of moisture films in air but that ammonia is not. TGSCC has been observed in CDA 102 and CDA 613 exposed to moist ammonia-containing environments whereas SCC has not been documented for CDA 715 under similar conditions. SCC is also promoted in copper by nitrite ions. Furthermore, phosphorus-deoxidized copper is unusually susceptible to embrittlement in such environments. The presence of tin in CDA 613 prevents IGSCC. It is believed that tin segregates to grain boundaries, where it oxidizes very slowly, thereby inhibiting the oxidation of aluminum. 117 refs., 27 figs., 9 tabs

  13. Dynamic and structural control utilizing smart materials and structures

    Science.gov (United States)

    Rogers, C. A.; Robertshaw, H. H.

    1989-01-01

    An account is given of several novel 'smart material' structural control concepts that are currently under development. The thrust of these investigations is the evolution of intelligent materials and structures superceding the recently defined variable-geometry trusses and shape memory alloy-reinforced composites; the substances envisioned will be able to autonomously evaluate emergent environmental conditions and adapt to them, and even change their operational objectives. While until now the primary objective of the developmental efforts presently discussed has been materials that mimic biological functions, entirely novel concepts may be formulated in due course.

  14. Oxide Thermoelectric Materials: A Structure-Property Relationship

    Science.gov (United States)

    Nag, Abanti; Shubha, V.

    2014-04-01

    Recent demand for thermoelectric materials for power harvesting from automobile and industrial waste heat requires oxide materials because of their potential advantages over intermetallic alloys in terms of chemical and thermal stability at high temperatures. Achievement of thermoelectric figure of merit equivalent to unity ( ZT ≈ 1) for transition-metal oxides necessitates a second look at the fundamental theory on the basis of the structure-property relationship giving rise to electron correlation accompanied by spin fluctuation. Promising transition-metal oxides based on wide-bandgap semiconductors, perovskite and layered oxides have been studied as potential candidate n- and p-type materials. This paper reviews the correlation between the crystal structure and thermoelectric properties of transition-metal oxides. The crystal-site-dependent electronic configuration and spin degeneracy to control the thermopower and electron-phonon interaction leading to polaron hopping to control electrical conductivity is discussed. Crystal structure tailoring leading to phonon scattering at interfaces and nanograin domains to achieve low thermal conductivity is also highlighted.

  15. Selection of candidate canister materials for high-level nuclear waste containment in a tuff repository

    International Nuclear Information System (INIS)

    A repository located at Yucca Mountain at the Nevada Test Site is a potential site for permanent geological disposal of high-level nuclear waste. The repository can be located in a horizon in welded tuff, a volcanic rock, which is above the static water level at this site. The environmental conditions in this unsaturated zone are expected to be air and water vapor dominated for much of the containment period. Type 304L stainless steel is the reference material for fabricating canisters to contain the solid high-level wastes. Alternative stainless alloys are considered because of possible susceptibility of 304L to localized and stress forms of corrosion. For the reprocessed glass wastes, the canisters serve as the recipient for pouring the glass with the result that a sensitized microstructure may develop because of the times at elevated temperatures. Corrosion testing of the reference and alternative materials has begun in tuff-conditioned water and steam environments. 21 references, 8 figures, 8 tables

  16. Compatibility of candidate overpack materials with deep argillaceous HLW disposal environments

    International Nuclear Information System (INIS)

    The Belgian R and D programme on the disposal of high level radioactive waste has been focused on the qualification of deep argillaceous formations for HLW disposal, because they have a number of inherent attractive characteristics and also because they are sufficiently abundant to cover the Belgian needs. A large number of corrosion resistant materials as well as some corrosion allowance materials have been tested. The laboratory test program included accelerated tests as well as exposure tests in simulated repository conditions. Initial ''field'' experiments have been performed in a near surface clay quarry. However, in order to obtain realistic corrosion rate estimates corrosion experiments with simultaneous monitoring of the clay environment parameters have been started in a 230 meters deep underground laboratory constructed in the Boom clay formation at Mol. Two types of experimental devices have been designed. In the first type coupons are mounted on an internally heated tubular holder and are directly exposed to the solid clay. In a second type of test a purge gas is used to extract corrosive products from the clay and circulate them subsequently over a number of metal coupons. Relevant parameters such as pH and Eh are continuously monitored for evaluating the evolution of soil agressivity after the initial chemical and mechanical disturbance of the clay, caused by the operations required for the introduction of the experimental devices. (author)

  17. Evaluation of the mechanical and physical properties of nuclear fuel candidate materials

    International Nuclear Information System (INIS)

    The most reliable material for the research and test reactor fuel is found to be U3Si2 so far. Aluminum can be added to improve the corrosion resistance when the fuel is designed in rod shape and the fuel is restrained in compressive stress. It is proposed that further development should be put forward to the study of U3Six alloy with small addition of Cu. Thus, Seven different alloys were made and fabricated in our laboratory, and the fundamental techniques related to the variation of fabrication parameters were developed in this study. Results from the heat treatment, density measurement, hardness tests and the observation of the microstructures have shown to be very close to those of other countries. These data shall be applied as a fundamental to the development of the fabrication technology for the domestic supply of KMRR nuclear fuel. (Author)

  18. Layer like porous materials with hierarchical structure.

    Science.gov (United States)

    Roth, Wieslaw J; Gil, Barbara; Makowski, Wacław; Marszalek, Bartosz; Eliášová, Pavla

    2016-06-13

    Many chemical compositions produce layered solids consisting of extended sheets with thickness not greater than a few nanometers. The layers are weakly bonded together in a crystal and can be modified into various nanoarchitectures including porous hierarchical structures. Several classes of 2-dimensional (2D) materials have been extensively studied and developed because of their potential usefulness as catalysts and sorbents. They are discussed in this review with focus on clays, layered transition metal oxides, silicates, layered double hydroxides, metal(iv) phosphates and phosphonates, especially zirconium, and zeolites. Pillaring and delamination are the primary methods for structural modification and pore tailoring. The reported approaches are described and compared for the different classes of materials. The methods of characterization include identification by X-ray diffraction and microscopy, pore size analysis and activity assessment by IR spectroscopy and catalytic testing. The discovery of layered zeolites was a fundamental breakthrough that created unprecedented opportunities because of (i) inherent strong acid sites that make them very active catalytically, (ii) porosity through the layers and (iii) bridging of 2D and 3D structures. Approximately 16 different types of layered zeolite structures and modifications have been identified as distinct forms. It is also expected that many among the over 200 recognized zeolite frameworks can produce layered precursors. Additional advances enabled by 2D zeolites include synthesis of layered materials by design, hierarchical structures obtained by direct synthesis and top-down preparation of layered materials from 3D frameworks. PMID:26489452

  19. The challenge of developing structural materials for fusion power systems

    International Nuclear Information System (INIS)

    Nuclear fusion can be one of the most attractive sources of energy from the viewpoint of safety and minimal environmental impact. Central in the goal of designing a safe, environmentally benign, and economically competitive fusion power system is the requirement for high performance, low activation materials. The general performance requirements for such materials have been defined and it is clear that materials developed for other applications (e.g. aerospace, nuclear fission, fossil energy systems) will not fully meet the needs of fusion. Advanced materials, with composition and microstructure tailored to yield properties that will satisfy the specific requirements of fusion must be developed. The international fusion programs have made significant progress towards this goal. Compositional requirements for low activation lead to a focus of development efforts on silicon carbide composites, vanadium alloys, and advanced martensitic steels as candidate structural material systems. Control of impurities will be critically important in actually achieving low activation but this appears possible. Neutron irradiation produces significant changes in the mechanical and physical properties of each of these material systems raising feasibility questions and design limitations. A focus of the research and development effort is to understand these effects, and through the development of specific compositions and microstructures, produce materials with improved and adequate performance. Other areas of research that are synergistic with the development of radiation resistant materials include fabrication, joining technology, chemical compatibility with coolants and tritium breeders and specific questions relating to the unique characteristics of a given material (e.g. coatings to reduce gas permeation in SiC composites) or design concept (e.g. electrical insulator coatings for liquid metal concepts). (orig.)

  20. Ceramic matrix composites -- Advanced high-temperature structural materials

    International Nuclear Information System (INIS)

    This symposium on Ceramic Matrix Composites: Advanced High-Temperature Structural Materials was held at the 1994 MRS Fall Meeting in Boston, Massachusetts on November 28--December 2. The symposium was sponsored by the Department of Energy's Office of Industrial Technology's Continuous Fiber Ceramic Composites Program, the Air Force Office of Scientific Research, and NASA Lewis Research Center. Among the competing materials for advanced, high-temperature applications, ceramic matrix composites are leading candidates. The symposium was organized such that papers concerning constituents--fibers and matrices--were presented first, followed by composite processing, modeling of mechanical behavior, and thermomechanical testing. More stable reinforcements are necessary to enhance the performance and life of fiber-reinforced ceramic composites, and to ensure final acceptance of these materials for high-temperature applications. Encouraging results in the areas of polymer-derived SiC fibers and single crystal oxide filaments were given, suggesting composites with improved thermomechanical properties and stability will be realized in the near future. The significance of the fiber-matrix interface in the design and performance of these materials is evident. Numerous mechanical models to relate interface properties to composite behavior, and interpret test methods and data, were enthusiastically discussed. One issue of great concern for any advanced material for use in extreme environments is stability. This theme arose frequently throughout the symposium and was the topic of focus on the final day. Fifty nine papers have been processed separately for inclusion on the data base

  1. Corrosion of structural materials by lead based reactor coolants

    International Nuclear Information System (INIS)

    Advanced nuclear reactor design has, in recent years, focused increasingly on the use of heavy-liquid-metal coolants, such as lead and lead-bismuth eutectic. Similarly, programs on accelerator-based transmutation systems have also considered the use of such coolants. Russian experience with heavy-metal coolants for nuclear reactors has lent credence to the validity of this approach. Of significant concern is the compatibility of structural materials with these coolants. We have used a thermal convection-based test method to allow exposure of candidate materials to molten lead and lead-bismuth flowing under a temperature gradient. The gradient was deemed essential in evaluating the behavior of the test materials in that should preferential dissolution of components of the test material occur we would expect dissolution in the hotter regions and deposition in the colder regions, thus promoting material transport. Results from the interactions of a Si-rich mild steel alloy, AISI S5, and a ferritic-martensitic stainless steel, HT-9, with the molten lead-bismuth are presented. (author)

  2. The future supply of and demand for candidate materials for the fabrication of nuclear fuel waste disposal containers

    International Nuclear Information System (INIS)

    This report summarizes the findings of a literature survey carried out to assess the future world supply of and demand for titanium, copper and lead. These metals are candidate materials for the fabrication of containers for the immobilization and disposal of Canada's nuclear used-fuel waste for a reference Used-fuel Disposal Centre. Such a facility may begin operation by approximately 2020, and continue for about 40 years. The survey shows that the world has abundant supplies of titanium minerals (mostly in the form of ilmenite), which are expected to last up to at least 2110. However, for copper and lead the balance between supply and demand may warrant increased monitoring beyond the year 2000. A number of factors that can influence future supply and demand are discussed in the report

  3. Formulation of a candidate glass for use as an acceptance test standard material

    International Nuclear Information System (INIS)

    In this report, the authors discuss the formulation of a glass that will be used in a laboratory testing program designed to measure the precision of test methods identified in the privatization contracts for the immobilization of Hanford low-activity wastes. Tests will be conducted with that glass to measure the reproducibility of tests and analyses that must be performed by glass producers as a part of the product acceptance procedure. Test results will be used to determine if the contractually required tests and analyses are adequate for evaluating the acceptability of likely immobilized low-activity waste (ILAW) products. They will also be used to evaluate if the glass designed for use in these tests can be used as an analytical standard test material for verifying results reported by vendors for tests withg ILAW products. The results of those tests and analyses will be presented in a separate report. The purpose of this report is to document the strategy used to formulate the glass to be used in the testing program. The low-activity waste reference glass LRM that will be used in the testing program was formulated to be compositionally similar to ILAW products to be made with wastes from Hanford. Since the ILAW product compositions have not been disclosed by the vendors participating in the Hanford privatization project, the composition of LRM was formulated based on simulated Hanford waste stream and amounts of added glass forming chemicals typical for vitrified waste forms. The major components are 54 mass % SiO2, 20 mass % Na2O, 10 mass % Al2O3, 8 mass % B2O3, and 1.5 mass % K2O. Small amounts of other chemicals not present in Hanford wastes were also included in the glass, since they may be included as chemical additives in ILAW products. This was done so that the use of LRM as a composition standard could be evaluated. Radionuclides were not included in LRM because a nonradioactive material was desired

  4. Corrosion Assessment of Candidate Materials for Fuel Cladding in Canadian SCWR

    Science.gov (United States)

    Zeng, Yimin; Guzonas, David

    2016-02-01

    The supercritical water-cooled reactor (SCWR) is an innovative next generation reactor that offers many promising features, but the high-temperature high-pressure coolant introduces unique challenges to the long-term safe and reliable operation of in-core components, in particular the fuel cladding. To achieve high thermal efficiency, the Canadian SCWR concept has a coolant core outlet temperature of 625°C at 25 MPa with a peak cladding temperature as high as 800°C. International and Canadian research programs on corrosion issues in supercritical water have been conducted to support the SCWR concept. This paper provides a brief review of corrosion in supercritical water and summarizes the Canadian corrosion assessment work on potential fuel cladding materials. Five alloys, SS 347H, SS310S, Alloy 800H, Alloy 625 and Alloy 214, have been shown to have sufficient corrosion resistance to be used as the fuel cladding. Additional work, including tests in an in-reactor loop, is needed to confirm that these alloys would work as the fuel cladding in the Canadian SCWR.

  5. Laboratory scale development of coating for improving characteristics of candidate materials for fusion reactor

    International Nuclear Information System (INIS)

    Application of coatings of refractory low atomic number materials on to different components of Tokamak type controlled thermonuclear reactor are expected to provide a degree of design flexibility. The project envisages to deal with the challenging problem on laboratory scale. Coatings investigated include carbon, beryllium, boron, titanium carbide and alumina and substrates chosen have been 304, 316 stainless steels, monel-400, molybdenum, copper, graphite, etc. For their deposition, different techniques (e.g. evaporation, sputtering and their different variants) have been tried, appropriate ones chosen and their parameters optimized. The coating composition has been analyzed using X-ray diffraction (XRD), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), Rutherford backscattering analysis (RBS) and secondary ions mass spectroscopy (SIMS). Surface morphology has been studied using scanning electron microscopy (SEM). Sebastian coating adherence tester has been used for adhesion measurement and Wilson's Tukon microhardness tester for their microhardness measurement. The coatings have been subjected to pulses from YAG laser to evaluate their thermal cycling behaviour. Deuterium ion bombardment (Energy: 20-120 keV; doses: 1019-9.3x1020 ions/cm2) behaviour has also been studied. In general, adherent and hard coatings capable of withstanding thermal cycling could be deposited. Out of the coatings studied, titanium carbide shows best results. The following pages are reprints and not mircrofiched: p. 25-32, 39-41, 57-81. Bibliographic description is on page 13

  6. Impact property at cryogenic temperature of candidate materials for fusion reactor and their electron beam welded joint

    International Nuclear Information System (INIS)

    Impact properties at cryogenic temperature of candidate materials for fusion reactor and their electron beam welded joints are investigated by using instrumented Charpy impact testing apparatus. Material used are aluminum alloys (A7N01, A5083, A6061), JFMS (Japanese Ferritic Martensitic Steel) and two kinds of high manganese steels. Although JFMS is a steel for high temperature use, the impact test is conducted at low temperature same as the cases of the other materials. Testing results are obtained as follows. 1. Base metals and welded joint of aluminum alloys exhibit high absorbed energy at low temperature. Ductility of each base metal and welded joint gradually decreases with decreasing of testing temperature. 2. Base metal and welded joint of JFMS exhibit an absorbed energy transition temperature at near a room temperature. 3. Base metal and welded joint of high manganese steel A-T (18Mn) exhibit abrupt decreasing of absorbed energy at 77K, but base metal and welded joint of high manganese steel B-T (22Mn-0.2N) exhibit gradual increasing of maximum strength and decreasing of ductility with decreasing of testing temperature. (author)

  7. The effects of gamma radiation on the corrosion of candidate materials for the fabrication of nuclear waste packages

    International Nuclear Information System (INIS)

    The influence of gamma radiation on the corrosion of candidate materials for the fabrication of nuclear waste packages has been comprehensively reviewed. The comparison of corrosion of the various materials was compared in three distinct environments: Environment A; Mg2+-enriched brines in which hydrolysis of the cation produces acidic environments and the Mg2+ interferes with the formation of protective films; Environment B; saline environments with a low Mg2+ content which remain neutral; Environment C; moist aerated conditions.The reference design of nuclear waste package for emplacement in the proposed waste repository in Yucca Mountain, Nevada, employs a dual wall arrangement, in which a 2 cm thick nickel alloy inner barrier is encapsulated within a 10 cm thick mild steel outer barrier. It is felt that this arrangement will give considerable containment lifetimes, since no common mode failure exists for the two barriers. The corrosion performance of this waste package will be determined by the exposure environment established within the emplacement drifts. Key features of the Yucca Mountain repository in controlling waste package degradation are expected to be the permanent availability of oxygen and the limited presence of water. When water contacts the surface of the waste package, its gamma radiolysis could produce an additional supply of corrosive agents. the gamma field will be produced by the radioactive decay of radionuclides within the waste form, and its magnitude will depend on the nature and age of the waste form as well as the material and wall thickness of the waste package

  8. Thermal emittance measurements on candidate refractory materials for application in nuclear space power systems

    International Nuclear Information System (INIS)

    The development of a highly efficient General Purpose Heat Source (GPHS) space power system requires that all of the available thermal energy from the GPHS modules be utilized in the most thermally efficient manner. This includes defining the heat transfer/thermal gradient profile between the surface of the GPHS's and the surface of the energy converter's hot end whose geometry is dependent on the converter technology selected. Control of the radiant heat transfer between these two surfaces is done by regulating how efficiently the selected converter's hot end surface can reject heat compared to a perfect blackbody, i.e. its infrared emittance. Several refractory materials of interest including niobium-1% zirconium, molybdenum-44.5% rhenium and L-605 (a cobalt-based alloy) were subjected to various surface treatments (grit blasting with either SiC or WC particulates) and heat treatments (up to 1198 K for up to 3000 hours). Room temperature infrared emittance values were then obtained using two different infrared reflectometers. Grit blasting with either SiC or WC tended to increase the emittance of flat or curved L-605 coupons by ∼0.2-0.3 independent of heat treatment. Heat treating L-605 coupons under 773 K for up to 2000 hours had only a slight effect on their emittance, while heat treating L-605 coupons at 973 K for over 150 hours appeared to significantly increase their emittance. For the temperatures and times studied here, the emittance values obtained on niobium-1% zirconium and molybdenum-44.5% rhenium coupons were independent of heat treat times and temperatures (except for the niobium-1% zirconium coupon that was heat treated at 1198 K for 150 hours)

  9. Joining Characteristics of Intermediate Heat Exchanger Candidate Materials in Very High Temperature Reactor(VHTR)

    International Nuclear Information System (INIS)

    Worldwide studies have shown an increasing need for energy with the use of all energy sources, ranging from renewable sources through nuclear power, gas, to a limited extent oil and finally to the most prolific fossil fuel, coal. Although this increased need for generation capacity can met with different fuel sources, maybe the main fuel worldwide for next generation is hydrogen. The very high temperature reactor(VHTR) can produce hydrogen from only heat and water by using thermochemical iodine-sulfur(I-S) process or from heat, water, and natural gas by applying the steam reformer technology to core outlet temperatures greater than about 950 .deg. C. An intermediate heat exchanger(IHX) is the component in which the heat from the primary circuit helium is transferred to the secondary circuit helium(about 950 .deg. at 1000psi), thus keeping the secondary circuit free of radioactive contamination. The IHX will be located with a pressure vessel within the reactor containment that will be attached to the reactor pressure vessel by the cross-vessel. Therefore, an intermediate heat exchanger(IHX) especially is a key component in a VHTR. The Status of the IHX design will probably be a compact, counter-flow heat exchanger design consisting of metallic plate construction with small channels etched into each plate and assembled into a module. This heat exchanger design is refereed to as a 'printed circuit heat exchanger'. Printed circuit type heat exchanger are constructed from flat metal plates into which fluid flow channels are chemically milled. The milled plates are stacked and diffusion bonded together. In this study, the effects of the brazing temperature and homogenizing time for brazed specimens on the joint and base material microstructures, elemental distribution within the microstructures and the resulting joint tensile strength and micro hardness of Ni-based superalloy such as Haynes 230 were investigated

  10. Hierarchically structured materials for lithium batteries

    International Nuclear Information System (INIS)

    The lithium-ion battery (LIB) is one of the most promising power sources to be deployed in electric vehicles, including solely battery powered vehicles, plug-in hybrid electric vehicles, and hybrid electric vehicles. With the increasing demand for devices of high-energy densities (>500 Wh kg−1), new energy storage systems, such as lithium–oxygen (Li–O2) batteries and other emerging systems beyond the conventional LIB, have attracted worldwide interest for both transportation and grid energy storage applications in recent years. It is well known that the electrochemical performance of these energy storage systems depends not only on the composition of the materials, but also on the structure of the electrode materials used in the batteries. Although the desired performance characteristics of batteries often have conflicting requirements with the micro/nano-structure of electrodes, hierarchically designed electrodes can be tailored to satisfy these conflicting requirements. This work will review hierarchically structured materials that have been successfully used in LIB and Li–O2 batteries. Our goal is to elucidate (1) how to realize the full potential of energy materials through the manipulation of morphologies, and (2) how the hierarchical structure benefits the charge transport, promotes the interfacial properties and prolongs the electrode stability and battery lifetime. (paper)

  11. Hierarchically structured materials for lithium batteries

    Science.gov (United States)

    Xiao, Jie; Zheng, Jianming; Li, Xiaolin; Shao, Yuyan; Zhang, Ji-Guang

    2013-10-01

    The lithium-ion battery (LIB) is one of the most promising power sources to be deployed in electric vehicles, including solely battery powered vehicles, plug-in hybrid electric vehicles, and hybrid electric vehicles. With the increasing demand for devices of high-energy densities (>500 Wh kg-1), new energy storage systems, such as lithium-oxygen (Li-O2) batteries and other emerging systems beyond the conventional LIB, have attracted worldwide interest for both transportation and grid energy storage applications in recent years. It is well known that the electrochemical performance of these energy storage systems depends not only on the composition of the materials, but also on the structure of the electrode materials used in the batteries. Although the desired performance characteristics of batteries often have conflicting requirements with the micro/nano-structure of electrodes, hierarchically designed electrodes can be tailored to satisfy these conflicting requirements. This work will review hierarchically structured materials that have been successfully used in LIB and Li-O2 batteries. Our goal is to elucidate (1) how to realize the full potential of energy materials through the manipulation of morphologies, and (2) how the hierarchical structure benefits the charge transport, promotes the interfacial properties and prolongs the electrode stability and battery lifetime.

  12. Ordered mesoporous silica materials with complicated structures

    KAUST Repository

    Han, Yu

    2012-05-01

    Periodically ordered mesoporous silicas constitute one of the most important branches of porous materials that are extensively employed in various chemical engineering applications including adsorption, separation and catalysis. This short review gives an introduction to recently developed mesoporous silicas with emphasis on their complicated structures and synthesis mechanisms. In addition, two powerful techniques for solving complex mesoporous structures, electron crystallography and electron tomography, are compared to elucidate their respective strength and limitations. Some critical issues and challenges regarding the development of novel mesoporous structures as well as their applications are also discussed. © 2011 Elsevier Ltd.

  13. Developing and Evaluating Candidate Materials for Generation IV Supercritical Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Sung; Kim, Sung Ho; Hwang Sung Sik and others

    2006-03-15

    High temperature mechanical behavior High temperature behavior of two F-M steels were investigated, considering the transient temperature range of the SCWR (above 800 .deg. C). T91 and T122 specimens were five times cyclically heat treated to the temperature 810 .deg. C and 845 .deg. C respectively. And the heat treatments were found to have little effect on the creep rupture behavior at 550, 600, or 650 .deg. C. However, the microstructural change was detected by the rapid hardness change after the holding the specimens at 840 .deg. C even for 10 sec. (by INL, previously ANL-W) A 20Cr Fe-base ODS alloy (MA956) was isothermally heat treated at 475 .deg. C for various times and then impact tested. The material was found to become very brittle after the heat treatment even for 100 hrs by the drastic decrease of the impact absorption energy (from 300 J to about the nil) and by the typically brittle fracture surface. (by KAIST) Corrosion and SCC Behavior in SCW (1) The corrosion behaviors of the F-M steels (T91, T92, and T122) and high Ni alloys (alloy 625, Alloy 690, and alloy 800H) and an ODS alloy (MA 956) were studied in the aerated SCW (8 ppm of D.O; dissolved oxygen) under 25 MPa from 300 to 600 .deg. C with an interval of 50 .deg. C. The test durations were 100, 200, and 500 hrs respectively. In general high Ni alloys were definitely more resistant to corrosion in SCW than F-M steels. As the Cr content increases the resistance of F-M steels to corrosion becomes better. The resistance of F-M steels to corrosion at 350 .deg. C, a subcritical temperature, was revealed to be comparatively similar to those at 550 .deg. C, a 200 .deg. C higher temperature. (2) The SCC resistance of F-M steels, T91 and T92, was evaluated by CERT (constant extension rate test) method. T91 specimens were tested at 500, 550 and 600 .deg. C in a fully deaerated SCW (below 10 ppb D.O), and SCC did not happen in the T91 specimens. T92 specimens were tested at 500 .deg. C in SCW of different

  14. Developing and Evaluating Candidate Materials for Generation IV Supercritical Water Reactors

    International Nuclear Information System (INIS)

    High temperature mechanical behavior High temperature behavior of two F-M steels were investigated, considering the transient temperature range of the SCWR (above 800 .deg. C). T91 and T122 specimens were five times cyclically heat treated to the temperature 810 .deg. C and 845 .deg. C respectively. And the heat treatments were found to have little effect on the creep rupture behavior at 550, 600, or 650 .deg. C. However, the microstructural change was detected by the rapid hardness change after the holding the specimens at 840 .deg. C even for 10 sec. (by INL, previously ANL-W) A 20Cr Fe-base ODS alloy (MA956) was isothermally heat treated at 475 .deg. C for various times and then impact tested. The material was found to become very brittle after the heat treatment even for 100 hrs by the drastic decrease of the impact absorption energy (from 300 J to about the nil) and by the typically brittle fracture surface. (by KAIST) Corrosion and SCC Behavior in SCW (1) The corrosion behaviors of the F-M steels (T91, T92, and T122) and high Ni alloys (alloy 625, Alloy 690, and alloy 800H) and an ODS alloy (MA 956) were studied in the aerated SCW (8 ppm of D.O; dissolved oxygen) under 25 MPa from 300 to 600 .deg. C with an interval of 50 .deg. C. The test durations were 100, 200, and 500 hrs respectively. In general high Ni alloys were definitely more resistant to corrosion in SCW than F-M steels. As the Cr content increases the resistance of F-M steels to corrosion becomes better. The resistance of F-M steels to corrosion at 350 .deg. C, a subcritical temperature, was revealed to be comparatively similar to those at 550 .deg. C, a 200 .deg. C higher temperature. (2) The SCC resistance of F-M steels, T91 and T92, was evaluated by CERT (constant extension rate test) method. T91 specimens were tested at 500, 550 and 600 .deg. C in a fully deaerated SCW (below 10 ppb D.O), and SCC did not happen in the T91 specimens. T92 specimens were tested at 500 .deg. C in SCW of different

  15. Developing and Evaluating Candidate Materials for Generation IV Supercritical Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Sung; Kim, Sung Ho; Hwang Sung Sik and others

    2006-03-15

    High temperature mechanical behavior High temperature behavior of two F-M steels were investigated, considering the transient temperature range of the SCWR (above 800 .deg. C). T91 and T122 specimens were five times cyclically heat treated to the temperature 810 .deg. C and 845 .deg. C respectively. And the heat treatments were found to have little effect on the creep rupture behavior at 550, 600, or 650 .deg. C. However, the microstructural change was detected by the rapid hardness change after the holding the specimens at 840 .deg. C even for 10 sec. (by INL, previously ANL-W) A 20Cr Fe-base ODS alloy (MA956) was isothermally heat treated at 475 .deg. C for various times and then impact tested. The material was found to become very brittle after the heat treatment even for 100 hrs by the drastic decrease of the impact absorption energy (from 300 J to about the nil) and by the typically brittle fracture surface. (by KAIST) Corrosion and SCC Behavior in SCW (1) The corrosion behaviors of the F-M steels (T91, T92, and T122) and high Ni alloys (alloy 625, Alloy 690, and alloy 800H) and an ODS alloy (MA 956) were studied in the aerated SCW (8 ppm of D.O; dissolved oxygen) under 25 MPa from 300 to 600 .deg. C with an interval of 50 .deg. C. The test durations were 100, 200, and 500 hrs respectively. In general high Ni alloys were definitely more resistant to corrosion in SCW than F-M steels. As the Cr content increases the resistance of F-M steels to corrosion becomes better. The resistance of F-M steels to corrosion at 350 .deg. C, a subcritical temperature, was revealed to be comparatively similar to those at 550 .deg. C, a 200 .deg. C higher temperature. (2) The SCC resistance of F-M steels, T91 and T92, was evaluated by CERT (constant extension rate test) method. T91 specimens were tested at 500, 550 and 600 .deg. C in a fully deaerated SCW (below 10 ppb D.O), and SCC did not happen in the T91 specimens. T92 specimens were tested at 500 .deg. C in SCW of different

  16. Fullerenic structures and such structures tethered to carbon materials

    Science.gov (United States)

    Goel, Anish; Howard, Jack B.; Vander Sande, John B.

    2010-01-05

    The fullerenic structures include fullerenes having molecular weights less than that of C.sub.60 with the exception of C.sub.36 and fullerenes having molecular weights greater than C.sub.60. Examples include fullerenes C.sub.50, C.sub.58, C.sub.130, and C.sub.176. Fullerenic structure chemically bonded to a carbon surface is also disclosed along with a method for tethering fullerenes to a carbon material. The method includes adding functionalized fullerene to a liquid suspension containing carbon material, drying the suspension to produce a powder, and heat treating the powder.

  17. Inner Structure of Protostellar Collapse Candidate B335 Derived from Millimeter-Wave Interferometry

    Science.gov (United States)

    Harvey, Daniel W. A.; Wilner, David J.; Myers, Philip C.; Tafalla, Mario; Mardones, Diego

    2003-02-01

    We present a study of the density structure of the protostellar collapse candidate B335 using continuum observations from the IRAM Plateau de Bure Interferometer made at wavelengths of 1.2 and 3.0 mm. We analyze these data, which probe spatial scales from 5000 to 500 AU, directly in the visibility domain by comparison with synthetic observations constructed from models that assume different physical conditions. This approach allows for much more stringent constraints to be derived from the data than from analysis of images. A single radial power law in density provides a good description of the data, with a best-fit power-law density index p=1.65+/-0.05. Through simulations, we quantify the sensitivity of this result to various model uncertainties, including assumptions of temperature distribution, outer boundary, dust opacity spectral index, and an unresolved central component. The largest uncertainty comes from the unknown presence of a centralized point source. The maximal point source, with 1.2 mm flux of F=12+/-7 mJy, reduces the power-law density index to p=1.47+/-0.07. The remaining sources of systematic uncertainty, of which the most important is the radial dependence of the temperature distribution, likely contribute a total uncertainty at the level of δpcrude model of the outflow as a hollow bipolar cone of constant opening angle improves the fit and leaves the resulting density power-law index unchanged. These results conform well to the generic paradigm of isolated, low-mass star formation, which predicts a power-law density index close to p=1.5 for an inner region of gravitational free fall onto the protostar. However, the standard inside-out collapse model does not fit the data as successfully as a simple p=1.5 power law, because of the relative shallowness of the predicted density profile just within the infall radius. Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG

  18. Materials and structures under shock and impact

    CERN Document Server

    Bailly, Patrice

    2013-01-01

    In risk studies, engineers often have to consider the consequences of an accident leading to a shock on a construction. This can concern the impact of a ground vehicle or aircraft, or the effects of an explosion on an industrial site.This book presents a didactic approach starting with the theoretical elements of the mechanics of materials and structures, in order to develop their applications in the cases of shocks and impacts. The latter are studied on a local scale at first. They lead to stresses and strains in the form of waves propagating through the material, this movement then extending

  19. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers. Final report

    International Nuclear Information System (INIS)

    One of the most significant factors impacting the performance of waste package container materials under repository relevant conditions is the thermal environment. This environment will be affected by the areal power density of the repository, which is dictated by facility design, and the dominant heat transfer mechanism at the site. The near-field environment will evolve as radioactive decay decreases the thermal output of each waste package. Recent calculations (Buscheck and Nitao, 1994) have addressed the importance of thermal loading conditions on waste package performance at the Yucca Mountain site. If a relatively low repository thermal loading design is employed, the temperature and relative humidity near the waste package may significantly affect the degradation of corrosion allowance barriers due to moist air oxidation and radiolytically enhanced corrosion. The purpose this report is to present a literature review of the potential degradation modes for moderately corrosion resistant nickel copper and nickel based candidate materials that may be applicable as alternate barriers for the ACD systems in the Yucca Mountain environment. This report presents a review of the corrosion of nickel-copper alloys, summaries of experimental evaluations of oxidation and atmospheric corrosion in nickel-copper alloys, views of experimental studies of aqueous corrosion in nickel copper alloys, a brief review of galvanic corrosion effects and a summary of stress corrosion cracking in these alloys

  20. High-strength reaction-sintered SiC: a new candidate material for large spaceborne telescope systems

    Science.gov (United States)

    Yui, Yukari Y.; Kimura, Toshiyoshi; Tange, Yoshio

    2004-11-01

    The high-strength reaction-sintered silicon carbide (RS-SiC) developed and manufactured by Toshiba and NEC-Toshiba Space Systems, NT-SiC, is one of the most promising, excellent and feasible candidates for light-weighted large-diameter space-borne optics that are applied to geostationary earth observations and astronomical observations. Small NT-SiC sample mirrors were manufactured to study basic physical parameters and features, and optical performances of the material, such as the surface conditions of polished NT-SiC, the condition of inner crystal grains, the correlation between the surface roughness and polishing, scattering characteristics, absorbance of solar light and infrared emissivity, and adhesiveness of metal coating. The current state of the art of the development of the NT-SiC mirror and the feasibility of light-weighted large-diameter NT-SiC mirrors for space-borne optics are described. Although technical challenges to achieve the surface roughness that is applicable to ultraviolet mirrors still remain, the optical performance and the physical properties of the present NT-SiC show that it is one of the most excellent mirror material in optical-infrared wavelength region.

  1. The electronic structure of hard materials

    Science.gov (United States)

    Winarski, Robert Paul

    This research dissertation involves an experimental as well as a theoretical examination of the electronic structure of hard materials. The materials that are presented in this dissertation cover a wide class of materials, consisting of transition metal borides, irradiated polymer films, theoretically predicted superhard semiconductors, doped intermetallic alloys, and transition metal carbides. The borides are traditionally used in high temperature, hard coating applications, such as rocket nozzle linings, extreme wear surfaces, and corrosion coatings. Measurements of the borides appear to show that the bonding in these hard materials is primarily between the boron atoms in these systems. Also of note are the remarkably short interatomic distances between the boron atoms and between the boron and metal atoms in these materials. Irradiated polymer films are being developed for electronic applications, in the hopes that circuits can be developed that can benefit from the high thermal stability, dielectric properties, and mechanical properties provided by these materials. C3N4 is a theoretically predicted superhard material, and some of the first soft x-ray emission measurements of well-characterized samples of this compound are discussed in this work. Intermetallic alloys, in particular Ni3Al, are rather hard, but brittle metallic alloys. It has been found that the addition of boron atoms, in rather low concentrations, can increase the ductility of these alloys, allowing them to be utilized in a wider variety of applications. Measurements of this system have examined a question regarding the positioning of the boron atoms in the structures of this alloy. Finally, the transition metal carbides are used extensively as coatings in industrial applications such as cutting and grinding tools, and polishing compounds. Measurements of these materials suggest that the high degree of covalency between the metal and carbon atoms is primarily responsible for the hardness of

  2. Engineering aspects of the application of structural materials in the 5 MW-ESS-mercury-target

    Energy Technology Data Exchange (ETDEWEB)

    Guttek, B. [Forschungszentrum Juelich GmbH (Germany)

    1996-06-01

    A main problem of the ESS-Hg-target development and the design of the components of its primary Hg-circuit is the choice of structural materials. As designing, calculations and experiments with elected materials take time and are very costy, a preview on their successful application has to be done before as detailed as possible. One aspect on this is to have the knowledge of characteristics values of the structural material candidates under the occuring mechanical and thermal loads, irradiation, corrosion and erosion. Another point is the technology of engineering concerning the manufacturing, welding, surface treatment, and quality control of such parts and components under the demand to reach maximum lifetime.

  3. Nondestructive Testing of Materials and Structures

    CERN Document Server

    Akkaya, Yılmaz

    2013-01-01

    Condition assessment and characterization of materials and structures by means of nondestructive testing (NDT) methods is a priority need around the world to meet the challenges associated with the durability, maintenance, rehabilitation, retrofitting, renewal and health monitoring of new and existing infrastructures including historic monuments. Numerous NDT methods that make use of certain components of the electromagnetic and acoustic spectra are currently in use to this effect with various levels of success and there is an intensive worldwide research effort aimed at improving the existing methods and developing new ones. The knowledge and information compiled in this book captures the current state-of-the-art in NDT methods and their application to civil and other engineering materials and structures. Critical reviews and advanced interdisciplinary discussions by world-renowned researchers point to the capabilities and limitations of the currently used NDT methods and shed light on current and future res...

  4. Nonlinearity in structural and electronic materials

    International Nuclear Information System (INIS)

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project strengthens a nonlinear technology base relevant to a variety of problems arising in condensed matter and materials science, and applies this technology to those problems. In this way the controlled synthesis of, and experiments on, novel electronic and structural materials provide an important focus for nonlinear science, while nonlinear techniques help advance the understanding of the scientific principles underlying the control of microstructure and dynamics in complex materials. This research is primarily focused on four topics: (1) materials microstructure: growth and evolution, and porous media; (2) textures in elastic/martensitic materials; (3) electro- and photo-active polymers; and (4) ultrafast photophysics in complex electronic materials. Accomplishments included the following: organization of a ''Nonlinear Materials'' seminar series and international conferences including ''Fracture, Friction and Deformation,'' ''Nonequilibrium Phase Transitions,'' and ''Landscape Paradigms in Physics and Biology''; invited talks at international conference on ''Synthetic Metals,'' ''Quantum Phase Transitions,'' ''1996 CECAM Euroconference,'' and the 1995 Fall Meeting of the Materials Research Society; large-scale simulations and microscopic modeling of nonlinear coherent energy storage at crack tips and sliding interfaces; large-scale simulation and microscopic elasticity theory for precursor microstructure and dynamics at solid-solid diffusionless phase transformations; large-scale simulation of self-assembling organic thin films on inorganic substrates; analysis and simulation of smoothing of rough atomic surfaces; and modeling and analysis of flux pattern formation in equilibrium and nonequilibrium Josephson junction arrays and layered superconductors

  5. Nonlinearity in structural and electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, A.R.; Beardmore, K.M.; Ben-Naim, E. [and others

    1997-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project strengthens a nonlinear technology base relevant to a variety of problems arising in condensed matter and materials science, and applies this technology to those problems. In this way the controlled synthesis of, and experiments on, novel electronic and structural materials provide an important focus for nonlinear science, while nonlinear techniques help advance the understanding of the scientific principles underlying the control of microstructure and dynamics in complex materials. This research is primarily focused on four topics: (1) materials microstructure: growth and evolution, and porous media; (2) textures in elastic/martensitic materials; (3) electro- and photo-active polymers; and (4) ultrafast photophysics in complex electronic materials. Accomplishments included the following: organization of a ``Nonlinear Materials`` seminar series and international conferences including ``Fracture, Friction and Deformation,`` ``Nonequilibrium Phase Transitions,`` and ``Landscape Paradigms in Physics and Biology``; invited talks at international conference on ``Synthetic Metals,`` ``Quantum Phase Transitions,`` ``1996 CECAM Euroconference,`` and the 1995 Fall Meeting of the Materials Research Society; large-scale simulations and microscopic modeling of nonlinear coherent energy storage at crack tips and sliding interfaces; large-scale simulation and microscopic elasticity theory for precursor microstructure and dynamics at solid-solid diffusionless phase transformations; large-scale simulation of self-assembling organic thin films on inorganic substrates; analysis and simulation of smoothing of rough atomic surfaces; and modeling and analysis of flux pattern formation in equilibrium and nonequilibrium Josephson junction arrays and layered superconductors.

  6. Strength of structural materials of nuclear reactors

    International Nuclear Information System (INIS)

    The monography reviews the phenomenon of stress-corrosion craving of zirconium-alloy fuel cans in the nuclear fuel fission products and ways of its prevention. Equations of creep and limiting state of FBR core materials were derived on the basis of the concept of deformation processes unity taking into account the degree of structural stability of alloys, temperature, nonstationary loading and aggressive media effects. Equations of durability under joint quasistatic and cyclic loading are developed. 146 refs.; 91 figs.; 16 tabs

  7. The effects of gamma radiation on the corrosion of candidate materials for the fabrication of nuclear waste packages

    Energy Technology Data Exchange (ETDEWEB)

    Shoesmith, D.W. [Univ. of Western Ontario, Dept. of Chemistry, London, Ontario (Canada); King, F

    1999-07-01

    The influence of gamma radiation on the corrosion of candidate materials for the fabrication of nuclear waste packages has been comprehensively reviewed. The comparison of corrosion of the various materials was compared in three distinct environments: Environment A; Mg{sup 2+}-enriched brines in which hydrolysis of the cation produces acidic environments and the Mg{sup 2+} interferes with the formation of protective films; Environment B; saline environments with a low Mg{sup 2+} content which remain neutral; Environment C; moist aerated conditions.The reference design of nuclear waste package for emplacement in the proposed waste repository in Yucca Mountain, Nevada, employs a dual wall arrangement, in which a 2 cm thick nickel alloy inner barrier is encapsulated within a 10 cm thick mild steel outer barrier. It is felt that this arrangement will give considerable containment lifetimes, since no common mode failure exists for the two barriers. The corrosion performance of this waste package will be determined by the exposure environment established within the emplacement drifts. Key features of the Yucca Mountain repository in controlling waste package degradation are expected to be the permanent availability of oxygen and the limited presence of water. When water contacts the surface of the waste package, its gamma radiolysis could produce an additional supply of corrosive agents. the gamma field will be produced by the radioactive decay of radionuclides within the waste form, and its magnitude will depend on the nature and age of the waste form as well as the material and wall thickness of the waste package.

  8. Template-assisted growth of nano structured functional materials

    International Nuclear Information System (INIS)

    Template-assisted growth is an important nano electrochemical deposition technique for synthesizing one-dimensional (1-D) nano structures with uniformly well-controlled shapes and sizes. A good template with well-defined dimensions is imperative for realizing this task. Porous anodic alumina (PAA) has been a favorable candidate for this purpose as it can be tailor-made with precise pore geometries, such as pore length and diameter as well as inter-pore distances, via the anodization of pure aluminium. This paper reports the fabrication of PAA templates and electrochemical synthesis of functional nano structures in the form of nano wires using PAA templates as scaffolds. Axial heterostructure and homogeneous nano wires formed by engineering materials configuration via composition and/ or layer thickness variations were fabricated for different functionalities. X-ray diffraction and imaging techniques were used to alucidate the microstructures, morphologies and chemical compositions of the nano wires produced. Due to their large surface area-to-volume ratios, and therefore high sensitivities, these functional nano structures have useful applications as critical components in nano sensor devices and various areas of nano technology. Potential applications include as hydrogen gas sensors in nuclear power plant for monitoring structural integrity of reactor components and containment building, as well as environmental monitoring of air pollution and leakages of toxic gases and chemicals. (Author)

  9. Contriving new spacer grid shapes and choosing the leading candidates of the spacer grid from the mechanical/structural point of view

    International Nuclear Information System (INIS)

    Based on the fuel assembly mechanical/thermal-hydraulic design experience and scrutinizing the design features on the foreign advanced nuclear fuel and the foreign patents of the spacer grid, 13 kinds of spacer grid candidates are derived. Among, the candidates the mechanical/structural performance on the five candidates was evaluated by the screening test and the analysis. As a result of the test and the analysis, two spacer grid shapes are finally selected to be the leading candidates in order to investigate the mechanical/structural performance in detail

  10. Dark matter candidates

    International Nuclear Information System (INIS)

    One of the simplest, yet most profound, questions we can ask about the Universe is, how much stuff is in it, and further what is that stuff composed of? Needless to say, the answer to this question has very important implications for the evolution of the Universe, determining both the ultimate fate and the course of structure formation. Remarkably, at this late date in the history of the Universe we still do not have a definitive answer to this simplest of questions---although we have some very intriguing clues. It is known with certainty that most of the material in the Universe is dark, and we have the strong suspicion that the dominant component of material in the Cosmos is not baryons, but rather is exotic relic elementary particles left over from the earliest, very hot epoch of the Universe. If true, the Dark Matter question is a most fundamental one facing both particle physics and cosmology. The leading particle dark matter candidates are: the axion, the neutralino, and a light neutrino species. All three candidates are accessible to experimental tests, and experiments are now in progress. In addition, there are several dark horse, long shot, candidates, including the superheavy magnetic monopole and soliton stars. 13 refs

  11. HCV INFECTION THROUGH PERFORATING AND CUTTING MATERIAL AMONG CANDIDATES FOR BLOOD DONATION IN BELÉM, BRAZILIAN AMAZON

    Directory of Open Access Journals (Sweden)

    Rubenilson Caldas Valois

    2014-12-01

    Full Text Available This study evaluated epidemiological factors for HCV infection associated with sharing perforating and cutting instruments among candidates for blood donation (CBD in the city of Belém, Pará, Brazilian Amazon. Two definitions of HCV infection cases were used: anti-HCV positivity shown by EIA, and HCV-RNA detection by PCR. Infected and uninfected CBD completed a questionnaire about possible risk factors associated with sharing perforating and cutting instruments. The information was evaluated using simple and multiple logistic regressions. Between May and November 2010, 146 (1.1% persons with anti-HCV antibodies and 106 (0.8% with HCV-RNA were detected among 13,772 CBD in Belém. Risk factors associated with HCV infection based on the EIA (model 1 and PCR (model 2 results were: use of needles and syringes sterilized at home; shared use of razors at home, sharing of disposable razors in barbershops, beauty salons etc.; and sharing manicure and pedicure material. The models of HCV infection associated with sharing perforating and cutting instruments should be taken into account by local and regional health authorities and by those of other countries with similar cultural practices, in order to provide useful information to guide political and public strategies to control HCV transmission.

  12. Impact of phase stability on the corrosion behavior of the austenitic candidate materials for NNWSI [Nevada Nuclear Waste Storage Investigations

    International Nuclear Information System (INIS)

    The Nuclear Waste Management Program at Lawrence Livermore National Laboratory is responsible for the development of the waste package design to meet the Nuclear Regulatory Commission licensing requirements for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. The metallic container component of the waste package is required to assist in providing substantially complete containment of the waste for a period of up to 1000 years. Long term phase stability of the austenitic candidate materials (304L and 316L stainless steels and alloy 825) over this time period at moderate temperatures (100-2500C) can impact the mechanical and corrosion behavior of the metal barrier. A review of the technical literature with respect to phase stability of 304L, 316L and 825 is presented. The impact of martensitic transformations, carbide precipitation and intermediate (σ, chi, and eta) phase formation on the mechanical properties and corrosion behavior of these alloys at repository relevant conditions is discussed. The effect of sensitization on intergranular stress corrosion cracking (IGSCC) of each alloy is also addressed. A summary of the impact of phase stability on the degradation of each alloy in the proposed repository environment is included. 32 refs., 6 figs

  13. Narrow gap HST welding process and its application to candidate pipe material for 700 C USC boiler component

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Gang; Sato, Takashi; Fukuda, Yuji [Babcock-Hitachi K.K., Hiroshima (Japan). Kure Research Lab.; Mitsuhata, Koichi [Babcock-Hitachi K.K., Hiroshima (Japan). Kure Div.

    2008-07-01

    Increasing steam temperature and pressure conditions of 700 C USC (Ultra Super Critical) power plants under consideration require the adoption of Ni-based alloys. One of the most crucial issues for the application of 700 C USC power plants is the establishment of welding technology for the thick-walled components. This paper reports the research results on the practicability of candidate material for the thickwalled components. The weld test was conducted on Ni-based Alloy617 (52Ni-22Cr- 13Co-9Mo-Ti-Al) by using the narrow gap HST (Hot wire Switching TIG) welding process developed by Babcock-Hitachi K.K with the matching filler wire of Alloy617. The weldability and strength properties of weld joint were examined. The sound weld joint was achieved. The advantages of narrow gap HST welding process for the thick-walled components of Ni-based alloy were discussed from the viewpoints of weld metal chemical composition and creep rupture strength. Due to the good shielding effect, the melting loss of alloy elements in the weld consumable during the narrow gap HST welding procedure was suppressed successfully. The narrow gap HST weld joint showed comparable strength with the parent metal. (orig.)

  14. Structural materials: New challenges, manufacturing and performance

    International Nuclear Information System (INIS)

    Full texct: This paper reviews international perspectives on materials, manufacturing and performance on structural materials for fast reactors. It is recognized that fast reactors with closed fuel cycle shall play an eminent and major role to realize energy sustainability. Large scale exploitation of fast reactors shall require meeting of sustainability requirements such as economic competitiveness, safe and optimized waste management, increased proliferation resistance, improved use of uranium and thorium and enhanced efficiency. The designers of these reactors along with material specialists have a key role in meeting the above mentioned criteria of sustainability. The paper shall describe features of advanced sodium cooled fast reactors and the resulting requirements on the performance of the structural materials. The choice of the fuel governs the cladding material for these reactors. Considering the choice as oxide, carbide, metallic with or without minor actinides; cladding materials are chosen based on performance modeling, available experience and expertise. Improved varieties of 316 austenitic stainless steels and oxide dispersion ferritice-martensitic steels emerge as front runners to meet the requirements. The developments in Ti modified 316 austenitic stainless steels give enough confidence to take these fuels to burn-up of 120,000 MWd/t. It is inferred that the target burn-up of 250,000 MWd/t would only be achieved with oxide dispersion strengthened iron- chromium base steels. Research and development of modified austenitic stainless steels and ODS alloys in Japan, Europe and India would be described in the paper. For achieving high burn-up of 250,000 MWd/t, ferritic-martensitic steel has emerged as the choice for the wrapper material. The current status of development and the challenges shall be described in the paper. In particular, the European contribution to this paper addresses the development and performance assessment of the preferred

  15. The LDCE Particle Impact Experiment as flown on STS-46. [limited duration space environment candidate materials exposure (LDCE)

    Science.gov (United States)

    Maag, Carl R.; Tanner, William G.; Borg, Janet; Bibring, Jean-Pierre; Alexander, W. Merle; Maag, Andrew J.

    1992-01-01

    Many materials and techniques have been developed by the authors to sample the flux of particles in Low Earth Orbit (LEO). Though regular in-site sampling of the flux in LEO the materials and techniques have produced data which compliment the data now being amassed by the Long Duration Exposure Facility (LDEF) research activities. Orbital debris models have not been able to describe the flux of particles with d sub p less than or = 0.05 cm, because of the lack of data. Even though LDEF will provide a much needed baseline flux measurement, the continuous monitoring of micron and sub-micron size particles must be carried out. A flight experiment was conducted on the Space Shuttle as part of the LDCE payload to develop an understanding of the Spatial Density (concentration) as a function of size (mass) for particle sizes 1 x 10(exp 6) cm and larger. In addition to the enumeration of particle impacts, it is the intent of the experiment that hypervelocity particles be captured and returned intact. Measurements will be performed post flight to determine the flux density, diameters, and subsequent effects on various optical, thermal control and structural materials. In addition to these principal measurements, the Particle Impact Experiment (PIE) also provides a structure and sample holders for the exposure of passive material samples to the space environment, e.g., thermal cycling, and atomic oxygen, etc. The experiment will measure the optical property changes of mirrors and will provide the fluence of the ambient atomic oxygen environment to other payload experimenters. In order to augment the amount of material returned in a form which can be analyzed, the survivability of the experiment as well as the captured particles will be assessed. Using Sandia National Laboratory's hydrodynamic computer code CTH, hypervelocity impacts on the materials which comprise the experiments have been investigated and the progress of these studies are reported.

  16. Ageing in civil engineering materials and structures

    International Nuclear Information System (INIS)

    SETEC TPI will address the 'Aging' topic of the Dijon Symposium by talking about: aging in civil engineering materials and structures, prevention of aging phenomena, in-operation monitoring of degradations related to aging and compensatory measures required to maintain a good safety level. Works as the Millau viaduct, the EdF skyscraper at La Defense - Paris, the renovation of the Grand Palais of Paris and special structures with Monaco's floating dam as well as the 'number 10' shaped gateway boat at Marseilles are illustrations for the issues discussed. The durability of civil engineering structures has become a major concern for designers. The Millau viaduct is designed for a service life of 120 years, and the Monaco dam for 100 years. Calculation rules have been evolving toward the incorporation of the concept of life cycle, for example, the Eurocodes 2 rules (reinforced concrete). The talk will expose the factors which are being taken into account to delay aging versus structure types. This part will be focused towards materials and corresponding regulations: - Reinforced concrete (coating of reinforcements, opening of cracks, choice of reinforcement types), BAEL and Eurocodes 2 rules; - Frame steel (protection, sacrificial anode), CM66 and Eurocodes 3 rules. New materials will also be mentioned: - Ultra high-performance fiber/concrete, with the example of CERACEM applied at Millau for the covering of the toll area barrier; - Titanium, which is starting to appear in the building trades, as for instance for the Beijing China Opera House shell. The second part of the talk will be devoted to a specific case namely, the 'number 10' shaped gateway bridge, a prestressed concrete structure immersed in the Port of Marseilles, which will be used to illustrate the aging phenomenon in a corrosive environment. We will focus on the types of inspection series performed by the Autonomous Port Authority of Marseilles to check the behavior of its structure and the repair series

  17. Structural Materials: New Challenges, Manufacturing and Performance

    International Nuclear Information System (INIS)

    Important criteria of innovative fast reactors and advanced fuel cycle initiatives are improved efficiency, economic competitiveness and reduction of waste. To reach these goals and keep high safety standards, at least at the level of currently operating nuclear reactors, key issues are the availability of suitable structural materials and their performance assessment. The authors, on the basis of the wealth of experience gained in the European Union, India and Japan, aim to define the challenges and current status of material development and set the agenda for R and D in the coming years and decades. It is hoped that the joint perspective would enable realizing the expected criteria of sustainability envisaged through sodium cooled fast reactors and closed fuel cycles. (author)

  18. Catalytic Metal Free Production of Large Cage Structure Carbon Particles: A Candidate for Hydrogen Storage

    Science.gov (United States)

    Kimura, Yuki; Nuth, Joseph A., III; Ferguson, Frank T.

    2005-01-01

    We will demonstrate that carbon particles consisting of large cages can be produced without catalytic metal. The carbon particles were produced in CO gas as well as by introduction of 5% methane gas into the CO gas. The gas-produced carbon particles were able to absorb approximately 16.2 wt% of hydrogen. This value is 2.5 times higher than the 6.5 wt% goal for the vehicular hydrogen storage proposed by the Department of Energy in the USA. Therefore, we believe that this carbon particle is an excellent candidate for hydrogen storage for fuel cells.

  19. Adhesion of Dental Materials to Tooth Structure

    Science.gov (United States)

    Mitra, Sumita B.

    2000-03-01

    The understanding and proper application of the principles of adhesion has brought forth a new paradigm in the realm of esthetic dentistry. Modern restorative tooth procedures can now conserve the remaining tooth-structure and also provide for the strengthening of the tooth. Adhesive restorative techniques call for the application and curing of the dental adhesive at the interface between the tooth tissue and the filling material. Hence the success of the restoration depends largely on the integrity of this interface. The mechanism of adhesion of the bonding materials to the dental hard tissue will be discussed in this paper. There are four main steps that occur during the application of the dental adhesive to the oral hard tissues: 1) The first step is the creation of a microstructure in the tooth enamel or dentin by means of an acidic material. This can be through the application of a separate etchant or can be accomplished in situ by the adhesive/primer. This agent has to be effective in removing or modifying the proteinaceous “smear” layer, which would otherwise act as a weak boundary layer on the surface to be bonded. 2) The primer/adhesive must then be able to wet and penetrate the microstructure created in the tooth. Since the surface energies of etched enamel and that of etched dentin are different finding one material to prime both types of dental tissues can be quite challenging. 3) The ionomer types of materials, particularly those that are carboxylate ion-containing, can chemically bond with the calcium ions of the hydroxyapatite mineral. 4) Polymerization in situ allows for micromechanical interlocking of the adhesive. The importance of having the right mechanical properties of the cured adhesive layer and its role in absorbing and dissipating stresses encountered by a restored tooth will also be discussed.

  20. Graphene/Epoxy Coating as Multifunctional Material for Aircraft Structures

    Directory of Open Access Journals (Sweden)

    Tullio Monetta

    2015-06-01

    Full Text Available Recently, the use of graphene as a conductive nanofiller in the preparation of inorganic/polymer nanocomposites has attracted increasing interest in the aerospace field. The reason for this is the possibility of overcoming problems strictly connected to the aircraft structures, such as electrical conductivity and thus lightning strike protection. In addition, graphene is an ideal candidate to enhance the anti-corrosion properties of the resin, since it absorbs most of the light and provides hydrophobicity for repelling water. An important aspect of these multifunctional materials is that all these improvements can be realized even at very low filler loadings in the polymer matrix. In this work, graphene nanoflakes were incorporated into a water-based epoxy resin, and then the hybrid coating was applied to Al 2024-T3 samples. The addition of graphene considerably improved some physical properties of the hybrid coating as demonstrated by Electrochemical Impedance Spectroscopy (EIS analysis, ameliorating anti-corrosion performances of raw material. DSC measurements and Cross-cut Test showed that graphene did not affect the curing process or the adhesion properties. Moreover, an increment of water contact angle was displayed.

  1. Producing and optimizing novel materials and structures

    Science.gov (United States)

    Ashrafi, Mahdi

    2011-12-01

    A series of detailed experimental and finite element investigations were carried out to study the response of selected objects which are currently utilized for load carrying. These investigations were later applied to optimize the mechanical performance of the studied structures and materials. First, a number of experiments and detailed finite element simulations were carried out to study the response and failure of single lap joints with non-flat interface under uniaxial tension. The adherents were made from fiber reinforced epoxy composite and the custom-made mold allowed the fibers to follow the profile of the bonded joint interface. The experiments showed that the interface shape has significant effect on the mechanical behavior and strength of the bonded joints. Finite element simulations were performed to estimate the distribution of shear and peeling stresses along the bonded joints and the results were linked to the experimental investigations. Additional parametric calculations were also carried out to highlight the role of interface shape on the distribution of stresses, and inherently the overall strength and behavior of the bonded joints. In addition, the role of a central void on the distribution of the stresses in a bonded joint with flat and non-flat sinusoidal interfaces was investigated. The second topic concerns Wood Plastic Composites (WPC) which are widely used in the industry due to its durability, low cost, and anti-moisture properties in comparison with the natural wood. In this research, we have produced flout shaped WPC samples using African black wood powder and Phenolic resin in a hot compression molding set-up. Initial WPC composites were produced by systematically changing the wood volume fraction. Based on these results the optimum temperature, pressure and wood volume fraction for developing WPC in a form of a flute is developed. A series of experimental procedures were performed to improve mechanical properties of WPC samples by

  2. Structural origination of charge transfer complex nanostructures: Excellent candidate for field emission

    Science.gov (United States)

    Pal, Shreyasi; Chattopadhyay, Kalyan Kumar

    2016-05-01

    Worldwide strategies for amalgamating rationally controlled one-dimensional organic nanowires are of fundamental importance for their applications in flexible, cheaper and lighter electronics. In this work we have fabricated large-area, ordered CuTCNQ (copper-7,7,8,8-tetracyanoquinodimethane) nano architecture arrays over flexible conducting substrate and discussed the rational growth and integration of nanostructures. Here we adopted the organic solid phase reaction (VLS) technique for the growth of organic hierarchies and investigated how field emission properties changes by tuning the nanostructures morphology i.e., by varying length, diameter, alignment and orientation over flexible substrate. The CuTCNQ nanowires with optimized geometry exhibit excellent high field emission performance with low turn-on and threshold field values. The result strongly indicate that CuTCNQ nanowires on flexible carbon cloth substrate are promising candidates for constructing cold cathode based emission display devices, vacuum nanoelectronics, and etc.

  3. Methods of using structures including catalytic materials disposed within porous zeolite materials to synthesize hydrocarbons

    Science.gov (United States)

    Rollins, Harry W.; Petkovic, Lucia M.; Ginosar, Daniel M.

    2011-02-01

    Catalytic structures include a catalytic material disposed within a zeolite material. The catalytic material may be capable of catalyzing a formation of methanol from carbon monoxide and/or carbon dioxide, and the zeolite material may be capable of catalyzing a formation of hydrocarbon molecules from methanol. The catalytic material may include copper and zinc oxide. The zeolite material may include a first plurality of pores substantially defined by a crystal structure of the zeolite material and a second plurality of pores dispersed throughout the zeolite material. Systems for synthesizing hydrocarbon molecules also include catalytic structures. Methods for synthesizing hydrocarbon molecules include contacting hydrogen and at least one of carbon monoxide and carbon dioxide with such catalytic structures. Catalytic structures are fabricated by forming a zeolite material at least partially around a template structure, removing the template structure, and introducing a catalytic material into the zeolite material.

  4. Recent progress in R and D on tungsten alloys for divertor structural and plasma facing materials

    International Nuclear Information System (INIS)

    Tungsten materials are candidates for plasma-facing components for the International Thermonuclear Experimental Reactor and the DEMOnstration power plant because of their superior thermophysical properties. Because these materials are not common structural materials like steels, knowledge and strategies to improve the properties are still under development. These strategies discussed here, include new alloying approaches and microstructural stabilization by oxide dispersion strengthened as well as TiC stabilized tungsten based materials. The fracture behavior is improved by using tungsten laminated and tungsten wire reinforced materials. Material development is accompanied by neutron irradiation campaigns. Self-passivation, which is essential in case of loss-of-coolant accidents for plasma facing materials, can be achieved by certain amounts of chromium and titanium. Furthermore, modeling and computer simulation on the influence of alloying elements and heat loading and helium bombardment will be presented

  5. Atmospheric corrosion of structural materials in Poland

    International Nuclear Information System (INIS)

    The paper presents investigations of the effects of aggressive atmospheric corrosion agents on the progress of corrosion of metal structure materials: carbon steel, zinc, copper and aluminium. The tests were performed at the corrosion stations according standards: ISO 9223:1992; ISO 9224:1992; ISO 9225:1992; ISO 9226:1992; ISO 8565:1992. As the result of 8 years of experience were determined main atmospheric factors influencing corrosion rates of the several standard metals. It was shown that except factors discussed in the standard ISO 9223:1992 (sulfur dioxide, time of wetness and chloride ion deposition) ozone play a main part in corrosion rates. Ozone accelerates particularly the corrosion of copper, however steel and aluminium too. (author)

  6. Innovative reactor systems and requirements for structural materials

    International Nuclear Information System (INIS)

    The fast growing energy demand requires nuclear energy to play a role among other energy sources to satisfy future energy needs of mankind. Generation III light water reactors (LWRs) are anticipated to be built in large numbers to replace existing nuclear power plants or to augment the nuclear production capacity. Beyond the commercialization of best available light water reactor technologies, it is essential to start now the development of breakthrough technologies that will be needed to prepare the longer term future for nuclear power. These innovative systems include fast neutron reactors with a closed fuel cycle, high temperature reactors which could be used for process heat applications, accelerator driven systems or fusion reactors. Key technologies for such nuclear systems encompass high temperature structural materials, fast neutron resistant fuels and core materials, advanced fuel recycle processes with co-management of actinides, possibly including minor actinides, and specific reactor and power conversion technologies (intermediate heat-exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes...). The paper will give a brief overview of various materials that are essential for above nuclear systems' feasibility and performance, such as ferritic/martensitic steels (9-12% Cr), nickel-based alloys (Haynes 230, Inconel 617...), oxide dispersion strengthened -ferritic/martensitic steels, and ceramics. The paper will also give an insight into the various natures of R and D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, multi-scale modelling to predict macroscopic materials properties and to direct innovative research for improvements, lab-scale tests to characterise candidate materials mechanical properties and corrosion resistance, as well as component mock-up tests on technology loops to

  7. ODS Steel As A Structural Material For High Temperature Nuclear Reactors

    International Nuclear Information System (INIS)

    Oxide-dispersed-strengthened (ODS) ferritic-martensitic steels are examined as possible candidates for the structural materials to be used in the future generation of High-Temperature Gas-Cooled Nuclear Reactors, and as a replacement for alternative high-temperature materials for tubing and other structural components. ODS steels are also being considered as possible material for use in future fusion applications. Since the oxide particles serve as an interfacial pinning mechanism for moving dislocations, the creep resistance of the material is improved. However, in order to use such materials in a reactor, their behaviour under irradiation must be thoroughly examined. In this work, the effects induced by He implantation are investigated the induced swelling is measured, and the mechanical behaviour of the irradiated surface is analysed. These first tests are performed at room temperature, for which clear evidence of swelling and hardening could be observed. (author)

  8. Perspective: Role of structure prediction in materials discovery and design

    OpenAIRE

    Richard J. Needs; Pickard, Chris J.

    2016-01-01

    Materials informatics owes much to bioinformatics and the Materials Genome Initiative has been inspired by the Human Genome Project. But there is more to bioinformatics than genomes, and the same is true for materials informatics. Here we describe the rapidly expanding role of searching for structures of materials using first-principles electronic-structure methods. Structure searching has played an important part in unraveling structures of dense hydrogen and in identifying the record-high-t...

  9. Mechanical and materials engineering of modern structure and component design

    CERN Document Server

    Altenbach, Holm

    2015-01-01

    This book presents the latest findings on mechanical and materials engineering as applied to the design of modern engineering materials and components. The contributions cover the classical fields of mechanical, civil and materials engineering, as well as bioengineering and advanced materials processing and optimization. The materials and structures discussed can be categorized into modern steels, aluminium and titanium alloys, polymers/composite materials, biological and natural materials, material hybrids and modern nano-based materials. Analytical modelling, numerical simulation, state-of-the-art design tools and advanced experimental techniques are applied to characterize the materials’ performance and to design and optimize structures in different fields of engineering applications.

  10. Selection of flowing liquid lead target structural materials for accelerator driven transmutation applications

    International Nuclear Information System (INIS)

    The beam entry window and container for a liquid lead spallation target will be exposed to high fluxes of protons and neutrons that are both higher in magnitude and energy than have been experienced in proton accelerators and fission reactors, as well as in a corrosive environment. The structural material of the target should have a good compatibility with liquid lead, a sufficient mechanical strength at elevated temperatures, a good performance under an intense irradiation environment, and a low neutron absorption cross section; these factors have been used to rank the applicability of a wide range of materials for structural containment Nb-1Zr has been selected for use as the structural container for the LANL ABC/ATW molten lead target. Corrosion and mass transfer behavior for various candidate structural materials in liquid lead are reviewed, together with the beneficial effects of inhibitors and various coatings to protect substrate against liquid lead corrosion. Mechanical properties of some candidate materials at elevated temperatures and the property changes resulting from 800 MeV proton irradiation are also reviewed

  11. Status of LWR primary pressure boundary structural materials

    International Nuclear Information System (INIS)

    The integrity of major systems, structures and components is a prerequisite to the economy and safety of an existing light water reactor and also for the next generation reactors. As few reactor structural materials are being manufactured by domestic companies, based on economic and safety reasons, a new demand to improve the quality of domestic reactor structural materials and to develop reactor structural steels has arisen. Investigations on the state-of-the-art of the materials specifications, performance and current state of structural materials development were performed as a first step to domestic reactor structural steel development and summarized the result in the present report. (Author) 10 refs., 10 figs., 21 tabs

  12. Dynamic response of structures constructed from smart materials

    OpenAIRE

    Caughey, T. K.

    1995-01-01

    The dynamic analysis of structures constructed of homogeneous smart materials is greatly simplified by the observation that the eigenfunctions of such structures are identical to those of the same structures constructed entirely of purely elastic materials. The dynamic analysis of such structures is thus reduced to the analysis of the temporal behaviour of the eigenmodes of the structure. The theory is illustrated for both continuous and discrete structures using the generalization of 'positi...

  13. Controlled structuration and functionalization of organic-inorganic hybrid materials

    International Nuclear Information System (INIS)

    Organic-inorganic hybrid materials obtained by sol-gel process are very interesting materials. Indeed, these materials have both the properties of the organic phase and those of the inorganic matrix. Two functionalization and structuration ways are presented here: 1)the meso-porous hybrid materials formed in presence of structuring surfactant and the lamellar hybrid materials obtained by auto-assembling. (O.M.)

  14. Comparing composite materials with structural steels in the design of the optical support structure of very large telescopes

    Science.gov (United States)

    Cheng, Andrew Y.; Li, Robert K.

    1992-03-01

    The method of finite element analysis is used to study some candidate composite materials: carbon filter reinforced epoxy and glass fiber reinforced epoxy. These composites may have real applications in the design of the optical support structures of very large telescopes where stringent thermomechanical stability are needed. The lightweight property of these materials allows one to build very stiff members for the optical support to withstand the structural deflections due to wind, vibration, and gravity. We have run finite element models of these composites using ABAQUS on a VAX VMS computer. Simple beams with rectangular cross- sections were computed for the composites with structural steel as a comparison. The static properties of these beams were studied.

  15. A strategic analysis of the development of structural materials for proto-type reactors for fusion

    International Nuclear Information System (INIS)

    Structural Materials Research and Development Subcommittee of Nuclear Materials Committee in Japan Atomic Energy Research Institute had made a study to propose a strategy how to expedite the research and development of structural materials for fusion reactors. This study was carried out along with the interim report of the Development of Structural Materials in Fusion Reactors proposed by Planning and Promotion Subcommittee of Fusion Council as well as with the Third Phase Basic Program of Fusion Research and Development settled by the Atomic Energy Commission. The present report was published to publicize the results of analyses of this study. In this report we focused mostly on the development of structural materials of blankets for tritium breeding because it is considered to be the most difficult task in the materials development due to severe conditions imposing on the blankets. We selected three candidate materials, namely, reduced low activation ferritic/ martensitic steel, SiC/SiC composites and Vanadium alloys, and elucidate the conditions in which these materials would be used as well as the design requirements for each material. Based on these conditions and requirements, we described the present status and the key issues of each material. For the development of the structural materials for the blankets, the keenest issue is the improvement and evaluation of radiation integrity and stability. Therefore, the necessity of radiation facilities, especially accelerator-type neutron sources with near fusion energy spectra was described. In addition the usage of fission reactors as irradiation facilities was also emphasized. In the processing of this reviewing we categorized reduced low activation ferritic/martensitic steel as advanced material, and SiC/SiC composites and Vanadium alloys as next-generation advanced material from the present status of developmental maturity. A periodical check and review in order to take the future progress in the development of

  16. Selection of candidate container materials for the conceptual waste package design for a potential high level nuclear waste repository at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Van Konynenburg, R.A.; Halsey, W.G.; McCright, R.D.; Clarke, W.L. Jr. [Lawrence Livermore National Lab., CA (United States); Gdowski, G.E. [KMI, Inc., Albuquerque, NM (United States)

    1993-02-01

    Preliminary selection criteria have been developed, peer-reviewed, and applied to a field of 41 candidate materials to choose three alloys for further consideration during the advanced conceptual design phase of waste package development for a potential high level nuclear waste repository at Yucca Mountain, Nevada. These three alloys are titanium grade 12, Alloy C-4, and Alloy 825. These selections are specific to the particular conceptual design outlined in the Site Characterization Plan. Other design concepts that may be considered in the advanced conceptual design phase may favor other materials choices.

  17. Selection of candidate container materials for the conceptual waste package design for a potential high level nuclear waste repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Preliminary selection criteria have been developed, peer-reviewed, and applied to a field of 41 candidate materials to choose three alloys for further consideration during the advanced conceptual design phase of waste package development for a potential high level nuclear waste repository at Yucca Mountain, Nevada. These three alloys are titanium grade 12, Alloy C-4, and Alloy 825. These selections are specific to the particular conceptual design outlined in the Site Characterization Plan. Other design concepts that may be considered in the advanced conceptual design phase may favor other materials choices

  18. Properties of structural materials in liquid metal environment

    International Nuclear Information System (INIS)

    The proceedings contain 16 contributions to the following topics: 1. Creep-Rupture Behaviour of Structural Materials in Liquid Metal Environment; 2. Behaviour of Materials in Liquid Metal Environment under Off-Normal Conditions; 3. Fatigue and Creep-Fatigue of Structural Materials in Liquid Metal Environment; and 4. Crack Propagation in Liquid Sodium. (MM)

  19. A novel candidate compound with urethane structure for anticancer drug development.

    Science.gov (United States)

    Matsuoka, Atsuko; Isama, Kazuo; Tanimura, Susumu; Kohno, Michiaki; Yamori, Takao

    2007-08-01

    Diethyl-4,4'-methylenebis(N-phenylcarbamate) (MDU) is a urethane compound that we originally synthesized, along with three other compounds, to investigate how polyurethane is hydrolysed. We tested the four compounds for cytotoxicity in two Chinese hamster cell lines (CHL and V79) and a human cancer cell line (HeLa S3). MDU showed the strongest cytotoxicity in all the cell lines with an IC50 of around 0.1 microg/ml. We further investigated MDU for its ability to induce chromosome aberrations (CAs) and micronuclei (MN) in CHL cells. MDU induced around 100% polyploid cells at 0.5 microg/ml after 24- and 48-h treatment in the CA test and a significantly increased frequency of micronuclei, polynuclear cells, and mitotic cells in the MN test, suggesting that it may induce numerical CAs. MDU's ability to cause mitotic arrest in CHL cells was greater than that of taxol and colchicine. Based on a COMPARE analysis using JFCR39, a panel of cancer cell lines, we predicted MDU to be a tubulin inhibitor. We confirmed this possibility in nerve growth factor-stimulated PC12 cells as well as in HT1080 cells, in which MDU exhibited the activity to inhibit tubulin polymerization. MDU is simpler in structure than existing anticancer drugs taxol and vincristine and can be synthesized relatively easily. Here we offer MDU as a potential new type of anticancer drug, stable even at room temperature, and inexpensive. PMID:17691911

  20. Structured Piezoelectric Composites: Materials and Applications

    NARCIS (Netherlands)

    Van den Ende, D.A.

    2012-01-01

    The piezoelectric effect, which causes a material to generate a voltage when it deforms, is very suitable for making integrated sensors, and (micro-) generators. However, conventional piezoelectric materials are either brittle ceramics or certain polymers with a low thermal stability, which limits t

  1. Material, Structural Design of Armour Units

    DEFF Research Database (Denmark)

    Burcharth, Hans F.

    Stone and concrete are two materials generally used for the construction of rubble mound breakwaters. This paper deals with concrete only.......Stone and concrete are two materials generally used for the construction of rubble mound breakwaters. This paper deals with concrete only....

  2. Hierarchical Optimization of Material and Structure

    DEFF Research Database (Denmark)

    Rodrigues, Helder C.; Guedes, Jose M.; Bendsøe, Martin P.

    2002-01-01

    This paper describes a hierarchical computational procedure for optimizing material distribution as well as the local material properties of mechanical elements. The local properties are designed using a topology design approach, leading to single scale microstructures, which may be restricted in...

  3. Perspective: Role of structure prediction in materials discovery and design

    Science.gov (United States)

    Needs, Richard J.; Pickard, Chris J.

    2016-05-01

    Materials informatics owes much to bioinformatics and the Materials Genome Initiative has been inspired by the Human Genome Project. But there is more to bioinformatics than genomes, and the same is true for materials informatics. Here we describe the rapidly expanding role of searching for structures of materials using first-principles electronic-structure methods. Structure searching has played an important part in unraveling structures of dense hydrogen and in identifying the record-high-temperature superconducting component in hydrogen sulfide at high pressures. We suggest that first-principles structure searching has already demonstrated its ability to determine structures of a wide range of materials and that it will play a central and increasing part in materials discovery and design.

  4. Structured materials for catalytic and sensing applications

    Science.gov (United States)

    Hokenek, Selma

    The optical and chemical properties of the materials used in catalytic and sensing applications directly determine the characteristics of the resultant catalyst or sensor. It is well known that a catalyst needs to have high activity, selectivity, and stability to be viable in an industrial setting. The hydrogenation activity of palladium catalysts is known to be excellent, but the industrial applications are limited by the cost of obtaining catalyst in amounts large enough to make their use economical. As a result, alloying palladium with a cheaper, more widely available metal while maintaining the high catalytic activity seen in monometallic catalysts is, therefore, an attractive option. Similarly, the optical properties of nanoscale materials used for sensing must be attuned to their application. By adjusting the shape and composition of nanoparticles used in such applications, very fine changes can be made to the frequency of light that they absorb most efficiently. The design, synthesis, and characterization of (i) size controlled monometallic palladium nanoparticles for catalytic applications, (ii) nickel-palladium bimetallic nanoparticles and (iii) silver-palladium nanoparticles with applications in drug detection and biosensing through surface plasmon resonance, respectively, will be discussed. The composition, size, and shape of the nanoparticles formed were controlled through the use of wet chemistry techniques. After synthesis, the nanoparticles were analyzed using physical and chemical characterization techniques such as X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy- Energy-Dispersive Spectrometry (STEM-EDX). The Pd and Ni-Pd nanoparticles were then supported on silica for catalytic testing using mass spectrometry. The optical properties of the Ag-Pd nanoparticles in suspension were further investigated using ultraviolet-visible spectrometry (UV-Vis). Monometallic palladium particles have

  5. Alternative modelling of brittle structures in a sub-area of the SKB candidate area at Forsmark, eastern Sweden.

    Energy Technology Data Exchange (ETDEWEB)

    Askling, Per; Tiren, Sven A.; Beckholmen, Monica; Straeng, Thomas (Geosigma AB, Uppsala (Sweden))

    2008-11-15

    One way to test the confidence of a presented model is to construct an alternative model. Such work is cognitive process of skill acquisition and also a process of understanding data in the sense of sorting and classifying data. This is of particular interest for the Swedish Radiation Safety Authority (SSM) in their technical review of SKB's on-going site investigation programme for potential repository sites. In this study, an alternative brittle deformation model of a selected part of the SKB candidate area in eastern Sweden was constructed. The input data set was obtained from SKB's database SICADA and is a selected set of data from five cored boreholes drilled from two drill-sites and comprises geophysical borehole logs, geological core-logs, hydrological logs (PFL; Posiva Flow Log) and borehole deviation measurements. Statistical cluster analysis applied on the geophysical borehole data were used to obtain the locations of bedrock with contrasting physical characteristics similar to those of brittle deformation zones. The cluster analysis is an objective procedure, contrasting with SKB's more subjective approach to the single-hole interpretation. Thus some differences are expected which could illustrate the effect of methodology that includes subjective 'expert judgement.' and indicate the possibility of alternative interpretations. The information about brittle structures in the geological boreholes logs was sorted and classification was made according to character of the structures (all fractures, open fractures, partly open fractures, frequency, orientate on/identification of fracture sets, sections of crush rock, and alteration). A separate study was performed to relate rock alteration with structures. The resolution applied in the fracture statistics is one metre, i.e. all studied entities were expressed per metre borehole length. All clusters were structurally characterized by the fractures inside the clusters (orientation and

  6. Alternative modelling of brittle structures in a sub-area of the SKB candidate area at Forsmark, eastern Sweden

    International Nuclear Information System (INIS)

    One way to test the confidence of a presented model is to construct an alternative model. Such work is cognitive process of skill acquisition and also a process of understanding data in the sense of sorting and classifying data. This is of particular interest for the Swedish Radiation Safety Authority (SSM) in their technical review of SKB's on-going site investigation programme for potential repository sites. In this study, an alternative brittle deformation model of a selected part of the SKB candidate area in eastern Sweden was constructed. The input data set was obtained from SKB's database SICADA and is a selected set of data from five cored boreholes drilled from two drill-sites and comprises geophysical borehole logs, geological core-logs, hydrological logs (PFL; Posiva Flow Log) and borehole deviation measurements. Statistical cluster analysis applied on the geophysical borehole data were used to obtain the locations of bedrock with contrasting physical characteristics similar to those of brittle deformation zones. The cluster analysis is an objective procedure, contrasting with SKB's more subjective approach to the single-hole interpretation. Thus some differences are expected which could illustrate the effect of methodology that includes subjective 'expert judgement.' and indicate the possibility of alternative interpretations. The information about brittle structures in the geological boreholes logs was sorted and classification was made according to character of the structures (all fractures, open fractures, partly open fractures, frequency, orientate on/identification of fracture sets, sections of crush rock, and alteration). A separate study was performed to relate rock alteration with structures. The resolution applied in the fracture statistics is one metre, i.e. all studied entities were expressed per metre borehole length. All clusters were structurally characterized by the fractures inside the clusters (orientation and density of fractures) and

  7. Innovated Building Material's Interactions with Structural Form in Architectural Projects

    OpenAIRE

    Mozaikci, Begüm

    2009-01-01

    ABSTRACT: Interpretation of building materials into architectural form, is gaining greater interest and attention due to the conservation of architectural heritage. This study highlight, the influences of technological developments of building materials and their interactions with structural form in architectural design projects. Architectural form and decisions can potentially effects by introduced new materials and this study focus on the interaction of new material and structural form...

  8. Multi-Material Design Optimization of Composite Structures

    OpenAIRE

    Hvejsel, Christian Frier

    2011-01-01

    This PhD thesis entitled “Multi-Material Design Optimization of Composite Structures” addresses the design problem of choosing materials in an optimal manner under a resource constraint so as to maximize the integral stiffness of a structure under static loading conditions. In particular stiffness design of laminated composite structures is studied including the problem of orienting orthotropic material optimally. The approach taken in this work is to consider this multi-material design probl...

  9. Optimization of Structure and Material Properties for Solids Composed of Softening Material

    DEFF Research Database (Denmark)

    Bendsøe, Martin P.; Guedes, J.M.; J.M., Plaxton; Taylor, J.E.

    1996-01-01

    Recent results on the design of material properties in the context of global structural optimization provide, in analytical form, a prediction of the optimal material tensor distributions for two or three dimensional continuum structures. The model developed for that purpose is extended here to...... cover the design of a structure and associated material properties for a system composed of a generic form of nonlinear softening material. As was established in the earlier study on design with linear materials, the formulation for combined 'material and structure' design with softening materials can...... be expressed as a convex problem. However, the optimal distribution of material properties predicted in the nonlinear problem depends on the magnitude of load, in contrast to the case with linear material. Computational solutions are presented for several example problems, showing how the optimal...

  10. Structural, phylogenetic and docking studies of D-amino acid oxidase activator (DAOA, a candidate schizophrenia gene

    Directory of Open Access Journals (Sweden)

    Sehgal Sheikh

    2013-01-01

    Full Text Available Abstract Background Schizophrenia is a neurodegenerative disorder that occurs worldwide and can be difficult to diagnose. It is the foremost neurological disorder leading to suicide among patients in both developed and underdeveloped countries. D-amino acid oxidase activator (DAOA, also known as G72, is directly implicated in the glutamateric hypothesis of schizophrenia. It activates D-amino acid oxidase, which oxidizes D-serine, leading to modulation of the N-methyl-D-aspartate receptor. Methods MODELLER (9v10 was utilized to generate three dimensional structures of the DAOA candidate gene. The HOPE server was used for mutational analysis. The Molecular Evolutionary Genetics Analysis (MEGA5 tool was utilized to reconstruct the evolutionary history of the candidate gene DAOA. AutoDock was used for protein-ligand docking and Gramm-X and PatchDock for protein-protein docking. Results A suitable template (1ZCA was selected by employing BLASTp on the basis of 33% query coverage, 27% identity and E-value 4.9. The Rampage evaluation tool showed 91.1% favored region, 4.9% allowed region and 4.1% outlier region in DAOA. ERRAT demonstrated that the predicted model had a 50.909% quality factor. Mutational analysis of DAOA revealed significant effects on hydrogen bonding and correct folding of the DAOA protein, which in turn affect protein conformation. Ciona was inferred as the outgroup. Tetrapods were in their appropriate clusters with bifurcations. Human amino acid sequences are conserved, with chimpanzee and gorilla showing more than 80% homology and bootstrap value based on 1000 replications. Molecular docking analysis was employed to elucidate the binding mode of the reported ligand complex for DAOA. The docking experiment demonstrated that DAOA is involved in major amino acid interactions: the residues that interact most strongly with the ligand C28H28N3O5PS2 are polar but uncharged (Gln36, Asn38, Thr 122 and non-polar hydrophobic (Ile119, Ser171

  11. A state-of-the-art-report on the compatibility of structural materials with sodium

    Energy Technology Data Exchange (ETDEWEB)

    Maeng, Wan Yung; Joo, Kee Nam; Ryoo, Woo Suk; Kang, Yung Hwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1993-12-01

    Compatibility of liquid metal reactor structural materials with sodium has been reviewed in terms of corrosion rate, selective leaching, deposition, transport of carbon and radioactivity. Various data show that corrosion rate is dependent on sodium flow rate, temperature and oxygen concentration while carburization is very sensitive to the difference in chemical activities of carbon in sodium and stainless steel materials. Under the sodium environment, tensile and creep strength decrease with increase of exposure rate while fatigue strength increases with time. Data analysis on compatibility of sodium with various candidate liquid metal reactor structural materials confirms that sodium technology has been concentrated on the reduction of deposition rate, increase in thermal and mechanical properties, and improvement of welding component properties. 19 figs., 1 tab., 15 refs. (Author).

  12. The Candidate

    OpenAIRE

    Osborn, John C

    2013-01-01

    ABSTRACT   The Candidate is an attempt to marry elements of journalism and gaming into a format that both entertains and educates the player. The Google-AP Scholarship, a new scholarship award that is given to several journalists a year to work on projects at the threshold of technology and journalism, funded the project. The objective in this prototype version of the game is to put the player in the shoes of a congressional candidate during an off-year election, specificall...

  13. Computational Design of Ageless Structural Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Crack initiation and propagation is a dominant failure mode for many materials and applications – usually managed via damage tolerance approaches." ...

  14. Damage evolution during fatigue in structural materials

    Czech Academy of Sciences Publication Activity Database

    Polák, Jaroslav; Man, Jiří; Petrenec, Martin

    2012-01-01

    Roč. 1, August (2012), s. 3-12. ISSN 2211-8128. [International Congress on Metallurgy and Materials - SAM/CONAMET 2011 /11./. Rosario, 18.10.2011-21.10.2011] R&D Projects: GA ČR GA106/09/1954 Institutional support: RVO:68081723 Keywords : cyclic plasticity * crack nucleation * crack growth * fatigue damage Subject RIV: JL - Materials Fatigue, Friction Mechanics

  15. HA03 as an Iranian Candidate Concealed Antigen for Vaccination against Hyalomma anatolicum anatolicum: Comparative Structural and In silico Studies

    Directory of Open Access Journals (Sweden)

    Mohammadi, A.

    2013-12-01

    Full Text Available In the last decades researchers had focused on developing a vaccine against tick based on protective antigen. Recombinant vaccines based on concealed antigen from Boophilus microplus have been developed in Australia and Cuba by the name of TICKGARD and GAVAC (De La Fuente and Kocan, 2006. Further studies on this antigen have shown some extent of protection against other species (De Vos et al., 2001. In Iran most important species is Hyalomma anatolicum and limited information about its control are available. This paper reports structural and polymorphic analysis of HA03 as an Iranian candidate concealed antigen of H. a. anatolicum deposited in Gen-Bank .(Aghaeipour et al. GQ228820. The comparison between this antigen and other mid gut concealed antigen that their characteristics are available in GenBank showed there are high rate of similarity between them. The HA03 amino acid sequence had a homology of around 89%, 64%, 56% with HA98, BM86, BM95 respectively. Potential of MHC class I and II binding region indicated a considerable variation between BM86 antigen and its efficiency against Iranian H. a. anatolicum. In addition, predicted major of hydrophobisity and similarity in N-glycosylation besides large amount of cystein and seven EGF like regions presented in protein structure revealed that value of HA03 as a new protective antigen and the necessity of the development, BM86 homolog of H. a. anatolicum HA03 based recombinant vaccine.

  16. VFV as a New Effective CYP51 Structure-Derived Drug Candidate for Chagas Disease and Visceral Leishmaniasis.

    Science.gov (United States)

    Lepesheva, Galina I; Hargrove, Tatiana Y; Rachakonda, Girish; Wawrzak, Zdzislaw; Pomel, Sébastien; Cojean, Sandrine; Nde, Pius N; Nes, W David; Locuson, Charles W; Calcutt, M Wade; Waterman, Michael R; Daniels, J Scott; Loiseau, Philippe M; Villalta, Fernando

    2015-11-01

    Sterol 14α-demethylases (CYP51) are the enzymes essential for sterol biosynthesis. They serve as clinical targets for antifungal azoles and are considered as targets for treatment of human Trypanosomatidae infections. Recently, we have shown that VNI, a potent and selective inhibitor of trypanosomal CYP51 that we identified and structurally characterized in complex with the enzyme, can cure the acute and chronic forms of Chagas disease. The purpose of this work was to apply the CYP51 structure/function for further development of the VNI scaffold. As anticipated, VFV (R)-N-(1-(3,4'-difluorobiphenyl-4-yl)-2-(1H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzamide, the derivative designed to fill the deepest portion of the CYP51 substrate-binding cavity, reveals a broader antiprotozoan spectrum of action. It has stronger antiparasitic activity in cellular experiments, cures the experimental Chagas disease with 100% efficacy, and suppresses visceral leishmaniasis by 89% (vs 60% for VNI). Oral bioavailability, low off-target activity, favorable pharmacokinetics and tissue distribution characterize VFV as a promising new drug candidate. PMID:25883390

  17. The dyslexia candidate locus on 2p12 is associated with general cognitive ability and white matter structure.

    Directory of Open Access Journals (Sweden)

    Thomas S Scerri

    Full Text Available Independent studies have shown that candidate genes for dyslexia and specific language impairment (SLI impact upon reading/language-specific traits in the general population. To further explore the effect of disorder-associated genes on cognitive functions, we investigated whether they play a role in broader cognitive traits. We tested a panel of dyslexia and SLI genetic risk factors for association with two measures of general cognitive abilities, or IQ, (verbal and non-verbal in the Avon Longitudinal Study of Parents and Children (ALSPAC cohort (N>5,000. Only the MRPL19/C2ORF3 locus showed statistically significant association (minimum P = 0.00009 which was further supported by independent replications following analysis in four other cohorts. In addition, a fifth independent sample showed association between the MRPL19/C2ORF3 locus and white matter structure in the posterior part of the corpus callosum and cingulum, connecting large parts of the cortex in the parietal, occipital and temporal lobes. These findings suggest that this locus, originally identified as being associated with dyslexia, is likely to harbour genetic variants associated with general cognitive abilities by influencing white matter structure in localised neuronal regions.

  18. Graphene/Epoxy Coating as Multifunctional Material for Aircraft Structures

    OpenAIRE

    Tullio Monetta; Annalisa Acquesta; Francesco Bellucci

    2015-01-01

    Recently, the use of graphene as a conductive nanofiller in the preparation of inorganic/polymer nanocomposites has attracted increasing interest in the aerospace field. The reason for this is the possibility of overcoming problems strictly connected to the aircraft structures, such as electrical conductivity and thus lightning strike protection. In addition, graphene is an ideal candidate to enhance the anti-corrosion properties of the resin, since it absorbs most of the light and provides ...

  19. Structure of random porous materials: Silica aerogel

    International Nuclear Information System (INIS)

    Using small-angle x-ray scattering, we show that porous silica aerogel has a fractal backbone structure. The observed structure is traced to the underlying chemical (polymerization) and physical (colloid aggregation) growth processes. Comparison of scattering curves for aerogel with silica aggregates confirms this interpretation

  20. Hypervelocity impact testing of advanced materials and structures for micrometeoroid and orbital debris shielding

    Science.gov (United States)

    Ryan, Shannon; Christiansen, Eric L.

    2013-02-01

    A series of 66 hypervelocity impact experiments have been performed to assess the potential of various materials (aluminium, titanium, copper, stainless steel, nickel, nickel/chromium, reticulated vitreous carbon, silver, ceramic, aramid, ceramic glass, and carbon fibre) and structures (monolithic plates, open-cell foam, flexible fabrics, rigid meshes) for micrometeoroid and orbital debris (MMOD) shielding. Arranged in various single-, double-, and triple-bumper configurations, screening tests were performed with 0.3175 cm diameter Al2017-T4 spherical projectiles at nominally 6.8 km/s and normal incidence. The top performing shields were identified through target damage assessments and their respective weight. The top performing candidate shield at the screening test condition was found to be a double-bumper configuration with a 0.25 mm thick Al3003 outer bumper, 6.35 mm thick 40 PPI aluminium foam inner bumper, and 1.016 mm thick Al2024-T3 rear wall (equal spacing between bumpers and rear wall). In general, double-bumper candidates with aluminium plate outer bumpers and foam inner bumpers were consistently found to be amongst the top performers. For this impact condition, potential weight savings of at least 47% over conventional all-aluminium Whipple shields are possible by utilizing the investigated materials and structures. The results of this study identify materials and structures of interest for further, more in-depth, impact investigations.

  1. Optical Spectroscopy of Nano Materials and Structures

    Science.gov (United States)

    Guo, Wenhao

    In this thesis, nanostructures and nanomaterials ranging from 3D to OD will be studied compresively, by using optical methods. Firstly, for 3D and 2D nanomaterials, nanoporous zeolite crystals, such as AFI and AEL are introduced as host materials to accommodate diatomic iodine molecules. Polarized Raman spectroscopy is utilized to identify the two configurations of iodine molecules to stay in the channels of AEL: the lying mode (the bond of the two atoms is parallel to the direction of the channels) and the standing mode (the bond is perpendicular to the direction of the channels). The lying mode and standing mode are switchable and can be well controlled by the amount of water molecules inside the crystal, revealed by both molecule dynamics simulation and experiment observation. With more water molecules inside, iodine molecules choose to stay in the standing mode, while with less water molecules, iodine molecules prefer to lie along the channel. Therefore, the configurations of molecules could be precisely controlled, globally by the surrounding pressure and temperature, and locally by the laser light. Ii is believed that this easy and reversible control of single molecule will be valuable in nanostructured devices, such as molecular sieving or molecular detection. Secondly, for 1D case, the PL spectrum of ZnO nanowire under uniaxial strain is studied. When a ZnO nanowire is bent, besides the lattice constant induced bandgap change on the tensile and compressive sides, there is a piezoelectric field generated along the cross section. This piezoelectric potential, together with the bandgap changes induced by the deformation, will redistribute the electrons excited by incident photons from valence band to conduction band. As a result, the electrons occupying the states at the tensile side will largely outnumbered the ones at the compressive side. Therefore, the PL spectrum we collected at the whole cross section will manifest a redshift, other than the peak

  2. Quantitative mineralogy and preliminary pore-water chemistry of candidate buffer and backfill materials for a nuclear fuel waste disposal vault

    International Nuclear Information System (INIS)

    The quantitative mineralogy of seven candidate buffer and backfill materials for a nuclear fuel waste disposal vault is presented. Two of the materials were coarse grained: one a blended very pure silica sand, and the other a crushed plagioclase-rich granite or granodiorite. Five materials were fine-grained soils containing abundant clay minerals. Of these, three were fairly pure, Cretaceous, ash-derived bentonites that contained up to 3 percent of soluble sulphates; one was a freshwater glacial clay containing 59 percent interlayered smectite-illite; and one was a crushed Paleozoic shale containing abundant illite and chlorite. The adsorbed cation regimes and the pore-water chemistry of the clays are discussed

  3. Challenges in structural materials for thermal reactors

    International Nuclear Information System (INIS)

    The safe, reliable and economic operation of nuclear power plants is critically dependent on good performance of materials. Material selection is one of the most important steps in the design of the engineering components. Functional requirements and operating conditions such as stress, temperature and environment dictate the choice of materials and their properties. Criteria for selection of materials for non-nuclear components include mechanical properties (strength-ductility-toughness), corrosion properties (resistance to uniform and localized corrosion), fabricability (forming-welding-heat treatment) and cost. Additional considerations for nuclear components include neutron absorption, induced radioactivity and resistance to radiation damage. Nuclear core components are continuously subjected to bombardment by fast neutrons. Important effects of fast neutron irradiation on properties of materials are : (i) change in mechanical properties by irradiation hardening and irradiation embrittlement (ii) dimensional changes by irradiation growth, irradiation creep and void swelling and (iii) change in corrosion properties like increase in corrosion rate and introduction of new corrosion mode. There are 2 types of thermal power reactors viz., Pressure Vessel Type (BWRs and PWRs) and Pressure Tube Type (PHWRs). A very wide range of materials are used for nuclear reactor components. These include carbon and low alloy steels, stainless steels (austenitic, martensitic, precipitation hardenable), nickel-base alloys (inconels, incoloys), zirconium base alloys, etc. Three most important classes of materials are : (1) Low alloy steels for Reactor Pressure Vessel : the main concerns are increase in Ductile-Brittle transition temperature (DBTT) and decrease in toughness due to neutron irradiation. (2) Zirconium Alloys for Reactor Core Components : main concerns are Delayed Hydride cracking (DHC) and change in dimensions due to Irradiation Creep and Growth. (3) Stainless Steels

  4. Development of Steel Foam Materials and Structures

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth Kremer; Anthony Liszkiewicz; James Adkins

    2004-10-20

    In the past few years there has been a growing interest in lightweight metal foams. Demands for weight reduction, improved fuel efficiency, and increased passenger safety in automobiles now has manufacturers seriously considering the use of metal foams, in contrast to a few years ago, when the same materials would have been ruled out for technical or economical reasons. The objective of this program was to advance the development and use of steel foam materials, by demonstrating the advantages of these novel lightweight materials in selected generic applications. Progress was made in defining materials and process parameters; characterization of physical and mechanical properties; and fabrication and testing of generic steel foam-filled shapes with compositions from 2.5 wt.% to 0.7 wt.% carbon. A means of producing steel foam shapes with uniform long range porosity levels of 50 to 60 percent was demonstrated and verified with NDE methods. Steel foam integrated beams, cylinders and plates were mechanically tested and demonstrated advantages in bend stiffness, bend resistance, and crush energy absorption. Methods of joining by welding, adhesive bonding, and mechanical fastening were investigated. It is important to keep in mind that steel foam is a conventional material in an unconventional form. A substantial amount of physical and mechanical properties are presented throughout the report and in a properties database at the end of the report to support designer's in applying steel foam in unconventional ways.

  5. Course Modules on Structural Health Monitoring with Smart Materials

    Science.gov (United States)

    Shih, Hui-Ru; Walters, Wilbur L.; Zheng, Wei; Everett, Jessica

    2009-01-01

    Structural Health Monitoring (SHM) is an emerging technology that has multiple applications. SHM emerged from the wide field of smart structures, and it also encompasses disciplines such as structural dynamics, materials and structures, nondestructive testing, sensors and actuators, data acquisition, signal processing, and possibly much more. To…

  6. Development of a candidate reference material for adventitious virus detection in vaccine and biologicals manufacturing by deep sequencing

    OpenAIRE

    Edward T Mee; Preston, Mark D.; Minor, Philip D.; ,; Huang, Xuening; Nguyen, Jenny; Wall, David; Hargrove, Stacey; Fu, Thomas; Xu, George; Li, Li; Cote, Colette; Delwart, Eric; Li, Linlin; Hewlett, Indira

    2016-01-01

    Background Unbiased deep sequencing offers the potential for improved adventitious virus screening in vaccines and biotherapeutics. Successful implementation of such assays will require appropriate control materials to confirm assay performance and sensitivity. Methods A common reference material containing 25 target viruses was produced and 16 laboratories were invited to process it using their preferred adventitious virus detection assay. Results Fifteen laboratories returned results, obtai...

  7. Lightweight Materials and Structures (LMS): Inflatable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Inflatable Structures (InSTAR) project goal is to demonstrate long term durability of inflatable habitat structures for potential utilization as either in-space...

  8. Quantitative property-structural relation modeling on polymeric dielectric materials

    Science.gov (United States)

    Wu, Ke

    Nowadays, polymeric materials have attracted more and more attention in dielectric applications. But searching for a material with desired properties is still largely based on trial and error. To facilitate the development of new polymeric materials, heuristic models built using the Quantitative Structure Property Relationships (QSPR) techniques can provide reliable "working solutions". In this thesis, the application of QSPR on polymeric materials is studied from two angles: descriptors and algorithms. A novel set of descriptors, called infinite chain descriptors (ICD), are developed to encode the chemical features of pure polymers. ICD is designed to eliminate the uncertainty of polymer conformations and inconsistency of molecular representation of polymers. Models for the dielectric constant, band gap, dielectric loss tangent and glass transition temperatures of organic polymers are built with high prediction accuracy. Two new algorithms, the physics-enlightened learning method (PELM) and multi-mechanism detection, are designed to deal with two typical challenges in material QSPR. PELM is a meta-algorithm that utilizes the classic physical theory as guidance to construct the candidate learning function. It shows better out-of-domain prediction accuracy compared to the classic machine learning algorithm (support vector machine). Multi-mechanism detection is built based on a cluster-weighted mixing model similar to a Gaussian mixture model. The idea is to separate the data into subsets where each subset can be modeled by a much simpler model. The case study on glass transition temperature shows that this method can provide better overall prediction accuracy even though less data is available for each subset model. In addition, the techniques developed in this work are also applied to polymer nanocomposites (PNC). PNC are new materials with outstanding dielectric properties. As a key factor in determining the dispersion state of nanoparticles in the polymer matrix

  9. Layer like porous materials with hierarchical structure

    Czech Academy of Sciences Publication Activity Database

    Roth, W. J.; Gil, B.; Makowski, W.; Marszalek, B.; Eliášová, Pavla

    -, - (2016). ISSN 0306-0012 R&D Projects: GA ČR GBP106/12/G015 Institutional support: RVO:61388955 Keywords : porous materials * physical chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 33.383, year: 2014

  10. Friction stir method for forming structures and materials

    Science.gov (United States)

    Feng, Zhili; David, Stan A.; Frederick, David Alan

    2011-11-22

    Processes for forming an enhanced material or structure are disclosed. The structure typically includes a preform that has a first common surface and a recess below the first common surface. A filler is added to the recess and seams are friction stir welded, and materials may be stir mixed.

  11. ACEE Composite Structures Technology: Review of selected NASA research on composite materials and structures

    Science.gov (United States)

    1984-01-01

    The NASA Aircraft Energy Efficiency (ACEE) Composite Primary Aircraft Structures Program was designed to develop technology for advanced composites in commercial aircraft. Research on composite materials, aircraft structures, and aircraft design is presented herein. The following parameters of composite materials were addressed: residual strength, damage tolerance, toughness, tensile strength, impact resistance, buckling, and noise transmission within composite materials structures.

  12. Band Structure Characteristics of Nacreous Composite Materials with Various Defects

    Science.gov (United States)

    Yin, J.; Zhang, S.; Zhang, H. W.; Chen, B. S.

    2016-06-01

    Nacreous composite materials have excellent mechanical properties, such as high strength, high toughness, and wide phononic band gap. In order to research band structure characteristics of nacreous composite materials with various defects, supercell models with the Brick-and-Mortar microstructure are considered. An efficient multi-level substructure algorithm is employed to discuss the band structure. Furthermore, two common systems with point and line defects and varied material parameters are discussed. In addition, band structures concerning straight and deflected crack defects are calculated by changing the shear modulus of the mortar. Finally, the sensitivity of band structures to the random material distribution is presented by considering different volume ratios of the brick. The results reveal that the first band gap of a nacreous composite material is insensitive to defects under certain conditions. It will be of great value to the design and synthesis of new nacreous composite materials for better dynamic properties.

  13. Neutronic analysis of alternative structural materials for fusion reactor blankets

    International Nuclear Information System (INIS)

    The neutronic performance of the International Tokamak Reactor (INTOR) blanket was studied when several alternative structural materials were used instead of the INTOR reference structural material, type 316 stainless steel. The alternative structural materials included: ferritic-, vanadium-, titanium-, long range ordered-, manganese austenitic-, and nimonic-alloys. All were treated both with and without a first-wall coating of beryllium or graphite. The tritium breeding ratio, the nuclear heating, and the gas (hydrogen and helium) production rates in the structural materials were calclated for the possible combinations of structural material and first-wall coating. These parameters were compared with those obtained by using SS-316. The nimonic alloy was the only one with worse neutronic performance than the SS-316. (orig.)

  14. Reactor structural materials and corrosion protection method therefor

    International Nuclear Information System (INIS)

    In the inside of a pressure vessel of a BWR-type reactor, structural materials, for example, a shroud disposed at the periphery of a reactor core comprise a material such as SUS 304, stainless steel, and inconel 600. A titanium oxide semiconductor layer having a predetermined thickness is formed on the surface of the structural materials, for example, by powder plasma flame-coating. The titanium oxide semiconductor layer is determined to have an oxygen-lacking structure. A slight amount of trivalent metals is preferably doped to the titanium oxide semiconductor layer. Since radiation rays are irradiated to the titanium oxide semiconductor layer, corrosion potential on the surface of the structural materials is lowered in the vicinity of the semiconductor layer by an anode reaction. This can improve corrosion resistance of the reactor structural materials in radiation and underwater circumstance for a long period of time. (I.N.)

  15. Graphene materials having randomly distributed two-dimensional structural defects

    Science.gov (United States)

    Kung, Harold H; Zhao, Xin; Hayner, Cary M; Kung, Mayfair C

    2013-10-08

    Graphene-based storage materials for high-power battery applications are provided. The storage materials are composed of vertical stacks of graphene sheets and have reduced resistance for Li ion transport. This reduced resistance is achieved by incorporating a random distribution of structural defects into the stacked graphene sheets, whereby the structural defects facilitate the diffusion of Li ions into the interior of the storage materials.

  16. Graphene materials having randomly distributed two-dimensional structural defects

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Harold H.; Zhao, Xin; Hayner, Cary M.; Kung, Mayfair C.

    2016-05-31

    Graphene-based storage materials for high-power battery applications are provided. The storage materials are composed of vertical stacks of graphene sheets and have reduced resistance for Li ion transport. This reduced resistance is achieved by incorporating a random distribution of structural defects into the stacked graphene sheets, whereby the structural defects facilitate the diffusion of Li ions into the interior of the storage materials.

  17. Polymer composite material structures comprising carbon based conductive loads

    OpenAIRE

    Jérôme, Robert; Pagnoulle, Christophe; Detrembleur, Christophe; Thomassin, Jean-Michel; Huynen, Isabelle; Bailly, Christian; Bednarz, Luikasz; Daussin, Raphaël; Saib, Aimad; Baudouin, Anne-Christine; Laloyaux, Xavier

    2007-01-01

    The present invention provides a polymer composite material structure comprising at least one layer of a foamed polymer composite material comprising a foamed polymer matrix and 0.1 wt % to 6 wt % carbon based conductive loads, such as e.g. carbon nanotubes, dispersed in the foamed polymer matrix. The polymer composite material structure according to embodiments of the present invention shows good shielding and absorbing properties notwithstanding the low amount of carbon based conductive loa...

  18. Polymer composite material structures comprising carbon based conductive loads

    OpenAIRE

    Jérôme, Robert; Pagnoulle, Christophe; Detrembleur, Christophe; Thomassin, Jean-Michel; Huynen, Isabelle; Bailly, Christian; Bednarz, Lucasz; Daussin, Raphaël; Saib, Aimad

    2006-01-01

    The present invention provides a polymer composite material structure comprising at least one layer of a foamed polymer composite material comprising a foamed polymer matrix and 0.1 to 6 wt% carbon based conductive loads, such as e.g. carbon nanotubes, dispersed in the foamed polymer matrix. The polymer composite material structure according to embodiments of the present invention shows good shielding and absorbing properties notwithstanding the low amount of carbon based conductive loads. Th...

  19. Structural Description of Powder Metallurgy Prepared Materials

    Czech Academy of Sciences Publication Activity Database

    Michalcová, A.; Vojtěch, D.; Kubatík, Tomáš František; Novák, P.; Dvořák, P.

    2014-01-01

    Roč. 14, č. 3 (2014), s. 359-362. ISSN 1213-2489. [Mezinárodní konference „Mikroskopie a nedestruktivní zkoušení materiálů/3./. Litoměřice, 22.10.2014-24.10.2014] Institutional support: RVO:61389021 Keywords : SPS * Intermetallics * powder metallurgy Subject RIV: JG - Metallurgy http://journal.strojirenskatechnologie.cz/templates/obalky_casopis/XIV_2014-3.pdf

  20. Smart Materials in Structural Health Monitoring, Control and Biomechanics

    CERN Document Server

    Soh, Chee-Kiong; Bhalla, Suresh

    2012-01-01

    "Smart Materials in Structural Health Monitoring, Control and Biomechanics" presents the latest developments in structural health monitoring, vibration control and biomechanics using smart materials. The book mainly focuses on piezoelectric, fibre optic and ionic polymer metal composite materials. It introduces concepts from the very basics and leads to advanced modelling (analytical/ numerical), practical aspects (including software/ hardware issues) and case studies spanning civil, mechanical and aerospace structures, including bridges, rocks and underground structures. This book is intended for practicing engineers, researchers from academic and R&D institutions and postgraduate students in the fields of smart materials and structures, structural health monitoring, vibration control and biomedical engineering. Professor Chee-Kiong Soh and Associate Professor Yaowen Yang both work at the School of Civil and Environmental Engineering, Nanyang Technological University, Singapore. Dr. Suresh Bhalla is an A...

  1. A data base for aging of structural materials

    International Nuclear Information System (INIS)

    The U.S. Nuclear Regulatory Commission (USNRC) initiated a Structural Aging (SAG) Program at the Oak Ridge National Laboratory (ORNL). The objective of the program is to provide assistance in identifying potential structural safety issues and to establish acceptance criteria for use in nuclear power plant evaluations for continued service. One of the main parts of the program focuses on the development of a Structural Materials Information Center where long-term and environment-dependent material properties are being collected and assembled into a data base. This data base is presented in two complementary formats. The Structural Materials Handbook is an expandable, hard-copy reference document that contains the complete data base for each material. The Structural Materials Electronic Data Base is accessible using an IBM-compatible personal computer. This paper presents an overview of the Structural Materials Information Center and briefly describes the features of the handbook and the electronic data base. In addition, a proposed method for using the data base to establish current property values for materials in existing concrete structures and to estimate the future performance of these materials is also presented. (author)

  2. A data base for aging of structural materials

    International Nuclear Information System (INIS)

    USNRC initiated a Structural Aging (SAG) Program ORNL. The objective of the program is to provide assistance in identifying potential structural safety issues and to establish acceptance criteria for use in nuclear power plant evaluations for continued service. One main part focuses on the development of a Structural Materials Information Center where long-term and environment-dependent material properties are being collected and assembled into a data base. This data base is presented in two complementary formats. The Structural Materials Handbook is an expandable, hard-copy reference document that contains the complete data base for each material. The Structural Materials Electronic Data Base is accessible using an IBM-compatible personal computer. This paper presents an overview of the Structural Materials Information Center and briefly describes the features of the handbook and the electronic data base. In addition, a proposed method for using the data base to establish current property values for materials in existing concrete structures and to estimate the future performance of these materials is also presented

  3. Design of Spintronic Materials with Simple Structures

    Energy Technology Data Exchange (ETDEWEB)

    Fong, C Y; Qian, M C; Liu, K; Yang, L H; Pask, J E

    2007-05-03

    A brief comparison of conventional electronics and spintronics is given. The key features of half metallic binary compounds with the zincblende structure are presented, using MnAs as an example. We discuss the interactions responsible for the half metallic properties. Special properties of superlattices and a digital ferromagnetic heterostructure incorporating zincblende half metals are also discussed.

  4. Design of Spintronic Materials with Simple Structures

    International Nuclear Information System (INIS)

    A brief comparison of conventional electronics and spintronics is given. The key features of half metallic binary compounds with the zincblende structure are presented, using MnAs as an example. We discuss the interactions responsible for the half metallic properties. Special properties of superlattices and a digital ferromagnetic heterostructure incorporating zincblende half metals are also discussed

  5. Surface structure evolution of cathode materials for Li-ion batteries

    Science.gov (United States)

    Yingchun, Lyu; Yali, Liu; Lin, Gu

    2016-01-01

    Lithium ion batteries are important electrochemical energy storage devices for consumer electronics and the most promising candidates for electrical/hybrid vehicles. The surface chemistry influences the performance of the batteries significantly. In this short review, the evolution of the surface structure of the cathode materials at different states of the pristine, storage and electrochemical reactions are summarized. The main methods for the surface modification are also introduced. Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB07030200) and the National Basic Research Program of China (Grant Nos. 2014CB921002 and 2012CB921702).

  6. Structural material requirements and related R and D for ITER plasma-facing components

    International Nuclear Information System (INIS)

    Solution-annealed 316 type austenitic steels have been selected as structural material for the frirst wall and blanket of ITER, with cold-worked 316 and MnCr austenitic steels as candidate alloys. The effects of irradiation on their properties: tensile, fracture toughness, low cycle fatigue, creep and rupture, swelling, stress corrosion cracking and hydrogen embrittlement, are discussed in terms of the proposed ITER operating conditions. Arguments for the selection of oxide dispersion strengthened Cu alloy for divertor plates are presented. Finally, the investigations which are being undertaken within the ITER Technology Programme to provide additional data are reviewed. (orig.)

  7. Structural materials for the next generation of technologies

    CERN Document Server

    Van de Voorde, Marcel Hubert

    1996-01-01

    1. Overview of advanced technologies; i.e. aerospace-aeronautics; automobile; energy technology; accelerator engineering etc. and the need for new structural materials. 2. Familiarisation with polymers, metals and alloys, structural ceramics, composites and surface engineering. The study of modern materials processing, generation of a materials data base, engineering properties includind NDE, radiation damage etc. 3. Development of new materials for the next generation of technologies; including the spin-off of materials developed for space and military purposes to industrial applications. 4. Materials selection for modern accelerator engineering. 5. Materials research in Europe, USA and Japan. Material R & D programmes sponsored by the European Union and the collaboration of CERN in EU sponsored programmes.

  8. Micro-and nano-structured conducting polymeric materials

    Institute of Scientific and Technical Information of China (English)

    LU Gewu; CHEN Feng'en; WU Xufeng; QU Liangti; ZHANG Jiaxin; SHI Gaoquan

    2005-01-01

    Conducting polymeric materials with micro-/nano-structures have potential applications in fabrication of various optical, electronic, sensing and electrochemical devices. This is mainly because these materials not only possess the characteristics of conducting polymers, but also have special functions based on their micro- or nano-structures. In this review, we summarize the recent work on "soft" and "hard" template-guided syntheses of micro-/nano-structured conducting polymers and open up the prospects of the main trends in this field.

  9. Development of a candidate reference material for adventitious virus detection in vaccine and biologicals manufacturing by deep sequencing

    Science.gov (United States)

    Mee, Edward T.; Preston, Mark D.; Minor, Philip D.; Schepelmann, Silke; Huang, Xuening; Nguyen, Jenny; Wall, David; Hargrove, Stacey; Fu, Thomas; Xu, George; Li, Li; Cote, Colette; Delwart, Eric; Li, Linlin; Hewlett, Indira; Simonyan, Vahan; Ragupathy, Viswanath; Alin, Voskanian-Kordi; Mermod, Nicolas; Hill, Christiane; Ottenwälder, Birgit; Richter, Daniel C.; Tehrani, Arman; Jacqueline, Weber-Lehmann; Cassart, Jean-Pol; Letellier, Carine; Vandeputte, Olivier; Ruelle, Jean-Louis; Deyati, Avisek; La Neve, Fabio; Modena, Chiara; Mee, Edward; Schepelmann, Silke; Preston, Mark; Minor, Philip; Eloit, Marc; Muth, Erika; Lamamy, Arnaud; Jagorel, Florence; Cheval, Justine; Anscombe, Catherine; Misra, Raju; Wooldridge, David; Gharbia, Saheer; Rose, Graham; Ng, Siemon H.S.; Charlebois, Robert L.; Gisonni-Lex, Lucy; Mallet, Laurent; Dorange, Fabien; Chiu, Charles; Naccache, Samia; Kellam, Paul; van der Hoek, Lia; Cotten, Matt; Mitchell, Christine; Baier, Brian S.; Sun, Wenping; Malicki, Heather D.

    2016-01-01

    Background Unbiased deep sequencing offers the potential for improved adventitious virus screening in vaccines and biotherapeutics. Successful implementation of such assays will require appropriate control materials to confirm assay performance and sensitivity. Methods A common reference material containing 25 target viruses was produced and 16 laboratories were invited to process it using their preferred adventitious virus detection assay. Results Fifteen laboratories returned results, obtained using a wide range of wet-lab and informatics methods. Six of 25 target viruses were detected by all laboratories, with the remaining viruses detected by 4–14 laboratories. Six non-target viruses were detected by three or more laboratories. Conclusion The study demonstrated that a wide range of methods are currently used for adventitious virus detection screening in biological products by deep sequencing and that they can yield significantly different results. This underscores the need for common reference materials to ensure satisfactory assay performance and enable comparisons between laboratories. PMID:26709640

  10. Family Structure, Materialism, and Compulsive Consumption.

    OpenAIRE

    Rindfleisch, Aric; Burroughs, James E; Denton, Frank

    1997-01-01

    Despite the rapid and dramatic changes in the structure of the American family over the past thirty years (e.g., divorce, single parenting), consumer researchers have largely neglected the issue of how alternative family forms influence consumer behavior. The authors' initial inquiry into this area finds that young adults reared in disrupted families are more materialistic and exhibit higher levels of compulsive consumption than young adults reared in intact families. Furthermore, they show t...

  11. Reactor structural materials study by PGNAA

    International Nuclear Information System (INIS)

    Prompt gamma neutron activation analysis (PGNAA) facility at Pakistan Research Reactor (PARR-I) has been used for the study of different kinds of materials. High efficiency, high-resolution gamma spectrometer based on high purity germanium detector is being employed. The cadmium ratio of the incident neutron beam is about 60 and the thermal neutron flux at the target positron is ∼2·106 n/cm2/s. The system is usually operated in Compton suppression mode to identify lower intensity gamma ray peaks in the lower energy region. The detection system is calibrated with standard radioactive sources from up to 1.5 MeV. In the higher energy region (up to 10 MeV), the energy calibration is done with prompt gamma rays from thermal neutron capture in chlorine and nitrogen. The aim of present study is to determine the quantity of boron in reactor grade steels as well as in some other materials containing boron because it is difficult to measure the concentration of boron by other analytical techniques. The results of boron assessment in SS-304L and ribbon will also be presented

  12. 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)

  13. Testing of the OMERACT 8 draft validation criteria for a soluble biomarker reflecting structural damage in rheumatoid arthritis: a systematic literature search on 5 candidate biomarkers

    DEFF Research Database (Denmark)

    Syversen, Silje W; Landewe, Robert; van der Heijde, Désirée;

    2009-01-01

    the importance of each individual criterion; (2) overall strength of evidence in support of each of the 5 candidate biomarkers as reflecting structural damage endpoints in rheumatoid arthritis (RA) and identification of omissions to the criteria set. RESULTS: The search identified 111 articles. The...

  14. NONLINEAR BUCKLING CHARACTERISTIC OF GRADED MULTIWEB STRUCTURE OF HETEROGENEOUS MATERIALS

    Institute of Scientific and Technical Information of China (English)

    LI Yong; ZHANG Zhi-min

    2005-01-01

    The graded multiweb structure of heterogeneous anisotropic materials, which makes full use of the continuous, gradual and changing physical mechanical performance of material properties, has a widespread application in aeroplane aerofoil structure and automobile lightweight structure. On the basis of laminate buckling theory,the equivalent rigidity method is adopted to establish the corresponding constitutive relation and the non-linear buckling governing equation for the graded multiweb structure. In finding the solution, the critical load of buckling under different complicated boundary conditions together with combined loads were obtained and testification of the experimental analysis shows that the calculation results can satisfy the requirements of engineering design in a satisfactory way. Results obtained from the research say that: graded materials can reduce the concentrated stress on the interface in an effective way and weaken the effect of initial defect in materials and thereby improve the strength and toughness of materials.

  15. Structural disorder in ion irradiated carbon materials

    International Nuclear Information System (INIS)

    The effects of ion irradiation on carbon based materials are reviewed laying emphasis on the well known ability of carbon to have different kinds of bonding configuration with the surrounding atoms. It was found that two kinds of bonding configuration of the carbon atoms are allowed in solid amorphous carbon phases. These rearrange the four valence electrons of carbon into sp2 (trigonal bond) and sp3 (tetrahedral bond) hybridizations. Driving the trigonal carbon fraction (x), the physical and chemical nature of solid carbon materials can change in a dramatic way ranging from metallic (x∼100%) to insulating (x∼0%) through semiconductor properties. The amount of the tetrahedral (or trigonal) carbon atoms can be controlled by ion beam irradiation, using suitable conditions and/or introducing foreign species such as hydrogen or silicon by the implantation technique. In hydrogenated amorphous carbon (a-C:H) and hydrogenated amorphous silicon-carbon alloys (a-Si1-xCx:H), the ion beam effects are able to produce stable and reproducible compounds, achieved by tuning the hydrogen (silicon) concentration with well defined equilibrium curves between the trigonal carbon fraction and hydrogen (silicon) content. Raman spectroscopy and temperature dependent conductivity experiments performed on these alloys suggest clustering effects in samples with high carbon content (x∼0.5) due to the strong binding energy of the C-C double bond with respect to C-Si and Si-Si. Several models and theoretical studies such as the 'random covalent network' (RCN) and molecular dynamics calculations have been used to fit the experimental results. It is shown that, while RCN models are highly inaccurate because of the clustering effects, molecular dynamics calculation data are very close to the experimental measured physical properties and confirm the ability of the trigonal carbon to cluster in graphite-like aggregate

  16. Method for fabricating high aspect ratio structures in perovskite material

    Science.gov (United States)

    Karapetrov, Goran T.; Kwok, Wai-Kwong; Crabtree, George W.; Iavarone, Maria

    2003-10-28

    A method of fabricating high aspect ratio ceramic structures in which a selected portion of perovskite or perovskite-like crystalline material is exposed to a high energy ion beam for a time sufficient to cause the crystalline material contacted by the ion beam to have substantially parallel columnar defects. Then selected portions of the material having substantially parallel columnar defects are etched leaving material with and without substantially parallel columnar defects in a predetermined shape having high aspect ratios of not less than 2 to 1. Etching is accomplished by optical or PMMA lithography. There is also disclosed a structure of a ceramic which is superconducting at a temperature in the range of from about 10.degree. K. to about 90.degree. K. with substantially parallel columnar defects in which the smallest lateral dimension of the structure is less than about 5 microns, and the thickness of the structure is greater than 2 times the smallest lateral dimension of the structure.

  17. Flight service environmental effects on composite materials and structures

    Science.gov (United States)

    Dexter, H. Benson; Baker, Donald J.

    1992-01-01

    NASA Langley and the U.S. Army have jointly sponsored programs to assess the effects of realistic flight environments and ground-based exposure on advanced composite materials and structures. Composite secondary structural components were initially installed on commercial transport aircraft in 1973; secondary and primary structural components were installed on commercial helicopters in 1979; and primary structural components were installed on commercial aircraft in the mid-to-late 1980's. Service performance, maintenance characteristics, and residual strength of numerous components are reported. In addition to data on flight components, 10 year ground exposure test results on material coupons are reported. Comparison between ground and flight environmental effects for several composite material systems are also presented. Test results indicate excellent in-service performance with the composite components during the 15 year period. Good correlation between ground-based material performance and operational structural performance has been achieved.

  18. Advanced structural integrity assessment procedures. Working material

    International Nuclear Information System (INIS)

    The purpose of the meeting was to provide an international forum for discussion on recent results in research and utility practice in the field of methodology for the structural integrity assessment of components including relevant non-codified procedures. The scope of the meeting included deterministic and probabilistic approaches. The papers covered the following topics: Leak-before-break concepts; non-destructive examination (NDE) and surveillance results; statistical evaluation of non-destructive examination data; pressurized thermal shock evaluation; fatigue effects (including vibration); and verification qualification. The meeting was attended by 32 specialists from 8 countries. Refs, figs and tabs

  19. Overview of European Community (Activity 3) work on materials properties of fast reactor structural materials

    International Nuclear Information System (INIS)

    The Fast Reactor Coordinating Committee set up in 1974 the Working Group Codes and Standards, and organized its work into four main activities: Manufacturing standards, Structural analysis, Materials and Classification of components. The main purpose of materials activity is to compare and contrast existing national specifications and associated properties relevant to structural materials in fast reactors. Funds are available on a yearly basis for tasks to be carried out through Study Contracts. At present about four Study Contract Reports are prepared each year

  20. Development of Structural Materials for JSFR - Overview and Current Status

    International Nuclear Information System (INIS)

    This paper summarized the ongoing efforts regarding new core and structural materials that are to applied to the Japanese sodium cooled fast breeder reactors (JSFR) of which demonstration plant's operation is envisioned in around 2025. For core materials, oxide dispersed strengthened steel (ODS) and precipitation hardened (PH) ferritic steels will be applied. For structural materials, 316FR stainless steel and Modified 9Cr-1Mo steel are applied. The current status alloy design, acquisition of data necessary to establish material strength standard, fabrication techniques to meet the requirements of the design of JSFR both in terms of quality and quantity, and codification of the material strength standards regarding the new materials are overviewed. Further described is path forward to the application of the materials to the JSFR. (author)

  1. Neutron Scattering Studies of Nanomagnetism and Artificially Structured Materials

    Energy Technology Data Exchange (ETDEWEB)

    Fitzsimmons, M.R.; Bader, S.D.; Borchers, J.A.; Felcher, G.P.; Furdyna, J.K.; Hoffmann, A.; Kortright, J.B.; Schuller, Ivan K.; Schulthess, T.C.; Sinha, S.K.; Toney, M.F.; Weller, D.; Wolf, S.

    2003-02-01

    Nanostructured magnetic materials are intensively studied due to their unusual properties and promise for possible applications. The key issues in these materials relate to the connection between their physical properties (transport, magnetism, mechanical, etc.) and their chemical-physical structure. In principle, a detailed knowledge of the chemical and physical structure allows calculation of their physical properties. Theoretical and computational methods are rapidly evolving so that magnetic properties of nanostructured materials might soon be predicted. Success in this endeavor requires detailed quantitative understanding of the magnetic structure and properties.

  2. Space Transportation Materials and Structures Technology Workshop. Volume 2; Proceedings

    Science.gov (United States)

    Cazier, Frank W., Jr. (Compiler); Gardner, James E. (Compiler)

    1993-01-01

    The Space Transportation Materials and Structures Technology Workshop was held on September 23-26, 1991, in Newport News, Virginia. The workshop, sponsored by the NASA Office of Space Flight and the NASA Office of Aeronautics and Space Technology, was held to provide a forum for communication within the space materials and structures technology developer and user communities. Workshop participants were organized into a Vehicle Technology Requirements session and three working panels: Materials and Structures Technologies for Vehicle Systems, Propulsion Systems, and Entry Systems.

  3. Effects of material disintegration on structural performance

    International Nuclear Information System (INIS)

    Using a state variable approach it will be shown how the results of appropriately chosen tests can be used to develop constitutive equations which describe the effects of creep deterioration on the deformation of metals operating at elevated temperatures. In this way a systematic phenomenological approach can be developed. Using this approach in conjunction with the results of multiaxial stress tests a set of constitutive equations are proposed which define the creep deformation rates in terms of applied stress and a material state variable, referred to as damage. In spite of the fact that the equations have been comstructed using purely phenomenological procedures, it is possible, nevertheless to demonstrate the physical interpretation of the damage state. Using the constitutive equations in conjunction with the virtual work relationships it is possible to obtain bounds on the rupture life of components subjected to both constant and cyclic loading. It is found convenient to express the results in terms of a so-called representative rupture stress, so that the uniaxial creep rupture curves can be used directly, thereby avoiding complex curve fitting procedures. The bounds are used to predict the rupture life of a number of components subjected to constant and variable load and comparison is made with experimental results. The components tested are: plane stress plates with holes and slots, subjected to uniaxial stress; plane stress plates with holes and slots subjected to biaxial tension; cylindrical bars with round notches; reinforced shell intersections subjected to internal pressure

  4. Improved structural materials for fast breeder reactors

    International Nuclear Information System (INIS)

    Electricity plays a crucial role in the economic development of our country. Coal is the primary fuel for generation of electricity in India as in many other countries. In India, generation of power by nuclear reactors is very important because of (i) availability of large thorium resource, (ii) constraints on setting up of fossil fuel based power plants and (iii) the negligibly small green house gas emissions by nuclear energy. The nuclear programme of the country is being implemented in three stages: (i) pressurized heavy water reactors of the CANDU type, (ii) sodium-cooled fast reactors and (iii) thorium-based reactors. Sodium-cooled fast reactor (SFR) technology is envisioned to make use of the large thorium reserves available. India has undertaken and made rapid strides in developing SFR technology and building of fast reactors for energy generation. A Fast Breeder Test Reactor (FBTR) of 40 MWt is operating successfully for over 25 years at Indira Gandhi Centre for Atomic Research. Based on the design, construction and operational experience, a 500 MWe Prototype Fast Breeder Reactor (PFBR) has been designed indigenously and is in an advanced stage of construction. Its design is being further optimised for enhanced economy with respect to cost of electricity production, for use in commercial reactors. Currently, several R and D programmes are under implementation for the development of new materials required for improved economy of commercial fast reactors

  5. Microfabrication of hierarchical structures for engineered mechanical materials

    Science.gov (United States)

    Vera Canudas, Marc

    Materials found in nature present, in some cases, unique properties from their constituents that are of great interest in engineered materials for applications ranging from structural materials for the construction of bridges, canals and buildings to the fabrication of new lightweight composites for airplane and automotive bodies, to protective thin film coatings, amongst other fields. Research in the growing field of biomimetic materials indicates that the micro-architectures present in natural materials are critical to their macroscopic mechanical properties. A better understanding of the effect that structure and hierarchy across scales have on the material properties will enable engineered materials with enhanced properties. At the moment, very few theoretical models predict mechanical properties of simple materials based on their microstructures. Moreover these models are based on observations from complex biological systems. One way to overcome this challenge is through the use of microfabrication techniques to design and fabricate simple materials, more appropriate for the study of hierarchical organizations and microstructured materials. Arrays of structures with controlled geometry and dimension can be designed and fabricated at different length scales, ranging from a few hundred nanometers to centimeters, in order to mimic similar systems found in nature. In this thesis, materials have been fabricated in order to gain fundamental insight into the complex hierarchical materials found in nature and to engineer novel materials with enhanced mechanical properties. The materials fabricated here were mechanically characterized and compared to simple mechanics models to describe their behavior with the goal of applying the knowledge acquired to the design and synthesis of future engineered materials with novel properties.

  6. Hydrophobic and breathable nanomembrane for food package material by mimicking cocoon’s structure

    Directory of Open Access Journals (Sweden)

    Zhang Zhen

    2015-01-01

    Full Text Available The aim of this study was to investigate the cross-linked poly(vinyl alcohol nanofibrous mats treated by flourinated alkane in supercritical carbon dioxide medium. The surface morphology and chemical structure of electrospun mats were analyzed by scanning electron microscopy and Fourier transform infrared. The results showed that the treated mats could maintain their integrity and fibrous morphology as well as their porous structure after being treated. However, the wettability was changed greatly, the average contact angle of treated nanofibrous mats increased from its original value of 28° to 134°, revealing that the treated mats had good water repellent properties. The paper concluded that the hydrophobic and breathable mats with porous structure might be an excellent candidate for food package materials.

  7. Estimation of radioactivity in structural materials of ETRR-1 reactor

    International Nuclear Information System (INIS)

    Precise knowledge of the thermal neutron flux in the different structural materials of a reactor is necessary to estimate the radioactive inventory in these materials that are needed in any decommissioning study of the reactor. ETRR-1 is a research reactor that went critical on 2/1691. In spite of this long age of the reactor, the effective operation time of this reactor is very short since the reactor was shutdown for long periods. Because of this long age one may think of reactor decommissioning. For this purpose, the radioactivity of the reactor structural materials was estimated. Apart from the reactor core, the important structural materials in the ETRR-1 are the reactor tank, shielding concrete, and the graphite thermal column. The thermal neutron flux was determined by the monte Carlo method in these materials and the isotope inventory and the radioactivity were calculated by the international code ORIGEN-JR. 1 fig

  8. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    International Nuclear Information System (INIS)

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute α grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase (α and β) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase α and near-α (Ti Gr 12) alloys

  9. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.

    1997-12-01

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute {alpha} grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase ({alpha} and {beta}) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase {alpha} and near-{alpha} (Ti Gr 12) alloys.

  10. Low Cost, Lightweight, Multifunctional Structural Shielding Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR involves the development of a lightweight innovative material for use as structure and radiation shielding in one. APS has assembled a uniquely qualified...

  11. Handbook for structural analysis of radioactive material transport casks

    International Nuclear Information System (INIS)

    This paper described structural analysis method of radioactive material transport casks for use of a handbook of safety analysis and evaluation. Safety analysis conditions, computer codes for analyses and stress evaluation method are also involved in the handbook. (author)

  12. Application of Advanced Radiation Shielding Materials to Inflatable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovation is a weight-optimized, inflatable structure that incorporates radiation shielding materials into its construction, for use as a habitation module or...

  13. Nuclear data for structural materials of fission and fusion reactors

    International Nuclear Information System (INIS)

    The document presents the status of nuclear reaction theory concerning optical model development, level density models and pre-equilibrium and direct processes used in calculation of neutron nuclear data for structural materials of fission and fusion reactors. 6 refs

  14. Classic and New Materials Used for Structural Rehabilitation. Case Study

    Science.gov (United States)

    Lute, M.

    2016-06-01

    New materials development with different combination of properties were always a challenge in terms of their adequate use in civil engineering. Introduction of carbon fibres as strength material for structures was a beginning of a new approach in structural rehabilitation, and sometimes meant the end of classic rehabilitation solution use. The present paper gives an example of a building rehabilitation that use a melt of both new and old solutions in order to achieve the optimum result for building itself. The problem was even more challenging, because the structure considered is only 22 years old, but having some design faults in terms of seismic behaviour and, in addition, one floor was added to existing structure. The chosen solution was a compromise between the use of old and new materials in places where their qualities were best suitable and their minuses could be compensated by the other material.

  15. Synthesis of Narrow Molecular Weight Distribution Norbornene-Lactone Functionalized Polymers by Nitroxide-Mediated Polymerization: Candidates for 193-nm Photoresist Materials

    Directory of Open Access Journals (Sweden)

    Zi Jun Wang

    2014-02-01

    Full Text Available One hundred ninety three-nanometer candidate photoresist materials were synthesized by nitroxide-mediated polymerization (NMP. Statistical copolymerizations of 5-methacryloyloxy-2,6-norboranecarbolactone (NLAM with 5–10 mol% of controlling co-monomers (which are necessary for controlled polymerizations of methacrylates by NMP with the initiator used in the feed, such as styrene (ST, p-acetoxystyrene (AcOST, 2-vinyl naphthalene (VN and pentafluorostyrene (PFS, using the unimolecular BlocBuilder® initiator in 35 wt% dioxane solution at 90 °C were performed. As little as 5 mol% controlling comonomer in the feed was demonstrated to be sufficient to lead to linear evolution of number average molecular weight  with respect to conversion up to 50%, and the resulting copolymers had dispersities  of ~1.3 in most cases, an attractive feature for reducing line width roughness (LWR in photoresists. The copolymers generally showed relatively low absorbance at 193 nm, comparable to other 193-nm candidate photoresists reported previously, despite the inclusion of a small amount of the styrenic co-monomers in the copolymer.

  16. Material and structural instabilities of single-wall carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    J. Wu; K. C. Hwang; J. Song; Y. Huang

    2008-01-01

    The nonlinear atomistic interactions usually involve softening behavior. Instability resulting directly from this softening are called the material instability, while those unrelated to this softening are called the structural instability. We use the finite-deformation shell theory based on the interatomic potential to show that the tension instability of single-wall carbon nanotubes is the material instability, while the compression and torsion instabilities are structural instability.

  17. Validation of induced radioactivity calculations for candidate fusion materials through measurements in a graphite-centered assembly

    International Nuclear Information System (INIS)

    Induced radioactivity measurements were carried out jointly by the USA and Japan in a graphite-centered assembly, in the framework of ITER Task T-218 entitled 'Shielding Blanket Neutronics Experiments'. An intense, accelerator-based D-T rotating target neutron source JAERI, with a nominal intensity of 5 x 1012 s-1, was used. Two locations, providing different neutron energy spectra, were chosen for irradiating samples of a range of materials of interest to ITER. Three independent experimental campaigns were conducted so as to accommodate a large number of samples, on one hand, and as many short and long half-life products as possible, on the other. The total neutron fluence ranged from 4.7 x 1011 to 1.5 x 1014 n cm-2. Altogether, samples of Mg, Al, SiO2, Ti, V, Cr, Mn, Fe, Co, Ni, FH82 steel, SS316LN steel (ITER grade), Cu, Zn, KCl, Zr, Nb, Mo, Ag, ln, Sn, Dy, Ta, Hf, Re, Au, Ir, and Pb were irradiated. The irradiated samples were cooled for variable periods ranging from 30 s to 250 days before their decay gamma-ray spectra were counted on high purity intrinsic germanium detectors. The half lives of the observed radioisotopes have ranged from 18.7 s (46mSc from Ti) to 5.3 years (60Co from Ni). The neutron energy spectra for the two locations were calculated using Monte Carlo code MCNP with FENDL-1 and ENDF/B-VI data libraries. The analysis of isotopic activities, expressed in Bq cc-1, of the irradiated materials has been carried out using REAC-3 radioactivity code, with FENDL-2A and FENDL-1A activation cross-section and decay data libraries. Typically, C/E lies in a band of 0.5-1.5 for the results being reported. (orig.)

  18. Validation of a liquid chromatographic method for determination of related substances in a candidate certified reference material of captopril

    Directory of Open Access Journals (Sweden)

    Raquel Nogueira

    2011-06-01

    Full Text Available This paper describes the validation of a reversed-phase high performance liquid chromatography method (RP-HPLC with diode array detection (DAD for determination of related substances (impurities from organic synthesis and degradation products of captopril according to the Brazilian Pharmacopeia IV. The aim of this study was to guarantee the method accuracy for quantification of related substances, an essential requisite to determine, using the mass balance approach, the captopril content in the first Brazilian certified reference material (CRM of an active pharmaceutical ingredient (API, developed by Inmetro. The captopril instability in solution is discussed and the captopril content determined by mass balance is compared to the results from titration and differential scanning calorimetry (DSC.Este artigo descreve a validação de método de cromatografia líquida de alta eficiência em fase reversa (CLAE-RP com detector de fotodiodos (DAD para determinação de substâncias relacionadas (impurezas orgânicas de síntese e produtos de degradação de captopril segundo Farmacopéia Brasileira IV ed. Este estudo teve como objetivo garantir que o método é capaz de quantificar com exatidão o teor de substâncias relacionadas, um requisito essencial para que o teor de captopril seja determinado por balanço de massa no primeiro material de referência certificado (MRC de fármacos brasileiro, o qual foi desenvolvido pelo Inmetro. A instabilidade do captopril em solução é discutida em detalhes e o teor de captopril determinado por balanço de massa é comparado com aqueles obtidos por titulação e por calorimetria exploratória diferencial (DSC.

  19. Simultaneous dynamic electrical and structural measurements of functional materials

    Energy Technology Data Exchange (ETDEWEB)

    Vecchini, C.; Stewart, M.; Muñiz-Piniella, A.; Wooldridge, J. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Thompson, P.; McMitchell, S. R. C.; Bouchenoire, L.; Brown, S.; Wermeille, D.; Lucas, C. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Liverpool, Liverpool L69 3BX (United Kingdom); Lepadatu, S. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Bikondoa, O.; Hase, T. P. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Lesourd, M. [ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Dontsov, D. [SIOS Meßtechnik GmbH, Am Vogelherd 46, 98693 Ilmenau (Germany); Cain, M. G. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Electrosciences Ltd., Farnham, Surrey GU9 9QT (United Kingdom)

    2015-10-15

    A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli.

  20. Dosimetry methods for fuels, cladding and structural materials

    International Nuclear Information System (INIS)

    This volume of the proceedings of the symposium on reactor dosimetry covers the following topics: the metallurgy and dosimetry interface, radiation damage correlations of structural materials and damage analyses techniques, dosimetry for fusion materials, light water reactor pressure vessel surveillance in practice and irradiation experiments, fast reactor and reseach reactor characterization

  1. Analysis and Design of Biological Materials and Structures

    CERN Document Server

    Öchsner, Andreas; Altenbach, Holm

    2012-01-01

    This collection provides researchers and scientists with advanced analyses and materials design techniques in Biomaterials and presents mechanical studies of biological structures. In 16 contributions well known experts present their research on Stress and Strain Analysis, Material Properties, Fluid and Gas mechanics and they show related problems.

  2. Extended propagation model for interfacial crack in composite material structure

    Institute of Scientific and Technical Information of China (English)

    闫相桥; 冯希金

    2002-01-01

    An interfacial crack is a common damage in a composite material structure . An extended propaga-tion model has been established for an interfacial crack to study the dependence of crack growth on the relativesizes of energy release rates at left and right crack tips and the properties of interfacial material characterize thegrowth of interfacial crack better.

  3. Spectrum Slam Fatigue Loading of Sandwich Materials for Marine Structures

    OpenAIRE

    Burman, Magnus; Rosén, Anders; Zenkert, Dan

    2010-01-01

    Sandwich materials are more frequently used in high speed craft and ferries. The motivation is reduced weight and associated operational cost. The hull structure in these vessels is subjected to repeated (fatigue) slamming loads (high strain rate loading). Scantling societies treat sandwich materials differently in their design rules. In common reduction or safety factors on the static strength of sandwich materials are used calculating the design stress. In most rules there is no explicit co...

  4. Structure and properties of sintered tool gradient materials

    OpenAIRE

    L.A. Dobrzański; B. Dołżańska

    2010-01-01

    Purpose: The main objective of the presented is to elaborate the fabrication technology of novel sintered tool gradient materials on the basis of hard wolfram carbide phase with cobalt binding phase, and to carry out research studies on the structure and properties of the newly elaborated sintered tool gradient materials.Design/methodology/approach: The following research studies have been carried out to elaborate a new group of sintered tool gradient materials, wolfram carbide with cobalt ma...

  5. Tunable structural color in organisms and photonic materials for design of bioinspired materials

    Directory of Open Access Journals (Sweden)

    Hiroshi Fudouzi

    2011-01-01

    Full Text Available In this paper, the key topics of tunable structural color in biology and material science are overviewed. Color in biology is considered for selected groups of tropical fish, octopus, squid and beetle. It is caused by nanoplates in iridophores and varies with their spacing, tilting angle and refractive index. These examples may provide valuable hints for the bioinspired design of photonic materials. 1D multilayer films and 3D colloidal crystals with tunable structural color are overviewed from the viewpoint of advanced materials. The tunability of structural color by swelling and strain is demonstrated on an example of opal composites.

  6. Assessment of homogeneity of candidate reference material at the nanogram level and investigation on representativeness of single particle analysis using electron probe X ray microanalysis

    International Nuclear Information System (INIS)

    Particulate samples of a candidate reference material are evaluated on their homogeneity from bottle to bottle using electron probe X ray microanalysis technique. The evaluation on the homogeneity is done by the utilization of the Kolmogorov-Smirnov statistics to the processing of the quantitative electron probe X ray microanalysis data. Due to a limitation, existing even in computer controlled electron probe X ray microanalysis, in terms of analysis time and expenses, the number of particles analyzed is much smaller compared to that in the sample. Therefore, it is investigated whether this technique provides representative analysis results for the characteristics of the sample, even though a very small portion of the sample is really analyzed. Furthermore, the required number of particles for the analysis, to insure a certain level of reproducibility, e.g. 5% relative standard deviation, is determined by the application of the Ingamells sampling theory. (author)

  7. FIRE PROTECTION OF TIMBER STRUCTURES STRENGTHENED WITH FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Radek Zigler

    2015-12-01

    Full Text Available Modern, progressive methods of structures’ strengthening based on the use of composite materials composed of high strength fibers (carbon, glass, aramid or basalt and matrices based on epoxy resins brings, among many indisputable advantages (low weight, high effectiveness, easy application etc. also some disadvantages. One of the major disadvantages is a low fire resistance of these materials due to the low glass transition temperature Tg of the resin used. Based on an extensive research of strengthening of historic structures with FRP materials [1], the article outlines possible approaches to this problem, especially while strengthening timber load- bearing structures of historic buildings.

  8. Spectral fine structure effects on material and doppler reactivity worth

    International Nuclear Information System (INIS)

    New formulations concerning the fine structure effects on the reactivity worth of resonances are developed and conclusions are derived following the extension to more general types of perturbations which include: the removal of resonance material at finite temperatures and the temperature variation of part of the resonance material. It is concluded that the flux method can overpredict the reactivity worth of resonance materials more than anticipated. Calculations on the Doppler worth were carried out; the results can be useful for asessing the contribution of the fine structure effects to the large discrepancy that exists between the calculated and measured small sample Doppler worths. (B.G.)

  9. Temperature Effects on the Mechanical Properties of Candidate SNS Target Container Materials after Proton and Neutron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Byun, T.S.

    2001-11-09

    This report presents the tensile properties of EC316LN austenitic stainless steel and 9Cr-2WVTa ferritic/martensitic steel after 800 MeV proton and spallation neutron irradiation to doses in the range 0.54 to 2.53 dpa. Irradiation temperatures were in the range 30 to 100 C. Tensile testing was performed at room temperature (20 C) and 164 C to study the effects of test temperature on the tensile properties. Test materials displayed significant radiation-induced hardening and loss of ductility due to irradiation. The EC316LN stainless steel maintained notable strain-hardening capability after irradiation, while the 9Cr-2WVTa ferritic/martensitic steel posted negative strain hardening. In the EC316LN stainless steel, increasing the test temperature from 20 C to 164 C decreased the strength by 13 to 18% and the ductility by 8 to 36%. The tensile data for the EC316LN stainless steel irradiated in spallation conditions were in line with the values in a database for 316 stainless steels for doses up to 1 dpa irradiated in fission reactors at temperatures below 200 C. However, extra strengthening induced by helium and hydrogen contents is evident in some specimens irradiated to above about 1 dpa. The effect of test temperature for the 9Cr-2WVTa ferritic/martensitic steel was less significant than for the EC316LN stainless steel. In addition, strain-hardening behaviors were analyzed for EC316LN and 316L stainless steels. The strain-hardening rate of the 316 stainless steels was largely dependent on test temperature. It was estimated that the 316 stainless steels would retain more than 1% true stains to necking at 164 C after irradiation to 5 dpa. A calculation using reduction of area (RA) measurements and stress-strain data predicted positive strain hardening during plastic instability.

  10. Point Defect Phenomena of Crystalline Structure in Some Common Structural Materials

    Institute of Scientific and Technical Information of China (English)

    RUAN Yu-Zhong; WU Ren-Ping; YU Yan

    2005-01-01

    The existence and its movement rule of crystalline structure defect are closely related to the diffusion, solid phase reaction, sintering, phase transformation as well as the physical and chemical properties of materials. Point defect theory has been widely applied in material mineralization research, unfavorable transformation controlling, material modification,the research and development of new materials and so on. Point defect theory is one of the important theories for new material research and development. Herein we mainly discuss the application of point defect theory in some structural material researches.

  11. NASA Subsonic Rotary Wing Project - Structures and Materials Discipline

    Science.gov (United States)

    Halbig, Michael C.; Johnson, Susan M.

    2008-01-01

    The Structures & Materials Discipline within the NASA Subsonic Rotary Wing Project is focused on developing rotorcraft technologies. The technologies being developed are within the task areas of: 5.1.1 Life Prediction Methods for Engine Structures & Components 5.1.2 Erosion Resistant Coatings for Improved Turbine Blade Life 5.2.1 Crashworthiness 5.2.2 Methods for Prediction of Fatigue Damage & Self Healing 5.3.1 Propulsion High Temperature Materials 5.3.2 Lightweight Structures and Noise Integration The presentation will discuss rotorcraft specific technical challenges and needs as well as details of the work being conducted in the six task areas.

  12. Corrosion of structural materials for Generation IV systems

    International Nuclear Information System (INIS)

    The Generation IV International Forum aims at developing future generation nuclear energy systems. Six systems have been selected for further consideration: sodium-cooled fast reactor (SFR), gas-cooled fast reactor (GFR), lead-cooled fast reactor (LFR), molten salt reactor (MSR), supercritical water-cooled reactor (SCWR) and very high temperature reactor (VHTR). CEA, in the frame of a national program, of EC projects and of the GIF, contributes to the structural materials developments and research programs. Particularly, corrosion studies are being performed in the complex environments of the GEN IV systems. As a matter of fact, structural materials encounter very severe conditions regarding corrosion concerns: high temperatures and possibly aggressive chemical environments. Therefore, the multiple environments considered require also a large diversity of materials. On the other hand, the similar levels of working temperatures as well as neutron spectrum imply also similar families of materials for the various systems. In this paper, status of the research performed in CEA on the corrosion behavior of the structural material in the different environments is presented. The materials studied are either metallic materials as austenitic (or Y, La, Ce doped) and ferrito-martensitic steels, Ni base alloys, ODS steels, or ceramics and composites. In all the environments studied, the scientific approach is identical, the objective being in all cases the understanding of the corrosion processes to establish recommendations on the chemistry control of the coolant and to predict the long term behavior of the materials by the development of corrosion models. (author)

  13. Low-Cost Composite Materials and Structures for Aircraft Applications

    Science.gov (United States)

    Deo, Ravi B.; Starnes, James H., Jr.; Holzwarth, Richard C.

    2003-01-01

    A survey of current applications of composite materials and structures in military, transport and General Aviation aircraft is presented to assess the maturity of composites technology, and the payoffs realized. The results of the survey show that performance requirements and the potential to reduce life cycle costs for military aircraft and direct operating costs for transport aircraft are the main reasons for the selection of composite materials for current aircraft applications. Initial acquisition costs of composite airframe components are affected by high material costs and complex certification tests which appear to discourage the widespread use of composite materials for aircraft applications. Material suppliers have performed very well to date in developing resin matrix and fiber systems for improved mechanical, durability and damage tolerance performance. The next challenge for material suppliers is to reduce material costs and to develop materials that are suitable for simplified and inexpensive manufacturing processes. The focus of airframe manufacturers should be on the development of structural designs that reduce assembly costs by the use of large-scale integration of airframe components with unitized structures and manufacturing processes that minimize excessive manual labor.

  14. 10th meeting of the International Conference on Protection of Materials and Structures from Space Environment

    CERN Document Server

    Tagawa, Masahito; Kimoto, Yugo; Protection of Materials and Structures From the Space Environment

    2013-01-01

    The goals of the 10th International Space Conference on “Protection of Materials and Structures from Space Environment” ICPMSE-10J, since its inception in 1992, have been to facilitate exchanges between members of the various engineering and science disciplines involved in the development of space materials, including aspects of LEO, GEO and Deep Space environments, ground-based qualification, and in-flight experiments and lessons learned from operational vehicles that are closely interrelated to disciplines of the atmospheric sciences, solar-terrestrial interactions and space life sciences. The knowledge of environmental conditions on and around the Moon, Mars, Venus and the low Earth orbit as well as other possible candidates for landing such as asteroids have become an important issue, and protecting both hardware and human life from the effects of space environments has taken on a new meaning in light of the increased interest in space travel and colonization of other planets.  And while many materia...

  15. Liquid-metal fast breeder reactor structural materials design considerations

    International Nuclear Information System (INIS)

    This paper gives a brief overview of the LMFBR, to describe its key components, addresses two key structural problems, reviews high-temperature materials utilized, and places bounds on expected operating conditions. The current status of materials utilization in the LMFBR is summarized as follows: with the exception of the reactor upper internals, design needs for the LMFBR can be met with currently approved Code materials; Inconel 718 can potentially solve the thermal striping problems in the reactor upper internals; temperature, stress-strain levels, and design lifetime of the LMFBR push currently approved Code materials toward their limits of usefulness

  16. Recent developments of discrete material optimization of laminated composite structures

    DEFF Research Database (Denmark)

    Lund, Erik; Sørensen, Rene

    2015-01-01

    This work will give a quick summary of recent developments of the Discrete Material Optimization approach for structural optimization of laminated composite structures. This approach can be seen as a multi-material topology optimization approach for selecting the best ply material and number of...... plies in a laminated composite structure. The conceptual combinatorial design problem is relaxed to a continuous problem such that well-established gradient based optimization techniques can be applied, and the optimization problem is solved on basis of interpolation schemes with penalization. The...... it possible also to include local criteria such as strength criteria in the formulations. This is illustrated by structural optimization of a corner hinged laminated plate in this paper, and at ICCM20 it will also be demonstrated for optimization of a main spar from a wind turbine blade....

  17. Basic reactions of osteoblasts on structured material surfaces

    Directory of Open Access Journals (Sweden)

    B�chter A.

    2005-04-01

    Full Text Available In order to assess how bone substitute materials determine bone formation in vivo it is useful to understand the mechanisms of the material surface/tissue interaction on a cellular level. Artificial materials are used in two applications, as biomaterials alone or as a scaffold for osteoblasts in a tissue engineering approach. Recently, many efforts have been undertaken to improve bone regeneration by the use of structured material surfaces. In vitro studies of bone cell responses to artificial materials are the basic tool to determine these interactions. Surface properties of materials surfaces as well as biophysical constraints at the biomaterial surface are of major importance since these features will direct the cell responses. Studies on osteoblastlike cell reactivity towards materials will have to focus on the different steps of protein and cell reactions towards defined surface properties. The introduction of new techniques allows nowadays the fabrication of materials with ordered surface structures. This paper gives a review of present knowledge on the various stages of osteoblast reactions on material surfaces, focused on basic cell events under in vitro conditions. Special emphasis is given to cellular reactions towards ordered nano-sized topographies.

  18. Tauro: a ceramic composite structural material self-cooled Pb-17Li breeder blanket concept

    International Nuclear Information System (INIS)

    The use of a low-activation (LA) ceramic composite (CC) as structural material appears essential to demonstrate the potential of fusion power reactors for being inherently or, at least, passively safe. Tauro is a self-cooled Pb-17Li breeder blanket with a SiC/SiC composite as structure. This study determines the required improvements for existing industrial LA composites (mainly SiC/SiC) in order to render them acceptable for blanket operating conditions. 3D SiC/SiC CC, recently launched on the market, is a promising candidate. A preliminary evaluation of a possible joining technique for SiC/SiC is also described. (orig.)

  19. Fluctuation electron microscopy studies of complex structured materials

    Science.gov (United States)

    Zhao, Gongpu; Rougée, Annick; Buseck, Peter; Treacy, Michael

    2008-03-01

    Fluctuation electron microscopy (FEM) is a hybrid imaging-diffraction technique. This technique is particularly sensitive to paracrystalline structures of dimension 0.5-2 nm, which are difficult to detect by either imaging or diffraction techniques alone. It has been successfully deployed to study paracrystalline structures in amorphous silicon, germanium thin film. This technique has also been used to study metallic glasses and oxide glasses. Until now, FEM has not been used to study disordered geological materials. In this talk we present our FEM studies of shungite, a naturally occurring disordered carbonaceous material, reveal that trace quantities of tightly curved graphene structures such as C60, or fragments of C60, is present in shungite. We also present results from our study of metamict zircon, whose crystal structure is destroyed by self-radiation during naturally occurring α decay events. Work is in progress to study the structural evolution during the metamictization process.

  20. Risks and reliability of manufacturing processes as related to composite materials for spacecraft structures

    Science.gov (United States)

    Bao, Han P.

    1995-01-01

    Fabricating primary aircraft and spacecraft structures using advanced composite materials entail both benefits and risks. The benefits come from much improved strength-to-weight ratios and stiffness-to-weight ratios, potential for less part count, ability to tailor properties, chemical and solvent resistance, and superior thermal properties. On the other hand, the risks involved include high material costs, lack of processing experience, expensive labor, poor reproducibility, high toxicity for some composites, and a variety of space induced risks. The purpose of this project is to generate a manufacturing database for a selected number of materials with potential for space applications, and to rely on this database to develop quantitative approaches to screen candidate materials and processes for space applications on the basis of their manufacturing risks including costs. So far, the following materials have been included in the database: epoxies, polycyanates, bismalemides, PMR-15, polyphenylene sulfides, polyetherimides, polyetheretherketone, and aluminum lithium. The first four materials are thermoset composites; the next three are thermoplastic composites, and the last one is is a metal. The emphasis of this database is on factors affecting manufacturing such as cost of raw material, handling aspects which include working life and shelf life of resins, process temperature, chemical/solvent resistance, moisture resistance, damage tolerance, toxicity, outgassing, thermal cycling, and void content, nature or type of process, associate tooling, and in-process quality assurance. Based on industry experience and published literature, a relative ranking was established for each of the factors affecting manufacturing as listed above. Potential applications of this database include the determination of a delta cost factor for specific structures with a given process plan and a general methodology to screen materials and processes for incorporation into the current

  1. Nuclear materials - fissile, fertile and dual-use structural materials involved in nuclear reactors

    International Nuclear Information System (INIS)

    The article presents a brief account of nuclear materials, with special emphasis on fissile, fertile and some important dual-use structural materials generally involved in nuclear reactors. The dual-use structural materials utilized in nuclear reactors have got important applications in both nuclear and non-nuclear fields. In the hostile environment, the important phenomena such as interactions between fission products and the surrounding elemental species, radiation-induced effects, corrosion, generation of gases, swelling and so forth, become increasingly complex and the performance of a nuclear reactor system thus becomes very much dependent on the physicochemical stability and nuclear compatibility of the dual-use structural materials used in fuel sub-assembly towards the fuel elements. In this context, the dual-use structural materials like stainless steel, zirconium alloys, etc. as claddings; water, liquid sodium or gases, etc. as coolants and water, boron, etc. as moderators, having good reliability and appropriate nuclear compatibility with the fuels, are of prime importance in reactor technology. In advanced designed reactors, development of novel fuels coupled with efficient dual-use structural materials may mitigate the challenges involved in optimizing the efficiency of the power reactors under specific experimental conditions. (author)

  2. Structure and properties of sintered tool gradient materials

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2010-12-01

    Full Text Available Purpose: The main objective of the presented is to elaborate the fabrication technology of novel sintered tool gradient materials on the basis of hard wolfram carbide phase with cobalt binding phase, and to carry out research studies on the structure and properties of the newly elaborated sintered tool gradient materials.Design/methodology/approach: The following research studies have been carried out to elaborate a new group of sintered tool gradient materials, wolfram carbide with cobalt matrix, to elaborate their fabrication technology and to determine their structure and properties: a fabrication technology of mixtures and the formation technology of wolfram carbide gradient materials with cobalt matrix WC-Co was applied and elaborated; sintering conditions were selected experimentally: time, temperature and sintering atmosphere as well as isostatic condensation, ensuring the best structure and properties; phase and chemical composition of the sintered gradient WC-Co materials was determined using EDX, EBSD methods and qualitative X-ray analysis; the structure of sintered gradient WC-Co materials was investigated using scanning microscopy and transmission electron microscopy; mechanical and physical properties of sintered gradient WC-Co materials was determined: porosity, density, hardness, resistance to abrasive wear, resistance to brittle cracking.Findings: The presented research results confirm that the newly elaborated technology of powder metallurgy, which consists in sequential coating of the moulding with layers having the increasing content of carbides and decreasing concentration of cobalt, and then sintering such a compact, ensures the acquisition of the required structure and properties, including the resistance to cracking and abrasive wear of tool gradient materials, due to earned high hardness and resistance to abrasive wear on the surface as well as high resistance to cracking in the core of the materials fabricated in such a

  3. Surface modification of active material structures in battery electrodes

    Science.gov (United States)

    Erickson, Michael; Tikhonov, Konstantin

    2016-02-02

    Provided herein are methods of processing electrode active material structures for use in electrochemical cells or, more specifically, methods of forming surface layers on these structures. The structures are combined with a liquid to form a mixture. The mixture includes a surface reagent that chemically reacts and forms a surface layer covalently bound to the structures. The surface reagent may be a part of the initial liquid or added to the mixture after the liquid is combined with the structures. In some embodiments, the mixture may be processed to form a powder containing the structures with the surface layer thereon. Alternatively, the mixture may be deposited onto a current collecting substrate and dried to form an electrode layer. Furthermore, the liquid may be an electrolyte containing the surface reagent and a salt. The liquid soaks the previously arranged electrodes in order to contact the structures with the surface reagent.

  4. Materializing a responsive interior: designing minimum energy structures

    DEFF Research Database (Denmark)

    Mossé, Aurélie; Kofod, Guggi; Ramsgaard Thomsen, Mette

    2011-01-01

    This paper discusses a series of design-led experiments investigating future possibilities for architectural materialization relying on minimum energy structures as an example of adaptive structure. The structures have been made as laminates of elastic membrane under high tension with flexible...... (Lendlein, Kelch 2002) or light (van Oosten, Bastiaansen et al. 2009). All in all, this approach could form a whole new design paradigm, in which efficient 2D-manufacturing can lead to highly flexible, low weight and adaptable 3D-structures. This is illustrated by the design and manufacture of electro...

  5. Advanced thermoelectric materials with enhanced crystal lattice structure and methods of preparation

    Science.gov (United States)

    Fleurial, Jean-Pierre (Inventor); Caillat, Thierry F. (Inventor); Borshchevsky, Alexander (Inventor)

    1998-01-01

    New skutterudite phases including Ru.sub.0.5 Pd.sub.0.5 Sb.sub.3, RuSb.sub.2 Te, and FeSb.sub.2 Te, have been prepared having desirable thermoelectric properties. In addition, a novel thermoelectric device has been prepared using skutterudite phase Fe.sub.0.5 Ni.sub.0.5 Sb.sub.3. The skutterudite-type crystal lattice structure of these semiconductor compounds and their enhanced thermoelectric properties results in semiconductor materials which may be used in the fabrication of thermoelectric elements to substantially improve the efficiency of the resulting thermoelectric device. Semiconductor materials having the desired skutterudite-type crystal lattice structure may be prepared in accordance with the present invention by using powder metallurgy techniques. Measurements of electrical and thermal transport properties of selected semiconductor materials prepared in accordance with the present invention, demonstrated high Hall mobilities and good Seebeck coefficients. These materials have low thermal conductivity and relatively low electrical resistivity, and are good candidates for low temperature thermoelectric applications.

  6. Strengthening of building structures using carbon composite materials

    Directory of Open Access Journals (Sweden)

    N.V. Paranicheva

    2010-03-01

    Full Text Available Currently, the question of ensuring the reliability of various building structures both at the stage of their construction and during operation is very urgent. There are a lot of different ways and constructive methods of structures strengthening. Аt the same time, traditional ways of concrete structures strengthening with steel reinforcement are such expensive, time consuming and in some cases require to interrupt the building operation. As an alternative, it is proposed to use composite materials based on high-strength carbon fibers.The authors consider the properties, advantages, disadvantages and the methods of application of these materials. This article presents results of a technical survey carried out in a public building in 2009. In this building the CFRP was used to strengthen concrete slabs, resting on the crossbar consoles. The calculation of the strength is adduced and the section selection is made. The authors demonstrate their conclusions about the feasibility of using carbon composite materials.

  7. Compatibility of structural materials with liquid bismuth, lead, and mercury

    Energy Technology Data Exchange (ETDEWEB)

    Weeks, J.R. [Brookhaven National Lab., Upton, NY (United States)

    1996-06-01

    During the 1950s and 1960s, a substantial program existed at Brookhaven National Laboratory as part of the Liquid Metal Fuel reactor program on the compatibility of bismuth, lead, and their alloys with structural materials. Subsequently, compatibility investigations of mercury with structural materials were performed in support of development of Rankine cycle mercury turbines for nuclear applications. The present talk will review present understanding of the corrosion/mass-transfer reactions of structural materials with these liquid metal coolants. Topics to be discussed include the basic solubility relationships of iron, chromium, nickel, and refractory metals in these liquid metals, the results of inhibition studies, the role of oxygen on the corrosion processes, and specialized topics such as cavitation-corrosion and liquid metal embrittlement. Emphasis will be placed on utilizing the understanding gained in this earlier work on the development of heavy liquid metal targets in spallation neutron sources.

  8. Study of the supermolecular structure of carbonaceous materials

    International Nuclear Information System (INIS)

    A method is proposed for calculating the form of structural pores and distortions of ordered crystalline regions in carbonaceous materials using X-ray parameters. The region of supermolecular structural order (SMO) of carbonaceous materials on thermal treatment and on neutron irradiation has been investigated. It has been established that the graphitization process is preceded by a qualitative change on the SMO of the initial materials. It has been shown that as the result of the neutron irradiation of graphite, with a rise in the temperature of irradiation the distortions in the crystalline regions grow, leading to irreversible processes of breakdown of the latter, to a redistribution and reorientation of the structural porosity, and to a change in the shape of the pores. 16 refs

  9. Material relation to assess the crashworthiness of ship structures

    OpenAIRE

    Ehlers, Sören

    2009-01-01

    A ship collision accident can result in severe environmental damage and loss of life. Therefore the non-linear finite element method with shell elements is used to assess the crashworthiness of ship steel structures through collision simulations. However, a non-linear finite element-based benchmark revealed inconsistencies and inaccuracies in the results of collision analysis using current material relations and failure criteria. To overcome these problems in this thesis, the steel material's...

  10. Structural integrity of materials in nuclear service: a bibliography

    International Nuclear Information System (INIS)

    This report contains 679 abstracts from the Nuclear Safety Information Center (NSIC) computer file dated 1973 through 1976 covering material properties with respect to structural integrity. All materials important to the nuclear industry (except concrete) are covered for mechanical properties, chemical properties, corrosion, fracture or failure, radiation damage, creep, cracking, and swelling. Keyword, author, and permuted-title indexes are included for the convenience of the user

  11. Structural integrity of materials in nuclear service: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Heddleson, F.A.

    1977-06-07

    This report contains 679 abstracts from the Nuclear Safety Information Center (NSIC) computer file dated 1973 through 1976 covering material properties with respect to structural integrity. All materials important to the nuclear industry (except concrete) are covered for mechanical properties, chemical properties, corrosion, fracture or failure, radiation damage, creep, cracking, and swelling. Keyword, author, and permuted-title indexes are included for the convenience of the user.

  12. Structural Damping by the Use of Fibrous Materials

    OpenAIRE

    Kim, Nicholas N.; Lee, Seungkyu; Bolton, J Stuart; Hollands, Sean; Yoo, Taewook

    2015-01-01

    Because of the increasing concern with vehicle weight, there is an interest in lightweight materials that can serve several functions at once. Here we consider the vibration damping performance provided by an “acoustical” material (i.e., a fibrous layer that would normally be used for airborne noise control). It has been previously established that the vibration of panel structures creates a non-propagating nearfield in the region close to the panel. In that region, there is an oscillatory, i...

  13. Code qualification of structural materials for AFCI advanced recycling reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Li, M.; Majumdar, S.; Nanstad, R.K.; Sham, T.-L. (Nuclear Engineering Division); (ORNL)

    2012-05-31

    This report summarizes the further findings from the assessments of current status and future needs in code qualification and licensing of reference structural materials and new advanced alloys for advanced recycling reactors (ARRs) in support of Advanced Fuel Cycle Initiative (AFCI). The work is a combined effort between Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL) with ANL as the technical lead, as part of Advanced Structural Materials Program for AFCI Reactor Campaign. The report is the second deliverable in FY08 (M505011401) under the work package 'Advanced Materials Code Qualification'. The overall objective of the Advanced Materials Code Qualification project is to evaluate key requirements for the ASME Code qualification and the Nuclear Regulatory Commission (NRC) approval of structural materials in support of the design and licensing of the ARR. Advanced materials are a critical element in the development of sodium reactor technologies. Enhanced materials performance not only improves safety margins and provides design flexibility, but also is essential for the economics of future advanced sodium reactors. Code qualification and licensing of advanced materials are prominent needs for developing and implementing advanced sodium reactor technologies. Nuclear structural component design in the U.S. must comply with the ASME Boiler and Pressure Vessel Code Section III (Rules for Construction of Nuclear Facility Components) and the NRC grants the operational license. As the ARR will operate at higher temperatures than the current light water reactors (LWRs), the design of elevated-temperature components must comply with ASME Subsection NH (Class 1 Components in Elevated Temperature Service). However, the NRC has not approved the use of Subsection NH for reactor components, and this puts additional burdens on materials qualification of the ARR. In the past licensing review for the Clinch River Breeder Reactor Project (CRBRP

  14. Low temperature mechanical properties of cryogenic structural materials

    International Nuclear Information System (INIS)

    The characteristics required for the structural materials for cryogenic use are different according to the kinds of object liquefied gas. The liquefied gases frequently used are LPG (liquefying temperature 230.9K), LNG (113K), liquefied oxygen (90K), liquefied nitrogen (77.4K) and so on, but recently, the use of liquefied hydrogen (20.4K) and liquefied helium (4.2K) increased with the development of the technology utilizing hydrogen and super-conduction. The research and development on the structural materials used for these two liquefied gases have become active. Kobe Steel Ltd. has established its own techniques of measuring very low temperature, and evaluated various metallic materials as the structural materials for very low temperature use, thus accumulated the data at very low temperature. Moreover, recently it has succeeded in the development of a new steel for very low temperature use. The use of the structural materials for very low temperature use and their required characteristics are discussed. The strength and ductility of austenitic stainless steel, titanium and its alloys, and aluminum alloys, notch tensile test, Charpy impact test and fracture toughness test for examining toughness, and the fatigue test at very low temperature are reported. (Kako, I.)

  15. Left Handed Materials: A New Paradigm in Structured Electromagnetics

    International Nuclear Information System (INIS)

    A new paradigm has emerged exhibiting reverse electromagnetic properties. Novel composite and micro-structured materials (metamaterials) have been designed to control electromagnetic radiation. Such substances have been called as Left Handed Material (LHM) with simultaneous negative permittivity and negative permeability and negative refractive index as well. Left handed materials are of importance because of their ability to influence the behavior of electromagnetic radiation and to display properties beyond those available in naturally occurring materials. Typically these are sub-wavelength artificial structures where the dimensions are very small compared to the working wavelength. These dimensions are normally of the order of λ/10 where λ is the wavelength of electromagnetic wave propagating in the material. Emergence of this new paradigm leads to some very interesting consequences, such as, to create lenses that are not diffraction limited, cloaking, sensors (chemical, biological and individual molecule), optical and radio communication. This new development in structured electromagnetic materials has had a dramatic impact on the physics, optics and engineering communities. (author)

  16. Synthesis and characterization of polymer matrix composite material with combination of ZnO filler and nata de coco fiber as a candidate of semiconductor material

    Science.gov (United States)

    Saputra, Asep Handaya; Anindita, Hana Nabila

    2015-12-01

    Synthesis of semiconductor composite using acrylic matrix filled with ZnO and nata de coco fiber has been conducted in this research. The purpose of this research is to obtain semiconductor composite material that has a good mechanical strength and thermal resistance. In situ polymerization method is used in this research and the composites are ready to be characterized after 12 hours. The main parameter that is characterized is the electric conductivity of the composite. Additional parameters are also characterized such as composite's elastic modulus and glass transition temperature. The composites that has been made in this research can be classified as semiconductor material because the conductivity is in the range of 10-8-103 S/cm. In general the addition of ZnO and nata de coco filler can increase the conductivity of the composite. The highest semiconductor characteristic in acrylic/ZnO composite is obtained from 30% volume filler that reach 3.4 x 10-7 S/cm. Similar with acrylic/ZnO composite, in acrylic/nata de coco fiber composite the highest semiconductor characteristic is also obtained from 30% volume filler that reach 1.15 x 10-7 S/cm. Combination of 20% volume of ZnO, 10% volume of nata de coco, and 70% volume of acrylic resulting in composite with electric conductivity of 1.92 x 10-7 S/cm. In addition, combination of ZnO and nata de coco fiber as filler in composite can also improve the characteristic of composite where composite with 20% volume of ZnO filler and 10% volume of nata de coco fiber resulting in composite with elastic modulus of 1.79 GPa and glass transition temperature of 175.73°C which is higher than those in acrylic/ZnO composite.

  17. Nuclear data for radiation damage estimates for reactor structural materials

    International Nuclear Information System (INIS)

    The IAEA Consultants' Meeting on Nuclear Data for Radiation Damage Estimates for Reactor Structural Materials was convened by the IAEA Nuclear Data Section in Santa Fe, New Mexico, USA from 20-22 May 1985. The meeting was attended by 17 participants from 10 countries and 2 international organizations. The main objectives of the meeting were to review the status of displacement cross sections and the requirements for nuclear data needed for radiation damage estimates in reactor structural materials, and to develop recommendations for future activities in this field. This publication contains the text of all the papers prepared especially for this meeting including the conclusions and recommendations worked out during the meeting

  18. 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

  19. 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.

  20. Modeling high temperature materials behavior for structural analysis

    CERN Document Server

    Naumenko, Konstantin

    2016-01-01

    This monograph presents approaches to characterize inelastic behavior of materials and structures at high temperature. Starting from experimental observations, it discusses basic features of inelastic phenomena including creep, plasticity, relaxation, low cycle and thermal fatigue. The authors formulate constitutive equations to describe the inelastic response for the given states of stress and microstructure. They introduce evolution equations to capture hardening, recovery, softening, ageing and damage processes. Principles of continuum mechanics and thermodynamics are presented to provide a framework for the modeling materials behavior with the aim of structural analysis of high-temperature engineering components.

  1. Structural materials performance research at JRC-Institute for Energy

    International Nuclear Information System (INIS)

    The DG-JRC structure and activities are presented in the paper. The Generation IV reactor concepts Very High Temperature Reactor (VHTR), Supercritical Water Reactor (SCWR) and Lead Cooled Reactor (LCR) are currently under study at the JRC. Requirements for innovative nuclear systems and material-related operational condition are under investigation. Considering the operational experience with current nuclear industry, these conditions imply demanding challenges from the structural materials point of view. The European Projects and initiatives and coordinated research programs are also presented

  2. Development, simulation and testing of structural materials for DEMO

    International Nuclear Information System (INIS)

    In DEMO the structural and functional materials of the in-vessel components will be exposed to a very intense flux of fusion neutrons with energies up to 14 MeV creating displacement cascades and gaseous transmutation products. Point defects and transmutations will induce new microstructures leading to changes in mechanical and physical properties such as hardening, swelling, loss of fracture toughness and creep strength. The kinetics of microstructural evolution depends on time, temperature and defect production rates. The structural materials to be used in DEMO should have very special properties: high radiation resistance up to the dose of 100 dpa, low residual activation, high creep strength and good compatibility with the cooling media in as wide a temperature operational window as possible for the achievement of high thermal efficiency. The most promising materials are: Reduced Activation Ferritic Martensitic (RAFM) steels (Eurofer and F82H), Oxide Dispersion Strengthened (ODS) RAFM and RAF steels, SiC fibres reinforced SiC matrix composites (SiCf/SiC), tungsten (W) and W-alloys. Each of these materials has its advantages and drawbacks and will be best used under certain conditions. Presently the best studied group of materials are the RAFM steels. They require the smallest extrapolation for use in DEMO but also offer the lowest upper temperature limit of operation (550 oC) and thus the lowest thermal efficiency. The other materials foreseen for more advanced breeder blanket and divertor concepts require intense fundamental R(and)D and testing before their acceptance, whereas the so-called Test Blanket Modules (TBMs) will be constructed using RAFM steel and tested in ITER. Validation of the DEMO structural materials will be done in IFMIF, the International Fusion Materials Irradiation Facility, which will produce neutron damage and transmutation products very similar to those characterising a fusion device and will allow accelerated testing with damage rates

  3. Influence of composite material's structure on its durability

    International Nuclear Information System (INIS)

    This article is devoted to influence of composite material's structure on its durability. The influence of volume content and the number of thermo cycles on durability of expanded-clay concrete was carried out. It was shown that volume content of needle fibre in expanded-clay concrete increased proportional to composite material's durability increase. But at the same time thermo cycles decreased the durability. Therefore, combining the needle fibre content and the number of thermo cycles it is possible to manage durability and viscosity of composite materials.

  4. Program complex PC 'CRISTA' for materials' roentgen-structural analysis

    International Nuclear Information System (INIS)

    The optimal diffractograms' analysis criteria, which were obtained with DRON-2 diffractometer, and algorithm of their processing were chosen. A special purpose program complex 'CRISTA' for automated processing of diffractogram data, which carries out preliminary processing of difractograms, identification of chemical compounds (phases), identification and concentration calculation (semi-quantitative analysis) reliability analysis was worked out. It was implemented expanded user's functions for semiautomatic or manual analysis of diffractograms, in particular, functions of visual observation of spectra, their superposition, separation of coinciding peaks etc. The outcomes can be used in conduction of roentgen-structural analysis of materials in the framework with materials testing investigations of complex compositional materials. (author)

  5. The Aviation Adaptability of the New Structure Framework Material

    OpenAIRE

    Jiang Jinsan

    2013-01-01

    In this study, 0Cr15Ni5Cu2Ti, stainless steel sheet material with high strength is introduced to replace light metal of magnesium as aviation structural material. The research on heat process technology is emphasized and overall welding of 0Cr15Ni5Cu2Ti sheet is employed, adopting such methods as argon arc protection, anti-deformation technology of hot bending forming, special heat treatment technology, five-axis numerical control machining. It is the first time for the new material applied t...

  6. Structural Integrity Analysis On Superheater Material Of Plt Surabaya

    International Nuclear Information System (INIS)

    Structural integrity analysis on superheater material of PLTU Suralaya has been carried out. Tested material was carbon steel SA 209 T1A and ferritic steel SA 213 T2 based on data specification from PLTU Suralaya. All stages in analysis include collection of operation history background and material specification, visual examination, radiography testing, chemical composition testing, hardness testing and metallography testing. From analysis and testing results, it is shown that material suffered from decarburization on outside surface (00), hardness decrease and pitting corrosion on 00 surface. Primary cause of pipe failure is decarburization due to carbon element inside material that diffuses from inside to OD surface so that microstructure is only pure ferrite

  7. Statistical study on the strength of structural materials and elements

    International Nuclear Information System (INIS)

    Strength data for structural materials and elements including concrete, reinforcing steel, structural steel, plywood elements, reinforced concrete beams, reinforced concrete columns, brick masonry elements, and concrete masonry walls were statistically analyzed. Sample statistics were computed for these data, and distribution parameters were derived for normal, lognormal, and Weibull distributions. Goodness-of-fit tests were performed on these distributions. Most data, except those for masonry elements, displayed fairly small dispersion. Dispersion in data for structural materials was generally found to be smaller than for structural elements. Lognormal and Weibull distributions displayed better overall fits to data than normal distribution, although either Weibull or lognormal distribution can be used to represent the data analyzed. (auth)

  8. 75 FR 1831 - Seeks Qualified Candidates for the Advisory Committee on Reactor Safeguards

    Science.gov (United States)

    2010-01-13

    ... least 10 years of broad experience in nuclear engineering coupled with operational exposure to issues... multinational design certifications, material and structural engineering, nuclear analysis and reactor core... engineering, or radiation protection. Candidates with pertinent graduate level experience will be...

  9. VAMAS tests of structural materials on aluminum alloy and composite material at cryogenic temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, T. [National Research Institute for Metals, Tsukuba, Ibaraki (Japan); Evans, D. [Rutherford Appleton Lab., Chilton (United Kingdom)

    1997-06-01

    A Technical Working Area 17, cryogenic structural materials, has been organized in the Versailles Project on Advanced Materials and Standards (VAMAS) to promote the prestandardization program on material properties tests of glass fiber reinforced polymer (GFRP) composite materials and alloys at liquid helium temperature. A series of international interlaboratory comparisons of both tensile and fracture toughness tests for aluminum alloy 2219 and compression and shear tests for composite material G-10CR were performed. Nine research institutes from seven nations have participated in this project. The results prove that there are few problems in cryogenic tensile tests for alloy materials. In compression and shear tests, the amount of data scatter was identified and further experiments are planned. This paper presents the program details and interim results of round robin tests.

  10. VAMAS tests of structural materials on aluminum alloy and composite material at cryogenic temperatures

    International Nuclear Information System (INIS)

    A Technical Working Area 17, cryogenic structural materials, has been organized in the Versailles Project on Advanced Materials and Standards (VAMAS) to promote the prestandardization program on material properties tests of glass fiber reinforced polymer (GFRP) composite materials and alloys at liquid helium temperature. A series of international interlaboratory comparisons of both tensile and fracture toughness tests for aluminum alloy 2219 and compression and shear tests for composite material G-10CR were performed. Nine research institutes from seven nations have participated in this project. The results prove that there are few problems in cryogenic tensile tests for alloy materials. In compression and shear tests, the amount of data scatter was identified and further experiments are planned. This paper presents the program details and interim results of round robin tests

  11. Cell-based composite materials with programmed structures and functions

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-03-01

    The present invention is directed to the use of silicic acid to transform biological materials, including cellular architecture into inorganic materials to provide biocomposites (nanomaterials) with stabilized structure and function. In the present invention, there has been discovered a means to stabilize the structure and function of biological materials, including cells, biomolecules, peptides, proteins (especially including enzymes), lipids, lipid vesicles, polysaccharides, cytoskeletal filaments, tissue and organs with silicic acid such that these materials may be used as biocomposites. In many instances, these materials retain their original biological activity and may be used in harsh conditions which would otherwise destroy the integrity of the biological material. In certain instances, these biomaterials may be storage stable for long periods of time and reconstituted after storage to return the biological material back to its original form. In addition, by exposing an entire cell to form CSCs, the CSCs may function to provide a unique system to study enzymes or a cascade of enzymes which are otherwise unavailable.

  12. Magnetic switch structure and method employing superconductive material

    International Nuclear Information System (INIS)

    Electrical switch structure is described comprising a magnetizable core, an electrical switch circuit which includes an electrically conductive winding and a source of electrical energy, the electrically conductive winding encompassing a portion of the magnetizable core, whereby electrical current flowing in the electrically conductive winding creates a first magnetic flux in the magnetizable core, a body of superconductive material encompassing a portion of the magnetizable core, the body of superconductive material having a superconductive state and a resistive state, the body of superconductive material including a primary current conduction plane, the electrical switch structure including means for conducting electrical current through the body of superconductive material in a direction angular with respect to the primary current conduction plane, whereby the body of superconductive material is placed in a resistive state when electrical current flows through the body of superconductive material in a direction angular with respect to the primary current conduction plane, whereby when the body of superconductive material is in its superconductive state current is induced therein by the first magnetic flux and whereby current flow in the body of superconductive material creates a second magnetic flux within the magnetizable core and the second magnetic flux cancels the first magnetic flux, whereby reactance within the electrically conductive winding is negligible and current flows through the electrically conductive winding, and whereby the electrical switch circuit is in its ''on'' state, and whereby when the body of superconductive material is in its resistive state no significant current is generated in the body of superconductive material and reactance within the electrically conductive winding prevents current flow in the electrical switch circuit and whereby the electrical switch circuit is in its off state

  13. Structural studies of ionic liquids and ionothermally-prepared materials

    OpenAIRE

    Byrne, Peter Joseph

    2009-01-01

    The aim of this thesis was to examine materials using high resolution X-ray diffraction techniques. Initial work involved the synthesis of various metal phosphates to investigate their suitability for charge density work. Many of these were discovered to be of insufficient quality for further study. Much of the phosphate synthesis work performed at the moment utilises an ionic liquid both as a solvent and structure directing agent which dictates the topology of the structure du...

  14. Nondestructive evaluation of critical composite material structural elements

    Science.gov (United States)

    Duke, John C., Jr.; Lesko, John J.; Weyers, R.

    1996-11-01

    A small span bridge that has suffered corrosive deterioration of a number of the steel structural members is in the process of being rehabilitated with glass and carbon fiber reinforced, pultruded polymer structural beams. As part of a comprehensive research program to develop methods for modeling long term durability of the composite material, nondestructive evaluation if being used to provide a preliminary assessment of the initial condition of the beams as well as to monitor the deterioration of the beams during service.

  15. Synthesis, Characterization and Pore Structure Analysis of Mesoporous Materials

    OpenAIRE

    Saldarriaga Lopez, Laura Carolina

    2014-01-01

    Self-assembly provides a route to make mesoporous structures that have accessible internal surface area. These types of materials show promise for use in opto-electronic devices as well as for energy storage devices. In this work we synthesize a range of mesoporous thin films from molecular and nanocrystal precursors. We characterize these films' porous structure and surface area using ellipsometric-porosimetry. This work is divided into three parts; the first section focuses on synthesizing ...

  16. Investigation results on irradiated Kazakhstan's reactor structural materials

    International Nuclear Information System (INIS)

    The investigation results are given for changes in structure, phase composition, mechanical properties and corrosion behaviour of a wide range of materials (steels 12Kh18N10T, 08Kh16N11M3, 12Kh13M2BFR, copper, aluminium, alloys Fe3Al, 03Kh20N45M4BCh, 03Kh20N45M4BRTs) irradiated in WWR-K, BN-350 reactors and U-150 cyclotron. The data on correlation between creep and hardening for irradiated materials are obtained. The role of stacking faults energy in swelling, irradiation creep and the behaviour of materials during post-irradiation annealing is discussed. A consideration is also given to corrosion processes running in irradiated materials on storage of spent fuel assemblies. The applicability of well-known approximating functions to the description of structural transformations in steels with radiation defects is investigated. The results of the study are incorporated into a data base of structural materials of Kazakhstan's nuclear reactors

  17. Modelling of advanced structural materials for GEN IV reactors

    International Nuclear Information System (INIS)

    The choice of suitable materials and the assessment of long-term materials damage are key issues that need to be addressed for the safe and reliable performance of nuclear power plants. Operating conditions such as high temperatures, irradiation and a corrosive environment degrade materials properties, posing the risk of very expensive or even catastrophic plant damage. Materials scientists are faced with the scientific challenge to determine the long-term damage evolution of materials under service exposure in advanced plants. A higher confidence in life-time assessments of these materials requires an understanding of the related physical phenomena on a range of scales from the microscopic level of single defect damage effects all the way up to macroscopic effects. To overcome lengthy and expensive trial-and-error experiments, the multiscale modelling of materials behaviour is a promising tool, bringing new insights into the fundamental understanding of basic mechanisms. This paper presents the multiscale modelling methodology which is taking root internationally to address the issues of advanced structural materials for Gen IV reactors

  18. Topology optimization of coated structures and material interface problems

    DEFF Research Database (Denmark)

    Clausen, Anders; Aage, Niels; Sigmund, Ole

    2015-01-01

    -step filtering/projection approach. The modeled coating thickness is derived analytically, and the coating is shown to be accurately controlled and applied in a highly uniform manner over the structure. An alternative interpretation of the model is to perform single-material design for additive manufacturing...

  19. Strain Engineering of the Electronic Structure of 2D Materials

    Czech Academy of Sciences Publication Activity Database

    Frank, Otakar; del Corro, Elena; Pea-Álvarez, M.; Morales-García, A.; Bouša, M.; Řáhová, Jaroslava; Kavan, Ladislav; Kalbáč, Martin

    Brno : Tanger Ltd., 2015. s. 33-33. ISBN 978-80-87294-59-8. [Nanocon 2015. International Conference /7./. 14.10.2015-16.10.2015, Ostrava] R&D Projects: GA ČR GA14-15357S Institutional support: RVO:61388955 Keywords : graphene * electronic structure * 2D materials Subject RIV: CF - Physical ; Theoretical Chemistry

  20. 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.)

  1. Survey on structural material investigations for SNR 300

    International Nuclear Information System (INIS)

    Type 304 SS in a modified, fully austenitic version has been used for the construction of the primary and secondary heat transfer system, including the vessel and the pumps; the steam generators were built of 2.25 Cr-1 Mo-Nb ferritic steel. Coordinated programs involving INTERATOM, KfK, ECN, TNO, CEN/Mol have been performed. The SNR-300 project related structural material activities have provided a broad base to describe materials properties behaviour and design limitations under aspects of long-term component reliability and availability. High temperature design needs have been covered by the development of constitutive relations and computational programs. Integrity considerations and deformation limits under hypothetical circumstances have been verified successfully. Investigations on alternative materials for permanent structure have been started

  2. Identification of material properties of sandwich structure with piezoelectric patches

    Directory of Open Access Journals (Sweden)

    Zemčík R.

    2008-11-01

    Full Text Available The work focuses on light-weight sandwich structures made of carbon-epoxy skins and foam core which have unique bending stiffness compared to conventional materials. The skins are manufactured by vacuum autoclave technology from unidirectional prepregs and the sandwich is then glued together. The resulting material properties of the structure usually differ from those provided by manufacturer or even those obtained from experimental tests on separate materials, which makes computational models unreliable. Therefore, the properties are identified using the combination of experimental analysis of the sandwich with attached piezoelectric transducer and corresponding static and modal finite element analyses. Simple mathematical optimization with repetitive finite element solution is used. The model is then verified by transient analysis when the piezoelectric patch is excited by harmonic signals covering the first two eigen-frequencies and the induced oscillations are measured by laser sensor.

  3. Prediction of degradation and fracture of structural materials

    International Nuclear Information System (INIS)

    Prediction of materials performance in an engineering integrity context requires the underpinning of predictive modelling tuned by inputs from design, fabrication, operating experience, and laboratory testing. In this regard, in addition to fracture resistance four important areas of time dependent degradation are considered - mechanical, environmental, irradiation and thermal. The status of prediction of materials performance is discussed in relation to a number of important components such as LWR reactor pressure vessels and steam generators, and Fast Reactor high temperature structures. In each case the role of materials modelling is examined and the balance of factors which contribute to the overall prediction of component integrity/reliability noted. Structural integrity arguments must follow a clear strategy if the required level of confidence is to be established. Various strategies and their evolution are discussed. (author)

  4. Structure and mechanics of interfaces in biological materials

    Science.gov (United States)

    Barthelat, Francois; Yin, Zhen; Buehler, Markus J.

    2016-04-01

    Hard biological materials — for example, seashells, bone or wood — fulfil critical structural functions and display unique and attractive combinations of stiffness, strength and toughness, owing to their intricate architectures, which are organized over several length scales. The size, shape and arrangement of the ‘building blocks’ of which these materials are made are essential for defining their properties and their exceptional performance, but there is growing evidence that their deformation and toughness are also largely governed by the interfaces that join these building blocks. These interfaces channel nonlinear deformations and deflect cracks into configurations in which propagation is more difficult. In this Review, we discuss comparatively the composition, structure and mechanics of a set of representative biological interfaces in nacre, bone and wood, and show that these interfaces possess unusual mechanical characteristics, which can encourage the development of advanced bioinspired composites. Finally, we highlight recent examples of synthetic materials inspired from the mechanics and architecture of natural interfaces.

  5. RILEM International Symposium on Materials and Joints in Timber Structures

    CERN Document Server

    Reinhardt, H-W; Garrecht, Harald

    2014-01-01

    This book contains the contributions from the RILEM International Symposium on Materials and Joints in Timber Structures that was held in Stuttgart, Germany from October 8 to 10, 2013. It covers recent developments in the materials and the joints used in modern timber structures. Regarding basic wooden materials, the contributions highlight the widened spectrum of products comprising cross-laminated timber, glulam and LVL from hardwoods and block glued elements. Timber concrete compounds, cement bonded wood composites and innovative light-weight constructions represent increasingly employed alternatives for floors, bridges and facades. With regard to jointing technologies, considerable advances in both mechanical connections and glued joints are presented. Self-tapping screws have created unprecedented options for reliable, strong as well as ductile joints and reinforcement technologies. Regarding adhesives, which constitute the basis of the jointing/laminating technology of modern timber products, extended o...

  6. Technical limitations of nuclear fuel materials and structures

    International Nuclear Information System (INIS)

    This report gives a summary of the tasks carried out within the project 'Technical limitations of nuclear fuel materials and structures' which belongs to the Finnish national research programme called 'Systems behaviour and operational aspects of safety'. The duration of the project was three years from 1990 to 1992. Most western LWR utilities, including the two Finnish ones have an incentive to implement extended burnup fuel cycles in their nuclear power plants. The aim of this project has been authorities to support them in the assessment and licensing of new fuel designs and materials. The research work of the project was focused on collecting and qualifying fuel performance data and on performing laboratory tests on fresh and irradiated cladding and structural materials. Moreover, knowledge of the high burnup phenomena was obtained through participation in international research projects such as OECD Halden Project and several Studsvik projects. Experimental work within the framework of the VVER fuel cooperative effort was also continued. (orig.)

  7. Long-term evaluation of solid oxide fuel cell candidate materials in a 3-cell generic short stack fixture, Part II: Sealing glass stability, microstructure and interfacial reactions

    Science.gov (United States)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.; Choi, Jung-Pyung

    2014-03-01

    A generic solid oxide fuel cell stack test fixture was developed to evaluate candidate materials and processing methods under realistic conditions. Part II of the work examined the sealing glass stability, microstructure development, interfacial reaction, and volatility issues of a 3-cell stack with LSM-based cells. After 6000 h of testing, the refractory sealing glass YSO7 showed desirable chemical compatibility with YSZ electrolyte in that no discernable interfacial reaction was identified. In addition, no glass penetration into the thin electrolyte was observed. At the aluminized AISI441 interface, the protective alumina coating appeared to be corroded by the sealing glass. Air side interactions appeared to be more severe than fuel side interactions. Metal species such as Cr, Mn, and Fe were detected in the glass, but were limited to the vicinity of the interface. No alkaline earth chromates were found at the air side. Volatility was also studied in a similar glass and weight loss in a wet reducing environment was determined. Using the steady-state volatility data, the life time weight loss of refractory sealing glass YSO77 was estimated to be less than 0.1 wt%.

  8. Use of neutron activation analysis and LC-ICP-MS in the development of candidate reference materials for As species determination

    International Nuclear Information System (INIS)

    Arsenic (As) is widely found in marine organisms, mainly as organic arsenical compounds. With the introduction of regulations for As species in foodstuffs and for environmental control, it has become more important to quantify the amount of arsenic species present. To address this concern new reference materials (RMs) for validation and quality assurance of As speciation measurements are being developed, including a tuna fish tissue and a robalo liver tissue. Instrumental neutron activation analysis (INAA) is used in this work as a proven analytical tool for As determinations and for validating the As mass fraction determined by liquid chromatography coupled to inductively coupled mass spectrometry (LC-ICP-MS) in extracts of the candidate RMs and other fish samples including certified RMs. Various methods for the extraction of water-soluble As species were evaluated. The best results were acquired after methanol/acetone/water extraction yielding in 93 % extractable As in the tuna RM. This procedure was used for the LC-ICP-MS studies. The results demonstrate that INAA can account for 100 % of the distribution of As species in analytical processes. It complements LC-ICP-MS for the validation of the characterization of As species in the development of RMs for such species. Excellent agreement of measured results in certified RMs with the reported values confirms the validity of the applied procedures. (author)

  9. Study of the effects of interleakage of ammonia and seawater on corrosion and scaling of candidate materials for OTEC heat exchngers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, W D; Schrieber, C F; Manning, J A

    1980-07-01

    Assessment has been made on the effect of small concentrations of ammonia in seawater and varying concentrations of seawater in anhydrous ammonia upon corrosion and scaling of candidate OTEC heat exchanger materials - A1-5052, Alclad 3003, copper alloys 706, 715 and 722, AL-6X stainless steel and CP titanium. Results are presented. AL-6X stainless steel and CP titanium showed exceptional corrosion resistance to all test environments. Alclad alloy 3003 showed satisfactory performance in seawater and seawater plus ammonia environments. Only minimal pitting was observed and this was limited to the sacrificial cladding in seawater plus ammonia only. Cladding alloy 7072 showed unacceptable corrosion resistance in anhydrous ammonia containing low seawater concentrations. Al-5052 tubes showed unsatisfactory corrosion behavior in the presence of seawater flow with ammonia interleakage. Copper alloys considered showed unacceptable corrosion resistance in all seawater environments containing ammonia. Low pressure differentials between seawater and anhydrous ammonia in the tube testing unit resulted in scaling and moderately efficient plug seal formation at the artificial leak sites of the tubes. It is recommended that Alclad 3003, CP titanium and AL-6X stainless steel tubes be assessed for suitability in the presence of probable OTEC cleaning systems.

  10. Structural integrity of engineering composite materials: a cracking good yarn.

    Science.gov (United States)

    Beaumont, Peter W R; Soutis, Costas

    2016-07-13

    Predicting precisely where a crack will develop in a material under stress and exactly when in time catastrophic fracture of the component will occur is one the oldest unsolved mysteries in the design and building of large-scale engineering structures. Where human life depends upon engineering ingenuity, the burden of testing to prove a 'fracture safe design' is immense. Fitness considerations for long-life implementation of large composite structures include understanding phenomena such as impact, fatigue, creep and stress corrosion cracking that affect reliability, life expectancy and durability of structure. Structural integrity analysis treats the design, the materials used, and figures out how best components and parts can be joined, and takes service duty into account. However, there are conflicting aims in the complete design process of designing simultaneously for high efficiency and safety assurance throughout an economically viable lifetime with an acceptable level of risk. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242293

  11. Basic materials and structures aspects for hypersonic transport vehicles (HTV)

    Science.gov (United States)

    Steinheil, E.; Uhse, W.

    A Mach 5 transport design is used to illustrate structural concepts and criteria for materials selections and also key technologies that must be followed in the areas of computational methods, materials and construction methods. Aside from the primary criteria of low weight, low costs, and conceivable risks, a number of additional requirements must be met, including stiffness and strength, corrosion resistance, durability, and a construction adequate for inspection, maintenance and repair. Current aircraft construction requirements are significantly extended for hypersonic vehicles. Additional consideration is given to long-duration temperature resistance of the airframe structure, the integration of large-volume cryogenic fuel tanks, computational tools, structural design, polymer matrix composites, and advanced manufacturing technologies.

  12. Light thermal structures and materials for high speed flight

    Science.gov (United States)

    Thornton, Earl A.

    1992-01-01

    Over the last twenty years, unified viscoplastic constitutive models have evolved to meet this need. These constitutive models provide a means for representing a material's response from the elastic through the plastic range including strain-rate dependent plastic flow, creep, and stress relaxation. Rate-dependent plasticity effects are known to be important at elevated temperatures. The purpose of this paper is to describe computational and experimental research programs underway at the Light Thermal Structures Center focused on the investigation of the response of structures and materials to local heating. In the first part of the paper, finite element thermoviscoplastic analysis is highlighted. In the second part of the paper, the thermal-structures experimental program is outlined.

  13. Interpenetration in coordination polymers: structural diversities toward porous functional materials

    Directory of Open Access Journals (Sweden)

    Ritesh Haldar

    2015-03-01

    Full Text Available Interpenetration is a natural phenomenon frequently encountered in porous coordination polymers (PCPs or metal-organic frameworks (MOFs. Traditionally interpenetration has been considered as a threat to permanent porosity and several strategies have been adopted to control the framework interpenetration. Recent literature reports have unveiled that interpenetration has paramount importance in several material properties particularly in storage and separation of small gas molecules. Such frameworks also show interesting structural flexibility based on shearing or movement of the nets and also reveals guest induced dynamic structural transformation for modulated specific functions. In this review, we will emphasize several interpenetration phenomena observed in coordination polymers, their intriguing structural aspects and fascinating material properties.

  14. Novel cost controlled materials and processing for primary structures

    Science.gov (United States)

    Dastin, S. J.

    1993-01-01

    Textile laminates, developed a number of years ago, have recently been shown to be applicable to primary aircraft structures for both small and large components. Such structures have the potential to reduce acquisition costs but require advanced automated processing to keep costs controlled while verifying product reliability and assuring structural integrity, durability and affordable life-cycle costs. Recently, resin systems and graphite-reinforced woven shapes have been developed that have the potential for improved RTM processes for aircraft structures. Ciba-Geigy, Brochier Division has registered an RTM prepreg reinforcement called 'Injectex' that has shown effectivity for aircraft components. Other novel approaches discussed are thermotropic resins producing components by injection molding and ceramic polymers for long-duration hot structures. The potential of such materials and processing will be reviewed along with initial information/data available to date.

  15. Failure modes and materials design for biomechanical layer structures

    Science.gov (United States)

    Deng, Yan

    Ceramic materials are finding increasing usage in the area of biomechanical replacements---dental crowns, hip and bone implants, etc.---where strength, wear resistance, biocompatibility, chemical durability and even aesthetics are critical issues. Aesthetic ceramic crowns have been widely used in dentistry to replace damaged or missing teeth. However, the failure rates of ceramic crowns, especially all-ceramic crowns, can be 1%˜6% per year, which is not satisfactory to patients. The materials limitations and underlying fracture mechanisms of these prostheses are not well understood. In this thesis, fundamental fracture and damage mechanisms in model dental bilayer and trilayer structures are studied. Principle failure modes are identified from in situ experimentation and confirmed by fracture mechanics analysis. In bilayer structures of ceramic/polycarbonate (representative of ceramic crown/dentin structure), three major damage sources are identified: (i) top-surface cone cracks or (ii) quasiplasticity, dominating in thick ceramic bilayers; (iii) bottom-surface radial cracks, dominating in thin ceramic bilayers. Critical load P for each damage mode are measured in six dental ceramics: Y-TZP zirconia, glass-infiltrated zirconia and alumina (InCeram), glass-ceramic (Empress II), Porcelain (Mark II and Empress) bonded to polymer substrates, as a function of ceramic thickness d in the range of 100 mum to 10 mm. P is found independent of d for mode (i) and (ii), but has a d 2 relations for mode (iii)---bottom surface radial cracking. In trilayer structures of glass/core-ceramic/polycarbonate (representing veneer porcelain/core/dentin structures), three inner fracture origins are identified: radial cracks from the bottom surface in the (i) first and (ii) second layers; and (iii) quasiplasticity in core-ceramic layer. The role of relative veneer/core thickness, d1/d 2 and materials properties is investigated for three core materials with different modulus (114--270GPa

  16. Using an SU-8 Photoresist Structure and Cytochrome C Thin Film Sensing Material for a Microbolometer

    Directory of Open Access Journals (Sweden)

    Guo-Dung John Su

    2012-11-01

    Full Text Available There are two critical parameters for microbolometers: the temperature coefficient of resistance (TCR of the sensing material, and the thermal conductance of the insulation structure. Cytochrome c protein, having a high TCR, is a good candidate for infrared detection. We can use SU-8 photoresist for the thermal insulation structure, given its low thermal conductance. In this study, we designed a platform structure based on a SU-8 photoresist. We fabricated an infrared sensing pixel and recorded a high TCR for this new structure. The SU-8 photoresist insulation structure was fabricated using the exposure dose method. We experimentally demonstrated high values of TCR from 22%/K to 25.7%/K, and the measured noise was 1.2 × 10–8 V2/Hz at 60 Hz. When the bias current was 2 μA, the calculated voltage responsivity was 1.16 × 105 V/W. This study presents a new kind of microbolometer based on cytochrome c protein on top of an SU-8 photoresist platform that does not require expensive vacuum deposition equipment.

  17. Stress Transfer and Structural Failure of Bilayered Material Systems

    Science.gov (United States)

    Prieto-Munoz, Pablo Arthur

    Bilayered material systems are common in naturally formed or artificially engineered structures. Understanding how loads transfer within these structural systems is necessary to predict failure and develop effective designs. Existing methods for evaluating the stress transfer in bilayered materials are limited to overly simplified models or require experimental calibration. As a result, these methods have failed to accurately account for such structural failures as the creep induced roofing panel collapse of Boston's I-90 connector tunnel, which was supported by adhesive anchors. The one-dimensional stress analyses currently used for adhesive anchor design cannot account for viscoelastic creep failure, and consequently results in dangerously under-designed structural systems. In this dissertation, a method for determining the two-dimensional stress and displacement fields for a generalized bilayered material system is developed, and proposes a closed-form analytical solution. A general linear-elastic solution is first proposed by decoupling the elastic governing equations from one another through the so-called plane assumption. Based on this general solution, an axisymmetric problem and a plane strain problem are formulated. These are applied to common bilayered material systems such as: (1) concrete adhesive anchors, (2) material coatings, (3) asphalt pavements, and (4) layered sedimentary rocks. The stress and displacement fields determined by this analytical analysis are validated through the use of finite element models. Through the correspondence principle, the linear-elastic solution is extended to consider time-dependent viscoelastic material properties, thus facilitating the analysis of adhesive anchors and asphalt pavements while incorporating their viscoelastic material behavior. Furthermore, the elastic stress analysis can explain the fracturing phenomenon of material coatings, pavements, and layered rocks, successfully predicting their fracture

  18. Ferromagnetic materials in the zinc-blende structure

    Science.gov (United States)

    Sanyal, B.; Bergqvist, L.; Eriksson, O.

    2003-08-01

    New materials are currently sought for use in spintronics applications. Ferromagnetic materials with half metallic properties are valuable in this respect. Here we present the electronic structure and magnetic properties of binary compounds consisting of 3d transition metals and group V elements, viz., P, Sb, and As in the zinc-blende structure. We demonstrate that compounds of V, Cr, and Mn show half metallic behavior for appropriate lattice constants. By comparing the total energies in the ferromagnetic and antiferromagnetic structures, we have ascertained that the ferromagnetic phase is stable over the antiferromagnetic one. Of the different compounds studied, the Cr based systems exhibit the strongest interatomic exchange interactions, and are hence predicted to have the highest critical temperatures. Also, we predict that VAs under certain growth conditions should be a semiconducting ferromagnet. Moreover, critical temperatures of selected half metallic compounds have been estimated from mean field theory and Monte Carlo simulations using parameters obtained from a ab initio noncollinear, tight binding linearized muffin-tin orbital method. From a simple model, we calculate the reflectance from an ideal MnAs/InAs interface considering the band structures of MnAs and InAs. Finally, we present results on the relative stabilities of MnAs and CrSb compounds in the NiAs and zinc-blende structures, and suggest a parameter space in substrate lattice spacings for when the zinc-blende structure is expected to be stable.

  19. Uncertainty Quantification in Experimental Structural Dynamics Identification of Composite Material Structures

    DEFF Research Database (Denmark)

    Luczak, Marcin; Peeters, Bart; Kahsin, Maciej;

    2014-01-01

    Aerospace and wind energy structures are extensively using components made of composite materials. Since these structures are subjected to dynamic environments with time-varying loading conditions, it is important to model their dynamic behavior and validate these models by means of vibration...... uncertainty evaluation in experimentally estimated models. Investigated structures are plates, fuselage panels and helicopter main rotor blades as they represent different complexity levels ranging from coupon, through sub-component up to fully assembled structures made of composite materials. To evaluate the...

  20. New polysilsesquioxane materials of ladder-like structure

    Science.gov (United States)

    Handke, M.; Handke, B.; Kowalewska, A.; Jastrzębski, W.

    2009-04-01

    Alkoxy derivatives of linear oligomethylsiloxanes were applied as substrates for preparation of novel type, ladder-like polymeric silsesquioxane-siloxane materials. A systematic study of the effect of diverging the structure of a polysiloxane chain (distribution of alkoxysilyl groups along the polymer chain) on the properties of silsesquioxane materials obtained by condensation of ethoxy groups, has been undertaken. A series of polysiloxane materials cross-linked with -SiOSi- bonds, forming ladder-like linkages between main siloxane chains was prepared. There were used siloxanes of a regular structure with formula [M(D 2D OR) 10D 2M] and [M(D 2D OR2) 10D 2M] ] as well as siloxane oligomers of random distribution of MeSi-OR (D OR) units along the main siloxane chain [MD (1-x)D ORxM ( x = 0.3, 0.5, 1.0)]. Alkoxy-functionalized oligosiloxane precursors were cross-linked under hydrolytic condensation conditions catalyzed by HCl/NH 4OH system or nucleophilic catalysts (TBAF and TBAH). The relationship between the structure of siloxane chain (the amount of Si-OR units and their distribution along the polymer backbone) and the properties of obtained preceramic materials was studied with FTIR (as a main method) and NMR, XRD, DTA. The surface area and pores distributions of the studied samples were measured using nitrogen adsorption methods (BET).

  1. Studying Radiation Damage in Structural Materials by Using Ion Accelerators

    Science.gov (United States)

    Hosemann, Peter

    2011-02-01

    Radiation damage in structural materials is of major concern and a limiting factor for a wide range of engineering and scientific applications, including nuclear power production, medical applications, or components for scientific radiation sources. The usefulness of these applications is largely limited by the damage a material can sustain in the extreme environments of radiation, temperature, stress, and fatigue, over long periods of time. Although a wide range of materials has been extensively studied in nuclear reactors and neutron spallation sources since the beginning of the nuclear age, ion beam irradiations using particle accelerators are a more cost-effective alternative to study radiation damage in materials in a rather short period of time, allowing researchers to gain fundamental insights into the damage processes and to estimate the property changes due to irradiation. However, the comparison of results gained from ion beam irradiation, large-scale neutron irradiation, and a variety of experimental setups is not straightforward, and several effects have to be taken into account. It is the intention of this article to introduce the reader to the basic phenomena taking place and to point out the differences between classic reactor irradiations and ion irradiations. It will also provide an assessment of how accelerator-based ion beam irradiation is used today to gain insight into the damage in structural materials for large-scale engineering applications.

  2. Structural Behaviour of Strengthened Composite Materials. Experimental Studies

    Directory of Open Access Journals (Sweden)

    Vlad Munteanu

    2007-01-01

    Full Text Available Masonry represents one of the earliest structural materials used by mankind. A lot of the ancient building structures were made using masonry. A large number of these buildings have been stated historical monuments. Most commonly masonry elements which are able to cover large spans was masonry arches. The paper makes a detailed presentation on structural behaviour and failure mechanisms of a horizontally loaded masonry arch. The arch model was built at a 1 : 1 scale using solid bricks and M10Z mortar. It was firstly loaded with vertically acting dead loads and with horizontal load acting in its plane. In this loading hypothesis, a plastic hinge occurred leading to the failure of the arch and loss of load bearing capacity. In the next stage of the experimental program, the arch was strengthened using a composite material membrane at the upper face. The membrane consisted in a continuous, glass-fiber fabric and epoxy resin. After proper curing, the same loading hypothesis was used. The failure mechanisms changed and a larger horizontal loading level was noticed. Further on, the arch was rehabilitated using a different composite material layout, the membrane was applied both on upper and bottom faces as well as partially on the lateral faces of the arch. This new rehabilitation layout leads to a significant increase in the load bearing capacity of the arch. The failure mechanisms were changed causing a significantly better overall structural behaviour of the arch.

  3. Focusing of Acoustic Waves through Acoustic Materials with Subwavelength Structures

    KAUST Repository

    Xiao, Bingmu

    2013-05-01

    In this thesis, wave propagation through acoustic materials with subwavelength slits structures is studied. Guided by the findings, acoustic wave focusing is achieved with a specific material design. By using a parameter retrieving method, an effective medium theory for a slab with periodic subwavelength cut-through slits is successfully derived. The theory is based on eigenfunction solutions to the acoustic wave equation. Numerical simulations are implemented by the finite-difference time-domain (FDTD) method for the two-dimensional acoustic wave equation. The theory provides the effective impedance and refractive index functions for the equivalent medium, which can reproduce the transmission and reflection spectral responses of the original structure. I analytically and numerically investigate both the validity and limitations of the theory, and the influences of material and geometry on the effective spectral responses are studied. Results show that large contrasts in impedance and density are conditions that validate the effective medium theory, and this approximation displays a better accuracy for a thick slab with narrow slits in it. Based on the effective medium theory developed, a design of a at slab with a snake shaped" subwavelength structure is proposed as a means of achieving acoustic focusing. The property of focusing is demonstrated by FDTD simulations. Good agreement is observed between the proposed structure and the equivalent lens pre- dicted by the theory, which leads to robust broadband focusing by a thin at slab.

  4. Fast Detection of Material Deformation through Structural Dissimilarity

    Energy Technology Data Exchange (ETDEWEB)

    Ushizima, Daniela; Perciano, Talita; Parkinson, Dilworth

    2015-10-29

    Designing materials that are resistant to extreme temperatures and brittleness relies on assessing structural dynamics of samples. Algorithms are critically important to characterize material deformation under stress conditions. Here, we report on our design of coarse-grain parallel algorithms for image quality assessment based on structural information and on crack detection of gigabyte-scale experimental datasets. We show how key steps can be decomposed into distinct processing flows, one based on structural similarity (SSIM) quality measure, and another on spectral content. These algorithms act upon image blocks that fit into memory, and can execute independently. We discuss the scientific relevance of the problem, key developments, and decomposition of complementary tasks into separate executions. We show how to apply SSIM to detect material degradation, and illustrate how this metric can be allied to spectral analysis for structure probing, while using tiled multi-resolution pyramids stored in HDF5 chunked multi-dimensional arrays. Results show that the proposed experimental data representation supports an average compression rate of 10X, and data compression scales linearly with the data size. We also illustrate how to correlate SSIM to crack formation, and how to use our numerical schemes to enable fast detection of deformation from 3D datasets evolving in time.

  5. Ferromagnetic nanocomposites as spintronic materials with controlled magnetic structure

    International Nuclear Information System (INIS)

    The physical properties of ferromagnetic dilute magnetic semiconductors and nanocomposites are considered. The latter have several advantages as spintronic materials with a controlled magnetic structure for weak magnetic field sensors. A characteristic feature of ferromagnetic nanocomposites is the spin dependent tunneling conductance, which is responsible for negative and positive magnetoresistance. The magnetoresistive effects have a wide range of applications. In particular, materials with such effects may be used in the development of magnetoresistive memory devices, weak magnetic field sensors, medical diagnostic devices and other items of electronic equipment.

  6. Fiber Optic Thermal Health Monitoring of Aerospace Structures and Materials

    Science.gov (United States)

    Wu, Meng-Chou; Winfree, William P.; Allison, Sidney G.

    2009-01-01

    A new technique is presented for thermographic detection of flaws in materials and structures by performing temperature measurements with fiber Bragg gratings. Individual optical fibers with multiple Bragg gratings employed as surface temperature sensors were bonded to the surfaces of structures with subsurface defects or thickness variations. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. The data obtained from grating sensors were further analyzed with thermal modeling to reveal particular characteristics of the interested areas. These results were found to be consistent with those from conventional thermography techniques. Limitations of the technique were investigated using both experimental and numerical simulation techniques. Methods for performing in-situ structural health monitoring are discussed.

  7. Polydimethylglutarimide (PMGI) as a structural material for surface micromachining

    International Nuclear Information System (INIS)

    This work investigates the use of polydimethylglutarimide, or PMGI, as a structural material for surface micromachining. PMGI is a commercially available, positive-toned deep-UV resist designed for use in bi-layer lift-off techniques. This paper presents a technique for the microfabrication of free-standing PMGI structures, and uses those structures to extract the coefficient of thermal expansion and Young's modulus for PMGI. Our study found PMGI's coefficient of thermal expansion to be 56 ± 6 ppm °C−1 and Young's modulus to be 5.0 ± 0.5 GPa. Active structures were also fabricated by including a patterned metal layer. This allows the fabrication of active devices, such as bent-beam actuators. PMGI is a commercially available polymer being used in micromachining, and this paper provides the first report of its thermo-mechanical properties

  8. TRADITIONAL METALLURGY, NANOTECHNOLOGIES AND STRUCTURAL MATERIALS: A SORBY AWARD LECTURE

    Energy Technology Data Exchange (ETDEWEB)

    Louthan, M

    2007-07-17

    Traditional metallurgical processes are among the many ''old fashion'' practices that use nanoparticles to control the behavior of materials. Many of these practices were developed long before microscopy could resolve nanoscale features, yet the practitioners learned to manipulate and control microstructural elements that they could neither see nor identify. Furthermore, these early practitioners used that control to modify microstructures and develop desired material properties. Centuries old colored glass, ancient high strength steels and medieval organ pipes derived many of their desirable features through control of nanoparticles in their microstructures. Henry Sorby was among the first to recognize that the properties of rocks, minerals, metals and organic materials were controlled by microstructure. However, Mr. Sorby was accused of the folly of trying to study mountains with a microscope. Although he could not resolve nanoscale microstructural features, Mr. Sorby's observations revolutionized the study of materials. The importance of nanoscale microstructural elements should be emphasized, however, because the present foundation for structural materials was built by manipulating those features. That foundation currently supports several multibillion dollar industries but is not generally considered when the nanomaterials revolution is discussed. This lecture demonstrates that using nanotechnologies to control the behavior of metallic materials is almost as old as the practice of metallurgy and that many of the emergent nanomaterials technologists are walking along pathways previously paved by traditional metallurgists.

  9. From natural attapulgite to phosphor materials: Characterization, photoluminescence and structure

    International Nuclear Information System (INIS)

    Highlights: • Sr2.965Al0.08Si0.92O5:0.025Ce3+, 0.01Eu2+ phosphor was synthesized from natural attapulgite. • Pure Sr3SiO5 phase can be easily obtained. • It provides a new application field as phosphor for natural attapulgite. - Abstract: Sr2.965Al0.08Si0.92O5:0.025Ce3+, 0.01Eu2+ (SrAlSiO:Ce3+, Eu2+) phosphor from natural attapulgite (ATP) was synthesized by solid-state reaction method. For the use of ATP as a source of Si and Al, pretreatment process including mechanical grinding and acid leaching were involved. X-ray diffraction patterns confirmed the formation of silicates in a wide temperature field, whereas Sr3SiO5 within a single step. The ATP fibers were tuning into phosphor particles (about 1.5–3.0 μm) after calcination. Furthermore, photoluminescence spectra of the SrAlSiO:Ce3+, Eu2+ phosphor was also in good agreement with the literature results, indicating a promising potential application as an effective candidate for warm-white LEDs materials

  10. Structural integrity of engineering composite materials: a cracking good yarn

    Science.gov (United States)

    Beaumont, Peter W. R.

    2016-01-01

    Predicting precisely where a crack will develop in a material under stress and exactly when in time catastrophic fracture of the component will occur is one the oldest unsolved mysteries in the design and building of large-scale engineering structures. Where human life depends upon engineering ingenuity, the burden of testing to prove a ‘fracture safe design’ is immense. Fitness considerations for long-life implementation of large composite structures include understanding phenomena such as impact, fatigue, creep and stress corrosion cracking that affect reliability, life expectancy and durability of structure. Structural integrity analysis treats the design, the materials used, and figures out how best components and parts can be joined, and takes service duty into account. However, there are conflicting aims in the complete design process of designing simultaneously for high efficiency and safety assurance throughout an economically viable lifetime with an acceptable level of risk. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’. PMID:27242293

  11. Nanomanufacturing : nano-structured materials made layer-by-layer.

    Energy Technology Data Exchange (ETDEWEB)

    Cox, James V.; Cheng, Shengfeng; Grest, Gary Stephen; Tjiptowidjojo, Kristianto (University of New Mexico); Reedy, Earl David, Jr.; Fan, Hongyou; Schunk, Peter Randall; Chandross, Michael Evan; Roberts, Scott A.

    2011-10-01

    Large-scale, high-throughput production of nano-structured materials (i.e. nanomanufacturing) is a strategic area in manufacturing, with markets projected to exceed $1T by 2015. Nanomanufacturing is still in its infancy; process/product developments are costly and only touch on potential opportunities enabled by growing nanoscience discoveries. The greatest promise for high-volume manufacturing lies in age-old coating and imprinting operations. For materials with tailored nm-scale structure, imprinting/embossing must be achieved at high speeds (roll-to-roll) and/or over large areas (batch operation) with feature sizes less than 100 nm. Dispersion coatings with nanoparticles can also tailor structure through self- or directed-assembly. Layering films structured with these processes have tremendous potential for efficient manufacturing of microelectronics, photovoltaics and other topical nano-structured devices. This project is designed to perform the requisite R and D to bring Sandia's technology base in computational mechanics to bear on this scale-up problem. Project focus is enforced by addressing a promising imprinting process currently being commercialized.

  12. Structure/property relationships in non-linear optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J.M. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)]|[Durham Univ. (United Kingdom); Howard, J.A.K. [Durham Univ. (United Kingdom); McIntyre, G.J. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    The application of neutrons to the study of structure/property relationships in organic non-linear optical materials (NLOs) is described. In particular, charge-transfer effects and intermolecular interactions are investigated. Charge-transfer effects are studied by charge-density analysis and an example of one such investigation is given. The study of intermolecular interactions concentrates on the effects of hydrogen-bonding and an example is given of two structurally similar molecules with very disparate NLO properties, as a result of different types of hydrogen-bonding. (author). 3 refs.

  13. Some Material Characteristics of Cold-Sprayed Structures

    Directory of Open Access Journals (Sweden)

    Victor K. Champagne

    2007-01-01

    Full Text Available The deposition and consolidation of metal powders by means of cold spray are methods whereby powder particles are accelerated to high velocity through entrainment in a gas undergoing expansion in a rocket nozzle and are subsequently impacted upon a surface. The impacted powder particles form a consolidated structure which can be several centimeters thick. The characteristics of this structure depend on the initial characteristics of the metal powder and upon impact velocity. The influence of impact velocity on strain hardening and porosity are examined. A materials model is proposed for these phenomena, and model calculation is compared with experiment for the cold spraying of aluminum.

  14. Geometric and material nonlinear analysis of tensegrity structures

    Institute of Scientific and Technical Information of China (English)

    Hoang Chi Tran; Jaehong Lee

    2011-01-01

    A numerical method is presented for the large deflection in elastic analysis of tensegrity structures including both geometric and material nonlinearities.The geometric nonlinearity is considered based on both total Lagrangian and updated Lagrangian formulations,while the material nonlinearity is treated through elastoplastic stressstrain relationship.The nonlinear equilibrium equations are solved using an incremental-iterative scheme in conjunction with the modified Newton-Raphson method.A computer program is developed to predict the mechanical responses of tensegrity systems under tensile,compressive and flexural loadings.Numerical results obtained are compared with those reported in the literature to demonstrate the accuracy and efficiency of the proposed program.The flexural behavior of the double layer quadruplex tensegrity grid is sufficiently good for lightweight large-span structural applications.On the other hand,its bending strength capacity is not sensitive to the self-stress level.

  15. Geometric and material nonlinear analysis of tensegrity structures

    Science.gov (United States)

    Tran, Hoang Chi; Lee, Jaehong

    2011-12-01

    A numerical method is presented for the large deflection in elastic analysis of tensegrity structures including both geometric and material nonlinearities. The geometric nonlinearity is considered based on both total Lagrangian and updated Lagrangian formulations, while the material nonlinearity is treated through elastoplastic stress-strain relationship. The nonlinear equilibrium equations are solved using an incremental-iterative scheme in conjunction with the modified Newton-Raphson method. A computer program is developed to predict the mechanical responses of tensegrity systems under tensile, compressive and flexural loadings. Numerical results obtained are compared with those reported in the literature to demonstrate the accuracy and efficiency of the proposed program. The flexural behavior of the double layer quadruplex tensegrity grid is sufficiently good for lightweight large-span structural applications. On the other hand, its bending strength capacity is not sensitive to the self-stress level.

  16. Innovative Structural Materials and Sections with Strain Hardening Cementitious Composites

    Science.gov (United States)

    Dey, Vikram

    The motivation of this work is based on development of new construction products with strain hardening cementitious composites (SHCC) geared towards sustainable residential applications. The proposed research has three main objectives: automation of existing manufacturing systems for SHCC laminates; multi-level characterization of mechanical properties of fiber, matrix, interface and composites phases using servo-hydraulic and digital image correlation techniques. Structural behavior of these systems were predicted using ductility based design procedures using classical laminate theory and structural mechanics. SHCC sections are made up of thin sections of matrix with Portland cement based binder and fine aggregates impregnating continuous one-dimensional fibers in individual or bundle form or two/three dimensional woven, bonded or knitted textiles. Traditional fiber reinforced concrete (FRC) use random dispersed chopped fibers in the matrix at a low volume fractions, typically 1-2% to avoid to avoid fiber agglomeration and balling. In conventional FRC, fracture localization occurs immediately after the first crack, resulting in only minor improvement in toughness and tensile strength. However in SHCC systems, distribution of cracking throughout the specimen is facilitated by the fiber bridging mechanism. Influence of material properties of yarn, composition, geometry and weave patterns of textile in the behavior of laminated SHCC skin composites were investigated. Contribution of the cementitious matrix in the early age and long-term performance of laminated composites was studied with supplementary cementitious materials such as fly ash, silica fume, and wollastonite. A closed form model with classical laminate theory and ply discount method, coupled with a damage evolution model was utilized to simulate the non-linear tensile response of these composite materials. A constitutive material model developed earlier in the group was utilized to characterize and

  17. Acousto-Ultrasonics to Assess Material and Structural Properties

    Science.gov (United States)

    Kautz, Harold E.

    2002-10-01

    This report was created to serve as a manual for applying the Acousto-Ultrasonic NDE method, as practiced at NASA Glenn, to the study of materials and structures for a wide range of applications. Three state of the art acousto-ultrasonic (A-U) analysis parameters, ultrasonic decay (UD) rate, mean time (or skewing factor, "s"), and the centroid of the power spectrum, "fc," have been studied and applied at GRC for NDE interrogation of various materials and structures of aerospace interest. In addition to this, a unique application of Lamb wave analysis is shown. An appendix gives a brief overview of Lamb Wave analysis. This paper presents the analysis employed to calculate these parameters and the development and reasoning behind their use. It also discusses the planning of A-U measurements for materials and structures to be studied. Types of transducer coupling are discussed including contact and non-contact via laser and air. Experimental planning includes matching transducer frequency range to material and geometry of the specimen to be studied. The effect on results of initially zeroing the DC component of the ultrasonic waveform is compared with not doing so. A wide range of interrogation problems are addressed via the application of these analysis parameters to real specimens is shown for five cases: Case 1: Differences in density in 0 SiC/RBSN ceramic matrix composite. Case 2: Effect of tensile fatigue cycling in +/-45 SiC/SiC ceramic matrix composite. Case 3: Detecting creep life, and failure, in Udimet 520 Nickel-Based Super Alloy. Case 4: Detecting Surface Layer Formation in T-650-35/PMR-15 Polymer Matrix Composites Panels due to Thermal Aging. Case 5: Detecting Spin Test Degradation in PMC Flywheels. Among these cases a wide range of materials and geometries are studied.

  18. Welcome to the 2014 volume of Smart Materials and Structures

    Science.gov (United States)

    Garcia, Ephrahim

    2014-01-01

    Welcome to Smart Materials and Structures (SMS). Smart materials and structures are comprised of structural matter that responds to a stimulus. These materials can be controlled or have properties that can be altered in a prescribed manner. Smart materials generate non-traditional forms of transduction. We are all familiar with common forms of transduction, electromechanical motors. Lorenz's forces utilize permanent and variable magnets, controlled by current, to generate magnetically generated forces that oppose each other. Utilizing this simple principal we have advanced the industrial revolution of the 19th Century by the creation of the servo-mechanism. Controlled velocity and position generation systems that have automated manufacturing, our machines and the very environs in which we dwell. Smart materials often rely on a variety of new and different methods of transduction. Piezoelectric, magnetostrictive, electrostrictive, and phase-change materials, such as shape memory alloys, are among the most common smart materials. Other approaches such as polymer actuators that rely on complex three-dimensional chemical-based composites are also emerging. The trinity of engineering research is analysis, simulation and experimentation. To perform analyses we must understand the physical phenomena at hand in order to develop a mathematical model for the problem. These models form the basis of simulation and complex computational modeling of a system. It is from these models that we begin to expand our understanding about what is possible, ultimately developing simulation-based tools that verify new designs and insights. Experimentation offers the opportunity to verify our analyses and simulations in addition to providing the 'proof of the pudding' so to speak. But it is our ability to simulate that guides us and our expectations, predicting the behavior of what we may see in the lab or in a prototype. Experimentation ultimately provides the feedback to our modeling

  19. Structure-property relationships in silica-siloxane nanocomposite materials

    Energy Technology Data Exchange (ETDEWEB)

    Ulibarri, T.A.; Derzon, D.K.; Wang, L.C.

    1997-03-01

    The simultaneous formation of a filler phase and a polymer matrix via in situ sol-gel techniques provides silica-siloxane nanocomposite materials of high strength. This study concentrates on the effects of temperature and relative humidity on a trimodal polymer system in an attempt to accelerate the reaction as well as evaluate subtle process- structure-property relations. It was found that successful process acceleration is only viable for high humidity systems when using the tin(IV) catalyst dibutyltin dilaurate. Processes involving low humidity were found to be very temperature and time dependent. Bimodal systems were investigated and demonstrated that the presence of a short-chain component led to enhanced material strength. This part of the study also revealed a link between the particle size and population density and the optimization of material properties.

  20. Use of UHPC in Bridge Structures: Material Modeling and Design

    Directory of Open Access Journals (Sweden)

    Oguz Gunes

    2012-01-01

    Full Text Available Ultra-high-performance concrete (UHPC is a promising new class of concrete material that is likely to make a significant contribution to addressing the challenges associated with the load capacity, durability, sustainability, economy, and environmental impact of concrete bridge infrastructures. This paper focuses on the material modeling of UHPC and design of bridge girders made of UHPC. A two-phase model used for modeling the behavior of UHPC was briefly discussed, and the model was implemented in a preliminary design case study. Based on the implemented design and the reported use of UHPC in bridge applications, the advantages, limitations, and future prospects of UHPC bridges were discussed, highlighting the need for innovative research and design to make optimum use of the favorable properties of the material in bridge structures.

  1. The Aviation Adaptability of the New Structure Framework Material

    Directory of Open Access Journals (Sweden)

    Jiang Jinsan

    2013-05-01

    Full Text Available In this study, 0Cr15Ni5Cu2Ti, stainless steel sheet material with high strength is introduced to replace light metal of magnesium as aviation structural material. The research on heat process technology is emphasized and overall welding of 0Cr15Ni5Cu2Ti sheet is employed, adopting such methods as argon arc protection, anti-deformation technology of hot bending forming, special heat treatment technology, five-axis numerical control machining. It is the first time for the new material applied to the external measuring set with pylon-balance of aircraft in our country, overcoming the weaknesses of the aluminum framework in strength and meeting the needs of new airborne equipment.

  2. Health sociology from post-structuralism to the new materialisms.

    Science.gov (United States)

    Fox, Nick J

    2016-01-01

    The article reviews the impact of post-structuralism and postmodern social theory upon health sociology during the past 20 years. It then addresses the emergence of new materialist perspectives, which to an extent build upon insights of post-structuralist concerning power, but mark a turn away from a textual or linguistic focus to address the range of materialities that affect health, illness and health care. I conclude by assessing the impact of these movements for health sociology. PMID:26572797

  3. Methods for Creating Curved Shell Structures From Sheet Materials

    OpenAIRE

    Bruno Postle

    2012-01-01

    This paper describes some methods for producing developable surfaces with practical applications for creating useful lightweight, rigid, jig-less and elegant structural forms from sheet materials. Multiple related techniques based on the same fundamental principle can be used to generate a variety of interesting singly curved and doubly curved shapes. The system requires a minimum of specialist software, and is described in simple steps that can be followed by the reader with access to basic ...

  4. Status of structural material data in the resolved resonance region

    International Nuclear Information System (INIS)

    This review is mainly concerned with the accuracy aspect of neutron capture data for structural materials. As examples data sets of 54Fe, 56Fe and 57Fe will be compared critically. The results of the investigation of the C6D6 detector performed at CBNM will be used to study the deviations in the different data sets. Recommendations to reduce the uncertainty of capture data and to improve the capture detectors using the weighting method will be given

  5. Long-term evaluation of solid oxide fuel cell candidate materials in a 3-cell generic short stack fixture, Part II: sealing glass stability, microstructure and interfacial reactions.

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Y. S.; Stevenson, Jeffry W.; Choi, Jung-Pyung

    2014-03-15

    A generic solid oxide fuel cell stack test fixture was developed to evaluate candidate materials and processing methods under realistic conditions. Part I of the work addressed the stack fixture, seal system and cell performance of a 3-cell short stack tested at 800oC for 6000h. Commercial NiO-YSZ anode-supported thin YSZ electrolyte cells with LSM cathodes were used for assessment and were tested in constant current mode with dilute (~50% H2) fuel versus air. Part II of the work examined the sealing glass stability, microstructure development, interfacial reactions, and volatility issues. Part III of the work investigated the stability of Ce-(Mn,Co) spinel coating, AISI441 metallic interconnect, alumina coating, and cell degradation. After 6000h of testing, the refractory sealing glass YSO77 (Ba-Sr-Y-B-Si) showed desirable chemical compatibility with YSZ electrolyte in that no discernable interfacial reaction was identified, consistent with thermodynamic calculations. In addition, no glass penetration into the thin electrolyte was observed. At the aluminized AISI441 interface, the protective alumina coating appeared to be corroded by the sealing glass. Air side interactions appeared to be more severe than fuel side interactions. Metal species such as Cr, Mn, and Fe were detected in the glass, but were limited to the vicinity of the interface. No alkaline earth chromates were found at the air side. Volatility was also studied in a similar glass and weight loss in a wet reducing environment was determined. Using the steady-state volatility data, the life time (40,000h) weight loss of refractory sealing glass YSO77 was estimated to be less than 0.1 wt%.

  6. Localized corrosion and stress corrosion cracking of candidate materials for high-level radioactive waste disposal containers in the US: A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; McCright, R.D.

    1988-11-04

    Container materials may undergo any of several modes of degradation in this environment, including: undesirable phase transformations due to lack of phase stability; atmospheric oxidation; general aqueous corrosion; pitting; crevice corrosion; intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This paper is an analysis of data from the literature relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of these alloys. Though all three austenitic candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these forms of localized attack. Both types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented for Alloy 825 under comparable conditions. Gamma irradiation has been found to enhance SCC of Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while microbiologically induced corrosion effects have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. Of the copper-based alloys, CDA 715 has the best overall resistance to localized attack. Its resistance to pitting is comparable to that of CDA 613 and superior to that of CDA 102. Observed rates of dealloying in CDA 715 are less than those observed in CDA 613 by orders of magnitude. The resistance of CDA 715 to SCC in tarnishing ammonical environments is comparable to that of CDA 102 and superior to that of CDA 613. Its resistance to SCC in nontarnishing ammonical environments is comparable to that of CDA 613 and superior to that of CDA 102. 22 refs., 8 figs., 4 tabs.

  7. Localized corrosion and stress corrosion cracking of candidate materials for high-level radioactive waste disposal containers in the US: A literature review

    International Nuclear Information System (INIS)

    Container materials may undergo any of several modes of degradation in this environment, including: undesirable phase transformations due to lack of phase stability; atmospheric oxidation; general aqueous corrosion; pitting; crevice corrosion; intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This paper is an analysis of data from the literature relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of these alloys. Though all three austenitic candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these forms of localized attack. Both types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented for Alloy 825 under comparable conditions. Gamma irradiation has been found to enhance SCC of Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while microbiologically induced corrosion effects have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. Of the copper-based alloys, CDA 715 has the best overall resistance to localized attack. Its resistance to pitting is comparable to that of CDA 613 and superior to that of CDA 102. Observed rates of dealloying in CDA 715 are less than those observed in CDA 613 by orders of magnitude. The resistance of CDA 715 to SCC in tarnishing ammonical environments is comparable to that of CDA 102 and superior to that of CDA 613. Its resistance to SCC in nontarnishing ammonical environments is comparable to that of CDA 613 and superior to that of CDA 102. 22 refs., 8 figs., 4 tabs

  8. Target and structural materials under dual-beam irradiation

    International Nuclear Information System (INIS)

    The European Spallation Source (ESS) is planned to have a beam power of 5 MW (3.75 mA of 1.334 GeV protons). This is by a factor 30 higher than the available most powerful spallation source ISIS at Rutherford-Appleton Lab. (RAL) in Great-Britain. This causes a damage rate of approx. 10 dpa (displacements per atom) per month in target materials (W or Ta) or structural materials. The problem of radiation damage by high energy protons in different alloys has been recently reviewed. At HMI, simulation irradiation using heavy ions and helium or hydrogen ions at the dual-beam facility are being out. Here, we report on some preliminary results obtained on tantalum as target material and on ferritic/martensitic steels (HT9 type steels or comparable steels), which are proposed to be used as structural materials. Goal of these investigations is to correlate the results with those obtained at spallation irradiated specimens and to investigate the unexplored field of simultaneous production of damage, helium and hydrogen at high levels. (author) 4 figs., 1 tab., 9 refs

  9. Development of fuels and structural materials for fast breeder reactors

    Indian Academy of Sciences (India)

    Baldev Raj; S L Mannan; P R Vasudeva Rao; M D Mathew

    2002-10-01

    Fast breeder reactors (FBRs) are destined to play a crucial role inthe Indian nuclear power programme in the foreseeable future. FBR technology involves a multi-disciplinary approach to solve the various challenges in the areas of fuel and materials development. Fuels for FBRs have significantly higher concentration of fissile material than in thermal reactors, with a matching increase in burn-up. The design of the fuel is an important aspect which has to be optimised for efficient, economic and safe production of power. FBR components operate under hostile and demanding environment of high neutron flux, liquid sodium coolant and elevated temperatures. Resistance to void swelling, irradiation creep, and irradiation embrittlement are therefore major considerations in the choice of materials for the core components. Structural and steam generator materials should have good resistance to creep, low cycle fatigue, creep-fatigue interaction and sodium corrosion. The development of carbide fuel and structural materials for the Fast Breeder Test Reactor at Kalpakkam was a great technological challenge. At the Indira Gandhi Centre for Atomic Research (IGCAR), advanced research facilities have been established, and extensive studies have been carried out in the areas of fuel and materials development. This has laid the foundation for the design and development of a 500 MWe Prototype Fast Breeder Reactor. Highlights of some of these studies are discussed in this paper in the context of our mission to develop and deploy FBR technology for the energy security of India in the 21st century.

  10. Material modeling and structural analysis with the microplane constitutive model

    Science.gov (United States)

    Brocca, Michele

    The microplane model is a versatile and powerful approach to constitutive modeling in which the stress-strain relations are defined in terms of vectors rather than tensors on planes of all possible orientations. Such planes are called the microplanes and are representative of the microstructure of the material. The microplane model with kinematic constraint has been successfully employed in the past in the modeling of concrete, soils, ice, rocks, fiber composites and other quasibrittle materials. The microplane model provides a powerful and efficient numerical and theoretical framework for the development and implementation of constitutive models for any kind of material. The dissertation presents a review of the background from which the microplane model stems, highlighting differences and similarities with other approaches. The basic structure of the microplane model is then presented, together with its extension to finite strain deformation. To show the effectiveness of the microplane model approach, some examples are given demonstrating applications of microplane models in structural analysis with the finite element method. Some new constitutive models are also introduced for materials characterized by very different properties and microstructures, showing that the approach is indeed very versatile and provides a robust basis for the study of a broad range of problems. New models are introduced for metal plasticity, shape memory alloys and cellular materials. The new models are compared quantitatively with the existing models and experimental data. In particular, the newly introduced microplane models for metal plasticity are compared with the classical J2-flow theory for incremental plasticity. An existing microplane model for concrete is employed in finite element analysis of the 'tube-squash' test, in which concrete undergoes very large deviatoric deformation, and of the size effect in compressive failure of concrete columns. The microplane model for shape

  11. Advanced gas cooled nuclear reactor materials evaluation and development program. Selection of candidate alloys. Vol. 1. Advanced gas cooled reactor systems definition

    International Nuclear Information System (INIS)

    Candidate alloys for a Very High Temperature Reactor (VHTR) Nuclear Process Heal (NPH) and Direct Cycle Helium Turbine (DCHT) applications in terms of the effect of the primary coolant exposure and thermal exposure were evaluated

  12. Advanced gas cooled nuclear reactor materials evaluation and development program. Selection of candidate alloys. Vol. 1. Advanced gas cooled reactor systems definition

    Energy Technology Data Exchange (ETDEWEB)

    Marvin, M.D.

    1978-10-31

    Candidate alloys for a Very High Temperature Reactor (VHTR) Nuclear Process Heal (NPH) and Direct Cycle Helium Turbine (DCHT) applications in terms of the effect of the primary coolant exposure and thermal exposure were evaluated. (FS)

  13. New smart materials to address issues of structural health monitoring.

    Energy Technology Data Exchange (ETDEWEB)

    Chaplya, Pavel Mikhail

    2004-12-01

    Nuclear weapons and their storage facilities may benefit from in-situ structural health monitoring systems. Appending health-monitoring functionality to conventional materials and structures has been only marginally successful. The purpose of this project was to evaluate feasibility of a new smart material that includes self-sensing health monitoring functions similar to that of a nervous system of a living organism. Reviews of current efforts in the fields of heath-monitoring, nanotechnology, micro-electromechanical systems (MEMS), and wireless sensor networks were conducted. Limitations of the current nanotechnology methods were identified and new approaches were proposed to accelerate the development of self-sensing materials. Wireless networks of MEMS sensors have been researched as possible prototypes of self-sensing materials. Sensor networks were also examined as enabling technologies for dense data collection techniques to be used for validation of numerical methods and material parameter identification. Each grain of the envisioned material contains sensors that are connected in a dendritic manner similar to networks of neurons in a nervous system. Each sensor/neuron can communicate with the neighboring grains. Both the state of the sensor (on/off) and the quality of communication signal (speed/amplitude) should indicate not only a presence of a structural defect but the nature of the defect as well. For example, a failed sensor may represent a through-grain crack, while a lost or degraded communication link may represent an inter-granular crack. A technology to create such material does not exist. While recent progress in the fields of MEMS and nanotechnology allows to envision these new smart materials, it is unrealistic to expect creation of self-sensing materials in the near future. The current state of MEMS, nanotechnology, communication, sensor networks, and data processing technologies indicates that it will take more than ten years for the

  14. Code qualification of structural materials for AFCI advanced recycling reactors

    International Nuclear Information System (INIS)

    This report summarizes the further findings from the assessments of current status and future needs in code qualification and licensing of reference structural materials and new advanced alloys for advanced recycling reactors (ARRs) in support of Advanced Fuel Cycle Initiative (AFCI). The work is a combined effort between Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL) with ANL as the technical lead, as part of Advanced Structural Materials Program for AFCI Reactor Campaign. The report is the second deliverable in FY08 (M505011401) under the work package 'Advanced Materials Code Qualification'. The overall objective of the Advanced Materials Code Qualification project is to evaluate key requirements for the ASME Code qualification and the Nuclear Regulatory Commission (NRC) approval of structural materials in support of the design and licensing of the ARR. Advanced materials are a critical element in the development of sodium reactor technologies. Enhanced materials performance not only improves safety margins and provides design flexibility, but also is essential for the economics of future advanced sodium reactors. Code qualification and licensing of advanced materials are prominent needs for developing and implementing advanced sodium reactor technologies. Nuclear structural component design in the U.S. must comply with the ASME Boiler and Pressure Vessel Code Section III (Rules for Construction of Nuclear Facility Components) and the NRC grants the operational license. As the ARR will operate at higher temperatures than the current light water reactors (LWRs), the design of elevated-temperature components must comply with ASME Subsection NH (Class 1 Components in Elevated Temperature Service). However, the NRC has not approved the use of Subsection NH for reactor components, and this puts additional burdens on materials qualification of the ARR. In the past licensing review for the Clinch River Breeder Reactor Project (CRBRP) and the

  15. Structural cardboard: feasibility study of cardboard as a long-term structural material in architecture

    OpenAIRE

    Sekulic, Branko

    2013-01-01

    This study aims to evaluate the feasibility of cardboard as a long-term structural material in architecture. Recent experiments with cardboard in architecture are based on assemble of structural elements with existing cardboard products, which are afterwards put to load tests. Obtained results are usually in lack of coherence, making difficult to have precise prediction of structural behavior on a long-term basis. On the other hand, information that comes from packaging industry d...

  16. Carbon nanotube-reinforced composites as structural materials for microactuators in microelectromechanical systems

    International Nuclear Information System (INIS)

    Nanocomposites are a promising new class of structural materials for the mechanical components of microelectromechanical systems (MEMS). This paper presents a detailed theoretical investigation of the utility of carbon nanotube-reinforced composites for designing actuators with low stiffness and high natural frequencies of vibration. The actuators are modelled as beams of solid rectangular cross-section consisting of an isotropic matrix reinforced with transversely isotropic carbon nanotubes. Three different types of nanotube reinforcements are considered: single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes (MWNTs) and arrays of SWNTs. The effects of nanotube aspect ratio, dispersion, alignment and volume fraction on the elastic modulus and longitudinal wave velocity are analysed by recourse to the Eshelby-Mori-Tanaka theory. The calculated bounds on Young's modulus and wave velocity capture the trend of the experimental results reported in the literature. Polymer-matrix nanocomposites reinforced with aligned, dispersed SWNTs are identified as excellent candidates for microactuators and microresonators, with properties rivalling those of monolithic metallic and ceramic structures used in the current generation of MEMS. A qualitative comparison between the state-of-the-art in nanocomposite manufacturing technology and the predicted upper bound on Young's modulus and longitudinal wave velocity highlights the enormous improvements needed in materials processing and micromachining to harness the full potential of carbon nanotube-reinforced composites for microactuator applications. These results have immediate and significant implications for the use of nanotube composites in MEMS

  17. Study on reactor building structure using ultrahigh strength materials, 5

    International Nuclear Information System (INIS)

    Reinforced concrete (RC) shear walls are the main members of a reactor building for the aseismatic design. The characteristics of nonlinear behavior have been clarified by a number of experimental studies, and the reliability of the nonlinear analysis of RC structures by FEM has been improved by the studies on the constitutive equation for concrete and the simulation analysis of test results. However, the characteristics of the RC shear walls made of ultrahigh strength materials have not been sufficiently studied. In this paper, the nonlinear analysis of the RC shear walls made of ultrahigh strength materials is discussed. Based on the results of a series of the material test and pure shear test on ultrahigh strength materials, the simulation analysis of bending shear test was performed by three-dimensional nonlinear FEM. The specimens used for the bending shear test were single story, single span model shear walls. The analytical method, the modeling of concrete and reinforcing bars, the properties of the materials used and the results of analysis on the effects of concrete strength and the quantity and grade of bars are reported. (K.I.)

  18. Protection and Reinforcement of Tooth Structures by Dental Coating Materials

    Directory of Open Access Journals (Sweden)

    Toru Nikaido

    2012-10-01

    Full Text Available It has been proposed that a resin coating can serve as a means to protect dental structure after preparation of the tooth for indirect restorations, sealing the exposed dentin. The resin coating is applied on the cut surfaces immediately after tooth preparation and before making an impression by assembling a dentin bonding system and a flowable composite. Resin coatings minimize pulp irritation and improve the bond strength between a resin cement and tooth when bonding the restoration to tooth. Recently, thin-film coating dental materials based on all-in-one adhesive technology were introduced for resin coating of indirect restorations. The thin coating materials are applied in a single clinical step and create a barrier-like film layer on the prepared dentin. The thin coatings play an important role in protecting the dentin from physical, chemical, and biological irritation. In addition, these thin-film coating materials reportedly prevent marginal leakage beneath inlays or crown restorations. In light of the many benefits provided by such a protective layer, these all-in-one adhesive materials may therefore also have the potential to cover exposed root dentin surfaces and prevent caries formation. In this paper, recent progress of the dental coating materials and their clinical applications are reviewed.

  19. Synthesis of Novel Mesoporous Silica Materials with Hierarchical Pore Structures

    International Nuclear Information System (INIS)

    Porous materials with various pore sizes in the range of micropore ( 50 nm) are attractive due to their many emerging applications such as catalysts, separation systems, and low dielectric constant materials. The discovery of new M41S mesoporous silica families with pore sizes larger than 2 nm in diameter in 1992 extended the applications into much wider pore ranges, bringing in a new prosperous era in porous material research. The synthesis of these silica materials has been mainly accomplished through a self-assembly between surfactant molecules and inorganic species under various pH conditions. Recently, core-shell nanoparticles with a silica core and mesoporous shell under basic conditions were synthesized using the silica nanoparticles as a core, and a silica precursor (TEOS) and cationic surfactant (CTABr) as a material for the formation of the mesoporous shell. The resultant materials were very monodispersive in size and showed a narrow pore size distribution in the range of ca 2-3 nm in diameter, depending on the alkyl-chain length of the surfactants used. In this work, the mesoporous shell coated-fumed silicas (denoted as MS M-5s) were synthesized by using fumed silica instead of the silica nanoparticle as a core based on previous reports. Also, the structural properties of the MS M-5s such as the specific surface area and pore volume were easily controlled by varying the amount of the silica precursor and surfactant. The resultant materials exhibited a BET surface area of ca 279-446 m2/g and total pore volume of ca 0.64-0.74 cm3/g and showed a narrow pore size distribution (PSD) due to the removal of the organic surfactant molecules

  20. Benchmark experiments of fusion neutron induced gamma-ray radioactivity in various structural materials

    International Nuclear Information System (INIS)

    The fusion reactor inventory code FISPACT, together with the European Activation File EAF, is the European reference software for calculating the neutron-induced activation of fusion reactor relevant materials. Experimental verifications (benchmarks) of the code predictions have been performed at ENEA Frascati by means of an irradiation facility consisting of a D-T neutron generator and a moderator/reflector structure which is employed to mimic the neutron spectrum at the a fusion device first wall. Various materials (vanadium alloy, SiC, AlSI 316, martensitic steel F82H, copper, tungsten, iron, niobium), candidates to e used in a fusion reactor, have been exposed to neutrons produced in the facility (about 109 n x cm-2 x s-1) and the short and medium-lived induced radioactivity has been measured by gamma-ray spectroscopy. The experimental results have been used to validate the inventory code FISPACT, the physical database EAF, including its uncertainty predictions, and the composition of the material irradiated in particular for its minor elements and impurities. The comparison between calculated (C) and experimental results (E) is reported as C/E values and shows a satisfactory agreement for almost all radionuclides. Radionuclides for which there is not agreement between calculations and experiments are also discussed and an analysis of the causes of the lack of agreement is carried out. (author)