International Science & Technology Center (ISTC)

Research and Development of Resource-Saving Technology for Manufacturing of Titanium Semifinished Items from Chips

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BackgroundTitanium and titanium alloys are widely used for fabrication of dental implants. Since the material composition and the surface topography of a biomaterial play a fundamental...Full Text Available

International Nuclear Information System (INIS)

Short communication.

Science.gov (United States)

... Title : Effect of Yttrium on the Microstructure of Titanium Alloys,. ... The yttrium was added in the melting stage as an oxide or in the elemental form. ...

International Nuclear Information System (INIS)

This paper describes a process for the direct production of a superconductive niobium-titanium alloy during reduction of niobium pentoxide. It comprises: mixing at least one of titanium metal powder and titanium dioxide powder with niobium pentoxide powder and aluminum powder; heating the resulting mixture to form a niobium-titanium alloy and a slag consisting essentially of aluminum oxide; and separating the alloy and the slag.

International Nuclear Information System (INIS)

Chemical and phase homogeneity of titanium-niobium sponge, produced by a combined magnesium-thermic reduction of niobium pentachloride and titanium tetrachloride mixtures, is investigated. It is ascertained that a sponge consists of spherical shape particles and has a large number of pores. Particle sizes are reduced with niobium being substituted for titanium from 50-500 #mu#m for titanium sponge to 1-40 #mu#m for niobium one, which testifies to the bormation in a titanium-niobium sponge of an alloy and not a mechanical mixture. A number of solid solutions is detected by X-ray phase analysis. Lattice parameters are determined.

Science.gov (United States)

... Accession Number : ADD151811. Title : Ultra High Strength Beta Titanium Alloy for Fasteners. Descriptive Note : Journal article,. ...

Science.gov (United States)

... Accession Number : ADD109273. Title : THERMAL STABILITY OF ALPHA-BETA TITANIUM ALLOY Ti-5Al-2Cr-1Fe,. Corporate Author : ...

International Nuclear Information System (INIS)

Consideration is given to the process of the formation of a titanium sponge alloyed with niobium or tantalum, in the joint metallic reduction of titanium, niobium and tantanum chlorides. A percentage composition of the phases observed and the structure of the alloyed sponge have been studied. It is shown that after one remelting operation of the alloyed sponge the alloys of titanium with niobium and tantalum have a uniform component distribution. At the stage of chloride reduction there appear solid solutions based on titanium and an alloying component. The stage of vacuum separation of the reaction mass is associated with a mutual dissolution of the primary phases and the formation of the solid solutions of the alloyed titanium sponge, which, by their composition, are close to the desired alloy composition. The principal features of the formation of a titanium ...

Science.gov (United States)

... Accession Number : ADD120492. Title : Environmental Cracking of the Alpha-Beta Titanium Alloy, Ti-6Al-6V-2Sn,. Corporate ...

Science.gov (United States)

... Title : DUCTILITY RATIO OF AGED BETA TITANIUM ALLOY. Corporate Author : NEW YORK UNIV NY SCHOOL OF ENGINEERING AND SCIENCE. ...

International Nuclear Information System (INIS)

Observations concerned with the formation of isothermal #omega# in the beta-titanium alloy RMI (38-6-44) are presented as part of a more general study of the aging characteristics of the alloy.

International Nuclear Information System (INIS)

(Nov 1973). United States Greenfield, MA Pierce, CM Chicago, IL.

Science.gov (United States)

An economical way to reduce the deleterious effects of titanium, one of the impurities present in metallurgical grade silicon material, is disclosed. By adding copper to approximately the same concentration level of the titanium during the melting process, the conversion efficiency will be restored to about 99.3% of what it would have been if the single crystal silicon had been grown free of titanium impurities.

International Nuclear Information System (INIS)

Cyclic strength of #alpha#+#beta#-titanium alloy BT3-1 is studied under load frequencies of 33 and 300 Hz. The increase in the cyclic strength with growing frequency is caused by formation of FCC interphase layers of titanium hydrides. Their formation is one of possible ways of raising the fatigue strength of titanium alloys. Peculiarities of FCC interlayer formation in #alpha#+#beta# phases under loading frequency variation are revealed.

Science.gov (United States)

... THE STRENGTH, TOUGHNESS, AND STRESS-CORROSION CRACKING SUSCEPTIBILITY OF A METASTABLE BETA TITANIUM ALLOY (Ti-11. ...

Energy Technology Data Exchange (ETDEWEB)

Results are reported which were obtained when investigating the anodic behavior of titanium in sodium iodide solutions. It was concluded that in order to explain the special features in the anodic behavior and anionic anodic activity of titanium one must take into account, both a redistribution of the potential drop between the oxide and the Helmholtz layer and a potential-dependent variation of the catalytic and adsorption properties of the oxidized titanium anode.

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No abstract prepared.

British Library Electronic Table of Contents (United Kingdom)

RESUME: Cet article propose une tude du r le croissant que joue l valuation dans la gouvernance des services domicile en Europe. L introduction de quasi march s dans plusieurs pays europ ens va de pair avec un processus d autonomisation de la fonction d valuation qui devient un v ritable outil de r gulation de la concurrence. Une analyse compar e des situations en Belgique, France et Royaume Uni, tant de la demande que de l offre de services, met en vidence les tensions r currentes dans les objectifs de l valuation (qualit des services, ma trise des budgets sociaux, cr ation d emploi), la faible prise en compte de la qualit de l emploi ainsi que les limites des dispositifs standardis s d valuation au regard de la rh torique du libre choix de l usager (consommateur).

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sur la médiatisation des élections Il s'est ouverte le 16 septembre 2011 à Matadi dans le Bas-Congo une formation sur la médiatisation des questions électorales,...

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The results make appear that the cesium 137 would be eliminated less quick than what the ICRP considered for its models. Pectin would accelerate the cesium elimination but less quick than what is announced by its promotors. Politically speaking, the pectin is ignored by the officials of medicine and radiation protection at the pretext that its efficiency is not proved but no study is made. (N.C.)

Science.gov (United States)

To study the effects of atmospheric species on the fatigue crack growth behavior of an a+B titanium

Science.gov (United States)

A novel reactor combining a flame-deposited nanostructured titanium dioxide film and a set of embedded ceramic electrodes was designed, developed and tested for degradation of methyl tert-butyl ether (MTBE) in water. On applying a voltage to the ceramic electrodes, a surface coro...

International Nuclear Information System (INIS)

... properties organic bromine compounds organic solvents ph value phenols

International Nuclear Information System (INIS)

17-4PH stainless steel was modified by direct current (DC) plasma nitriding and titanium nitride film duplex treatment in this study. The microstructure, wear resistance and corrosion resistance were characterized by X-ray diffraction (XRD), pin-on-disk tribological test and polarization experiment. The results revealed that the DC plasma nitriding pretreatment was in favor of improving properties of titanium nitride film. The corrosion resistance and wear resistance of duplex treatment specimen was more superior to that of only coated titanium nitride film.

International Nuclear Information System (INIS)

1970. United States Crossley, FA Lindberg, RW Lockheed Missiles and

Science.gov (United States)

... Accession Number : ADD100229. Title : DEFORMATION BEHAVIOR OF AN OMEGA HARDENED ALPHA-BETA TITANIUM ALLOY,. ...

Science.gov (United States)

... Accession Number : ADA136144. Title : Characteristics of the Mechanical Properties and the Fractures of an Alpha Beta Titanium Alloy,. ...

Science.gov (United States)

A number of alloys of zirconium have been investigated as part of a program aimed at improving the high-temperature tensile and creep strength of zirconium. These alloys include aluminum, beryllium, lead, magnesium, molybdenum, niobium, tantalum, tin, titanium, tungsten, vanadium, and zinc, binary and ternary alloys. The data indicate that aluminum, lead, molybdenum niobium, tin, titanium, tungsten, and vanadium can be used successfully to harden zirconium, and that aluminum, tin, titanium, and vanadium are particularly effective in maintaining the strength of zirconium at elevated temperatures.

Science.gov (United States)

A beta titanium alloy was evaluated for use in orthodontic appliances. Standard mechanical tests and aspecially designed spring test were used. Two particular thermo-mechanical treatments resulted in titanium springs with 1.8 times the extension of comparable stainless steel springs, and a 2.2 fold reduction in force per unit displacement. PMID:283089

International Nuclear Information System (INIS)

L'invention concerne un procede de triage de cristaux irradies. Ce procede non destructeur comporte l'irradiation des cristaux par un rayonnement ionisant pendant une duree et avec une intensite telles qu'il se forme des centres colores distinctifs dans les matieres contenant des ions aluminium. Les cristaux colores qui correspondent en teinte et en profondeur de couleur a des teneurs en aluminium en dehors de la teneur desiree peuvent etre separes. On peut isoler ainsi des matieres de quartz, de verre, de silicates exemptes d'aluminium dans un melange, ou bien on peut choisir des fractions de ces matieres, chacune contenant une teneur uniforme en aluminium.

Energy Technology Data Exchange (ETDEWEB)

The project is devoted to the development of novel insoluble anodes for copper electrowinning and electrolytic manganese dioxide (EMD) production. The anodes are made of titanium-lead composite material produced by techniques of powder metallurgy, compaction of titanium powder, sintering and subsequent lead infiltration. The titanium-lead anode combines beneficial electrochemical behavior of a lead anode with high mechanical properties and corrosion resistance of a titanium anode. In the titanium-lead anode, the titanium stabilizes the lead, preventing it from spalling, and the lead sheathes the titanium, protecting it from passivation. Interconnections between manufacturing process, structure, composition and properties of the titanium-lead composite material were investigated. The material containing 20-30 vol.% of ...

Science.gov (United States)

... Producers and their Impacts on Women in Central Java, IndonesiaActions basées sur des scénarios visant à élever ... impact sur les femmes dans le centre de Java, en IndonésieInvestigación-acción basada en...

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After a presentation of methods and tools for the basic and extensive characterization of polluted sites and the study of evolution and transfer of current organic pollutants in the ground, the example of the rehabilitation of an old Rhone-Poulenc site (at Chauny, France) polluted with metals and arsenic, is described: soil and aquifer diagnosis, risk analysis and determination of migration schemes

International Nuclear Information System (INIS)

By the methods of microstructural and electron-microscopic analyses by the tension test and impact test studied is the effect of quenching conditions on structure and mechanical properties of the TS6 titanium-#beta# alloy. It is shown that low temperature quenching from 700 deg C, recommended earlier for analogous VT15 titanium alloy, leads to appearence of intercrystalline fracture and to sharp decrease of impact strength of the TS6 alloy. Established are optimum conditions for quenching of half-finished products and articles of the TS6 alloy depending on their subsequent working or operation.

Energy Technology Data Exchange (ETDEWEB)

The feasibility of the anodic protection of titanium evaporators in Al[sub 2](SO[sub 4])[sub 3] solution was studied by the measurement of polarization curves, weight loss, solubility of passive film and AC impedance. The protection parameters and efficiency were determined. In addition, the practical technology of anodic protection was studied by screening reference electrodes and auxiliary cathodes. Throwing power was also measured. Four rows of tube-type evaporators of titanium have been anodically protected in situ. Field tests lasting more than one year shows satisfactory results. (orig.)

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Low-cost fabrication of PMC composite sandwich panels, including metallic surface preparations for bonding the PMC to titanium honeycomb. ...

KoreaScience (Korea)

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Science.gov (United States)

... [11]Richter, K., Orban, S., and Nowotny, S., Laser cladding of the titanium alloy TI6242 to restore damaged blades, Proceedings of the 23rd ...

Science.gov (United States)

Development efforts have been undertaken to improve the processing and structural efficiencies of

International Nuclear Information System (INIS)

Corrosion tests of titanium alloys VTI-0, OT4, VT5-1 and steel Kh18N1OT in 10% and 18% HCl with additions of carnallite at 40 deg C have been carried out. It has been established that titanium alloys in 10% and 18% HCl containing 5 and 10% carnallite are sufficiently corrosion resistant in the presence of 0.1-1% FeCl or HNO_3 and can be used for manufacturing the equipment of recirculation gas scrubbers. Steel Kh18N10T is unstable in all the media tested. It is subjected to intensive pitting. Specimens of steel Kh18N10T have also revealed edge cracking.

International Nuclear Information System (INIS)

(Feb 1972). United States Nelson, HG Williams, DP Stein, JE v. 3(2)

Science.gov (United States)

Procedures for a New High-Strength, Beta Titanium Alloy having. Superior Formability, " Technical Report AFML-TR-69-171, Air ...

Science.gov (United States)

... transformed at 705°C. The cooling rate and temperature dependence of matrix decomposition for Ti6242 was thus similar to that for Ti64 x [9]. ...

International Nuclear Information System (INIS)

The influence of heat treatment on the structure, mechanical properties and fracture peculiarities of high-strength (#alpha#+#beta#)-titanium alloy VT22 has been studied. It is ascertained that thermal cycling and subsequent high-temperature aging permit to reduce considerably crack growth rate. Thermal cycling is realized in the following mode: heating in #beta#-region, cooling and allowance in (#alpha#+#beta#)-region, heating in #beta#-region.

International Nuclear Information System (INIS)

VT6 titanium alloy long-range fibers have been extracted from the suspended melt drop with the following high-rate solidification. Formation of the structure of fibrous porous material prepared from these fibers has been studied. 7 refs.; 5 figs.; 2 tabs.

International Nuclear Information System (INIS)

The influence of structure on mechanical properties in the course of tensile tests in a wide range of temperatures was studied, using the VT16 structure thermally strengthened (alpha+beta)-titanium alloy by way of example. It is ascertained that transition from ductile to brittle fracture at the temperature of -196 deg C is observed only in coarse-grain alloy having alpha-eldging of beta grains.

International Nuclear Information System (INIS)

The relationships of hydrogen alloyed #beta#-titanium alloy deformation behaviour to its microstructure and texture are investigated. It is shown that plasticity increases and strain induced texture changes at low hydrogen contents (0.1-0.2 mass %). Possible mechanisms responsible for specific features of #beta#-Ti alloy deformation are discussed. The study is made using alloy VT35 doped with hydrogen

International Nuclear Information System (INIS)

Peculiarities of metastable #beta#-solid solution decmposition in titanium alloy VT30 in the process of isothermal ageing in the range 500-650 deg C are investigated. Using the methods of transmittion electron microscopy, X-ray diffraction analysis, etc., it is shown that in the case of alloy quenching from the temperature below the point of complete polymorphous transformation (T_t_._t_.), as well as after warm rolling the course of subsequent decomposition of solid solution can be consierably complicated.

UK PubMed Central (United Kingdom)

This study prospectively assessed the outcome of 134 cemented titanium stems and serum ion levels. The stems were polished (0.1 μm Ra) with circular cross section. At the end point,...Full Text Available

International Nuclear Information System (INIS)

Slurry aluminizing is one method of protecting titanium alloys and intermetallics at temperatures at which oxidation would otherwise significantly degrade mechanical properties. The technique produces a continuous layer of alumina-forming TiAl_3 on exposed surfaces. The influence of composition, film thickness, and diffusion temperature upon the oxidation resistance of these slurry aluminides was studied in cyclic tests to 816degC (1500deg F). Degradation of slurry aluminized #beta#-titanium alloy and #alpha#-Z titanium aluminide intermetallic occurs by localized oxidation at cracks in the coating layer. These cracks are probably due to mismatch of coefficients of thermal expansion between the coatings and substrates. Addition of silicon to the slurry modifies the oxidation behaviour around a crack by introducing a continuous layer of titanium silicide at the boundary of the aluminide coating and ...

Energy Technology Data Exchange (ETDEWEB)

The European gas market is continuing to expand due to increased industrial, domestic and power generation demand. As a result of this demand, and the trend toward liberalization of the market, the need for storage of gas is also increasing. One key segment of the large scale storage of gas is underground storage, either in partially depleted gas or oil fields, naturally occurring caverns, aquifers and salt cavities. In most cases the gas produced after storage requires conditioning to meet the water of hydrocarbon dew point specification of the gas transmission system. For that reason export gas from storage will require gas conditioning in order to meet pipeline specifications. Adsorption as a feasible and reliable process will be presented in detail and especially in regards to hydrocarbon dew-pointing compared with other process options. (author)

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The in-situ observation of dendritic growth in lithium/polymer electrolyte-LiTFSI/lithium battery cells shows that dendrites grow up with about the same rate as anion migration. Memory effects have been evidenced in cycling experiments and limit the dendrites length. An overall movement of the electrolyte due to variations of electrolyte concentration in the vicinity of the electrodes has been observed too. (J.S.) 13 refs.

Energy Technology Data Exchange (ETDEWEB)

The Purex process and the fluorescence spectrometry are first recalled, then uranyl fluorescence is studied in a pure nitric medium without other elements to establish a theoretical model, allowing the description of uranium fluorescence signal with a general equation. The influence of different parameters (temperature, inhibitors, dynamic quenching of iron and cerium) is investigated to develop the model. A quantitative analysis method without addition of reagents is proposed to validate the model.

Energy Technology Data Exchange (ETDEWEB)

This work gives a global view of legislations in which are included metals chemical states, briefly recalls the conditions to be respected for the CRM (Certified Reference Materials), and describes the results of some current plans for the Norms, Measures and Tests program. (O.M.) 23 refs.

Science.gov (United States)

Natural bone consists of hard nanostructured hydroxyapatite (HA) in a nanostructured protein-based soft hydrogel template (ie, mostly collagen). For this reason, nanostructured HA has been an intriguing coating material on traditionally used titanium for improving orthopedic applications. In addition, helical rosette nanotubes (HRNs), newly developed materials which form through the self-assembly process of DNA base pair building blocks in body solutions, are soft nanotubes with a helical architecture that mimics natural collagen. Thus, the objective of this in vitro study was for the first time to combine the promising attributes of HRNs and nanocrystalline HA on titanium and assess osteoblast (bone-forming cell) functions. Different sizes of nanocrystalline HA were synthesized in this study through a wet chemical precipitation process following either hydrothermal treatment or sintering. Transmission electron microscopy images showed that ...

British Library Electronic Table of Contents (United Kingdom)

Fluoroalkyl end-capped vinyltrimethoxysilane oligomer suffered the sol-gel reaction under alkaline conditions in the presence of titanium oxide nanoparticles in tetrahydrofuran to afford the corresponding fluorinated oligomer/titanium oxide nanocomposites[RF-(VM-SiO2)n-RF/TiO2] in excellent to moderate isolated yields. These fluorinated composites thus obtained were nanometer size-controlled fine particles, and exhibited good dispersibility and stability in traditional organic solvents except for water. These fluorinated nanocomposites were applied to the surface modification of glass to exhibit not only a completely superhydrophobic characteristic (a water contact angle: 180degree) with a non-wetting property against water droplets but also a good oleophobicity imparted by fluoroalkyl seg...

International Nuclear Information System (INIS)

A thermodynamic analysis of the behaviour of Alloy 800 in helium based atmospheres relevant to the High Temperature Gas Cooled Reactor indicates that, depending upon the precise gas composition, oxidation and carburisation, or carburisation alone may be expected. The prime influence appears to be the moisture level. The morphology and structure of the reaction products are discussed. It is shown that the 'reactive' elements chromium, manganese, titanium and silicon are concentrated in the oxide scale which is normally duplex in structure. Aluminium oxide is formed at grain boundaries and in an internal oxidation zone together with titanium and sometimes silicon. In carburising conditions, mixed titanium-chromium carbides are formed. When this occurs, intergranular penetration is maximised. Weight gain data are assessed and briefly described and a tentative model for the mechanism of corrosion of Alloy 800 in HTR helium is ...

Energy Technology Data Exchange (ETDEWEB)

Titanium oxides were grown anodically to selected final potentials on grade II polycrystalline titanium under different anodization rates. XPS and RBS results show that the oxide consists of primarily TiO2 with a non-stoichiometric oxide/metal interface, with the slower growth rate associated with a thicker layer at the interface. Characterization using TEM reveals that the structure of the oxide evolves from a primarily amorphous phase to islands of crystallites in an amorphous matrix, to an entirely crystalline phase by increasing the polarization potential. Slower growth rates tend to remain crystalline at higher potentials. The mechanical strength of oxide films extracted from load-depth data by nanoindentation varies dramatically for oxide films grown by different rates at 9.4 V, and to a lesser extent at lower potentials. The variation of film strength is associated with both compositional and structural characteristics.

Energy Technology Data Exchange (ETDEWEB)

An inorganic particulate adsorbent of a titania-alumina is described for treating a superheated water containing radioactive materials such as cobalt ions, which is free from release of corrosive impruities, and which has a high adsorption capacity of radioactive materials and a high mechanical strength is prepared by hydrolyzing a titanium alkoxide and an aluminum alkoxide, thereby forming a hydrous titanium oxide and a hydrous aluminum oxide, respectively; precalcining the hydrous titanium oxide and aluminum oxide, mixing and molding the resulting titania and alumina into a particulate mixture thereof having a titania mole fraction of 0.2 to 0.9, and calcining the particulate mixture at 500/sup 0/-700/sup 0/C. This absorbent is effectively used in treat boiling water-type nuclear reactor core-circulating water to remove radioactive substances therefrom.

Energy Technology Data Exchange (ETDEWEB)

Titanium diboride was heated to high temperatures using microwaves. The highest temperature obtained was 2245/degree/C. Unfortunately, oxidation was a problem, especially at the higher temperatures, although an argon flush and a carbon getter were used. To completely stop oxidation, the oxygen potential must be below 10/sup /minus/18/ atmospheres. Using an argon flush and a carbon getter, titanium diboride was successfully densified to 82% of theoretical without measurable oxidation by heating with microwaves to 1860/degree/C. Density actually decreased upon reaching temperatures above 1860/degree/C due to void formation adjacent to the surface. Void formation is thought to be due to the formation of B/sub 2/O/sub 3/(g) which evolves rapidly above 1860/degree/C because of the loss of a TiO/sub 2/ protective film which melts at this temperature. 9 refs., 12 figs., 2 tabs.

British Library Electronic Table of Contents (United Kingdom)

Asymmetric Incremental Sheet Forming (AISF) is a relatively new manufacturing process. In AISF, a CNC driven forming tool imposes a localized plastic deformation as it moves along the contour of the desired part. Thus, the final shape is obtained by a sequence of localized plastic deformations. AISF is suitable for small series production of sheet metal parts as needed in aeronautical and medical applications. Two main process limits restrict the range of application of AISF in these fields. These are the low geometrical accuracy of parts made from titanium alloys or high strength steels and, for titanium alloys, the limited formability at room temperature. In this paper a new concept for laser-assisted AISF is introduced including the required components. Furthermore, the CAX tools used f...

International Nuclear Information System (INIS)

The effect of various hydrogen concentrations on the crystal lattice period and the hardness of titanium alloy was examined, the alloy containing about 16 at.% Mo (27.5 wt. % Mo) and having #beta# structure. The peculiar features of the mechanism of plastic deformation of the alloy were studied after adding hydrogen to it. A dependence of the crystal lattice period on the concentration of hydrogen was obtained for TixMoxH_2 alloy. It has been established that the hardness of the Ti-Mo alloy does not change when hydrogen is added to it. The presence of hydrogen introduces changes into the mechanism of deformation of #beta#-titanium alloy. The configuration of the inverse pole figures after rolling proves that the transverse slip process in an alloy with hydrogen is hampered, and that the coplanar slip process is developing in it.

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Titanium is the most biocompatible metal used for dental casting; however, there is concern about its marginal accuracy after porcelain application since this aspect has direct influence on marginal fit. Purpose The purpose of this study was to determine the effect that metal selection and the porcelain firing procedure have on the marginal accuracy of metal ceramic prostheses. Material and methods Cast CP Ti, milled CP Ti, cast Ti-6Al-7Nb, and cast Ni-Cr copings (n=5) were fired with compatible porcelains (Triceram for titanium-based metals and VITA VMK 95 for Ni-Cr alloy). The Ni-Cr alloy fired with its porcelain served as the control. Photographs of metal copings placed on a master die were made. Marginal discrepancy was determined on the photographs using an image ...

International Nuclear Information System (INIS)

A method is described for determination of aluminium, cadmium, cobalt, chromium, copper, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, zinc, titanium and vanadium in iron ore. After dissolution, a 1 gram sample of iron ore is applied to a column of AGI-X8 anion exchange resin (chloride form), in 100 ml of 7M HCl. Aluminium, chromium, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, titanium and vanadium are eluted with 7M HCl; iron, copper and cobalt are eluted with 0.5M HCl; cadmium and zinc are eluted with 2M HNO_3. Iron is subsequently removed from copper and cobalt by a solvent extraction with methyl isobutyl ketone. The elements are determined in the eluates by atomic absorption spectrometry, except for titanium and vanadium, which are determined spectrophotometrically.

International Nuclear Information System (INIS)

Stemming from their unique combination of elevated strength, low density, and good overall corrosion resistance, beta titanium alloys have become attractive candidate materials for critical, high-stress, components in corrosive services. An overview of the comparative corrosion resistance of beta alloys to conventional alpha and alpha/beta titanium alloys in common industrial and aerospace service environments generally reveals attractive behavior depending on the environment and alloy composition and, in some cases, alloy condition. Expanded performance windows are especially noted for the molybdenum-rich beta alloys, particularly in regard to resisting reducing acids, stress corrosion, and high temperature localized chloride attack, along with hydrogen and oxidation resistance. Where applicable, implications of this enhanced corrosion performance on current and perspective beta alloy applications are also noted.

Science.gov (United States)

The beta titanium alloy, however, can be d_,_wn. _,plusor minus 0.010-inch_after the parts have been cold. Its availability in strip lengths and its good ...

International Nuclear Information System (INIS)

The methods of surface modification of Ti-Zr alloy by laser treatment are considered. Characteristics of laser modification without- and with surface melting and with melting in different gaseous environments and with nickel microalloying are presented. Maximum depth, hardness and corrosion resistance are observed under nickel laser alloying.

UK PubMed Central (United Kingdom)

In the body, vascular cells continuously interact with tissues that possess nanostructured surface features due to the presence of proteins (such as collagen and elastin) embedded in the vascular wall....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The authors investigate the possibility of the direct heterogeneous catalytic synthesis of ethylbenzoate from benzonitrile. The catalysts tested were oxides of aluminium, titanium, and vanadium. The main conversion product detected chromatographically was ethylbenzoate; benzaldehyde, benzamide, and benzanilide were also identified. Aluminium oxide was found to be the most effective catalyst.

International Nuclear Information System (INIS)

(Dec 1970). United States Feeney, JA Boeing Co., Renton, Wash.

Energy Technology Data Exchange (ETDEWEB)

The desorption of uranium from the granular titanium-activated carbon composite adsorbent (concentration of uranium: 25.5 mg/l-Ad), which adsorbed uranium from natural sea water, was examined by the column process with acidic eluent at room temperature. The column operation was able to be carried out without destruction of the granular adsorbent by the generation of the carbon dioxide, and free from disturbance of the eluent flow by precipitate of calcium sulfate dihydrate with sulfuric acid eluent. The amount of acid consumption by the adsorbent was 0.87 eq/l-Ad. The alkaline earth metals were eluted in the range of elution volume below 2l/l-Ad, whereas uranium, iron, and titanium were eluted above 2l/l-Ad. Therefore, uranium was separable from the alkaline earth metals which were adsorbed in the most quantity in the adsorbent. In the range of elution volume 2 to 12l/l-Ad, the percentage of desorbed uranium and the concentration ratio of ...

Science.gov (United States)

Gerard, G. and Papirno, R. , "Ductility Ratio of Aged Beta Titanium Alloy,. I t. Transactions of the ASM, VO~. 55, NO. 3, pp. 373-388, Sept. 1962. ...

International Nuclear Information System (INIS)

The threshold stress intensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking (SCC) in aqueous sodium chloride solutions (marine atmosphere). However, in methanolic solutions, the alloy was very susceptible to SCC. This marked susceptibility in methanolic solutions can be mitigated by the addition of an inhibitor: sodium nitrate. Crack extension in the alloy was transgranular and failure occurred by brittle quasi-cleavage in methanolic solutions.

International Nuclear Information System (INIS)

SP-700, an emerging #beta#-rich #alpha#+#beta# titanium alloy, is designed to improve superplastic formability as well as mechanical properties over Ti-6Al-4V alloy. Owing to its fine microstructure and low #beta#-transus temperature, it is superplastic-formable at temperature below 1,073K (800 C) with low flow stress. Remarkable workability of this alloy is also retained in conventional Manufacturing processes. Another advantage of SP-700 is heat treatment response which includes deep hardenability and quick aging kinetics. Corrosion resistance and machinability are equivalent to or better than Ti-6Al-4V alloy.

International Nuclear Information System (INIS)

The prospect for the recovery of rare earths from red mud, the bauxite tailings from the production of alumina is examined. The Jamaican red mud by far has the higher trace concentrations of lanthanum, cerium, neodymium, and yttrium. Scandium is also present. The dissolution of the rare earth is a major extraction problem because of the large volume of other materials. The recovery processes that have been proposed include the production of co-products such as iron, alumina, and titanium concentrates, with the rare earths going with the titanium. In this paper a critical examination of the possible processes are presented with the recommended research projects to be carried out.

Energy Technology Data Exchange (ETDEWEB)

A study was made of the variation in strength characteristics of group IV transition metal carbon nitrides alloyed with carbides or group V metal nitrides. A complex solid solution of titanium-niobium carbonitride was preliminarily synthesized to a homogeneous equilibrium state and then crushed. The calculated quantity of binder metal was added as elemental powders, the mixture was vibration ball milled in ethanol and the plasticized charge was used to press experimental specimens for mechanical testing. The studies showed that the high-temperature strength properties of the new cermet are superior to standard type KNT. The material is thus promising for use in the manufacture of tools. 8 references, 3 figures.

International Nuclear Information System (INIS)

The influence of deformation on the corrosion behavior of a newly developed multifunctional beta titanium alloy Ti-23Nb-0.7Ta-2Zr-O (mol%) in Ringer's solution at 310 K was evaluated using an electron backscatter diffraction technique and electrochemical measurements. The results showed that the effect of deformation on the corrosion resistance of the beta titanium alloy is complicated. Small levels of plastic deformation are detrimental to the corrosion resistance, whereas large deformations tend to eliminate this detrimental effect.

International Nuclear Information System (INIS)

This work presents results of investigations on d.c. glow discharge nitriding of #alpha#+#beta# Ti-6Al-4V titanium alloy. The treatment was performed at 843 K in nitrogen-hydrogen atmosphere, pressure 300 Pa. Special attention was paid to nitriding mechanism and determination of the role of ion bombarding in nitriding process of titanium alloys. Produced as a result of d.c. plasma nitriding surface layers were subjected to macroscopic observations, microstructure studies, microhardness testing and X-ray analysis. (author)

International Nuclear Information System (INIS)

The temperature dependences of the heat capacity of commercial titanium VT1-0 and alloys on its base, VT5 and VT5-1, have been derived in the temperature range of 4 to 290 K. For comparison, similar measurements have been conducted on pure titanium and specially prepared solid solutions on its base (Ti+3.7 at.% Al and Ti+0.82 at.% Sn). The measurement accuracy has been sufficient for comparing the results with calculation data. The obtained results are interpreted using the known concepts of the role of the mass of interstitial atoms and changes in the interatomic bond forces. It is shown that the phonon components of the molar heat capacities of solid solutions of Al in titanium have lower values in the entire temperature range, as compared to titanium. The corresponding differences are proportional to the Al concentrations. The lower molar heat capacity in the case of dissolution of Al is due to the ...

British Library Electronic Table of Contents (United Kingdom)

Similar to many other countries, an educational reform anchored in a managerial discourse was proposed in Israel in 2004 by the Dovrat Committee, encouraged by the 'inter-state education gap' social problem that economist Dan Ben-David formulated on the basis of international examinations, such as PISA and TIMMS. Through a neo-Weberian approach this study follows the construction of a managerial discourse from the 1970s onwards that led to the Dovrat report. In the first period, managerial discourse was constructed around decentralization, parent choice and school autonomy 'social objects' by an expanding reformist network of educational scholars and figures from the Ministry of Education and local authorities. The pervasion of managerial discourse paved the way for the nomination of Shlom...

Energy Technology Data Exchange (ETDEWEB)

This poster presentation gave an overview of the subaqueous deposition of reactive mine tailings in the open trench Don Rouyn, located near Rouyn-Noranda, Quebec. The author began by providing a brief background of subaqueous mine tailing storage, and discussed the interest of the Don Rouyn trench. The site was described according to geomorphological and geological aspects. The hydrology conditions existing at the site were mentioned, and the results of the hydrology analysis performed were indicated. Close monitoring of the situation was maintained, and the chemical and physical stability of the tailings were evaluated. The conditions that prevailed both before and after the flooding of the site were explained. Water quality is being monitored, and the results obtained at this site might be used at other locations. 40 figs.

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The elastic behaviour of YBaCuO specimens has been studied by very low-frequency isothermal internal-friction measurements. A relaxation peak is observed which is attributed to oxygen atom jumps, between A(1/2 0 0) and B(0 1/2 0) sites, in the CuO planes of the orthorhombic phase. A limit relaxation time {tau}{sub 0}, 2.6 {center dot} 10{sup -15}s, and an activation energy, 1.3eV, have been obtained from the shift of the maximum damping frequency observed when the measurement temperature is changed. The proposed values for the limit relaxation time and the activation energy are in good agreement with those previously proposed in the literature.

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Radon ({sup 222}Rn) is a naturally occurring radioactive gas and can be used as a tracer in hydrogeologic studies. Radon concentration measurements have been achieved in ground-air and in groundwater by means of nuclear track detectors to estimate long-term variations. Continuous measurements have been conducted using an electronic automatic probe, to evaluate short-term variations. The results obtained from bore-holes show a good correlation between the aquifer`s structural characteristics and the radon concentrations. The continuous measurements specify rainfall influence. (author). 10 refs., 7 figs., 2 tabs.

British Library Electronic Table of Contents (United Kingdom)

More and more reforms in public administrations are being conducted that are based on the principles and instruments of ''new public management''. They have set off protest and collective actions by several professional groups in various sectors (health, education, justice, social work, research...), whence questions about the future of professional groups in public services, in particular about their autonomy, which these reforms threaten. The opposition between this new public management and certain professional groups, is not the final explanation to draw from an analysis of this situation. Should these changes be seen as the decline of professional groups and of their autonomy, as a mutation of professional models, an overhaul of professionalism, etc.? These questions, which current ev...

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The last developments in lithium batteries design have demonstrated the advantages of graphite: competitive cost, flat output curve, high capacity thanks to the obtention of a final compound close to LiC{sub 6}, good behaviour during cycling and a high mass energy. However, these advantages are slightly tarnished by parasite secondary reactions during the evolution of the element. Two different cases are encountered: the formation of a passivation layer (loss of Li ions and formation of irreversible bounds) and the formation of a passivation layer with a reaction between graphite and the solvent (partial destruction of the graphite crystal lattice). In the first case, the theoretical graphite insertion capacity remains at 372 mAh/g while in the second case the insertion capacity is greatly reduced. Abstract only. (J.S.)

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Industrial premises bear more and more important thermal constraints which can commonly reach 150 W/m{sup 2} and more. The reason is the general development of automation and automatic devices and the better thermal insulation of buildings. Production quality requires also more and more strict ambient conditions (temperature, humidity, air quality, air flow etc..). Thus, the air-conditioning market in the industrial sector is more linked to economic factors such as productivity and profit than to thermal comfort of workers. However, the air-conditioning potentialities in the industrial sector remains under-exploited in France. This paper analyzes the reasons of this situation in terms of investments and equipments. (J.S.)

Energy Technology Data Exchange (ETDEWEB)

This two-tomes book brings together the 108 presentations given at the first conference of the international institute of refrigeration (IIF/IIR) about air conditioning in high rise office buildings. The main themes are: general design and control systems, including split systems, radiant panels, fluctuating and gravity ventilation etc..; energy consumption, optimization and heat recovery; cold storage for peak shaving, including ice slurry circulation; indoor air quality; fire and smokes protection, protection against chimney effects and lighting spots; use of fuzzy logic and of neural networks. It includes also a description of the high rise building situation and works in progress in China, Japan and in some other countries. (J.S.)

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Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti{sub 2}N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 {mu}m{sup 2}/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near ...

International Nuclear Information System (INIS)

A rapid and sensitive method for the separation and determination of titanium and iron in thiocyanate system has been developed. The extractability of Ti(II) by high molecular weight (HMWA) in organic solvent (HCl/sub 3/) and its separation from Fe(III) was examined. The yellow coloured complex of Ti(II)-SCN in quantitatively extracted into the organic phase containing tribenzyl tribenzylamine (TBA) - a high molecular weight amine, whereas the blood red coloured complex of Fe(III)-SCN formed under the same conditions get separated in the aqueous phase. On the basis of the selective extractability, a method has been developed for the separation as well as simultaneous determination of Ti(II) and Fe(III) in presence of many other elements. The molar extinction coefficients were found to be 1.9 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ and 1.11 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ respectively for Ti(II) and Fe(III). The extractability of the complex of fully applied to ...

International Nuclear Information System (INIS)

Samples of 316L stainless steel, Vitalium and Ti6A14V titanium alloy have been implanted with doses of 1.5, 3, and 4.5 x 10"1"7 Si"+/cm"2. Transmission electron microscopy shows that during ion implantation amorphous layers are formed. When samples of titanium alloy were implanted with a dose of 0.5 x 10"1"7 Si"+/cm"2, the implanted layer consisted of a dispersion of fine silicide crystallites instead of being amorphous. The corrosion resistance was analyzed by electrochemical techniques in 0.9% NaCl at the temperature of 37 C. The increase of corrosion resistance has been observed as a result of structural modifications of the surface layer. (author). 7 refs, 4 tabs.

International Nuclear Information System (INIS)

A new high strength titanium alloy has been developed primarily intended for fastener applications. While Ti-6Al-4V is used extensively as a fastener alloy in the aerospace industry, its shear strength allowable is limited to 655 MPa (95 ksi). For higher shear strength requirements, various steels or nickel-based alloys are used (up to 860 MPa (125 ksi)), but with the attendant density penalty. This new alloy is intended to provide the 860 MPa shear strength at roughly a 40% weight savings. After screening various alloy systems, the optimum chemistry has been selected as follows: Ti-6.0V-6.2Mo-5.7Fe-3Al. In light of its 125 ksi shear strength goal, the alloy has been designated TIMETAL reg-sign 125.

International Nuclear Information System (INIS)

The fatigue life variability of the #alpha#+#beta# titanium alloy, Ti-6Al-2Sn-4Zr-6Mo increased with decreasing stress level. The variability in life was found to be due to segregation of lives due to two failure mechanisms. A bimodal cumulative distribution model was shown to accurately describe the combined failure modes. The nominal failure processes for the two regimes were similar, with crack nucleation occurring in equiaxed #alpha#p particles, irrespective of life or stress level. However the variability in life was not controlled by the size of the crack-nucleating #alpha#p, but rather by the ability of the material to distribute deformation and avoid early crack nucleation.

Energy Technology Data Exchange (ETDEWEB)

Gas and plasma nitriding processes were executed in the magnesium with modification by titanium in search for an effective surface treatment method for magnesium alloys. Magnesium-nitrogen system has completely no solid solution or solubility, so that nitride should be only formed by eutectic reaction in the liquid phase. Hence, magnesium is difficult or nearly impossible to have its surface modified by nitriding. Addition of nitride forming element into magnesium enables us to lower the onset temperature of nitriding. Magnesium-titanium alloys with 1 to 5 wt% are yielded by the bulk mechanical alloying and, subjected to gas nitriding for various process conditions. Successful co-formation of Mg{sub 3}N{sub 2} as well as TiN becomes a proof to demonstrate the possibility of gas/plasma nitriding in the solid-state magnesium with aid of nitride former. (orig.)

International Nuclear Information System (INIS)

Strain embrittlement in Ti base alloys during tensile testing was investigated. Results show that in an #alpha#-#beta# titanium alloy the local activity of H in alpha phase (#alpha#/sub H//sup #alpha#) increases and activity of H in beta phase (#alpha#/sub H//sup #beta#) decreases as the equiaxed #alpha# particle size decreases at constant volume fraction of phases. Thus with decreasing particle size there would be a tendency for H to move from #alpha# to #beta#, decreasing the H content of #alpha#. Also whether H tended to move from #beta# to #alpha# or from #alpha# interiors to the #alpha#-#beta# interface this tendency would be reduced by surface tension effects, making the alloy less susceptible to embrittlement.

Energy Technology Data Exchange (ETDEWEB)

Photodestruction has received much attention in recent years. In particular, titanium dioxide (TiO{sub 2}) and ozonolysis have attained a position of prominence. These technologies hold promise for the destruction of trace amounts of aqueous high explosives that are generated by load and pack operations, as well as demilitarization activities. Currently this water is treated by passing through a bed of activated carbon. The carbon is then steam regenerated and reused, thus creating a second waste stream which must be disposed of, or the carbon is burned directly. Recent trends in environmental regulation have shown that this may not be a viable option for process water remediation in the future. This talk will discuss efforts to employ alternate aqueous treatment techniques that not only remove the explosives compounds but are able to transform the parent compound into carbon dioxide and water. Titanium dioxide photocatalysis as well as ...

Science.gov (United States)

Experimental tests were performed in a continuous-flow hydrotreating unit at Pittsburgh Energy Technology Center to evaluate the performance of hydrous titanium-oxide supported (HTO) catalysts as hydrotreating catalysts for use in two-stage coal liquiefaction. Catalysts containing either a combination of CO, Ni, and Mo as the active metal components or Pd as the active metal componet were tested with representative hydrotreater feed stocks from the Wilsonville Advanced Coal Liquefaction Research and Development Facility. Catalyst performance evaluation was based on desulfurization and denitrogenation activity, the conversion of cyclohexane-insolbule material, and hydrogenation activity during 100-hour reactor runs. Results indicated that the HTO catalysts were comparable to a commercial Ni/Mo-alumina supported catalyst in the areas evaluated. 11 refs., 1 fig., 6 tabs.

British Library Electronic Table of Contents (United Kingdom)

Regularities of deformation-induced dissolution of a surface layer of iron oxides in matrixes of iron-based alloys with bcc and fcc lattices have been studied by the methods of M?ssbauer spectroscopy, transmission electron microscopy, and X-ray diffraction. A method of producing iron alloys strengthened by dispersed oxide nanoparticles and alloyed with elements possessing a high affinity to oxygen (titanium and yttrium) has been proposed, which implies a dynamic dissolution of a surface layer of iron oxides upon strong cold deformation and a precipitation of secondary yttrium and titanium nanooxides upon a subsequent high-temperature sintering of mechanically alloyed powders. There has been demonstrated a possibility of oxide strengthening of pure iron upon its interaction with air without...

International Nuclear Information System (INIS)

To study #beta# #reversible# #omega#-transformation in pseudo-#beta#-titanium alloy VT30, doped by hydrogen, methods of X-ray diffraction and thermodifferential analyses are used. It is established that in the process of heating of the hardened alloy from 0.004-0.1% H first formation and then dissolution of #omega# phase take place. An increase in hydrogen content to 0.1% decreases thermal effect of the processes and does not affect the temperature of #beta# #reversible# #omega#-transformation. Introduction of hydrogen in the concentration of 0.2% and higher suppresses completely #beta# #reversible# #omega# - transformation. A decrease in heating rate displaces #beta# #reversible# #omega#-transformation to lower temperatures.

International Nuclear Information System (INIS)

A study is made into textures of deformation and primary recrystallization forming in a #beta#-titanium alloy doped with hydrogen in amounts from 0.04 to 0.55 mass. %, on cold rolling with a 70%-reduction and dehydrogenating annealing at 860 deg C. It is shown that a volume fraction of recrystallization texture components is determined by the nature of corresponding deformation texture, in its turn, depending on hydrogen concentration in the alloy. At low hydrogen contents the main texture components are #left brace#111#right brace# and #left brace#001#right brace#. A hydrogen content increase up to 0.09 - 0.18 mass. % results in formation of dominant components of #left brace#111#right brace# and #left brace#112#right brace#

International Nuclear Information System (INIS)

Results of investigation on the effect of microstructure and deformation conditions (temperature and strain rate) on flow stress and critical strain in two phase #alpha# + #beta# titanium alloy Ti-6Al-5Mo-5V-1Cr-1Fe is presented in the paper. The alloy is deformed or torsional plastometer at temperature range 1073-1173 K and at the strain rate #epsilon# = 0.04-4.0 s"-"1. Sequential deformation at 1173 K at the strain rate of 0.4 s"-"1 was also performed with holding times in the range 1-100 s. The fraction of dynamically and metadynamically recrystallized #beta# phase was determined on the basis of results of sequential deformation test. Microstructure was examined using LM and TEM techniques. (author)

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT Purpose: The aim of this two-center study was to evaluate screw-type titanium implants with a chemically modified, sandblasted and acid-etched surface when placed in the posterior maxilla or mandible, and loaded 21 days after placement. Material and Methods: All 56 patients met strict inclusion criteria and provided informed consent. Each patient displayed either a single-tooth gap, an extended edentulous space, or a distal extension situation in the posterior mandible or maxilla. Eighty-nine dental implants (SLActive, Institut Straumann AG, Basel, Switzerland) were inserted according to an established nonsubmerged protocol and underwent undisturbed healing for a period of 21 days. Where appropriate, the implants were loaded after 21 days of healing with provisional restorations i...

Science.gov (United States)

During this reporting period two direct coal liquefaction experiments have been completed and a third is underway. These experiments have produced conversion and selectivity data on samples of Alabama bituminous coal slurried in tetralin and catalyzed using iron-titanium hydride. The experiments address the liquefaction of an agglomerating coal. Conversions of 45 to 55% DAF in 30 min have been recorded at 500/sup 0/F and 520 psia. Equipment modifications were made in an attempt to eliminate the problem of alloy binding in the hydride formation vessel. 4 figs., 4 tabs.

International Nuclear Information System (INIS)

The gliding modes of a duplex Ti-6Al-4V titanium alloy were investigated through in situ (scanning electron microscopy) tensile tests. A method based on electron back-scattering diffraction (EBSD) measurements was used to identify activated slip systems. The approach applied to a large number of grains allowed a statistical analysis of the nature (basal, prismatic, pyramidal) and distribution of the slip systems according to the crystallographic texture. A discussion concerning the pertinence of Schmid's law to explain the occurrence and succession of slip events is then proposed. The domain in favor of each type of slip system is finally presented by using inverse pole figures mapped with Schmid's factor iso-curves.

International Nuclear Information System (INIS)

The project is intended to yield information on the transfer factors describing the transfer of ingested radionuclides to breast milk for the following elements: antimony, cerium, chromium, cobalt, gallium, lanthanum, molybdenum, niobium, radium, ruthenium, silver, thorium, titanium, and uranium. Those yet unknown or poorly known transfer factors are required in order to be able to develop a reliable model for description and assessment of the transfer of the radionuclides and the possibly resulting hazardous doses to infants, and for subsequent formulation of recommendations for radiological protection of the population. (orig./CB)

Science.gov (United States)

The effect of solution treatment temperature and oxygen content on the microstructure and age hardening response of the metastable beta alloy Ti-11.5Mo-6Zr-4.5Sn have been studied. Kinetics of formation of the equilibrium alpha-phase and the metastable om...

International Nuclear Information System (INIS)

Zircaloy fabrication plant manufactures all the necessary Zr-2 components like fuel canning tubes, calandria tubes and other rod and sheet products. This plant is having a capacity of producing about 4 lakh nos. of PHWR fuel tubes per annum. These tubes are seamless, thin walled with close dimensional tolerances and stringent mechanical properties. The plant has established all the facilities required to produce these tubes with required quality.

Science.gov (United States)

In a redox battery using a titanium redox system or chromium redox system as an active material for the negative electrode or a manganese redox system as an active material for the positive electrode, the electromotive force of the battery and the stability of electrolyte solutions are enhanced by addition of a chelating agent such as citric acid or a complexing agent such as phosphoric acid to the redox system used therein.

International Nuclear Information System (INIS)

Brief summaries are given of research carried out in the following areas: absorption spectroscopy of titanium, niobium, and molybdenum in uranium alloys; atomic absorption spectroscopy of selenium in stainless steel, computer program improvements for spectrophotometer control, and detection of beryllium in stack gases; electrolysis for inactivation of bacteria in cooling-tower water; improved solvent analysis by gas chromatography; sequential radionuclide separation for various sample matrices; progress on an electron microprobe analyzer; and miscellaneous projects.

Energy Technology Data Exchange (ETDEWEB)

Achievements in the field of sorption recovery of uranium from sea water are considered in brief. Polyacryl amidoxime chelate iorites are shown to exceed in sorption properties both titanium dioxide base natural adsorbents and styrene base synthetic resins. Merits of sorbents containing fixed layer of humic acid are pointed out, different methods of their application are considered. The cost of uranium recovery from sea water using different sorbents is estimated.

International Nuclear Information System (INIS)

The mechanical properties of TS 6 (Ti--10 percent Cr--7 percent V--3.5 percent Mo--3 percent Al) alloy were studied. Results are presented in plots showing yield stress vs cold work, notched tensile strength vs unnotched tensile strength, and ultimate tensile strength vs test temperature.

Science.gov (United States)

In this Communication, we report the fabrication of well-crystallized rutile-phase TiO2 hollow spheres using potassium titanium oxalate as the precursor. The spheres exhibited unique three-dimensional hierarchical architectures and demonstrated a significantly improved photocatalytic performance. The synthetic strategy used in this process represents a general approach and therefore may contribute to the formation mechanisms of hollow nanostructures. PMID:16634578

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The review provides a general idea about the types of metallic alloys and the pure metals used as implant materials in dental and orthopedic surgery. Their corrosive behavior in both real solutions and various media that model human biological fluids is described. Based on the literature data, it is concluded that multicomponent alloys containing titanium, niobium, zirconium, tungsten, molybdenum, aluminum, and silicon are the most resistant to corrosion. Implants made of different types of stainless steel are preferred when manufacturing orthopedic devices for short-term use.

International Nuclear Information System (INIS)

It is shown that bending tests on microsamples can be used to study the conditions in which hydrogen brittleness develops. In such tests hydrogen brittleness develops in the VTI5 alloy within the temperature range +5 to -20"0C. The tendency of VTI5 to develop hydrogen brittleness is enhanced with bending in salt water. (author).

International Nuclear Information System (INIS)

A historical overview of corrosion problems found in power plant condensers and mitigation procedures is presented. The paper is organized according to alloy type and failure mode. Alloys considered are copper-base alloys, stainless steels and titanium. Failure modes discussed include erosion-corrosion, sulfide attack, environmentally assisted cracking, galvanic corrosion, steam condensate corrosion, pitting corrosion, and dealloying. Mitigation procedures discussed include cathodic protection, ferrous ion injection, as well as tube cleaning and layup practices.

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The goal of the invention is to increase the effectiveness of the isolation process through increasing the waterproofing of the stratum. The cited goal is achieved by isolating water influx into a well through introduction of a chemical reagent into the stratum. To interact with the stratum, an alloy of titanium and iron is introduced into the stratum as the chemical reagent with subsequent pumping of hydrogen into the stratum at 100 to 200C.

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Acid mine drainage represents one of the most important environmental problem facing the mining industry. If the tailings contain sulphur, acid mine drainage will be generated as soon as the tailings are exposed to oxygen. In this paper, the authors discussed a technique for the storage of acid mine drainage generating tailings that delays and even eliminates the occurrence. It was suggested that tailings should be piled by incorporating, at regular intervals, compacted waste rock. Thermal convection and diffusion will prevent oxygen from reaching the tailings, and limit water circulation. The modelling of transfer processes (heat, water, oxygen) in a well known tailings dump, the Doyon Mine, was performed, and the results compared to the modelling where compacted waste rock had been incorporated at regular intervals. The results indicated that by remaining saturated, the layers acted as capillary barriers preventing oxygen from reaching the tailings, therefore reducing significantly ...

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Dual-fuel engines are modified diesel engines burning simultaneously two fuels inside the cylinder: a gaseous one, called the primary fuel and a liquid one, called the pilot fuel. The thermal efficiency of the dual-fuel engine and of the diesel engine are comparable; the level of emissions is lower compared to the diesel one. This article presents a new procedure for the combustion modeling in a LPG-diesel dual-fuel engine. The procedures deals with the ignition delay period and with the rate of heat release inside the cylinder. This procedure is validated using experimental data issued front a collaboration with the Indian Institute of Technology from Madras, India. The used engine is a single-cylinder one, air-cooled. The pilot fuel is direct injected inside the cylinder The engine was run at constant load and with different diesel substitutions, i.e. for different air to fuel ratios of the primary fuel-air mixture. The general error of the procedure is below 10%. (authors)

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The aim of this thesis is to study the coherent transport in semiconducting-superconducting junctions. The SnPb-GaAs system has been studied. It has been shown that the behaviour of this junction is controlled by the disordered area induced by the annealing of the connection near the interface. For a few resistant junction, a conductance anomaly under the gap has been observed and has been explained by a mesoscopic effect in the limit of the very high disorders. The conductance of more resistant junctions has only been bound to the properties of the very disordered area of the semiconductor. The part of the electron-electron interactions on the phase coherence length and on the conductance has been studied. The evolving of the correction of the conductance due to interactions in magnetic field has been followed. The effect of the spin degeneration suppression in CdTe and the GaAs sign inversion in Shubnikov de Haas oscillations rate has been observed. At last has been studied the ...

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The control of nitrogen oxides (NO{sub x}) emissions will become a major challenge in the forthcoming years, in the domain of automotive industry or industrial burners. Pulsed combustion offers an imaginative solution which does not affect the combustion efficiency. In this paper, the efficiency of this method is demonstrated using the burner of a 20 kW domestic boiler. The actuator is simply installed on the air intake. Two types of actuators have been tested successfully: a loudspeaker and a rotative valve. Both can produce 100 to 1000 Hz frequencies and can lead to a reduction of 20% of NO{sub x} emissions. The feasibility of the concept is also demonstrated on a 840 kW liquid fuel-oil burner. The mechanisms involved during an excitation are explained using the CH{sup *} radical imaging. Results show an important reorganization of the flow and of the flame structure. During each excitation cycle, an annular swirl occurs at the leading edge of the flame catching and develops during ...

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Passive films, formed on annealed and cold worked AISI 304 stainless steel in hot chloride media, were examined using polarization resistance and impedance measurements. The obtained results show the influence of cold work on film conductivity, which can be correlated to conditions of susceptibility to stress corrosion cracking. Capacitance measurements, using the Mott-Schottky approach, revealed that a change from n to p type semi-conductivity is associated to susceptible conditions with an increase in the doping density estimated for cold worked samples in the presence of chloride. It is assumed that p-type semi-conductivity of the passive film together with the position of the flat band potential has a strong influence on the dissolution processes at the corrosion potential. Based on this analysis the influence of plastic deformation, at the dislocation scale, is discussed. (authors)

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The suitability of the turbulent combustion flamelets model in order to predict the index of NO{sub x} production in turbulent flames of hydrogen diffusion is analyzed. In the flamelet approach, the turbulent flame is equivalent to a group of laminar flames submitted to a mechanical stretching which generates a chemical disequilibrium. This effect can be described by the stretching or by the scalar dissipation ratio. A numerical modeling is performed in order to evaluate the advantages of both approaches and to compare the behaviour of the NO{sub x} emission index with the experiments of Chen and Driscoll. This study shows that predictions of NO{sub x} emission indexes have a correct behaviour with respect to the Damkoehler number only when the scalar dissipation ratio is used as a parameter to describe the chemical state outside equilibrium. Predictions of the flamelet models are improving when the Damkoehler number increases. On the other hand, the absolute NO{sub x} concentrations ...

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The deposition of platinum on various carbon blacks was carried out by forming active functional groups on the surface of the carbon support, and exchanging these active groups with different platinum complexes. Using H{sub 2}PtCl{sub 6} solution, an impregnation rather than an exchange takes place. However, using divalent platinum complexes [Pt(NH{sub 3}){sub 4}]{sup 2+}, a fast exchange takes place which leads to extremely small platinum particles highly dispersed on the surface of carbon black. A comparison of the catalytic activities of platinum supported on various carbon blacks was also carried out. The performances of PEFC (Polymer Electrolyte Fuel Cell) based on the process of the ion exchange are reported. (authors) 3 refs.

British Library Electronic Table of Contents (United Kingdom)

ResumeObjectif determiner dans une etude randomisee l'impact d'un enregistrement continu du glucose sous-cutane pendant 48 heures sur le controle glycemique trois mois plus tard chez des patients presentant un diabete de type 1 (DT1) ou de type 2 (DT2). Methodes Quarante-huit patients avec un mauvais equilibre glycemique (HbA1c : 8-10,5 %) ont beneficie d'un enregistrement continu du glucose sous-cutane pendant 48 heures avec le systeme GlucoDay (A. Menarini Diagnostics) et ont ete randomises en deux groupes : ajustement de traitement en fonction de l'autosurveillance glycemique capillaire (groupe ASG) ou du profil d'enregistrement continu du glucose sous-cutane (groupe CGM). Le dosage d'HbA1c et le port du GlucoDay ont ete renouveles trois mois plus tard. Resultats Trente-quatre patients ...

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ABO{sub 3} perovskite-type oxides having vacancies in the A-sites of their structure are interesting candidates for solid electrolytes when their A-sites are occupied by Li{sup +} ions having a high mobility. This is the case with the [Li{sub 3x}La{sub 2/3-x}]TiO{sub 3} solid solution compound which has a 10{sup -3} S cm{sup -1} ionic conductivity at ambient temperature. Electrochemical intercalation in this material is possible thanks to the presence of Ti{sup 4+} but the small amount of vacancies (0.33 maximum) leads to a low intercalation rate. In order to solve this problem, the LiLaNb{sub 2}O{sub 7} material which has a greater amount of vacancies has been studied and the results relative to the electrochemical intercalation of lithium in this perovskite are presented. The thermodynamical and kinetics properties of the lithium intercalation reaction have been studied by intermittent galvano-static discharges and impedance spectroscopy in LiClO{sub 4}-propylene carbonate medium. ...

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This study examines some radiation accidents occurred in the past. This information has been systematically assessed to get global lessons. The experience feedback shows that the most of accidents happened in certain conditions. These conditions can be distributed in four categories: 1- perception and vigilance in occupation: accidental exposure happened by lack of vigilance in details and lack of vigilance and perception; 2- procedures: accidental exposure happened following a lack of procedures or control that were not enough complete, not enough documented or not completely implemented; 3- training and understanding: accidental exposures happened because the personnel was not enough qualified and educated, did not get the general training nor the the necessary specialized training; 4- liabilities: accidental exposures happened following lacks and ambiguity in the definition of functions of the personnel and in the hierarchy liabilities. In these precise cases the safety tasks have ...

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Individual monitoring of personal exposure to inhalation of uranium oxides throughout the manufacture of fuel for pressurized water reactor (PWR) includes lung gamma-spectrometry, fecal analysis and urine analysis. Examination of the results shows the following: internal exposure is the consequence of repeated intake incidents as revealed by early peaks of urinary and particularly fecal elimination; a shift is often observed with the results of aerosol concentration measured through air collectors; the measured variations of uranium lung incorporations are relatively fast (apparent mean period 165 d). Correct evaluation of the effective dose equivalent from inhalation requires further information concerning the aerosol size distribution at work stations, the physico-chemical characteristics of the product leading to an estimate of its actual biological solubility, and the measurement of the fraction of aerosol liable to intake with an individual portable collector.

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Cooperation for low carbon and energy efficient development is a high priority for France, in line with the United Nations Framework Convention on Climate Change. France contributes to tackling climate change by working with its partners on all continents to implement projects both to mitigate greenhouse gas emissions and to adapt to climate change. Within the framework of the Marrakech Accords, France also encourages the implementation of the Kyoto Protocol Clean Development Mechanism, in particular between French business and non-Annex I countries; this mechanism will facilitate the financing of mitigation projects and contribute to the sustainable development of host countries in the South. At multilateral level, France is a major donor. At a bilateral level, an initial analysis of cooperation projects which are strongly linked to tackling climate change identified public support of 136 millions euros per year, as an average over the past few years. Some project examples, mostly ...

Energy Technology Data Exchange (ETDEWEB)

ACRO, a NGO equipped with a laboratory to measure radioactivity, runs the Citizen Watchdog of Radioactivity in the Environment. Involving many volunteers, it monitors regularly the French coast of the Channel and many rivers of the North half of France. It also makes investigations in other places. Such an action is aimed to supplement the official monitoring, not to replace it, in order to answer to the worries of the population. This monitoring shows that some radioelements, such as iodine 129, cobalt 60, tritium, etc. released in the environment by nuclear facilities can be detected on very large areas. Carbon 14 was detected up to almost 4 times the background in vegetables around the reprocessing plant of La Hague. ACRO also sits in many official committees to transmit the point of view of the populations exposed to the radioactive pollution. It is lobbying for a decrease of the release authorization, especially for the elements that are discharged in large quantity in the ...

Energy Technology Data Exchange (ETDEWEB)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostics system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

Energy Technology Data Exchange (ETDEWEB)

This article, published in issue 80 of 'l'ACROnique du nucleaire', aims to retrace the early steps in the consideration of the possibility of a nuclear accident in France, with the inclusion of 'non-institutional' participants and applying the lessons learned in Belarus in the contaminated territories around the Chernobyl nuclear power plant. After a review of the origin of the involvement of the Association pour le Controle de la Radioactivite dans l'Ouest (ACRO) in addressing post-accident issues alongside the populations living in an environment polluted by radioactivity, it discusses, from the critical viewpoint of an NGO, the context and the working method adopted for this examination. This is followed by some key elements of the programme and unresolved questions about the available body of knowledge which motivates research and about the method adopted for the work. The conclusion, moderately optimistic, ...

Energy Technology Data Exchange (ETDEWEB)

In the first part of the nineties many office buildings were equipped with indoor climate installations which do not meet present standards. Several options are available to improve such installations for ventilation capacity, cooling capacity, thermal comfort and air quality. One of the options concern the installation of an air conditioner in combination with heat recovery. In this article attention is paid to the renovation of the air conditioning system in the Printer house, an office building in Zwolle, Netherlands. [Dutch] Begin jaren negentig zijn veel kantoorpanden gebouwd waarvan de klimaatinstallatie tegenwoordig niet meer voldoet. De ventilatiecapaciteit is ontoereikend en koeling is mondjesmaat aanwezig, of slechts als topkoeling. Het comfort en de luchtkwaliteit zijn dan ook onder de maat. Er zijn verschillende mogelijkheden om dit te verbeteren. Plaatsing van een nieuwe luchtbehandelingskast met warmteterugwinning is daar een van. In dit artikel wordt ...

International Nuclear Information System (INIS)

Beta-21S is a new, metastable-beta titanium alloy which exhibits excellent oxidation resistance and mechanical properties at elevated temperatures. From a weld solidification standpoint, this alloy chemistry is of particular interest because its major beta-stabilizing elements (Mo and Nb) both exhibit equilibrium partitioning ratios (k_o) greater than unity, indicating their simultaneous partitioning during weld solidification to the initial solid to form (i.e., dendrite cores), and correspondingly their depletion in the final regions of solidification (i.e., dendrite interstices). Such elemental partitioning, if retained down to room temperature, may be expected to promote local variations in the postweld aging response. The objectives of the present investigation were to characterize Gas Tungsten-Arc weld solidification and HAZ liquation phenomena in Beta-21S and to examine the influence of residual microsegregation in the weld zone on alpha precipitation during ...

Science.gov (United States)

The spectral dependences of absorption photoinduced in a pure bismuth titanium oxide crystal by 532-nm laser pulses are studied. It is shown that optical absorption in the crystal in the range from 492 to 840 nm increases with increasing exposure. The photoinduced absorption relaxes in the dark for more than 60 hours. A model of photoinduced absorption is proposed which assumes the population of two trap centres with the normal energy distribution law for the concentrations of electrons photoexcited from donors to the conduction band. This model well describes the spectral dependences of photoinduced absorption by using the average ionisation energies of the traps E{sub 1} = 1.60 eV and E{sub 2} = 2.57 eV. The model is used to estimate the increase in the photorefractive sensitivity of a bismuth titanium oxide crystal in the near IR region, which was earlier observed after exposing the crystal to visible radiation. It is predicted that the ...

International Nuclear Information System (INIS)

Based on information contained in literature, patents and catalogs a review is presented of powder-rolling metallurgy abroad. Statistics are given on the output of powder metallurgy in several countries. In the USA both the dense type of rolled metal for manufacturing various machine parts and the porous variety for making filters are produced. Four main types of technological processes are analysed: the usual flow chart for cold rolling, rolling of preheated powder, rolling in free-flowing state, and rolling with heated rollers. Of these four processes the first is most widely used. Fowders consisting of spherical particles (heat-stable alloys from nickel or high titanium alloys), which are difficult to work with, have not yet found wide practical application in powder metallurgy abroad. Literature data show that granulated heat-resistant alloys can be cold-treated under pressure only after they are powdered. The best methods for pulverizing are: cold-stream ...

International Nuclear Information System (INIS)

Mechanical properties of cold-worked molybdenum, grade 4 titanium, and an #alpha#-#beta# titanium alloy are measured with tensile tests and by indentations using conical indenters with 105, 120, and 137 deg included angles. The extent of plastic deformation and pileup around an indentation is measured using profilometry. Various models predicting the extent of plastic deformation and pileup are compared to the actual measured values. As inferred from indentation, the calculated yield strength of the material from the mean pressure does not correlate well to the yield strength measured by tensile testing. The plastic zone size surrounding an indentation can also be used to determine the yield strength of the material, and this does correlate to the yield strength measured by tensile tests. Furthermore, the extent of plastic deformation is relatively independent of the included angle of the indenter for the range of materials used in this system. ...

Energy Technology Data Exchange (ETDEWEB)

Transmission electron microscopy studies on solution-annealed Alloy 800 revealed small (100-200 nm), spherical-shaped titanium carbide (face centered cubic structure) and large (200 nm-5 {mu}m), faceted titanium nitride (hexagonal structure) particles randomly distributed in the austenite matrix. The volume fraction of former particles was found to be greater than that of the latter. Corrosion studies of the alloy in acidic, chlorides and acidic chloride environments at room temperature indicated that the passivity of Alloy 800 was adversely affected by the addition Cl{sup -} ions. X-ray photoelectron spectroscopy revealed that the surface film formed on the alloy at the onset of passivity consisted of Cr{sup 3+} (as Cr{sub 2}O{sub 3}), without any Fe{sup 3+}/Fe{sup 2+} or Ni{sup 2+}. Scanning electron microscopy studies indicated initiation of pitting at large, faceted particles, not at small, spherical-shaped ones.

Energy Technology Data Exchange (ETDEWEB)

To improve the surface properties of magnesium alloy, a lining process using shot peening was carried out. The lining of magnesium alloy with metals such as titanium and nickel is useful in heightening the corrosion and wear properties for the components. In the shot peening experiment, the foil set on the magnesium workpiece is pelted with many shots at a high velocity. The foil is bonded to the surface of the workpiece due to plastic deformation induced by the collision of the shots. A pure aluminum foil is inserted between the hard foil and magnesium workpiece to assist the bonding. To heighten the bondability, the foil and workpiece are heated and the flow stresses of the metals are reduced. In this experiment, a centrifugal shot peening machine with an electrical heater was employed. The workpieces were commercially magnesium alloys AZ31B and AZ91D, and the foils were commercially pure aluminum, pure titanium and pure nickel. The effects ...

Energy Technology Data Exchange (ETDEWEB)

The usually low wear resistance of titanium materials can be increased by the thermochemical surface treatment nitriding. In result of comparative investigations of gas and plasma nitriding it will be shown that it is possible to obtain a specific variation of the properties in the highly stressed case by means of these both technologies on example of the ({alpha}+{beta}) alloy Ti-6Al-4V. Gas and plasma nitriding was carried out in the temperature range from 650 to 800 C over 4 to 48 h in different gas atmospheres, i.e. 100% NH{sub 3} (gas), 100% N{sub 2} (gas and plasma), 20% H{sub 2} + 80% N{sub 2} and 20% Ar + 20% H{sub 2} (plasma). The temperature range was fixed in the middle of ({alpha}+{beta}) region, because the core properties are influenced negative in the field of {beta}-transustemperature. The relations between the applied nitriding technologies, the layer structure (chemical, phases, geometrical) and selected layer properties (microroughness, ...

International Nuclear Information System (INIS)

The effect of mean stress, or the stress ratio (R), on the fatigue-crack growth (FCG) behavior of #alpha#-aged and #omega#-aged microstructures of the beta titanium alloy Ti-10V-2Fe-3Al was investigated. While the mean stress had a negligible effect on the FCG behavior of the #alpha#-aged microstructure, a strong effect was observed in the #omega#-aged microstructure. In particular, the values of the threshold stress-intensity range (#DELTA#K_t_h) exhibited a strong dependence on R in the #omega#-aged microstructure, while this dependence was weak in the #alpha#-aged microstructure. These effects seem to arise primarily from fracture-surface roughness-induced crack closure. The crack closure levels for the #alpha#-aged microstructure were found to be very low compared to those for the #omega#-aged microstructure. Transmission electron microscopy and scanning electron microscopy studies of microstructures and fracture surfaces were performed to gain insight into the ...

British Library Electronic Table of Contents (United Kingdom)

A Ni3Al coating was prepared by plasma spraying technique on the surface of titanium alloy. Ni-Al mixed powders, coatings and reaction products were investigated by scanning electron microscope, EDS, DSC and XRD. A tight bonding between the coating and the substrate was formed. The X-ray diffraction analysis of the patterns showed that the coating not only had Ni3Al phase, but also had NiO and Al2O3 phase microcontent. Comparing Ni coated Al to Ni3Al at 900^oC, the diffusion was stronger and the diffusion layer was thicker. A minute pore structure was formed at 1200^oC in the front edge of solid-state reaction layer. So Ni3Al restrained the solid-state reaction of the coating with the substrate, and as a whole weakened the entry of oxygen atoms into the substrate and quenched the out-diffu...

International Nuclear Information System (INIS)

The commercial detergents, which are cleansing cream, shampoo, neutral detergent, etc., were examined in order to select the body cleaners that are substitutes for the titanium dioxide paste. JNC entrusted Japan Environment Research Corporation Limited with these examinations since 1997. In 1997 and 1998, the commercial detergents were examined for Ce-144, Cs-137 and Ru-106. In 1999, 22 detergents were examined for Co-60 from the result of the past examinations. In this examination, the radioactive solution of Co-60 was dropped on the pig-skin samples. These samples were washed with each detergent after 5 minutes and 40 minutes. The decontamination factors of detergents were estimated by the radioactive ratio of the samples before and after washing. As a result of this examination, the decontamination factors for Co-60 was the same as the decontamination factors for Ce-144 and Cs-137, and 11 detergents were nominated as the cleaner that have the decontamination ...

Energy Technology Data Exchange (ETDEWEB)

For a better understanding of sulphidation mechanisms, some alloys (alloy 600, alloy 800, Uranus S, iron-chromium-aluminium-alloy) and metals (iron, chromium, nickel, molybdenum, titanium) were tested at 773, 873, 1 073 K in gaseous sulphur dioxide. Total pressure was 760 torrs. Sulphur dioxide pressure was 760, 100 and 10 torrs. Argon, oxygen, water vapor were used, successively, as pressure complement. Oxygen supply, generally speaking cause decay of corrosion resistance in SO/sub 2/ atmospheres especially at 1 073 K with low ratio p/sub O2//P/sub SO/sub 2//. Water vapor supply act similarly. Temperature laws and pressure laws do not give monotonous rise of corrosion values. There are maximas suggesting corrosion products undertaking a volatilization process. According to test conditions, Uranus S, chromium, alloy 800 (and titanium at some extent) showed good corrosion resistance. That results are supporting those obtained by JRC Ispra team, ...

Energy Technology Data Exchange (ETDEWEB)

Bench-scale batch equilibration tests have been conducted with supernatants from two underground tanks at the Melton Valley Storage Tank (MVST) Facility at Oak Ridge National Laboratory (ORNL) to determine the effectiveness of selected ion exchangers in removing cesium, strontium, and technetium. Seven sorbents were evaluated for cesium removal, nine for strontium removal, and four for technetium removal. The results indicate that granular potassium cobalt hexacyanoferrate was the most effective of the exchangers evaluated for removing cesium from the supernatants. The powdered forms of sodium titanate (NaTiO) and cystalline silicotitanate (CST) were superior in removing the strontium; however, for the sorbents of suitable particle size for column use, titanium monohydrogen phosphate (TiHP {phi}), sodium titanate/polyacrylonitrile (NaTiO-PAN), and titanium monohydrogen phosphate/polyacrylonitrile (TiP-PAN) gave the best results and were about ...

Energy Technology Data Exchange (ETDEWEB)

Deposition of hard coatings may influence the mechanical properties of the bulk material and its corrosion resistance. In this work we study the hardness of the coated and the back side of 100Cr6 steel plates. Electrochemical corrosion tests were performed in O{sub 2}-saturated acetate buffer of pH 5.6 at 25degC. Chromium nitride and titanium nitride coatings prepared by different physical vapour deposition processes, such as arc, thermionic arc evaporation, magnetron sputtering and ion-beam-assisted deposition (IBAD) were compared. The results show that, for sufficient corrosion protection, chromium nitride layers have to be thicker than 500 nm. An increased nitrogen partial pressure in the evaporation chamber of the IBAD process improves the corrosion resistance significantly. The hardness of the substrates was reduced in the case of thermoionic arc evaporation only, indicating a deposition temperature of more than 250degC. For this process, however, we obtained ...

International Nuclear Information System (INIS)

Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT images were obtained preoperatively ...

Science.gov (United States)

With the help of self-assembly, thermal sintering, selective etching techniques and sol-gel process, the non-close packed (ncp) face-centered cubic (fcc) photonic crystals of titanium dioxide (TiO2) hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The photonic bandgap calculations indicate that the ncp structure of TiO2 hollow spheres was easier to open the pseudogaps than close packed system at the lowest energy. PMID:17097102

International Nuclear Information System (INIS)

Phase transformations occuring during cold deformation in hardened #alpha#+#beta# titanium alloy of the Ti-Al-Mo-Zr-Sn-Si system with 10% summary content of alloying elements are studied by X-ray diffraction analysis. Two stages of trapsformation of metastable #alpha#''-phase are found. A conclusiop is made that ability of the alloy containing #alpha#''-phase to cold deformation is determined by the presence of favourable texture, by high degree of metastability and by volume portion of #alpha#''-phase in the alloy structure.

International Nuclear Information System (INIS)

High temperature deformation behavior of an alpha + beta titanium alloy Ti-3Al-4V has been investigated at 910 deg. C. by using the method of cross head speed cycling. On the basis of flow stress, strain rate and strain rate sensitivity data, the alloy was found to exhibit strain hardening at this temperature which resulted in degradation in superplastic properties of the alloy. A high beta-phase volume fraction and grain-growth in both alpha and beta phases were considered responsible for the observed hardening effect. (author)

International Nuclear Information System (INIS)

The description is presented of binary phase diagrams of titanium alloyed with the following elements: silver, aluminium, arsenic, gold, boron, barium, beryllium, bismuth, carbon, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, hydrogen, hafnium, indium, iridium, potassium, lithium, magnesium, manganese, molybdenum, nitrogen, sodium, niobium, nickel, oxygen, osmium, phosphorus, lead, palladium, platinum, plutonium, rhenium, lanthanium, cerium, preseodymium, neodymium, gadolinium, erbium, terbium, thulium, lutetium, rhodium, ruthenium, scandium, silicon, tin, strontium, tantalum, technetium, thorium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc and zirconium.

International Nuclear Information System (INIS)

Beta-C trademark is a metastable beta titanium alloy which can be heat treated to achieve a good combination of properties such as tensile strength, fatigue strength, ductility and toughness, such as needed in aircraft fasteners. Variations in hot and cold processing parameters and solution heat treatment can affect the resultant grain structure which in turn affects subsequent aging response and mechanical properties. Several processing/heat treating routes on round bar are explored in this study to determine the effects on microstructure and various mechanical properties.

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N-curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle-fatigue, crack initiation was most likely caused by inclusions like Titanium Carbonitrides or Aluminium Oxides. A model was developed to describe the influence of the magnitude of these inclusions on the lifetime. A weakest link model, using the statistical distribution of inclusions and surface flaws, was used to describe the fatigue limit. (orig.)

International Nuclear Information System (INIS)

The influence of microalloying vanadium or titanium on improving the corrosion resistance of mild steel in saturated calcium hydroxide solution was investigated. Potential-time, potentiodynamic polarization, and impedance measurement techniques were employed. The corrosion products have been examined by infrared and X-ray diffraction analysis and by scanning electron microscopy. It has been shown that the grain refining, due to microalloying, plays an important role in enhancing the corrosion resistance of steel. Scales of calcite and iron oxides on top of a protective oxide are formed on the investigated steels.

International Nuclear Information System (INIS)

In a program to develop a metastable beta alloy with improved fracture toughness, it was found that the tensile ductility of the alloy Ti-8 Mo-4.5 Cr-2.5 Al was strongly dependent on both processing history and annealing temperature. Evaluation of the microfracture mode of tensile samples by scanning electron microscope and metallographic techniques showed that the presence of a continuous grain boundary alpha is the most significant parameter controlling the ductility and is highly detrimental. It is concluded that, for optimum processing, the material must be worked prior to aging to avoid this grain boundary phase.

Energy Technology Data Exchange (ETDEWEB)

In the early 1970s Yang and Menichelli demonstrated that direct laser illumination of low-density secondary explosive prr:ssings through a transparent window could produce detonation. 'The energy requirement for threshold initiation of detonation was reduced when a thin metal coating of metal covered the side of the window against which the low-density explosive was pressed. We have obtained experimental results that are in general agreement with the results of Renllund, Stanton and Trott (1 989) and recent: work by Nagayama, hou and Nakahara (2001). We report exploration of the effects of laser beam diameter, PEiTN density and specific surface area, and thickness of a titanium coating on the window.

Energy Technology Data Exchange (ETDEWEB)

The theoretical principles underlying the formation of oxide and, in particular, anodic oxide coatings on metals produced by chemical oxidation, anodizing in solutions, and anodizing in cold plasmas are reviewed. The mechanisms and conditions of anodic oxidation are described, and the structure of anodic oxide coatings on aluminum, magnesium, beryllium, zinc, cadmium, iron, cobalt, nickel, titanium, zirconium, tantalum, and chromium alloys is examined. Attention is also given to various applictins of anodized coatings. 54 references.

International Nuclear Information System (INIS)

The single specimen unloading compliance technique has become the preferred method for evaluating J-integrals. It involves data acquisition and analysis using a computer. This paper describes in detail the development of a simple experimental system and related software that can be used in a laboratory equipped with a microcomputer and with access to a minicomputer. The effects of loading rate, test temperature, specimen geometry and material composition can be readily evaluated using this system. The results on a pressure vessel steel and an #alpha#-#beta# titanium alloy are discussed in Part II. (author).

International Nuclear Information System (INIS)

The development of the microstructure on aging of an (#alpha# + #beta#) type titanium alloy containing 6Al-1.6Zr-3.3Mo-0.3Si (VT9) (in weight percent) has been studied. The #beta#-transus temperature of this alloy is approximately 1243 K. Solution treatment in the #beta#-phase field of the alloy followed by quenching in water at room temperature resulted in the formation of a single-phase martensite structure. The martensitic structure was confirmed to be orthorhombic (#alpha# double-prime) using X-ray diffraction. The water-quenched (WQ) specimens were subjected to aging treatments at temperatures of 823, 873, and 973 K for various lengths of time. Aging at 823 K for times between 24 and 100 hours did not bring about any noticeable change in the microstructure. Aging at 823 K for 200 and 300 hours resulted in the heterogeneous precipitation of s_2 silicide particles and thin films of #beta# sandwiched between the interplatelet boundaries of martensite. Electron ...

International Nuclear Information System (INIS)

Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium and cobalt chromium alloys and carbon fiber-reinforced polymers. Implant-related susceptibility artifacts can decrease the quality of MRI scans. The aim of this cadaveric study was to demonstrate the extent that implant-related MRI artifacting affects the postfusion differentiation of determined regions of interest (ROIs). In six cadaveric porcine spines, we evaluated the postimplantation MRI scans of a titanium, cobalt-chromium and carbon spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into ROIs to characterize the spinal canal as well as the intervertebral disc space. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists the artifact-affected image quality of the median MRI slice was rated ...

International Nuclear Information System (INIS)

Ti-10V-2Fe-3Al is high strength, metastable beta titanium alloy developed by the Timet Division, Titanium Metals Corporation of America for enhanced forgeability and excellent mechanical property combinations, including deep hardening characteristics. Ti-10-2-3 has been the subject of intense thermomechanical processing (TMP) development and reduction to commercial practice for the full range of open die, closed-die and precision forged products utilized in aerospace and other applications. With commercially proven TMP, Ti-10-2-3 forgings provide a range of strength-fracture toughness combinations from 180 Ksi (1,240 MPa) minimum U.T.S. to 140 Ksi (965 MPa) minimum U.T.S with commensurate fracture toughness. With optimal TMP and these strength-toughness combinations, Ti-10-2-3 forgings are found provide superior smooth and notched fatigue properties critical to aerospace applications over incumbent alpha-beta alloys. The alloy retains 80 ...

Energy Technology Data Exchange (ETDEWEB)

{sup 60}Co is produced as an activation product and is present in the low-level aqueous radioactive waste released from the La Hague plant. At present, the concentration in the sea (non filtered at 0.45 {mu}m) at the Goury site are close to or even below, the detection limit: 0.2 mBq.l{sup -1}. The {sup 60}Co speciation depends on the type of effluent considered: in the effluent A ('active'), the cobalt is in the form of a stable trivalent complex; in the effluent V (to be checked), the cobalt is in majority (50% of the activity release) in the form of particles (>0.45 {mu}m), and then in the form of two soluble species: ionic divalent (Co{sup 2+}) and some stable complexes. The evolution of the reprocessing techniques used does not affect the speciation. So, since the nuclear reprocessing plant started at the La Hague plant in 1966, the chemical species discharged in the sea shows time variation related to the evolution of the type of effluent discharged. ...

Energy Technology Data Exchange (ETDEWEB)

This study resumes the discovery of an excess of actinium 227 found around by EL4 nuclear reactor actually in dismantling. The search for the origin of this excess revealed a real inquiry of investigation during three years. Because a nuclear reactor existed in this area a particular attention will have concerned this region. The doubt became the line of conduct to find the answer to the human or natural origin of this excess. Finally and against any evidence, it appears that the origin of this phenomenon was natural, consequence of the particular local geology. The detail of the different investigations is given: search of a possible correlation with the composition of elevations constituent of lanes, search (and underlining) of new sites in the surroundings of the Rusquec pond and the Plouenez station, study of the atmospheric deposits under winds of the nuclear power plant and in the east direction, search of a possible relationship with the gaseous effluents of the nuclear power ...

Energy Technology Data Exchange (ETDEWEB)

When liquids are confined in nano-scopic dimensions, their properties differ from the corresponding bulk liquid, due to their reduced dimensionality and surface effects. Phase transition temperatures and pressures are often shifted from the bulk values and new phases can appear due to the strong interactions of the molecules with the confining walls. We have studied the structural and dynamical properties of aromatic liquids such as benzene, toluene, and ortho-terphenyl confined in nano-porous materials, MCM-41 and SBA-15, synthesized and characterized in our laboratory. A non-trivial dependence of the glass transition temperature, T{sub g}, on the pore size and surface treatment of nano-porous materials is confirmed and interpreted as resulting from a competition between the fluid-wall and fluid-fluid intermolecular interactions. An increase of T{sub g} is observed for small pore sizes and attractive surface while T{sub g} decreases for non attractive surface, whatever the pore size. ...

Energy Technology Data Exchange (ETDEWEB)

This thesis presents the work achieved to instrument the ATLAS software framework, ATHENA, with a library of tools and utensils for the physics analysis as well as the extraction of the jet energy scale using physics events (in-situ calibration). The software part presents the various components of the ATHENA framework which handles the simulated and reconstructed data flow as well as the different stages of this process, before and during the data taking. The building of a library of tools easing the reconstruction of physics objects, their association with Monte-Carlo particles and their API is then explained. The need for common language and collaboration-wide utensils is emphasised as it allows to share the workload of validating these tools and to get reproducible physics results. The analysis part deals with the implementation of a light jet energy scale calibration algorithm within the C++ framework. This calibration algorithm makes use of W bosons decaying into light jets ...

Energy Technology Data Exchange (ETDEWEB)

Although the standard model of particle physics agrees perfectly with experimental data, it is unlikely the final theory describing particles and their interactions. New phenomena has been searched in the jets and missing transverse energy topology. Such phenomena may be due to the pair production of leptoquarks decaying into a quark and a neutrino or the pair production of stops decaying into a charm and a neutralino which is assumed to be the lightest supersymmetric particle. These searches have been performed with the Ddiamter detector at hadronic collider TeVatron with a center of mass energy of 1.96 TeV. This kind of searches needs a good understanding of the jet energy calibration. The determination of the relative jet energy scale has allowed us to reduce the systematic uncertainties on the jet energy measurement when comparing the data and the simulation. Moreover a new method has been developed in order to correct simulated jets for the differences observed in the jet energy ...

Energy Technology Data Exchange (ETDEWEB)

The aim of this study concerns the use of numerical methods for the resolution of the Reynolds Averaged Navier Stokes equations adapted to the simulation of the cooling of the trailing edge of a stator in a high pressure turbine. These methods, based on the elsA solver developed at ONERA, use a four steps Runge Kutta time discretization scheme and a Jameson centered space discretization scheme. The scheme is applied through a finite volume approach on control volume centered on the cells of a multi-block structured mesh. Turbulence is simulated either through the algebraic Michel model, or through the one-transport-equation Spalart-Allmaras model, or through the two-transport-equations k 1, k {omega} and k {epsilon} models, and through ASM model. A simulation of the flow in a bidimensional stator, without cooling, is carried out. The cooling, which is realized with trailing edge slots, is then simulated on a bidimensional stator. Because the slot is represented by meshes overlapping ...

Energy Technology Data Exchange (ETDEWEB)

In front of the risks linked with the increase of the greenhouse gas emissions in the atmosphere, the decision makers must take into consideration first, the scientific advice of climatic change experts, and second, the considerable inertia of the climatic system. Thus, any action implemented so far will have an impact all along the 21. century and later whatever the future human activities. The aim of this memento is to sensibilize the decision makers about the possible consequences of their choice in terms of volume of greenhouse gases and of medium- and long-term evolution: 1 - stakes, role of local decision-makers (greenhouse effect and climatic change, France's international commitment, stakes, liabilities of local decision makers, decentralization laws, local plans of fight against greenhouse effect, public information and dialogue); 2 - urbanism and transports (urban displacements, alternatives to individual cars, collective transportation systems, parking, inter-region ...

Energy Technology Data Exchange (ETDEWEB)

This document deals with the couplings between the W boson and Z and gamma particles. WWZ and WW{gamma} vertex are predicted by the electroweak theory based on the symmetry group SU(2){sub L}*U(1){sub Y}, their existence is confirmed by the measurement of the production cross-section of W pairs at LEP. The effective values of the couplings are modified by the introduction of standard model particle loops at the vertex level, the impact on the coupling value is assessed to reach 10{sup -3}. These loops can also include beyond-the-standard-model particles, their impact is in the magnitude order of 10{sup -3} for most models. The fully description of these loops requires the values of 14 complex parameters whose measurement will give information about the existence of new particles. Nevertheless the number of events at LEP is not sufficient to measure all the parameters simultaneously. As a consequence the analysis is limited to the 3 most promising parameters: g{sub 1}{sup Z}, ...

Energy Technology Data Exchange (ETDEWEB)

The school building complex Waterland in The Hague, Netherlands, was built with a hybrid ventilation system. The indoor environment and energy consumption were monitored for one year. Air quality and thermal comfort are of a high quality and the consumption of energy for heating is circa 35% lower than normal. The Waterland project was one of eight demonstration projects, carried out within the framework of the ECBS-Annex 35: Hybrid ventilation in New and retrofitted Office Buildings. ECBS stands for the IEA-program Energy Conservation in Buildings and Community Systems. [Dutch] In ECBCs-annex 35 (ECBS staat voor het IEA-programma Energy Conservation in Buildings and Community Systems) is uitgebreid onderzoek gedaan naar hybride ventilatiesystemen in kantoren en scholen. Dit project heeft geleid tot acht internationale voorbeeldprojecten, waarvan scholencomplex Waterland te Den Haag er een van is. Het scholencomplex is in 2003 opgeleverd met een hybride ventilatiesysteem. Het ...

Energy Technology Data Exchange (ETDEWEB)

Qualitative interpretation of data of different nature and sources, based on segmentation techniques such as discriminant analysis, is useful to characterize and monitor hydrocarbon reservoirs. In order to make this interpretation more reliable, it is necessary to characterize uncertainties attached to data and then, to propagate them in the interpretation work-flow. In this thesis, uncertainties are represented by intervals, because usually, little is known about input data errors. The uncertainty characterization issue is dealt with specifically for each case study. The uncertainty propagation issue is treated by a new technique, based on interval analysis, which consists in extending to intervals various popular approaches (non parametric, quadratic and linear) to discriminant analysis: Firstly, a learning phase allows calibrating an imprecise classifying model on the basis of pre-interpreted data. If the quality of this model is good enough, it is used to interpret the whole set of ...

Science.gov (United States)

Feasibility of depositing continuous films of nano-porous alumino-silicates, primarily zeolites and MCM-41, on metallic and non-metallic substrates was examined with an aim to develop membranes for separation of gaseous mixtures and also for application as hydrogen storage material. Mesoporous silica was deposited in-side the pores of these nano-porous disks with an aim to develop membranes for selective separations. Our study involves supported zeolite film growth on substrates using in-situ hydrothermal synthesis. Faujasite, Silicalite and Mesoporous silica have been grown on various metallic and non-metallic supports. Metallic substrates used for film growth included anodized titanium, sodium hydroxide treated Titanium, Anodized aluminum, and sintered copper. A non-metallic substrate used was nano-porous aluminum oxide. Zeolite film growth was characterized using Scanning Electron Microscope (AMRAY 1820) and High Resolution Transmission ...

International Nuclear Information System (INIS)

Zirconium is a transition element located along with sister elements titanium and hafnium in Group IVB of the periodic table. It is grayish white metal, with a density somewhat less than carbon steel. Zirconium is the ninth most common metallic element in the earth's crust, and is more abundant than zinc, lead, nickel, or even copper. Zirconium is exceptionally resistant to corrosion by many common acids and alkalis. It is resistant to most organic acids, such as formic, acetic, lactic, and oxalic acids. It also has a high resistance to localized forms of corrosion, such as pitting, crevice corrosion, and stress corrosion cracking. Its corrosion resistance is caused by the formation of a dense, tenaciously adherent, chemically inert oxide film on the surface. This oxide film protects the base metal from both chemical and mechanical attack at temperatures up to about 400 C (750 F). This article describes zirconium's formability, machinability, corrosion resistance, ...

British Library Electronic Table of Contents (United Kingdom)

A series of cleavable water-soluble silicone surfactants were prepared by the reaction of a hydroxyl-terminated polyester and an organopolysiloxane. Cleavable surfactants can decompose into water-insoluble moiety of silanol and two water-soluble products under acidic conditions, whereas these compounds are stable under neutral or alkaline conditions. The structure change of theses cleavage products are confirmed by IR and UV spectra analysis. The fundamental surface activity including surface tension, foaming, contact angle and viscosity are studied. The photocatalytic degradation of modified silicone surfactants with UV light over titanium oxide was investigated. Experimental results have confirmed that products are slowly degraded by direct photolysis. However, the cleavable silicone sur...

International Nuclear Information System (INIS)

The constituent phases and associated deformed microstructure of the quenched Ti-xNb-(0.5-1.5) at.% Si alloy consisting of non-cytotoxicity elements, where x = 24-30 at.%, were investigated to provide pseudoelasticity for biomedical and sensor applications. Optical microscopy revealed that stress-induced martensitic transformation takes place during the deformation in the present alloys. It is confirmed from the X-ray diffraction results of the deformed specimens that the crystal structure of the stress-induced martensite phase is the orthorhombic so-called #alpha#'' structure. Within the alloys having #beta#(bcc) phase studied Nb-poor region appeared to exhibit a dominant behavior for stress-induced martensitic transformation than Nb-rich region. This result suggests that metastable #beta# phase is superior to stable #beta# phase for the occurrence of stress-induced martensitic transformation in the present alloy system.

Energy Technology Data Exchange (ETDEWEB)

Real-time neutron radiography (RTNR) is now proving to be a valuable research tool in the study of hydrogenous fluid flow. One of the most significant advantages of neutron radiography is the ability to image hydrogenous substances (such as lubricants, coolants, and fuels) inside metallic materials such as aluminum and titanium engines. By using RTNR, one can then study dynamic events such as the movement of liquids inside these solids. The Phoenix Memorial Laboratory (PML) at the University of Michigan has recently developed and installed a facility dedicated to RTNR. The work at PML has shown that RTNR of dynamic events can provide information enabling the researcher to follow dynamic events that were previously impossible or impractical. This paper will show the variety of uses of RTNR presently being pursued at PML.

Energy Technology Data Exchange (ETDEWEB)

The goal of this research program is to determine whether pulsed laser deposition is an effective alternative method for growing TiCN thin films. Pulsed laser deposition (PLD) is chosen because of its well-documented capability for growing uniform, stoichiometric films in ultra-high vacuum or gaseous environments. Processing of thin films by PLD is also achieved at relatively low temperatures compared with CVD processing. Given these attributes, the primary objectives in this article are to determine whether nitrogen may be readily incorporated into films resulting from the laser-ablation of TiC in an N{sub 2} environment, determine what effect nitrogen has on mechanical properties, and determine whether nitrogen incorporation is strongly influenced by processes unrelated to laser deposition (e.g., thermally-activated surface reactions).

International Nuclear Information System (INIS)

The #beta#-CEZ alloy : Ti-5%Al-2%Sn-4%Zr-4%Mo-2%Cr-1%Fe is a near #beta# titanium alloy. Since its processing routes include heat treatment (consisting of solution treatment and ageing), it has been decided to study the influence of the #beta# phase stability on #alpha# phase precipitation and hardening kinetics. Small sized specimens, coming from industrial heats, have been heat treated above and below the #beta# transus, and then water quenched. Therefore, several degree of #beta# stability are obtained. When it is increased (i.e. the solution treatment temperature is lowered), #alpha# or #omega# phases precipitations are delayed, as well as the hardening phenomena. Moreover, the #omega# stability domain is reduced. The mechanisms of #alpha# or #omega# precipitation are discussed, and related to the hardening kinetics. (orig.).

International Nuclear Information System (INIS)

This pilot project was carried out for the purpose of testing methods for active biological monitoring. It covered a period of three years (until September 1994), including two years of exposure. The measurements served to determine pollutant levels in plants used as animal fodder and dust-borne heavy metal concentrations in different sites and, on this basis, to obtain indirect information on human exposure. Among others, the pilot project investigated the suitability of Italian rye-grass as a biological indicator for aluminium, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, magnesium, manganese, nickel, lead, platinum, antimony, titanium, and zinc. (orig./GL).

International Nuclear Information System (INIS)

In connection with the different cyclical strengths of the two-phase (#alpha# + #beta#) titanium alloy in the case of the acicular and rounded formations of the #alpha#-phase, we have studied, employing the X-ray diffraction method, the phase composition of the alloy and the influence of heat treatment upon it. Using the method of electronic fractography, we examined the fractures in samples destroyed by the asymmetric twisting, in order to find out why the durability of the alloy is dependent upon the #alpha# - phase structure. It has been found that in the BT22 alloy, the decay the #beta#-phase may proceed in two ways; either with the formation of the martensite #alpha#'-phase of the acicular shape or with the separation of the non-martensite round-shaped #alpha#-phase. The character of the phase transformations #beta# - #alpha# or #beta#-#alpha#' is, to a considerable extent, the conseguence of the prehystory of the alloy and is dependent but weakly on the ...

International Nuclear Information System (INIS)

In the frame of the Primary Wall Module prototype manufacturing for ITER, a consistent R and D phase was conducted in order to identify the industrial allowable tolerances and manufacturing problems which would occur when joining pieces by HIPping process during the PW module manufacturing. The purpose of this development was to give as industrial as possible manufacturing routes for joining together large Stainless Steel or DS-Copper pieces with Stainless Steel tubes and for bonding Beryllium tiles onto a curved component surface. The study concerned surface preparations, allowable gaps and joint geometry, Beryllium tile geometry, Titanium interlayer thickness, etc. This R and D phase also allowed the development and validation of different ultrasonic inspection tools needed for plate-plate, tube-plate, edge to edge plate bonding.

British Library Electronic Table of Contents (United Kingdom)

Low pressure turbine blades (LPT) made by investment casting from intermetallic titanium aluminide alloys for aero-engine applications in lengths between 200 and 400 mm require very demanding and sophisticated process for their manufacturing. Middle line shrinkage porosity along the airfoil and dimensional tolerances by near-net-shape casting are especially sensitive issues concerning Quality assurance. Nevertheless the urgency to manufacture safer environmental-friendly high performance aero-engines requires the introduction of new high performance components like LPT blades made of TiAl, which are about 50% lighter than their nickel-based counterparts. The present work is based on process engineering taking into account different melting and casting technologies in order to develop a dep...

British Library Electronic Table of Contents (United Kingdom)

Ceramic coatings with high emission were fabricated on Ti6Al4V alloy by microarc oxidation (MAO) with additive FeSO4 into the electrolyte. The microstructure, chemical composition and chemical state of the coatings were determined by SEM, XRD, EDS and XPS, respectively. The bonding strength between the coating and substrate was studied by tensile strength test, together with the thermal shock resistance of the coating. The results showed that Fe content in the coating layer significantly affect its thermal emissivity. The relative content of Fe in the coatings surface increased at first and then decreased with increasing the concentration of FeSO4 in electrolytes, so does the emissivity of the coatings. The bonding strength became weaker with increasing the concentration of FeSO4. In addit...

International Nuclear Information System (INIS)

High temperature deformation behaviour of an experimental Beta-titanium alloy Ti-10V has been studied in the temperature range 800 to 945 degree C by using the method of crosshead speed cycling. Although subgrain formation was observed but the alloy did not exhibit superplastic behaviour in the entire temperature range studied. A very large initial grain size and elongation of grains during the deformation are considered the main factors responsible for absence of superplastic behaviour. The activation energy values for regions II and III of the ln sigma vs. ln small epsilon plots are close to the lower of the two activation energy values proposed together to describe self diffusion in beta-phase suggesting that the rate controlling mechanism is that for lattice diffusion rather then grain boundary diffusion. (author)

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle fatigue, crack initiation was most likely caused by inclusions like Titanium Carbon nitrides or Aluminium Oxides. A micro mechanical model for the crack initiation by inclusions was developed. Another model was developed to describe the influence of these inclusions on the lifetime. A weakest-link model, using the statistical distribution of inclusions and surface flaws, was used to describe the endurance limit. (orig.)

International Nuclear Information System (INIS)

By varying different variables (potential, chloride content, surface pretreatment etc.) it is possible to show the effect of increasingly harsher corrosion conditions on passive-layer stability. These changes will not be detected by conventional methods e.g. measurement of passive current density, until a very late stage. Electrochemical noise measurement will allow the action of inhibitors to be detected in a rapid and effective manner. High-alloy steels and titanium claddings subjected to pitting corrosion in chloride-containing media demonstrate how to use this method for problem solutions and to open up new practical applications. The effect of mechanical stresses (natural, tensile) on the corrosion system can be detected by electrochemical noise which opens up new methods for crack corrosion studying and monitoring. (orig./DG).

British Library Electronic Table of Contents (United Kingdom)

A microanalytical characterization of cast magnesium alloys of eutectic origin based on the Mg?Al?Ca ternary matrix system has been carried out in order to investigate the influence of alloying elements on their microstructure as well as microchemistry-processing-microstructural relations using structure-sensitive techniques of electron microscopy, mechanical spectroscopy (internal friction), X-ray diffractometry, and advanced microanalytical methods including electron probe compositional analysis. Following the data obtained here there is direct correlation of microstructure with creep properties of the new experimental magnesium alloys. The creep and heat-induced properties of the multicomponent magnesium alloys containing low range of inexpensive additions of titanium (0.07?0.2%) or str...

Energy Technology Data Exchange (ETDEWEB)

Titanium stabilized austenitic steel is sensitive to SCC in the secondary water under the horizontal steam generator operating conditions. SCC was observed under crevice conditions both at the primary collector flanges and the heat exchange tubes. In the crevice environment sulfates and chlorides as aggressive species and silicates and alumino-silicates as ''non-aggressive'' species are present in significant amounts. Local water chemistry parameters were evaluated using the MULTEQ Code. SCC experiments were carried out by rising displacement tests ar 275 deg C in an environment simulating the crevice conditions. Crack growth rate and K{sub IS}8C{sub C} were determined for the environment where contents of some species were from 10{sup 2} to 10{sup 4} times higher than in blowdowns. (authors)

British Library Electronic Table of Contents (United Kingdom)

Statement of problem. The popularity of base metal alloys has considerably increased in recent years because of their superior mechanical properties as well as the high cost of noble alloys. However, there is disagreement about their effect on the opaque porcelain color and the color differences among base metal alloys. Purpose. The purpose of this in vitro study was to determine and compare the influence of various commercially available base metal alloys (excluding titanium-based systems) on the resulting color of opaque porcelain with the use of a colorimetric device. Material and methods. Fourteen different types of Ni-Cr and 3 different types of Co-Cr porcelain bonding alloys were selected with a Au-Pd alloy (V-Delta SF) as the control group for colorimetric measurements and determina...

Energy Technology Data Exchange (ETDEWEB)

Spiral orbit tribometry friction tests performed on Ni-rich Ni55Ti45 titanium ball bearings indicate that this alloy is a promising candidate for future aerospace bearing applications. Microstructural characterization of the bearing specimens was performed using transmission electron microscopy and energy dispersive spectroscopy, with NiTi, Ni4Ti3, Ni3Ti, and Ni2Ti4Ox phases identified within the microstructure of the alloy. Density functional theory was applied to predict the electronic structure of the NixTiy phases, including the band structure and site projected density of states. Ultraviolet photoemission spectroscopy was used to verify the density of states results from the density functional theory calculations, with good agreement observed between experiment and theory.

International Nuclear Information System (INIS)

Precipitation-hardened single crystals of a beta (bcc) Ti--40 at. percent V--1.0 at. percent Si alloy were deformed in compression at 77 and 298"0K. The dependence of the yield stress upon aging time at 843"0K for solution-treated crystals shows two maxima which are caused by silicide precipitates. The orientation dependence of the yield stress and of the active macroscopic slip plane were determined as a function of aging time. The solution-treated as well as aged crystals exhibit an asymmetry of both the yield stress and the plane of slip, the degree of asymmetry being larger at 77 than at 298"0K. The asymmetry of slip and yielding is not affected by the presence of precipitation hardening. Results indicate that the effect of the dislocation core structure on dislocation motion is independent of the presence of precipitates. (auth).

International Nuclear Information System (INIS)

Activation energy values for high temperature deformation of a beta -titanium alloy Ti-10V were determined from the flow stress strain rate data taken from the second increasing strain rate cycles, in order to find the rate controlling mechanism. Although the data obtained from first increasing strain rate cycles are considered most appropriated by the author in a previous study due to obvious reasons, the values obtained in present work are again indicative of lattice self diffusion in beta -phase as the rate controlling mechanism for this alloy and nevertheless suggest that two different activation energy values for a deformation process could be possible in a given temperature range, depending upon the data. (author)

International Nuclear Information System (INIS)

The published literature is reviewed and supplemented by current information from the author's laboratory, to show the influence of various compositional, heat treatment and thermomechanical factors on the structural characteristics of Alloy 800. The features discussed include carbon, aluminium, titanium and boron, solution treatment, ageing treatments with and without applied strain, and cold working. Examples of the aspects reviewed include the effect of heat treatment and service or testing temperature on the austenite grain size, and the relative importance of M_2_3C_6 and TiC, the influence of carbon level on gamma prime, the effect of residual or steady stress combined with time at temperature on changes in carbide or gamma prime morphology, and on the appearance of sigma or other intermetallic phases. The questions posed by these features are discussed generally, in terms of their effect on the mechanical properties at ambient and elevated temperatures and ...

Energy Technology Data Exchange (ETDEWEB)

The titanium stabilized austenitic steel similar to the type of 321 is sensitive to the stress corrosion crackingunder horizontal steam generator operating condition. SCC was observed under crevice corrosion parameters and has resulted in the transgranular or intergranular cracking at the both, components primary collectors and heat exchange tubes. The crevice environment is characterized by aggressive impurities and 'non aggressive' compounds. Sulfates and chlorides as aggressive species and silicates and alumino-silicates as 'non aggressive' species on the other hand are present in significant amount in the crevice environment under operating condition. Local water chemistry parameters were evaluated with MULTEQ Code. As input data the measured operational values of local and bulk environments have been used. The determined parameters were compared with the results of thread hole environment analyses and tube surface ...

International Nuclear Information System (INIS)

The effect of electron beam welding parameters on fusion zone (FZ) microstructure and porosity in a Ti-6.8 Al-3.42 Mo-1.9 Zr-0.21 Si alloy (Russian designation VT 9) has been investigated. It has been observed that the FZ grain width increased continuously with increase in heat input when the base metal was in the #beta# heat-treated condition, while in the #alpha# + #beta# heat-treated base metal welds, the FZ grain width increased only after a threshold energy input. The difference is attributed to both the weld thermal cycle and the pinning effect of equiaxed primary alpha on grain growth in the heat-affected zone (HAZ) of #alpha# + #beta# heat-treated base metal. Postweld heat treatment (PWHT) in the subtransus and supertransus regions did not alter the columnar grain morphology in the FZ, possibly due to the lack of enough driving force for the formation of new grains by the breaking up of the columnar grains and grain boundary movement for grain growth. The highest porosity was ...

Science.gov (United States)

Based on a recent investigation that modeled the elastic properties (ie, strength, stiffness and range) of multistranded wires made from linearly elastic materials, three-stranded (triple) and six-stranded coaxial (coax) stainless steel (SS) wires were compared to single-stranded (single) SS and conventional nickel titanium (NiTi) leveling wires. To measure Young's modulus of elasticity (E), flexural tests were performed with an Instron mechanical testing machine in a three-point bending arrangement having a span length of 8.9 mm or 12.5 mm. A strong correlation between wire stiffness and the area moment of inertia demonstrated that strand interaction was negligible at low activations and that E = 199 GPa was constant even for the heavily drawn coax strands. Using the Instron with an extensometer, the 0.1% yield strengths (sigma(YS)) of the single SS wires and the straight inner strands within the coax wires were tested. The ratio of the sigma(YS) to the ultimate ...

Energy Technology Data Exchange (ETDEWEB)

The INTEGRAL/SPI spectrometer was designed to observe the sky in the energy band of 20 keV to 8 MeV. The specificity of instrument SPI rests on the excellent spectral resolution (2.3 keV with 1 MeV) of its detecting plan, composed of 19 cooled germanium crystals; covering an effective area of 508 cm{sup 2}. The use of a coded mask, located at 1.7 m above the detection plan ensures to it a resolving power of 2.5 degrees. The aim of this thesis, begun before the INTEGRAL launch, is made up of two parts. The first part relates to the analysis of the spectrometer calibration data. The objective was to measure and check the performances of the telescope, in particular to validate simulations of the INTEGRAL/SPI instrument response. This objective was successfully achieved. This analysis also highlights the presence of a significant instrumental background noise. Whereas, the second part concentrates on the data analysis of the Vela region observations. I have approached two astrophysical ...