International Nuclear Information System (INIS)

A method that employs simultaneous neutron and #gamma#-ray diffraction techniques is proposed for accurate measurements of strains with or without an applied electric field (0-100 kV m"-"1). Instead of an absolute determination of the position of the neutron Bragg peak, a relative measurement of the neutron and #gamma# peak positions is used and allows a determination of the lattice-parameter changes with an accuracy of within 2 x 10"-"6. This technique avoids systematic errors originating in sample rotations by taking advantage of a reference directly related to the crystal lattice. The method appears to be particularly important for crystals that exhibit structural phase transitions, as demonstrated by the measurement of the strain U_x_x in KH_2PO_4 crystals as a function of temperature and applied electric field. In this case the errors would amount to #+-#20%. The results demonstrate the need to ...

British Library Electronic Table of Contents (United Kingdom)

Depending on the soil environment, selenium (Se) can exist as several species differing greatly in bioavailability. Characterization of soil Se reserves is thus necessary in assessing the nutritional supply of this essential element. In low-Se areas, Se fertilization is an option for securing adequate Se nutrition. Fertilization is, however, challenged by the unknown fate of the residual Se. In this study, we aimed to clarify the Se status of selenate-fertilized field soils by fractionating soil Se into five pools: salt-soluble (KCl), adsorbed (KH2PO4/K2HPO4), organically associated (NaOH), elemental (Na2SO3) and recalcitrant Se (NaOCl). Changes induced in these fractions by repeated application of low selenate doses were examined by comparing samples collected from the same locations in 1...

Science.gov (United States)

... HARDENED CUP AND CARBURIZED AND HARDENED CORES HAVE BEEN PROFILED USING 2 TYPES OF EDDY CURRENT PROBES. ...

International Nuclear Information System (INIS)

A total dose hardening treatment is applied to SIMOX buried oxides. Total ionizing dose radiation testing is performed on fully-depleted transistors fabricated on both hardened and non-hardened substrates. At 200 krads x-ray dose, the front gate shift is reduced from -0.7 to -0.2 V for FETs built on the hardened wafers.

British Library Electronic Table of Contents (United Kingdom)

A formula is obtained which describes the kinetics of low-temperature radiation hardening caused by creation of dislocation loops of interstitial type during irradiation. The radiation hardening of aluminum and vanadium is estimated using this formula and results of experiments on studying processes of nucleation and growth of interstitial dislocation loops in these materials by transparent electron microscopy. It is shown that the proposed formula is valid for description of the kinetics of low-temperature radiation hardening.

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... defects doped materials germanium infrared radiation monocrystals neutron

International Nuclear Information System (INIS)

Argon ions irradiation of 12% Cr steels and Fe/Cr alloys results in the hardening up to 10000 MPa. This value exceeds the hardening level even for martensitic transformation. Along with the increase of microhardness following irradiation the shape of X-ray graph of the affected materials changes considerable. Hardening value and behavior are determined by temperature radiation doze, preliminary ageing, extent of cold strain and alloying. The odserved phenomenon is supposed to be caused by irradiation-induced structural transformations. Reversibility of radiation hardening of the materials in question was observed.

International Nuclear Information System (INIS)

This talk sketches out the main parameters (technology, circuit design) that have an influence on the hardening of digital CMOS integrated circuits. For each technology the more common defects are mentioned. General design rules are proposed to prevent or limit those defects. (D.L.). 2 refs., 2 figs.

International Nuclear Information System (INIS)

This paper addresses the background and the continuously evolving topics of hardening and electronic components. Typical radiation environments from 1960 are described. Examples of a civilian satellite and of future particle physics colliders help illustrate hardening problems. Effects in components, limits of shielding, and three methods of providing components are described. The authors conclude by focusing on both future trends of radiation environments and anticipated progress in electronics. (authors). 10 refs., 9 figs., 4 tabs.

International Nuclear Information System (INIS)

A program was undertaken to radiation harden an existing power integrated circuit technology (BCDMOS) to total dose, gamma dot, SEU, and neutrons. Efforts have centered around hardening and optimizing our CMOS, DMOS, and NPN devices. Initial results indicate a substantial improvement in hardness over our existing commercial technology.

International Nuclear Information System (INIS)

The Guarantee Outline presents the technical demands of design and contents of assessment for radiation hardening in satellite engineering in China. It includes the basis of design in space environment of polar orbit, the contents of design for general radiation hardening, the requirements and assessments of the single-board computer, the requirements of design for circuits (including hardware and software), the choices and assessments for devices, and the primary stipulations for the requirements of design and assessments against the phenomenon of charge and discharge.

International Nuclear Information System (INIS)

Neutron irradiation embrittlement of reactor pressure vessel (RPV) steels is one of the critical issues on aging management for long term operation of nuclear power plants. Mechanistic understanding of embrittlement is a key to accurate prediction of embrittlement, especially after long term operation where the mechanical test data are sparse. Since matrix hardening is the source of the embrittlement, we focus on matrix hardening of A533B bainitic pressure vessel steel. Bainitic matrix is composed of lath structure made by ferrite and carbides, therefore it is important to understand how this structure affects hardening behavior, and to understand irradiation response of each phase. As the typical dimension of lath structure of A533B is about one micron, nanoindentation technique is suitable for the estimation of hardening of each phase. MV ion accelerators were used for controlled irradiation because ...

International Nuclear Information System (INIS)

Assessments of the hardening and embrittlement of pressure vessel steels and welds as a function of neutron dose use trend curves derived from surveillance programs and accelerated irradiation data. A temperature dependent factor is incorporated for assessing vessel locations operating at different temperatures. As hardening and embrittlement arise from the sum of matrix damage and copper impurity precipitation, the influence of irradiation temperature on each process needs to be established. For irradiations performed below #approx# 300 C recent data shows that the dose-dependent growth of copper precipitates ceases at a mean diameter of about 2 nm that also corresponds to peak hardening and embrittlement by copper. For doses beyond this peak copper dose the property-dependence on irradiation temperature can be identified with that of matrix damage alone. An analysis of several experiments on plate steels, performed at ...

International Nuclear Information System (INIS)

Comprehensive investigation has been made into the application of the polymerization hardening by radiation, particularly electron beam, to the composites of polymers and other materials. The report is divided into four parts, namely 1) characteristics and problems of the reaction of curing by radiation polymerization, 2) improvement of the bonding capability of high molecular weight materials, 3) bonding by radiation, and 4) composites made by the impregnation and polymerization hardening of monomers. The first part includes the effects of dose rate, temperature rise during the hardening, the peculiarity of electron beam irradiation at high dose rate, reaction environment and additive effects. Main conclusions are as follows: caution must be taken to the amount of residual double bonds because they affect the quality of hardened polymers; the polymerization hardening reaction at ...

Energy Technology Data Exchange (ETDEWEB)

Tribological performance of alumina and silicon carbide ceramics as well as of the hardened steel 100Cr6 for reference was studied during reciprocating sliding and cavitation erosion in isooctane as substitute of gasoline and in distilled water. It was the aim to characterize effects of surface finish of the specimens and the liquid media on friction, resistance to sliding wear and cavitation erosion. Sliding wear tests were run on the self-mated ceramics and ceramic/steel pairs under conditions of boundary lubrication using a laboratory tribometer with cylinder-on-plate geometry. Vibratory cavitation erosion tests were conducted according to ASTM G 32-92. High initial surface roughness of coarse ground specimens led to a distinct running-in period during sliding contact with a transition from high to low values of friction coefficient and wear intensity. Incubation time was reduced with increasing surface roughness in the cavitation tests. ...

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)

Total dose irradiation effects on a VDMOS developed at Institute of Microelectronics, CAS were investigated, particularly the electric parameter changes under different bias conditions. It was found that the breakdown voltage degradation by the irradiation depended mainly on the drain bias, whereas the threshold voltage degradation depended mainly on the gate bias. Thus, an innovative and effective method to domestic VDMOS total dose ionization characterization is that threshold voltage radiation hardening characterization should be tested on gate bias condition, and the breakdown voltage radiation hardening characterization, be tested on the drain bias. (authors)

International Nuclear Information System (INIS)

... University, Fracture and Reliability Research Institute, Sendai, Miyagi (Japan)

Energy Technology Data Exchange (ETDEWEB)

Formulas were developed based on an aqueous solution of hydrolyzed polyacrylonitrile widely used in the oil industry. The additive used consisted of products of industrial production: synthetic resin TEG-1 with hardening agent PEPA (polyehtylene polyamine) and technical formalin. The mixtures containing about 80-85% by volume 5% hydrolyzed polyacrylonitrile, 10-15% by volume of resin TEG-1 with hardening agent PEPA and 3-5% by volume formalin satisfy the requirements made for the plugging materials. The initial mixtures are distinguished by technological efficiency of preparation and have controllable hardening periods. Physical-chemical properties are given for the gel polymers. In the set of properties, the mixtures based on hydrolyzed polyacrylonitrile, resin TEG-1 with hardening agent PEPA and formalin can be recommended as plugging materials of temporary action with complex treatment of the ...

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.).

British Library Electronic Table of Contents (United Kingdom)

A fully lamellar ferrite/cementite nanostructure was designed in a low C steel by using a specific thermal treatment. The strengthening of such microstructure has been investigated as a function of prestrain by rolling up to a deformation of 300%. As in usual pearlitic structure, its work-hardening shows no saturation and its elongation to fracture remains rather constant instead of decreasing drastically as conventional steels. The hardening by a similitude effect is thus not the privilege of pearlitic steels. Nevertheless, its lower initial work-hardening rate at low strain compared to an equivalent pearlitic steel and a lower hardening potential at high strain let us suspect major differences in the nature and the behaviour of ferrite channels in relation to the morphogenesis of the mic...

Science.gov (United States)

... Other Sources Toxics Intranet Subsurface Injection of Liquid Waste -- Florida Surface features of a typical...

J-STORE (Japan)

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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)

Mechanical properties of vanadium, irradiated with fast neutrons up to 8.6x10"-"4 dpa depending on postirradiation annealing temperature, are studied. It is shown that radiation-annealing hardening (RAH) is observed at 300 deg C, which agrees with earlier performed studies. It is first stated that RAH is accompanied by plasticity decrease. Phenomenological model permitting to explain RAH dependence on irradiation temperature and dose and also on content of chemically active alloying impurities is suggested.

Energy Technology Data Exchange (ETDEWEB)

An evaluation of eastern shale oil (ESO) residue as an asphalt additive to reduce oxidative age-hardening and moisture susceptibility was conducted. Rheological and infrared analyses of the unaged and aged asphalts and blends were then conducted to evaluate oxidative age-hardening. 18 refs., 5 figs., 6 tabs.

International Nuclear Information System (INIS)

Generally, neutron, ion and electron Irradiations cause a substantial amount of hardening and significantly alter the deformation behavior of metals and alloys at relatively low irradiation temperatures. A radiation hardening is caused by the formation of microstructural defects such as dislocation loops, voids and precipitates under irradiation. Therefore, it is important to have a better knowledge of the irradiation induced microstructural defects under irradiation condition. As a part of the National mid- and long-term atomic energy R and D program, we are dealing with the radiation hardening behavior in Fe-Cr binary alloy. Fe-Cr binary alloy is a base alloy of Ferritic/Martensitic steel(F/M steel) planning to use for the Gen IV nuclear system. In this work, we investigated the radiation hardening and microstructural defect evolution in ion irradiated Fe-Cr alloys with irradiation temperature using ...

International Nuclear Information System (INIS)

Fe-Cu binary alloys are often used to mimic the behaviour of reactor pressure vessel steels. Their study allows identifying some of the defects responsible for irradiation-induced hardening. But recently the influence of manganese and nickel in low-Cu steels has been found to be important as well. In contrast with existing models found in the literature, which predict that hardening saturates after a certain dose, Fe alloys containing nickel and manganese irradiated in a material test reactor (BR2) show a continuous increase of hardening, up to doses equivalent to about 40 years of operation. Considerations based on positron annihilation spectroscopy analyses suggest that the main objects causing hardening in Cu-free alloys are most probably self-interstitial clusters decorated with manganese. In low-Cu reactor pressure vessel steels and in Fe-CuMnNi alloys, the main effect is still due to Cu-rich ...

International Nuclear Information System (INIS)

The effects of key metallurgical variables on the low fluence hardening in a set of A533B model steels were evaluated over a wide range of irradiation temperatures. Above about 163 degrees C hardening increased with higher copper and nickel contents, as is typical of the pressure vessel operating regime around 290 degrees C. However, at 121 degrees C the hardening was generally lower and unaffected by copper and nickel variations. This observation of decreased hardening with lower temperature (e.g. an open-quotes invertedclose quotes temperature dependence) is tentatively attributed to a reduced contribution of copper precipitation. Tensile data for a set of commercial steels with a range of (uncontrolled) compositions also showed minimal sensitivity to copper variations at 121 degrees C. Unlike the hardness data no systematic reductions in the yield stress increases were observed between 163 and 121 ...

International Nuclear Information System (INIS)

The thermal transpiration method has been employed to replace the temperature of liquid nitrogen by #approx#12 K. This is done by bubbling He (g) through the liquid nitrogen.

Energy Technology Data Exchange (ETDEWEB)

Fatigue tests were accomplished with a series of specimens doped with trace elements of a hardened Fe-Ni-Cr alloy, cast and hardened with intermetallic phases for determining the influence of these elements on the high temperature strength properties. The results of extensive fatigue tests show that even small contents of Te, Bi, Se, Pb, Tl and Zn considerably influence the life and creep processes especially after longer running periods, when added individually or combinedly. In contrast to this, the fatigue ductility is reduced by trace element additions even with short running periods. The order in which the metallic trace elements influence the fatigue properties nearly correlates with earlier work concerning Ni- and Co-superalloys. (orig.)

International Nuclear Information System (INIS)

Defect cluster formation in 14-MeV neutron irradiated polycrystalline copper has been observed by transmission electron microscopy (TEM) and correlated with the increase in yield stress. The measurements indicate that the radiation hardening component of the yield strength in polycrystals is not directly additive to the unirradiated yield strength. A transitional behavior was observed for radiation hardening at low fluences, which produces an anomalous variation of the defect cluster barrier strength with fluence. The behavior is attributed to the effect of grain boundaries on slip band transmission. An upper limit for the room temperature barrier strength of defect clusters in neutron-irradiated copper was determined to be #alpha#=0.23. (orig.).

International Nuclear Information System (INIS)

Nano indentation analysis and transmission electron microscopy observation were performed to investigate a microstructural evolution and its influence on the hardening behavior in Fe-Cr alloys after an irradiation with 8 MeV Fe4+ ions at room temperature. Nano indentation analysis shows that an irradiation induced hardening is generated more considerably in the Fe-15Cr alloy than in the Fe-5Cr alloy by the ion irradiation. TEM observation reveals a significant population of the a0 dislocation loops in the Fe-15Cr alloy and an agglomeration of the 1/2a0 dislocation loops in the Fe-5Cr alloy. The results indicate that the a0 dislocation loops will act as stronger obstacles to a dislocation motion than 1/2a0 dislocation loops.

International Nuclear Information System (INIS)

By method of transmission electron microscopy and measuring of microhardness the peculiarities of influence of radiation defect clusters on molybdenum radiation hardening along range path of protons with 30 MeV initial energy are studied. Decrease effect of hardening growth value and even its absence depending on irradiation dose in the range of 10-20 MeV proton energies in presence of high density of radiation defect dispersed clusters is revealed. It is shown experimentally that this effect is connected with accumulation of hydrogen up to not very high concentrations (not more than 5x10"-"4 at.%) at the expense of elastic and inelastic proton scattering. 5 refs.; 5 figs.

British Library Electronic Table of Contents (United Kingdom)

This paper provides a physically-based engineering model to estimate radiation hardening of 9%Cr-steels under both displacement damage (dpa) and helium. The model is essentially based on the dispersed barrier hardening theory and the dynamic re-solution of helium under displacement cascades but incorporating a number of assumptions and simplifications [Trinkaus, J. Nucl. Mater. 318 (2003) 234-340]. As a result, the kinetics of the damage accumulation kept fixed, its amplitude is fitted on one experimental condition. The model was rationalized on an experimental database that mainly consists of 9%Cr-steels irradiated in the range of 50-600degreeC up to 50dpa and with a He-content up to 5000appm. The test temperature effect is taken into account through a normalization procedure based on the...

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No abstract prepared.

Science.gov (United States)

... Accession Number : ADA350829. Title : Operational Characteristics of a Liquid Nitrogen Powered Automobile. Descriptive Note : Master's thesis. ...

Science.gov (United States)

... MAGMA © : A LIQUID SOFTWARE APPROACH TO FAULT TOLERANCE, COMPUTER NETWORK SECURITY, AND SURVIVABLE NETWORKING ...

Energy Technology Data Exchange (ETDEWEB)

The present invention is a device for a solar heating system having a solar collector, a storage tank connected to the solar collector, a pump for circulating liquid from the tank to the solar collector, a supply of liquid at a temperature above freezing and a connection from the supply of liquid to the solar collector for replacing any liquid lost from said solar collector. The device comprises a sensor for sensing the temperature of liquid in the solar collector, and a valve for bleeding liquid from the solar collector when the sensed temperature falls below a predetermined minimum whereby cool liquid in the solar collector is automatically replaced by liquid at a temperature above freezing.

International Nuclear Information System (INIS)

Simultaneous nitriding and ageing heat treatments of precipitation hardenable tool steel was carried out inside a DC-pulsed plasma nitriding reactor. A single heat treatment cycle was done, as the plasma nitriding and age hardening processes occur approximately at the same ranges of temperatures and times. Specimens of Cr-Ni-Mo-Al age hardenable steel, in the solubilized and solubilized and aged conditions, were tested. Plasma nitriding and ageing, carried out at 500 deg. C for times ranging between 2 and 8 h, increased the surface hardness up to 1000 HV, producing case depths between 100 and 200 #mu#m. The core hardness of solubilized samples increased from 30 to 39 Rockwell C after the plasma nitriding treatment proving the possibility of nitriding and ageing at the same treatment cycle. The pre-aged samples did not show any overageing after the simultaneous plasma nitriding and ageing treatments. The corrosion resistance ...

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.

International Nuclear Information System (INIS)

Field Programmable Gate Arrays (FPGAs) are being used in space applications because of attractive attributes: good density, moderate speed, low cost, and quick turn-around time. However, these devices are susceptible to Single Event Upsets (SEUs). An approach using triple modular redundancy (TMR) and feedback was developed for flip-flop hardening in these devices. Test data showed excellent results for this circuit topology. Total dose and Single Event Effect (SEE) testing have been performed on recently released technologies. Failures are analyzed and test methodology is discussed.

Energy Technology Data Exchange (ETDEWEB)

The authors have measured the noise of MOS transistors of the United Technology Microelectronics Center (UTMC) 1.2 [mu]m radiation hardened CMOS P-well process from the weak to moderate inversion region. The noise power spectral densities of both NMOS and PMOS devices were measured from 1 KHz to 50 MHz. The bandwidth was chosen such that the important components of the spectral densities such as the white thermal noise and the 1/f noise could be easily resolved and analyzed in detail. In this paper the effects of different device terminal DC biases and channel geometries on the noise are described.

British Library Electronic Table of Contents (United Kingdom)

There is proposed the nonlinear model of dose dependence saturation of the yield strength on the base of the vacancy and interstitial barrier interaction in this work. Processes of mutual recombination of vacancy and interstitial barriers and formation of vacancy and interstitial clusters are taken into consideration. In the framework of the model, the analytical equations corresponding to the evolution of the barrier densities and yield strength are obtained. It is shown that the yield strength of irradiated materials decreases with the increasing intensity of barrier recombination processes, the dependence being nonlinear. Also it is shown that the model is valid both for low doses and large doses on the stage of radiation hardening.

International Nuclear Information System (INIS)

Corrosion testings of model alloys, corresponding by chemical composition to simple and complex-alloyed #gamma#- and #gamma#'-phases of nickel heat-resistant alloys are conducted in sodium sulfate and chloride melts. It is ascertained that heat resistant nickel alloys containing over 50 % of hardening #gamma#'-phase, are subject to disastrous sulfide corrosion (SC). Resistance against SC alloys containing below 50 % of #gamma#'-phase is determined by the resistance of #gamma#-solid solution. 10 refs., 3 figs., 2 tabs.

International Nuclear Information System (INIS)

Full text of publication follows: Radiation hardening and embrittlement due to high-energy neutron radiation around 623 K are the important issues on reduced-activation ferritic/martensitic (RAF/M) steels. It is expected that the improvement of radiation hardening might be one of effective ways to control the mechanical properties of RAF/M after irradiation. It has been reported that the weld joint has less hardening than the base metal from the tensile test results of TIG weldments irradiated in HFIR. This report indicated that radiation hardening can be reduced by the optimization of heat treatment condition for F82H. The purposes of this study are to establish the condition of heat treatment for minimum of radiation hardening in F82H steel using Neutron/Ion-irradiation and to examine a correlation between tensile property and micro-hardness before/after irradiation. The materials ...

International Nuclear Information System (INIS)

Hardened CMOS/SOI 29101 microprocessor, elementary cells and transistor shave been irradiated at levels between 10 Mrad(SiO_2) and 1 Grad(SiO_2) ("6"0Co and 10 keV x-rays). SIMOX buried oxide behavior in the range of 100 Mrad(SiO_2) and a channel-stopped MOS/SOI structure avoiding lateral leakage current are presented. These two items indicate the feasibility of a CMOS/SOI technology operating in the hundred Mrad(SiO_2) range.

Energy Technology Data Exchange (ETDEWEB)

Biomass and nutrient dynamics of black spruce seedlings during the hardening phase of the greenhouse rotation were examined after four pre-hardening fertilization regimes - conventional, constant-rate loading, exponential loading, and high exponential loading (delivering respectively 15, 40, 40 and 60 mg N seedling{sup -1}) - in order to assess nutrient dilution and steady-state nutrition. Although height growth of seedlings had virtually ceased during hardening, shoot biomass increased 99-142% and root biomass increased five- to tenfold depending on treatment. The biomass increase compromised steady-state nutrient status by diluting internal nutrient pools as nutrient supply was unable to keep up with growth. Soil nutrient levels were rapidly depleted during this period because of plant uptake and lack of fertilizer supplementation. Pre-hardening nutrient loading partly countered and delayed dilution ...

Energy Technology Data Exchange (ETDEWEB)

A number of different theoretical approaches have been used to model to atomic structure and properties of solid-liquid interfaces. Most calculations indicate that ordering occurs in the first several layers of the liquid, adjacent to the crystal surface. In contrast to the numerous theoretical investigations, there have been no direct experimental observations of the atomic structure of a solid-liquid interface for comparison. Saka et al. examined solid-liquid interfaces in In and In-Sb at lattice-fringe resolution in the TEM, but their data do not reveal information about the atomic structure of the liquid phase. The purpose of this study is to determine the atomic structure of a solid-liquid interface using a highly viscous supercooled liquid, i.e., a crystal-amorphous interface.

Science.gov (United States)

The biological age (BA) of the majority of the liquidators of the consequences of the radiation accidents in the Navy and of the liquidators of the Chernobyl' APS accident exceeds the medium standard and the DBA (due BA). The index of the BA can be a characteristic of the influence of the social-hygienic factors on the health condition of the Special Risk Subunit--the liquidators of the consequences of the radiation accidents. It was established, that the radiation influence concerns to the factors dramatically increasing the BA and the rate of senescence of the liquidators of the consequences of the radiation accidents. PMID:21809627

International Nuclear Information System (INIS)

An experimental investigation of the effect of nickel content on irradiation hardening of reactor pressure vessel steels was conducted. The alloys studied, with nickel contents ranging from 0 to 1.7%, included five sets of steels representing variations in copper contents and other metallurgical variables. Various subsets of the alloys were irradiated at selected combinations of flux, fluence, and irradiation temperature. Irradiation hardening was measured by either changes in the uniaxial yield stress or diamond pyramid hardness. Higher hardening rates with increasing nickel were observed in controlled experiments on commercial-type steels containing high copper concentrations (0.4% Cu). The effect of nickel increased with increasing fluence and decreasing temperature. At high fluence (>10"1"9 n/cm"2) the hardening increased with nickel at an average rate of about 100 MPa/%Ni. There also appeared to ...

International Nuclear Information System (INIS)

The first essential before embarking on the radiation-hardening of electrical insulation - mostly magnet coils - in any beam line application is to obtain a reliable estimate of the dose to the components. These are examples ( switchyards at SLAC and LAMPF) where the degree of hardness specified was much higher than was required. Although experience shows that the cost premium for substantial radiation - hardening is of the order of 10%, it has also become clear that well - designed beam line have negligible losses: hardening is required only in the vicinity of targets, collimators or other beam - intercepting devices. Where the beam is deliberately scraped, local shielding will minimize the associated radiation in the surroundings. Electron machines have their own special problems due to synchrotron radiation, so certainly coils and other electrical equipment should be kept away from the beam bend - plane. Because proton ...

International Nuclear Information System (INIS)

The influence of the main factors on device efficiency of pulsed liquid jet pump with gas-liquid piston is analysed, the theoretical equation and its time-averaged solution of pulsed liquid jet pump device efficiency are derived. The theoretical and experimental results show that the efficiency of transmission of energy and mass to use pulsed jet is greatly raised, compared with steady jet, in the same device of liquid jet pump. The calculating results of time-averaged efficiency of pulsed liquid jet pump are approximately in agreement with the experimental results in our and foreign countries

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... Title : Wear Rate and Friction Coefficient in Liquid Nitrogen and Hydrogen of Steel Sliding on Polymer Laminates (Various Fabrics and Polymers. ...

Science.gov (United States)

Sep 21, 2006 ... NASA has selected Air Products and Chemicals, Inc., Allentown, Pa., to design, furnish and install a plant to produce liquid nitrogen for ...

Science.gov (United States)

Al2O3-based ceramic is one of the most widely used materials for tools employed in hardened steel turning applications due to its high hardness, wear resistance, heat resistance and chemical stability. The objective of this work is to predict the lives of Al2O3-(W, Ti)C ceramic tools in intermittent turning of hardened AISI 1045 steel by means of damage evolution model taking into account the mechanical loading and thermal effect in the cutting process. A damage evolution model analyzing the RVE with uniformly distributed interacting cracks is constructed based on micromechanics. The calculated results of the proposed damage evolution model are compared with the lives of two kinds of Al2O3-(W, Ti)C ceramic tools obtained through experiments. It is found that the proposed model can be used to predict the lives of the ceramic cutting tools in intermittent turning operation.

Energy Technology Data Exchange (ETDEWEB)

Hard surface finishing represents the final manufacturing step for functional areas of machine elements in state-of-the-art production. Raceways of rolling bearing rings are ground and honed to the required low roughness. Plastic deformation is restricted to a narrow edge zone of the hardened steel. Reheating of the machined components below the martensite tempering or bainite transformation temperature results in a marked decrease of the XRD line width on the surface. The investigated samples are made of through-hardened standard bearing steel 100Cr6 (international denotation: SAE 52100). On the basis of a material model that explains the effect as a complex diffusion process of dislocational carbon segregation, i.e. static strain aging, the measured kinetics of the XRD line width reduction is simulated by an Arrhenius-type equation, which describes the rate-controlling reaction step of temper carbide dissolution. The formation of a small ...

International Nuclear Information System (INIS)

Pressureless-sintered AlN and hot-pressed, pressureless-sintered and reaction-bonded SiC were neutron irradiated at temperatures between 100 and 785degC up to a fluence of 5.2 x 10"2"4 n/m"2. The hardness was increased by up to 51% in AlN and 84% in SiC. The hardness decreased after annealing at temperatures around the irradiation temperature. At the same temperatures, the macroscopic length, which was increased by irradiation, also began to decrease. The hardness and length were almost recovered after 1,200 #approx# 1,400degC annealing. Thus, hardening in irradiated AlN and SiC is controlled by the number of point defects, or, more precisely, by the strain caused by small point defect clusters which pin down dislocation movement. Dislocation loops were still observed in some samples after 1,400degC annealing while the hardness was almost recovered to that in the unirradiated state. Thus, the existence of dislocation loops is not grounds for ...

CERN Document Server

Volume sources is used for standard sources by radioactive measurement using Ge semiconductor detector of environmental sample, e.g. water, soil and etc. that require large volume. The commercial volume source used in measurement of the water sample is made of agar-agar, and that used in measurement of the soil sample is made of alumina powder. When the plastic receptacles of this two kinds of volume sources were damaged, the leakage contents cause contamination. Moreover, if hermetically sealing performance of volume source made of agar-agar fell, volume decrease due to an evaporation off moisture gives an error to radioactive measurement. Therefore, we developed the two type methods using unsaturated polyester resin, vinilester resin, their hardening agent and acrylicresin. The first type is due to dispersing the hydrochloric acid solution included the radioisotopes uniformly in each resin and hardening the resin. The second is due to ...

CERN Document Server

The massive stars in the Galactic center inner arcsecond share analogous properties with the so-called Hot Jupiters. Most of these young stars have highly eccentric orbits, and were probably not formed in-situ. It has been proposed that these stars acquired their current orbits from the tidal disruption of compact massive binaries scattered toward the proximity of the central supermassive black hole. Assuming a binary star formed in a thin gaseous disk beyond 0.1 pc from the central object, we investigate the relevance of disk-satellite interactions to harden the binding energy of the binary, and to drive its inward migration. A massive, equal-mass binary star is found to become more tightly wound as it migrates inwards toward the central black hole. The migration timescale is very similar to that of a single-star satellite of the same mass. The binary's hardening is caused by the formation of spiral tails lagging the stars inside the binary's ...

International Nuclear Information System (INIS)

Tungsten (W) coating on fusion candidate V-4Cr-4Ti (NIFS-HEAT-2) substrate was demonstrated with plasma spray process for the purpose of applying to protection of the plasma facing surface of a fusion blanket. Increase in plasma input power and temperature of the substrate was effective to reduce porosity of the coating, but resulted in hardening of the substrate and degradation of impact property at 77 K. The hardening seemed to be due to contamination with gaseous impurities and deformation by thermal stress during the coating process. Since all the samples showed good ductility at room temperature, further heating seems to be acceptable for the vanadium substrate. The fracture stress of the W coating was estimated from bending tests as at least 313 MPa, which well exceeds the design stress for the vanadium structure in fusion blanket. (author)

International Nuclear Information System (INIS)

By means of the light microscopy and by the measurement of the mechanical properties one investigated into the phase composition and the properties of Al-Mg-Ce and Al-Mg-Y system alloys. One plotted the isothermal cross sections of the mentioned systems under 430 and 275 deg C temperatures at up to 16% magnesium concentration and up to 0.7% yttrium concentration. One determined the yield limit and strength, the relative elongation of Al-Mg base hardened and deformed alloys containing 7.0-9.9% Mg and Ce, Y, Mn, Zr dopes upon ageing under 175, 200, 250 and 300 deg C temperatures within the ageing time ensuring the hardening maximum effect

International Nuclear Information System (INIS)

Smooth and notched fatigue behavior is presented for an age-hardenable metastable #beta#-titanium alloy (Ti-3Al-8V-6Cr-4Mo-4Zr). The as-solution heat treated condition exhibits low fatigue limits and high ductility, while the high-strength condition has higher fatigue limits, but poor ductility. A new thermomechanical technique employs shot peening and heat treating to selectively age-harden only the surface. The fatigue limit is improved to levels well above that of the high strength condition, while retaining appreciable ductility, since the bulk material remains in the solution heat treated condition. (orig./MM).

International Nuclear Information System (INIS)

The RD50 collaboration has been exploring the development of radiation hard semiconductor devices for very high-luminosity colliders since 2002. The target fluence to qualify detectors set by the anticipated dose for the innermost tracking layers of the future upgrade of the CERN large hadron collider (LHC) is 1016 1 MeV neutron equivalent (neq) cm-2. This is about an order of magnitude higher than the maximum dose for the most exposed silicon detectors in the current machine. RD50 investigates the radiation hardening of silicon sensors from many angles: improvement of the intrinsic tolerance of the substrate material, optimisation of the readout geometry and study of novel design of detectors. A review of some of the recent activities within RD50 is here presented.

International Nuclear Information System (INIS)

Modern commercial alloys are not suited for future steam turbines of operating temperatures beyond 700 C. #gamma#'-hardened alloys like Waspaloy have good mechanical characteristics but have defects when large batches are melted. #gamma#'/#gamma#''-hardened alloys like Inconel 706, on the other hand, are easy to produce but have insufficient microstructural long-term stability and insufficient creep strength. Mixed crystal solidified alloys like Inconel 617 have excessive yield stress at forging temperatures. Two new alloys were therefore developed. Results so far show that they have good production characteristics but insufficient mechanical characteristics. The reasons for this are currently under investigation. (orig.)

International Nuclear Information System (INIS)

The condition for obtaining a calorimetric response linear with energy for hadronic showers and an energy resolution that improves as the incident energy increases is the equalization of the electromagnetic (e) and the hadronic (#pi#) signal responses. This equalization is obtained by exploiting a local hardening effect realized through the insertion of low-Z thin plates between the high-Z absorbers and the active material in a hadronic calorimeter with silicon readout. This effect, which allows the reduction of the calorimeter response to the electromagnetic component of the incoming hadronic showers, has been investigated for different low-Z materials. The relevance of some aspects of this study to the radiation hardness of the calorimeters is also addressed. (orig.).

British Library Electronic Table of Contents (United Kingdom)

The determination of residual stress (RS) in case-hardened steel gear truck synchronisers coated with thermal sprayed molybdenum was carried out using neutron and synchrotron X-ray diffraction. Two samples with different coating thicknesses (about 120 ?m and 1.4 mm) and different steel substrates (16MnCr5 and SAE4140, respectively) were investigated. Microanalysis revealed substantial porosity in both samples and some debonding was observed between the thin coating and the substrate. The bulk hardness of the SAE 4140 proved to be much higher than the 16MnCr5 and the surface case-hardening increased it by a further 20%. The full three-dimensional stress depth-profile was determined by neutron diffraction (ND) in both the coatings and the substrates, while synchrotron radiation allowed a dep...

International Nuclear Information System (INIS)

... The results show that a system decontamination factor of 10^ to 10* can be

Science.gov (United States)

In order to reduce the potential for severe liquid pipeline accidents, the U.S. Materials Transportation Bureau (MTB) proposes to require a hydrostatic test on all onshore pipelines carrying highly volatile liquids which have not been previously tested to at least 1.25 times their maximum operating pressure for at least 24 hr. Comments should be received by the MTB by 2/15/79. Late filed comments will be considered as far as practicable.

International Nuclear Information System (INIS)

The review is devoted to the use of ionic liquids as solvents, immobilized organocatalysts and reagents in reactions involving carbon acids and 1,3-dipoles, which are widely used to prepare practically valuable organic compounds of various classes. The characteristic features of processes in the presence of ionic liquids, the effects of the structure of cations and anions on the regio-, stereo- and enantioselectivities of reactions and methods of recovery of ionic liquids are considered.

CERN Document Server

A qualitatively different manifestation of the Rayleigh instability is demonstrated, where, instead of the usual extended undulations and breakup of the liquid into many droplets, the instability is localized, leading to an isolated narrowing of the liquid filament. The localized instability, caused by a nonuniform curvature of the liquid domain, plays a key role in the evaporation of thin liquid films off solid surfaces.

British Library Electronic Table of Contents (United Kingdom)

Tthe acceleration of a liquid from a cylindrical container by the products of instantaneous detonation of a superimposed explosive charge (implosion method) is studies numerically in a two-dimensional formulation. Analytical formulas for the asymptotic velocities of liquid expansion and acceleration of the container body were obtained using numerical calculations in a one-dimensional approximation. The effect of the fracture of the body on the velocity of liquid expansion was studied in a two-dimensional formulation.

Science.gov (United States)

A description is given of an automatic liquid nitrogen pumping system. Pamping of liquid nitrogen iato cooling traps up to a predetermined level is achieved by an automatically controlled compressed air system. An impontant feature of the equipment is the ability to switch automatically from an empty liquid nitrogen reservoir to a full one. This allows for a much more flexible operation than in conventional systems where the reservoir has to be replaced manually when empty. (auth)

Energy Technology Data Exchange (ETDEWEB)

Hydrothermal systems typically consist of hot permeable rock which contains either liquid or liquid and saturated steam within the voids. These systems vent fluids at the surface through hot springs, fumaroles, mud pools, steaming ground and geysers. They are simultaneously recharged as meteoric water percolates through the surrounding rock or through the active injection of water at various geothermal reservoirs. In a number of geothermal reservoirs from which significant amounts of hot fluid have been extracted and passed through turbines, superheated regions of vapor have developed. As liquid migrates through a superheated region of a hydrothermal system, some of the liquid vaporizes at a migrating liquid-vapor interface. Using simple physical arguments, and analogue laboratory experiments we show that, under the influence of gravity, the liquid-vapor ...

International Nuclear Information System (INIS)

Thermal hydraulics of a liquid metal is important to design the blanket of a magnetic confined fusion reactor. Since a liquid metal has high thermal and electrical conductivity, the flow characteristics are often different from those of an ordinary liquid like water especially in thermal convection and under a magnetic field. It is difficult to simulate such flows in a liquid metal cooled blanket by water. Flow visualization is a popular method to study thermal hydraulics. Since most of metals are visible by neutron rays, neutron radiography is available to the flow visualization of a liquid metal. The purpose of this study is to develop a visualization technique of the flow in a liquid metal by real-time neutron radiography using the tracer and the dye injection methods. A real-time thermal neutron radiography system of JRR-3M in Japan Atomic Energy Research ...

British Library Electronic Table of Contents (United Kingdom)

The atomic mechanism of a glass-to-liquid transition in a monatomic Lennard-Jones (LJ) glass was studied using the molecular dynamics (MD) method. Glassy models were heated up from low temperature at two different heating rates and a glass-to-liquid transition found to occur at the higher heating rate. The temperature dependence of the potential energy, mean-squared-displacements (MSD) of the atoms and the self-intermediate scattering function indicate clearly that a glass transition occurs in the system. The atomic mechanism of the glass-to-liquid transition was investigated by analyzing the spatio-temporal arrangement of liquid-like atoms in the system upon heating. Liquid-like atoms were detected using the Lindemann-melting-like criterion. Upon heating, liquid-like atoms occur at temper...

Energy Technology Data Exchange (ETDEWEB)

The temperature and pressure dependence of the mobilities of negative charges injected into liquid hydrogen and deuterium have been measured. The authors propose the existence of two types of charge carriers in liquid parahydrogen. One is a bubble with an electron inside while the other has higher mobility. Relaxation of the current through liquid hydrogen was observed. It is suggested that in liquid and solid hydrogen under {beta}-irradiation neutral complexes are created which can trap the negative charges and have a lifetime of about 10 hours. 6 refs., 5 figs.

Energy Technology Data Exchange (ETDEWEB)

The strain gradient crystal plasticity theory is applied to study the deformation of planar single crystal with a void under a nominally uniaxial tension. The crystal theory assumes elevated strain hardening due to slip gradients and has a constitutive length scale. The effects of the void size with respect to the constitutive length scale on the single crystal deformation are investigated.

Energy Technology Data Exchange (ETDEWEB)

Stress relaxation was studied at 408 K on AZ31 reinforced by ceramic foam produced by in situ foaming of filler loaded preceramic polymer melt. Reinforcement causes significant enhancement of the resistance against stress relaxation compared to AZ91. It is correlated with hardening by the ceramic skeleton as well as ceramic particles formed in the AZ31-matrix. (orig.)

International Nuclear Information System (INIS)

The influence of additionally injected short-wavelength photobleaching light on the radiation hardness of Ge-doped graded index fibers working at 1,300 nm wavelength is investigated. Predictions are complicated by the fact that more efficient shortwave bleaching light experiences higher radiation-induced loss. Promising results are found for low fiber temperatures (approx-lt -50 C) and bleaching light of about 835 nm wavelength.

International Nuclear Information System (INIS)

The influence of RTA (Rapid Thermal Anneal) treatment on MOS radiation hardness is demonstrated and compared with classical furnace treatment. In the case of the RTA, the oxide trapped charge is found to depend on: (i) the anneal temperature as expected, data are in good agreement with a recently developed model of oxygen out-diffusion; (ii) the location across the wafer with a radial dependence, results could be related to stress induced by thermal gradient.

Energy Technology Data Exchange (ETDEWEB)

Carbide reactions occurring in a precipitation-hardening gamma/gamma-prime Ni-Cr alloy during prolonged high-temperature aging are investigated experimentally. It is found that the decomposition of primary MC carbides, which is accompanied by the precipitation of M23C6 particles, may lead to void nucleation and growth. The effect of carbide transformations on the residual properties of the material at temperatures above the equicohesion temperature is observed at the late stages of aging only. 6 references.

Science.gov (United States)

An instrument has been constructed for the measurement of residual stress in steel. If necessary, large objects can be examined in situ. An account is given of the principles and construction. A special stressing frame provides for calibration. An application to residual stress in gear blanks has established a systematic variation of surface stress with nickel content and confirmed the overall effect of the surface hardening treatment.

Science.gov (United States)

Critical power at boiling transition is an important factor in a boiling water reactor (BWR) fuel bundle design. Boiling transition under high quality accounts for dryout as the result of the complete disappearance of film flow on a fuel rod. This liquid film vanishing process can be calculated by the liquid film model, which takes into account the evaporation due to heat from the rod surface, liquid film entrainment by steam flow, and liquid droplet deposition. It is known that spacers affect liquid film entrainment and liquid droplet deposition, so the detailed study of spacer effects on hydrodynamic characteristics is necessary for critical power prediction based on the film flow model. Many studies have been conducted to examine spacer effects on liquid film flow. However, most of them are restricted to simple test sections such as a ...

International Nuclear Information System (INIS)

Purpose: To enable the solidification of liquid waste containing radioactive substance in a free shape with large volume reduction ratio without a pulverizing step by producing solute in the liquid waste as a slurry in a predetermined organic solvent and forming it into a cake by mechanical exfoliation. Method: Liquid waste containing suitably concentrated radioactive substances is supplied to a centrifugal thin film evaporator together with an organic agent having a higher boiling point than water and a non aqueous solution to evaporate the water content, the solute in the waste is produced as a slurry in the organic solvent, and removed as cake-state solute slightly residued with the organic solvent by the mechanical exfoliation such as centrifugal exfoliation or settling exfoliation from the slurry-state liquid. Accordingly, it can be increased in size as compared with the powder reduced in volume of ...

Science.gov (United States)

The classical Stefan theory for the melting of a solid or the freezing of a liquid is too simplistic to describe phenomena such as supercooling, in which a liquid supports temperatures below its freezing point, or superheating, the analog for solids, or d...

Energy Technology Data Exchange (ETDEWEB)

By a direct Archimedes' technique, volumetric data were obtained for liquid In, Mg, Pb, and Sb and mixtures of In-Sb, Mg-Sb, and Pb-Sb. In this paper the excess volumes for the alloys studied are presented and discussed.

Energy Technology Data Exchange (ETDEWEB)

The use of ionic liquids for post combustion capture was discussed. Compared to other solvents, ionic liquids can be used in higher concentrations. Other advantages include the large variation in physical and chemical properties and the non measurable vapor pressure. In this study, 78 different ionic liquids were synthesized and the carbon dioxide absorption rate was measured. The most promising ionic liquids were produced and various tests were made to identify the most suitable absorption solvent. The vapor-liquid equilibrium curve was measured between 40 and 110 degrees C. Pilot plant tests with MEA and one selected ionic liquid test with 30 per cent MEA at the pilot plant at the EVNs Duernrohr Power Station in Lower Austria are running successfully with a capture performance of approximately 87 per cent. The experiments will provide a direct comparison of ...

Energy Technology Data Exchange (ETDEWEB)

Ionic liquids can enhance the activity, selectivity, and stability of enzyme catalysts. Enzymes and ionic liquids as catalysts are seen as a more environmentally friendly technology than the use of traditional catalyst materials in biofuels production. This study investigated the lipase catalyzed esterification reaction for biodiesel production in the presence of the ionic liquid BMIM PF{sub 6}. Methyl acetate was used as the acyl acceptor. A titremetric assay was conducted to measure the activity of the lipase with various amounts of ionic liquid. Reaction parameters were investigated in order to determine their effects on biodiesel conversion. An 80 per cent overall methyl oleate biodiesel yield was successfully produced in the presence of the ionic liquid. The ionic liquid improved lipase activity as well as overall biodiesel yield. Results also showed that ...

UK PubMed Central (United Kingdom)

Denaturing high-performance liquid chromatography (DHPLC) has been used extensively to detect genetic variation. We used this method to detect and identify Yersinia pestis KIM5 ciprofloxacin-resistant...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A consistent statistical theory of the crystal-liquid phase transition is developed, being based on a method which takes into account liquidlike fluctuations in crystals and solidlike clusters in liquids. It is shown that degenerate fluidlike droplets have a finite number density at zero temperature, while nondegenerate fluctuations disappear when the temperature goes to zero. The existence of a melting point is proved. This method, which takes into consideration the heterophase fluctuations, provides the possibility of describing metastable states such as a supercooled liquid or an overheated crystal. Conditions for the existence of metastable states are found. The liquid-glass transition can also be described by the method presented here.

Energy Technology Data Exchange (ETDEWEB)

We searched for signs of an instability on the interface between the two phases of a binary-liquid mixture, isobutyric acid and water, after the mixture was quenched further into the two-phase region. Such an instability would be the liquid-liquid analog of the Mullins-Sekerka instability seen in quenched alloys. Never is any dramatic growth observed, but under conditions of small dimensionless quench depth (theta<1.5 x 10/sup -3/), the intensity of light scattered from the interface grows for small values of the momentum transfer k.

Science.gov (United States)

Subcritical cryogenic fluid management has long been recognized as an enabling technology for key

Energy Technology Data Exchange (ETDEWEB)

Scintillation light in liquid xenon excited by 100 MeV/n Al ions was detected with a home-made silicon photodiode. The diameter of the photodiode was 2 inch. The effective quantum efficiency was observed to be 22% for the wavelength of liquid xenon scintillation light (170 nm), while the effective quantum efficiency for 5.486 MeV alpha-particle excitation was 44%. An energy resolution of 0.5% rms was achieved for the energy deposition of 2.5 GeV in liquid xenon using a fast preamplifier ({approx equal} 20 ns). (orig.).

Science.gov (United States)

Gaseous Nitrogen Dewar apparatus developed by Dr. Alex McPherson of the University of California,

International Nuclear Information System (INIS)

... fast reactors fbr type reactors fuels liquid metal cooled reactors materials nuclear

Energy Technology Data Exchange (ETDEWEB)

Computational fluid dynamics(CFD) code FLUENT was used to simulate the thermal hydraulic processes occurring in conceptual design of the accelerator-driven subcritical reactor(ADSR) liquid lead target. The purpose of the analysis is to investigate the thermal hydraulic characteristics of liquid lead as ADSR target material with various target geometries and injection locations of proton beam. In the calculation analysis, the local temperature of the liquid lead target rises to the boiling temperature very rapidly. When the proton beam is injected from the bottom of the target system, the duration time to reach the boiling temperature is longer and the temperature distribution is flatter than other cases.

CERN Document Server

The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the gas phase, except in the case of xenon for which measurements are available in the liquid. The scattering length mayplace constraints on the design of some large-scale detectors, using uv luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas mixtures is also discussed.

Science.gov (United States)

A cryostat is described that was developed for irradiating a number of small metal specimens with a high beamcurrent of heavy particles at liquid nitrogen temperature. The specimens, which are mounted on a block, are taken out of the cryostat after irradiation and subsequently annealed in a temperature bath. The progress of annealing is followed by measuring the change in electrical resistivity of the specimens in liquid helium. (auth)

International Nuclear Information System (INIS)

It if first shown, that the effective field of uniaxial magnetic anisotropy of Fe-Cr-P-C and Fe-Ni-B-Si system amorphous alloys is reduced with an increase of the source melt isothermal exposure time. The behaviour noted is conditioned by microcoherence and relaxation processes in the nonequilibrium liquid phase after crystal-liquid phase transition.

Energy Technology Data Exchange (ETDEWEB)

A hose lining process, used widely for underground service structures, such as for city gas, and water and sewerage pipes, was adopted to repair interiors of underground wire raceways, and improvements were made for power cable pipe use, including long size construction, inner diameter assurance, and flame retardation. The sealing hose as a lining material consists of a fabric layer woven by warps of polybutylene terephthalate (PBT) and wefts of combined PBT fibers and glassfibers, the fabric being coated with polyurethane resin on one side. The other side of the fabric is coated with heat hardening resin made of epoxy resin as the main ingredient and aromatic amine as the hardening agent to assure close adhesion of the sealing hose onto the pipe interior. Mimic raceways were used to verify the lining material for its abrasion coefficient, mechanical strength, wear resistance, water cut-off performance, chemical resistance, and shape retention ...

International Nuclear Information System (INIS)

Radiation damage of the final optical components in an Inertial Confinement Fusion (ICF) reactor is a crucial issue for development of a laser-fusion reactor. To some extent, this problem will be encountered in the National Ignition Facility (NIF), but there, the integrated radiation dose will be considerably less than that encountered in a future reactor. This extremely harsh radiation environment necessitates shielding the ICF optics from direct neutron and x-ray bombardment. Several approaches have been suggested, such as the use of grazing incidence metal mirrors or fused silica wedge deflectors. While metal mirrors can withstand a larger radiation dose, their focusing qualities pose problems. Therefore wedge deflectors, originally suggested by Lawrence Livermore National Laboratory (LLNL) staff, represent a promising alternative. Radiation hardening of the fused silica deflectors using a new combined thermal/optical annealing approach is examined here as a ...

International Nuclear Information System (INIS)

Total-dose irradiation seriously damages MOS devices and their circuit performance. Threshold voltage shifts, transconductance degradation and increase in off-state leakage current are generally observed for irradiated devices. These instabilities are essentially due to positive and/or negative charge trapping in SiO_2 and interface trap generation at the SiO_2/Si interface. Radiation hardening of CMOS VLSIs is to eliminate these trapping effects, and for this purpose, special considerations for fabrication processes and layout design are necessary. In this paper, basic mechanisms for radiation-induced charge trapping and related effects on MOS devices are reviewed. Also discussed are radiation-hardening technologies from both fabrication-process and layout-design viewpoints. Using these technologies, 1 #mu#m radiation-hard CMOS gate arrays have been successfully developed. Experimental data taken for 2k-gate test chips indicate that radiation ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this program is to tool-harden and make commercially available an existing wireless MWD tool to reliably operate in an air, air-mist, or air-foam environment during Appalachian Basin oil and gas directional drilling operations in conjunction with downhole motors and/or (other) bottom-hole assemblies. The application of this technology is required for drilling high angle (holes) and horizontal well drilling in low-pressure, water sensitive, tight gas formations that require air, air-mist, and foam drilling fluids. The basic approach to accomplishing this objective was to modify GEC's existing electromagnetic (e-m) CABLELESS''{trademark} MWD tool to improve its reliability in air drilling by increasing its tolerance to higher vibration and shock levels (hardening). Another important aim of the program is to provide for continuing availability of the resultant tool for use on DOE-sponsored, and other, ...

International Nuclear Information System (INIS)

Contrary to previous plans for the preparation of diagnostic systems for D-T break-even experiments in the Tokamak Fusion Test Reactor (TFTR), it now appears that a limited Q#approx#1 demonstration can be carried out without constructing a close-fitting igloo radiation shield around the tokamak. In order to assess the impact of D-T operation of TFTR without an igloo shield, particularly with regard to hardening of diagonstic systems, we have mapped neutron and gamma fluxes inside the test cell and test cell basement, using a variety of radiation measurements. The measurements are sufficiently detailed to resolve massive hardware components, such as neutral beams and shielded diagnostic systems, and can be used to predict local fluxes. By comparing the measurements with transport code calculations for the case of a bare tokamak, we conclude that the models have substantially overestimated fluxes both inside and outside the TFTR shield walls. It may be possible to ...

International Nuclear Information System (INIS)

For an assessment of the future US spallation neutron source (SNS) target performance, radiation induced hardening and microstructural evolution were investigated as a function of ion dose for EC316LN stainless steel. Irradiation was carried out using 3.5 MeV Fe"+, 360 keV He"+, and 180 keV H"+ simultaneous ion-beams at 200 deg. C to simulate the damage, He and H production in the SNS target vessel wall. At low dose (< 1 dpa), the predominant defects were black dots whose number density saturated rapidly within a few dpa. This was followed by the evolution of interstitial loops whose number density saturated below 15 dpa. Although He-bubbles were not visible, severely scalloped loops suggested that the implanted He/H atoms existed in the form of small clusters. Comparison with reported neutron irradiation data showed that hardening and ductility loss occurred mostly in the black dot regime (< 1 dpa), but that good ductility (>20% ...

Energy Technology Data Exchange (ETDEWEB)

Effect of the coverage of shot peening, the surface roughness and shot shape, etc. on the stress corrosion cracking (SCC) of Alloy 800 in alkaline solutions was studied. Alloy 800 specimens were cracked in boiling alkaline solutions at the potntial range of {minus} 100 to 0mV in the boiling 50%NaOH+0.3%SiO {sub 2} solution. U bend specimens were tested under the polarized condition at the controlled potential to 0mV, showing that shot peened specimens cracked more easily. Tests of specimens with the same hardness showed that specimens hardened by cold working showed the higher susceptivity than that of surface hardened specimens. In these connections, U bend specimens of higher shot peened coverage were cracked at conditions of 593K and 10%NaOH solution. O-ring specimens of smaller stress level did not show any cracks independent of surface treatments. 8 refs., 9 figs., 5 tabs.

International Nuclear Information System (INIS)

Plasma nitriding is a powerful technique for modifying the phase-structure of the material surface layers, which affect the mechanical, physical and chemical properties of material. The effect of plasma nitriding on the surface properties of three types of steel (low carbon, AISI-304 and H13 (hardened)) has been investigated. The steel samples were plasma nitrided in vacuum of 10"-"1Pa with gas mixture of (N_2, H_2) at 530 Centigrade degree for a duration of 14 hours. Vickers microhardness measurements and XRD phase analysis of the treated and untreated samples were carried out. The diffraction patterns of treated steels revealed that new phases of #gamma#-Fe_4N, #epsilon#-Fe_3N and (Fe,Cr)_2N were formed. The maximum treated depths were about 5, 6 and 45 #mu#m for low carbon, AISI-304 and H13 (hardened) nitrided steel respectively. The microhardness was increased by about 150%, 200% and 140% for low carbon, AISI-304 and H13 nitrided samples ...

International Nuclear Information System (INIS)

The theoretical hardness against total dose of the six-transistor SRAM cell is investigated in detail. An explicit analytical expression of the maximum tolerable threshold voltage shift is derived for two cross-coupled inverters. A numerical method is used to explore the hardness of the read and write operations. Both N- and P-channel access transistors designs are considered and their respective advantages are compared. The study points out that the radiation hardness mainly relies on the technology. Results obtained with the very robust Gate-All-Around process are finally presented.

British Library Electronic Table of Contents (United Kingdom)

The shrinkage of the cement paste with low water-cement ratio at different relative humidity was observed and analyzed with ESEM and deformation map technique. The crack morphology was observed with different magnification with SEM and FESEM, and the formation of the crack was observed with AFM between two C-S-H nano particles. The observation by multi technique at multi scale indicated that the shrinkage was increase with the decrease of the humidity due to the increase of the pressure of the capillary pressure, the morphology of the crack in smaller scale was similar to that in the bigger scale, the smaller crack distributed in the latticework of the bigger ones, and the crack propagated along the gap between two nano particles of C-S-H with weaker bonding.

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)

Compositions (oligomers with suitable properties and Al, Fe, Cu, Ta, W powders) were hardured by the flux of accelerated electrons at 10 mA beam current and 1.5 MeV energy. Dielectric and mechanical properties of metal-filled polymeric compositions as well as their radioply sicl properties in SHF-range are studied. It is shown that the produced compositions belong tot he absorbing protective materials in which the protection effect is mainly achieved through the absorption losses. 6 refs.; 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

Steel is one of the most versatile materials known to mankind. It is used in a variety of applications. In many of these applications, it is exposed to the atmosphere, leading to rust formation, which weakens structures made using steel. Hence, protection is important. The popular methods to prevent corrosion are painting, galvanizing, electroplating etc. The widely used Chrome etching process is very effective in corrosion inhibition as well as in hardening the steel. But, Chromium and its compounds are highly placed among the toxic chemicals listed under pollution prevention initiatives of the EPA. Hence, it was decided to find alternatives to this process.

International Nuclear Information System (INIS)

A study is made into microhardness and structure of coatings on various system steels (37G2S, 25Kh5M, R6M5), obtained by ion nitriding in a low pressure (10"-"1 Pa) arc discharge plasma. A comparison of properties is accomplished for steels nitrided in an arc gas discharge and in a furnace. It is stated that ion-plasma nitriding in an arc gas plasma generator is an efficient method of alloy steels hardening which allows changing the structure and increasing the hardness of a surface layer up to rather great depth

Energy Technology Data Exchange (ETDEWEB)

By characterising the microstructure, quantitative image analysis allows to draw conclusions on the mechanical properties of materials. On fine microstructures with low contrast, e.g. of hardened steels, texture analysis has to be applied for quantification. Feeding texture parameters according to Haralick into a trained neural network, a correlation between the microstructure and the hardness of the steels C45 and 100Cr6 can be achieved. (orig.)

International Nuclear Information System (INIS)

The evolution of metallic substance atomic structure is studied on temperature variation including crystal heating up to melting points, a crystal- liquid phase transition and initiation of a high-density liquid specific structure. It is marked that heat induced changes of simple metal structure can be described as changes around a natural elementary cell which is common for both a crystal and a liquid and consists of a central atom and Z_1 atoms of the first coordination sphere. On this basis the vacancy model of melting is verified. Concentrations of melting vacancies are determined by coordination numbers in the form of Z_1/(1+Z_1)"2 which are the same for both a crystal and a natural elementary cell. The size of natural elementary cells is in an agreement with that of the coordination sphere featured in the liquid and phase transition statistical theory. Calculated data are given for a number of ...

Science.gov (United States)

The thermal conductivity of liquid CHCl3, C6H6, and CCl4 is measured by a steady-state method under saturated vapor pressure in the temperature regions corresponding to pre-crystallization temperatures. The experimental results obtained are used to investigate the isobaric thermal conductivity jump ??p at the crystal-liquid phase transition in CHCl3, C6H6, and CCl4. The contributions of the phonon-phonon and phonon-rotational interaction to the total thermal resistance in solid and liquid state are specified using a modified method of reduced coordinates. The decrease in the thermal conductivity at the crystal-liquid phase transition, ??p, is explained by a combined effect of variations in positional distribution of molecules and in the form of rotational molecular motion.

International Nuclear Information System (INIS)

A detergent-containing radioactive liquid waste originating from atomic power plants is concentrated to have about 10 wt. % detergent concentration, then dried in a thin film evaporator, and converted into powder. Powdered activated carbon is added to the radioactive waste in advance to prevent the liquid waste from foaming in the evaporator by the action of surface active agents contained in the detergent. The activated carbon is added in accordance with the COD concentration of the radioactive liquid waste to be treated, and usually at a concentration 2-4 times as large as the COD concentration of the liquid waste to be treated. A powdery product having a moisture content of not more than 15 wt. % is obtained from the evaporator, and pelletized and then packed into drums to be stored for a predetermined period.

International Nuclear Information System (INIS)

Object: To minimize the range of the liquid level variation of the cooling system and reduce the time required for the liquid level control by sealing the gas of a cover gas respiration system which acts upon an evaporator and pump overflow column. Structure: In liquid level control by the cover gas pressure of a high-speed reactor secondary cooling system, upon occurrence of a sudden change in the rate of flow of the recirculated liquid, automatic check valves provided in an evaporator and pump overflow column cover gas respiration system are completely or substantially closed, while at the same time the recirculation cooling medium is sucked up and an automatic check valve provided in the overflow system is closed. (Kamimura, M.).

British Library Electronic Table of Contents (United Kingdom)

A qualitative method, involving supported liquid?liquid extraction (SLE) and ultra high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS?MS), was developed for the rapid tentative identification of various drugs of abuse in urine. In this study, 28 drugs and metabolites were covered by the screening procedure. Before analysis, urine samples were extracted by SLE and good extraction recoveries were obtained for most investigated compounds. The UHPLC strategy was then selected for the rapid separation of amphetamines, cocaine, opiates and related compounds in urine. Using columns packed with sub-2??m particles, analysis time was reduced down to 2?min, while maintaining acceptable performance. Finally, the detection was by tandem MS operating in the single reaction...

Energy Technology Data Exchange (ETDEWEB)

In this study samples of AISI 4140 steel were pretreated by plasma nitriding and coated with two different physical vapour deposited coatings (TiN and TiAlN). A hardened AISI 4140 sample and a coated sample were also included in the investigation. To examine the influence of the nitrided zone on the performance of the coating-substrate composite, two different nitriding conditions - a conventional 25% N{sub 2} and an N{sub 2}-poor gas mixture - were used. The specimens were investigated with respect to their microhardness, surface roughness, scratch adhesion and dry sliding wear resistance. Wear tests in which the duplex-treated pins were mated to hardened ball bearing steel discs were performed in a pin-on-disc machine under dry sliding conditions. Metallography, scanning electron microscopy and profilometry were used to analyse the worn surfaces in order to determine the dominant friction and wear characteristics of the samples investigated. ...

Energy Technology Data Exchange (ETDEWEB)

High temperature structures of LMR experience inelastic deformation such as plasticity and creep due to high temperature operating temperature of 530{approx}550 .deg. C. The generated creep strains are connected with the stress relaxations, redistributions and/or progressive deformations. The superposition of primary and secondary stresses may lead to enhanced creep deformations. The term 'creep ratchetting' refer to the phenomenon where enhanced creep occurs with plasticity ratcheting. The interchange of elastoplastic and creep strains is important for its understanding. Since creep ratcheting is highly nonlinear structural behavior, it is required to secure the proper analysis technique to evaluate inelastic strain due to enhanced creep. In this project, the simplified evaluation method for enhanced creep using core stress concept was investigated and the enhanced creep of pipe subjected to sustained axial tensile loading and transient thermal loading with hold time ...

International Nuclear Information System (INIS)

Full text of publication follows: Fission neutron irradiation to steels doped with isotope boron-10 is frequently conducted to study effects of the helium production on mechanical properties. The intrinsic mechanical properties of F82H steels could have been changed due to the boron doping. Recently, we reported that co-doping with boron and nitrogen to F82H (F82H+B+N) improved the mechanical properties of F82H doped only with boron. The mechanical properties of F82H+B+N are successfully comparable with the non-doped F82H before irradiation. In order to evaluate the effects of initial microstructure and helium production on radiation hardening, F82H and F82H+B+N were irradiate d Specimens used in this study were standard F82H martensitic steels, F82H steels doped with 60 mass ppm 10B and 200 ppm N (F82H+10B+N) and F82H steels doped with 60 mass ppm 11B and 200 ppm N (F82H+11B+N). Initial microstructures were changed by tempering conditions, and the tempering ...

International Nuclear Information System (INIS)

A post-irradiation annealing study was conducted with use of reactor pressure vessel(RPV) steel A533B C1.1 base metal irradiated to a dose of 4.84x10"1"8 n/cm"2 at about 380 deg C. Microhardness and positron annihilation (PA) methods were used to obtain better understanding of the recovery of radiation hardening. Isochronal anneal experiments indicated that two recovery processes occur during annealing of irradiated specimens. The first recovery process occurs in the temperature of 280-305 deg C. The variations of Ip, Iw and R parameters indicated that the formation of vacancy clusters by vacancy aggromeration and the annihilation parameters measured indicated that the dissolution of carbon atoms decorated around vacancy-type defects and possible precipitates, and the annihilation of monovacancies give rise to the second recovery process. It was further indicated that radiation anneal hardening (RAH) in the range of 305-405 deg C between the ...

Energy Technology Data Exchange (ETDEWEB)

An examination of chemical and radiological characteristics of RI organic liquid waste, wet oxidation by Fenton reaction and decomposition liquid waste treatment process were studied. These items will be applied to develop the equipment of wet oxidation and decomposition liquid waste treatment mixed processes for the safe treatment of RI organic liquid waste which is consisted of organic solvents such as toluene, alcohol and acetone. Two types of toluene solutions were selected as a candidate decomposition material. As for the first type, the concentration of toluene was above 20 vol percent. As for the second type, the solubility of toluene was considered. The decomposition ration by Fenton reaction was above 95 percent for both of them. From the adsorption equilibrium tests, a -Na{sup +} substituted/acid treated activated carbon and Zeocarbon mixed adsorbent was selected for the fixed adsorption ...

International Nuclear Information System (INIS)

Purpose: To permit accurate detection of sodium leakage by distinguishing between variations in the overflow tank level due to changes in sodium temperature accompanying changes in the power level or operating state of a liquid metal sodium cooled fast breeder, and a reduction in power level due to duct leakage. Constitution: The volume of sodium in the primary cooling system is roughly estimated from the temperatures of hot and cold legs, and the duct leak preset level with respect to the sodium liquid level within an overflow tank when the plant is normal is varied according to the state of the plant. More particularly, the volume of sodium within the overflow tank is calculated on the basis of a signal representing the liquid level detected by a liquid level gauge in the overflow tank and a signal representing the temperature detected by hot leg and cold leg thermometers, thereby obtaining the preset ...

Energy Technology Data Exchange (ETDEWEB)

Film boiling is the mode if boiling during which the hot surface is separated from the vaporizing liquid by a nearly continuous film vapor. Film boiling is usually considered a very undesirable boiling regime since it is a relatively quiet and inefficient mode of heat transfer, particularly as compared to nucleate boiling. It is customary to analyze the two-phase flow regime of laminar flow film boiling by assuming the two-phase flow regime of laminar flow film boiling by assuming an idealized vapor film flow characterized by a smooth liquid-vapor interface. However, during stable flow film boiling, the wavy nature of the liquid-vapor interface and its role in local heat and mass transport have been largely ignored. The vapor interface is rarely stationary. Interfacial waves may substantially augment the heat transfer rates throughout the layer. The present analysis treats stagnation point flow film boiling on a sphere ...

International Nuclear Information System (INIS)

Object: To control the average liquid level of each steam generator at a constant level irrespective of the flow rate of sodium thereby to decrease change in the retained amount of sodium and at the same time to improve the load response characteristic. Construction: A method for decreasing to as large an extent as possible a change in the amount of sodium retained in a steam generator due to change in the flow rate, which comprises the steps of detecting the main recirculating flow rate of liquid sodium by the use of a sodium flow rate detector, amplifying the detected flow rate signal depending upon the ratio between the flow rates respectively in a super-heater and a re-heater (distribution ratio), delivering the amplified signal to a function generator which generates a liquid level setting signal for maintaining the respective average liquid levels of the super-heater and the re-heater at constant ...

International Nuclear Information System (INIS)

In the region of annular liquid film-mist flow, the behavior of the droplets formed from the liquid film and the rate of formation are the subjects to be clarified in connection with the forecast of dry-out point, which becomes a problem in the region of high dryness such as reactor cooling system and steam generators. Many researches have been performed on such problem in vertical tubes, but the characteristics in horizontal flow have not yet been sufficiently clarified. This series of research is to clarify various characteristics, such as the velocity of vapor phase, the flow rate distribution of droplets, the formation and adhesion of droplets and the structure of liquid film, in the region of liquid film-mist flow, where liquid film exists on the bottom of a horizontal rectangular channel, and vapor flow is accompanied by droplets. In this study, by the measurement of the flow ...

Energy Technology Data Exchange (ETDEWEB)

Grout has been evaluated as a means of containing low-level radioactive waste for long-term disposal. Concerns about hydrogen and reactive gas generation in the Hanford Site grout disposal facility lead to the development of the G3 model, which has predicted buildup of radiolytically formed gases in the grout region and their migration to air-filled regions. The G3 model is a one-dimensional code that couples models of gas diffusion with two-phase gas and liquid flow. It was coupled to a compartment diffusion model and these models predicted the concentrations of hydrogen I nitrous oxide, and other gases in air-filled regions of the grout disposal facility. The results have served as the technical basis for safety studies. A unique finding of the G3 model was that a liquid return, or expulsion of unbound liquid from the grout region, could occur. This liquid return is driven by displacement caused by ...

Science.gov (United States)

A nitrogen liquefier and computer controlled valving system have been added to the Bevatron cryoliner vacuum system to cut operating costs by reducing liquid nitrogen consumption. The computer and interface electronic systems, which control the temperatures of twenty-eight liquid nitrogen circuits, have been chosen and designed to operate in the Bevatron's pulsating magnetic field. The nitrogen exhaust is routed back to a liquefier, of about five kilowatt capacity, liquefied, and rerouted through the cooling circuits. A description of the system and operating results are presented.

Energy Technology Data Exchange (ETDEWEB)

The US DOE is calling on the nations' industries and academic institutions to develop a new approach for converting coal into liquid fuels at costs that can be competitive with imported oil. Based on a number of innovations, the department is looking for new approaches that can substantially reduce the cost of liquids from coal, essentially capping the price of imported oil. If successful, the new process will define the next generation of coal liquefaction technology and represent a dramatic improvement over the current state-of-the-art integrated two-stage process. 1 fig.

International Nuclear Information System (INIS)

A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO_2) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO_2 were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.

CERN Document Server

We show that in the Landau gauge of the SU(2) Yang-Mills theory the residual global symmetry supports existence of the topological vortices which resemble disclination defects in the nematic liquid crystals and the Alice (half-quantum) vortices in the superfluid heluim 3 in the A-phase. The theory also possesses half-integer and integer charged monopoles which are analogous to the point-like defects in the nematic crystal and in the liquid helium. We argue that the deconfinement phase transition in the Yang-Mills theory in the Landau gauge is associated with the proliferation of these vortices and/or monopoles. The disorder caused by these defects is suggested to be responsible for the confinement of quarks in the low-temperature phase.

Science.gov (United States)

Biomass can provide a substantial energy source. Liquids are preferred for use as transportation fuels because of their high energy density and handling ease and safety. Liquid fuel production from biomass can be accomplished by any of several different processes including hydrolysis and fermentation of the carbohydrates to alcohol fuels, thermal gasification and synthesis of alcohol or hydrocarbon fuels, direct extraction of biologically produced hydrocarbons such as seed oils or algae lipids, or direct thermochemical conversion of the biomass to liquids and catalytic upgrading to hydrocarbon fuels. This report discusses direct thermochemical conversion to achieve biomass liquefaction and the requirements for wastewater treatment inherent in such processing. 21 refs.

Energy Technology Data Exchange (ETDEWEB)

The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through September 1999.

British Library Electronic Table of Contents (United Kingdom)

I formulate a model in which money coexists with equity shares on a risky aggregate endowment. Agents can use equity as a means of payment, so shocks to equity prices translate into aggregate liquidity shocks that disrupt the mechanism of exchange. I characterize a family of optimal monetary policies and find that the resulting equity prices are independent of monetary considerations. I also study a perturbation of the family of optimal policies that targets a positive constant nominal interest rate and find that in this case the real equity return includes a liquidity return that depends on monetary considerations.

Energy Technology Data Exchange (ETDEWEB)

Solid-state acoustic sensors for monitoring conditions at a surface immersed in a liquid and for monitoring concentrations of species in a liquid and for monitoring electrical properties of a liquid are formed by placing interdigital input and output transducers on a piezoelectric substrate and propagating acoustic plate modes therebetween. The deposition or removal of material on or from, respectively, a thin film in contact with the surface, or changes in the mechanical properties of a thin film in contact with the surface, or changes in the electrical characteristics of the solution, create perturbations in the velocity and attenuation of the acoustic plate modes as a function of these properties or changes in them.

International Nuclear Information System (INIS)

We examined the spectral behaviors of lasing from a asymmetrically deformed liquid jet (a ? 14 ?m) which is induced by a laterally flowing gas. Th liquid sample was methanols which contains DCM dye. When n distortion is induced, the lasing spectrum appears as two periodic peaks which are corresponding to the resonance modes of cylindrical cavity. As the distortion parameter exceeds about 4%, the lasing spectrum shifts continuously to short wavelength. When the distortion parameter reaches ? 10%, the amount of blue shift was ? 30 nm. The blue shift can be explained as the shift of optimum wavelength of threshold curves. From the absorption and fluorescence curve of liquid sample, we estimated the spoiled Q with the distortion parameter.

Science.gov (United States)

In order to support long duration cryogenic propellant storage, the Cryogenic Fluid Management (CFM)

International Nuclear Information System (INIS)

The two-fluid model representation for calculations of two-phase flow characteristics in the FBR fuel pin bundles with liquid metal cooling is presented and analysed. Two conservation equations systems of the mass, momentum and energy have been written for each phase. Components accounted the mass-, momentum- and heat transfer throughout the interface occur in the macro-field equations after the averaging procedure realisation. The pattern map and correlations for two-fluid model in vertical liquid metal flows are presented. The description of processes interphase mass- and heat exchange and interphase friction is determined by the two-phase flow regime. The opportunity of the liquid metal two-phase flow regime definition is analysed. (author)

International Nuclear Information System (INIS)

Inorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM). Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect of surface ...

Science.gov (United States)

... MPS) Advanced Liquid Crystalline Optical Materials Superconductivity Computation and Visualization ... Cement-Based Materials Synthesis, Growth, and Analysis of Electronic Materials Photoinduced Charge ...

Science.gov (United States)

... The phenol and cresylic acid stream is flashed in a thin film evaporator over a concentrated sulfuric acid mixture to remove pyridine type substances ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Visualization of a liquid metal flow and image processing methods to measure the vector field are carried out by real-time neutron radiography. The JRR-3M real-time thermal neutron radiography facility in the Japan Atomic Energy Research Institute was used. Lead-bismuth eutectic was used as a working fluid. Particles made from a gold-cadmium intermetallic compound (AuCd{sub 3}) were used as the tracer for the visualization. The flow vector field was obtained by image processing methods. It was shown that the liquid metal flow vector field was obtainable by real-time neutron radiography when the attenuation of neutron rays due to the liquid metal was less than l/e and the particle size of the tracer was larger than one image element size digitized for the image processing. (orig.).

International Nuclear Information System (INIS)

... 1535-DR(Vol.4). Available from INIS in electronic form breeder reactors

Energy Technology Data Exchange (ETDEWEB)

Two-phase flow in horizontal parallel channels has been experimentally investigated under fuel cell related operating conditions. Pronounced hysteresis is observed in the pressure drop versus flow characteristic curve when starting from either flooded or dry conditions. When gas is introduced into channels initially filled with water (flooded initial condition), both gas and liquid tend to flow predominantly in one channel at low gas or liquid flow velocities. As the gas flow velocity increases, even distribution of gas and liquid flow in both channels is observed, accompanied with a sudden decrease in the pressure drop. On the other hand, even gas and liquid flow distribution between both channels is found at comparatively lower gas flow velocities when starting with dry-gas flow conditions with liquid introduced into channels filled with gas (stratified flow regime). The flow ...

Energy Technology Data Exchange (ETDEWEB)

Apparatus and method are described for the vaporization of liquid fuel oils to produce a gaseous mixture suitable for burning in a burner normally designed for operation utilizing natural gas.

Energy Technology Data Exchange (ETDEWEB)

We investigate Fermi liquid in the single-channel U-infinite N fold degenerate Anderson lattice with use of the expansion from the large limit of the spin-orbital degeneracy N. By collecting all diagrams up to O(N{sup -2}) of the imaginary part of the self-energy of the conduction electrons, the sum of those is shown to be given by a form proportional to {omega}{sup 2} + {pi}{sup 2}T{sup 2} up to O(N{sup -2}) in the single-channel model. On the other hand, the imaginary part of the self-energy of O(N{sup -1}) in the multichannel model has more singular frequency-/temperature-dependence, so the system is regarded as non-Fermi liquid. (author)

British Library Electronic Table of Contents (United Kingdom)

A novel electrogenerated chemiluminescence (ECL) sensor based on natural clay and ionic liquid was fabricated. Tris(2,2prime-bipyridine)ruthenium(II) (Ru(bpy)32+) was immobilized on natural clay surface through simple adsorption. An ECL sensor was prepared by mixing Ru(bpy)32+-incorporated clay, graphite powder and an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) as the binder. The electrochemical behavior and ECL of the immobilized Ru(bpy)32+ was investigated. It was observed that the ECL of immobilized Ru(bpy)32+ was activated by the ionic liquid. The proposed ECL sensor showed high sensitivity to tri-n-propylamine (TPrA) and the detection limit was found to be 20 pM. In addition, the ECL sensor displayed good stability for TPrA detection and long-term storage stability.

International Nuclear Information System (INIS)

The virucidal effect of _6_0Co gamma radiation was studied in cell culture medium and in liquid swine manure involving the most important porcine viruses that can be spread by liquid manure. The radiation doses (20 kGy and 30 kGy) were determined in preliminary experiments employing a porcine enterovirus from the serogroup 1 (Teschen group). In the main experiment, the following viruses were employed: swine vesicular disease (SVD) virus, type C foot-and-mouth disease (FMD) virus, a field strain of Aujeszky's disease (AD) virus, transmissible gastroenteritis (TGE) virus, as well as bovine viral diarrhoea (BVD) virus. The latter strain served as a model for hog cholera virus. The results of the experiments indicate that safe disinfection of the virus infected liquid swine manure by ionizing radiation requires a radiation dose of 30 kGy. (author).

UK PubMed Central (United Kingdom)

BackgroundIn nuclear medicine, liquid radiopharmaceuticals for diagnostic or therapeutic purposes are administered to patients by using various types of syringes with different volumes....Full Text Available

UK PubMed Central (United Kingdom)

Budding yeasts are highly suitable for aging studies, because the number of bud scars (stage) proportionally correlates with age. Its maximum stages are known ...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

An efficient micropropagation protocol was established for Cryptocoryne wendtii and Cryptocoryne becketti using shoot tips explants. Multiple shoots were induced from shoot tip explants of both species cultured on agar-gelled as well as liquid MS medium supplemented with 0.5?mg/L BA and 0.2?mg/L IBA (proliferation medium). The multiple shoots of both the species formed on agar-gelled as well as liquid medium were vigorously growing with well-developed roots and leaves after 4?weeks of culture. Highest number of multiple shoots was obtained from shoot tip explants of both the species cultured in liquid proliferation medium after 4?weeks of culture. The shoot tip explants of C. wendtii and C. becketti, that were cultured in liquid proliferation medium (2?weeks) followed by culturing on agar-...

CERN Document Server

Although hydrogen is the simplest of atoms, it does not form the simplest of solids or liquids. Quantum effects in these phases are considerable (a consequence of the light proton mass) and they have a demonstrable and often puzzling influence on many physical properties, including spatial order. To date, the structure of dense hydrogen remains experimentally elusive. Recent studies of the melting curve of hydrogen indicate that at high (but experimentally accessible) pressures, compressed hydrogen will adopt a liquid state, even at low temperatures. In reaching this phase, hydrogen is also projected to pass through an insulator-to-metal transition. This raises the possibility of new state of matter: a near ground-state liquid metal, and its ordered states in the quantum domain. Ordered quantum fluids are traditionally categorized as superconductors or superfluids; these respective systems feature dissipationless electrical ...

Energy Technology Data Exchange (ETDEWEB)

This report describes work accomplished in the project, titled ''Development of Appropriate Resistance Spot Welding Practice for Transformation-Hardened Steels.'' The Phase 1 of the program involved development of in-situ temper diagrams for two gauges of representative dual-phase and martensitic grades of steels. The results showed that tempering is an effective way of reducing hold-time sensitivity (HTS) in hardenable high-strength sheet steels. In Phase 2, post-weld cooling rate techniques, incorporating tempering, were evaluated to reduce HTS for the same four steels. Three alternative methods, viz., post-heating, downsloping, and spike tempering, for HTS reduction were investigated. Downsloping was selected for detailed additional study, as it appeared to be the most promising of the cooling rate control methods. The downsloping maps for each of the candidate steels were used to locate the conditions ...

International Nuclear Information System (INIS)

The effect of W and V on the high temperature strength properties of 12%Cr-15%Mn austenitic steels was studied from the view point of precipitation hardening and internal stress. The contribution of W addition to the tensile and creep-rupture strength was not so large. By contrast the combined addition of W and V increased the strength considerably. These are resulted from the precipitation of fine vanadium nitride (VN) within grains and the enhancement of M_2_3C_6 type carbide precipitation at grain boundaries. The V added material had large internal stress value which is considered to be due to dislocation movement disturbed by fine vanadium nitrides. (author).

British Library Electronic Table of Contents (United Kingdom)

Irradiation of EP-823 (16Cr12MoWsiVNbB) ferritic-martensitic steel with 7-MeV Ni++ ions and with 30- and 70-keV He+ ions at a temperature of 500?C was followed by an increase in the microhardness, which was due to both radiation point defects and changes in the phase composition and the dislocation structure of the steel. It was found that the dependence of the largest relative increase in the microhardness on the concentration of radiation-induced point defects in the near-surface region of the steel under irradiation with different ions correlated with an analogous dependence of the surface segregation of silicon and chromium.

British Library Electronic Table of Contents (United Kingdom)

Plastic injection molds are an important economic sector due to the increasing use of injection molded plastic components. The selection of mold steel material, its processing conditions, and the way it is machined and hardened all have an impact on how it performs during use across its lifecycle for injection molding. For this study, injection molding conditions seen during high volume manufacturing were used to induce wear that would be typical during processing. A 50wt.% glass fiber reinforced Polybutylene Terephthalate (PBT) was used for the research. After 3000 injection operations, surface damage was found only on the steel used for the stationary half of the mold cavity and the corresponding surface of the molded parts. In contrast, the moving half showed no surface damage or increa...

International Nuclear Information System (INIS)

Weld metal, base material and stainless steel overlay specimens for Charpy tests and static tensile tests were irradiated for a year in a power reactor of the Bohunice nuclear power plant in place of the evaluated surveillance specimens. The material of the specimens was identical with that of the WWER-440 reactor pressure vessels, and was exposed to a fluence of (1.2 - 4.5) x 10"2"3 m"-"2 (E > 0.5 MeV) at approximately 270 degC. Some of the irradiated as well as unirradiated specimens were subjected to regeneration annealing at 475 degC for 168 h. The behavior of the materials after irradiation and annealing was evaluated. (author). 33 tabs., 32 figs., 8 refs.

International Nuclear Information System (INIS)

Early failure of an induction-hardening carbon steel pipe, which was used to transport tailing slurry, was caused by pitting corrosion. The microstructure on the internal pipe surface layer was found being a mixture of martensite, pearlite and ferrite. In this work, the pitting corrosion behavior of each constitute in the microstructure of steel is investigated with electrochemical noise analyses; the electronic properties of passive films were studied with Mott-Schottky relationship. It is found that the passive films formed on the materials under investigation are highly disordered n-type semiconductors. The high-to-low pitting susceptibility is ferrite > martensite > pearlite. The pitting resistance is related to the semiconductive nature of the passive film formed on each constitute. The pitting susceptibility increases with the donor concentration in the passive films. (author)

Energy Technology Data Exchange (ETDEWEB)

The present conference discusses plasma-assisted surface coating/modification processes, the applications to date of ion nitriding, the effects of nitrogen on metal surfaces, ion nitriding mechanisms in Cr, Al and Cr + Al-containing 1040 steel, ion nitriding of Al and its alloys, life enhancement for forging dies, novel anode plasma nitriding developments, and a comparative study of the pulsed and dc ion-nitriding behavior in specimens with blind holes. Also discussed are the influence of heating method on ion nitriding, surface hardening of marage steels by ion nitriding without core hardness reduction, plasma nitriding of nodular cast iron sput gears, NbN composites for superconductors, the carburization of tungsten in a glow discharge methane plasma, economic considerations concerning plasma nitriding, and the corrosion properties obtained by ion nitriding.

Energy Technology Data Exchange (ETDEWEB)

Results of strain controlled fatigue and tensile tests are presented for two nickel base solution hardened alloys which are reference structural alloys for use in several high temperature gas cooled reactor concepts. These alloys, Hastelloy X Inconel 617, were tested at temperatures ranging from room temperature to 871/sup 0/C in air and impure helium. Materials were tested in the solution annealed as well as in the pre-aged condition where aging consisted of isothermal exposure at one of several temperatures for periods of up to 20,000 h. Comparisons are also given between the strain controlled fatigue lives of these alloys and several other commonly used alloys all tested at 538/sup 0/C.

Energy Technology Data Exchange (ETDEWEB)

The conference proceedings contains 30 papers of which five are abstracted separately. The subjects covered include fatigue crack growth in aircraft materials, fractographic measurements, fatigue cracks in nylon 66 blends, cyclic inelastic deformation aspects, prestressing, tensile cracks in creeping solids, creep-crack-growth in 304 stainless steel, high-temperature fatigue, parallel impact loading, numerical fracture dynamic code, J-resistance curves, specimen geometry effects, reactor piping systems, temperature dependence of fracture toughness, small-scale yielding, compact specimens, power hardening materials, semi-empirical fracture analyses, pipeline girth welds, wrought steels, and A36 bridge steels.

Energy Technology Data Exchange (ETDEWEB)

Effect of final temperature and duration of coking on the properties of formed coke from weakly-caking Donetsk and Kuznetsk coals was studied. An increase of the final temperature to 850 C produced significant changes in the mechanical and chemical properties of the coke. Increasing the temperature beyond this point did not affect the mechanical strength significantly, but did increase hardness, real density and electroconductivity of the coke and decrease reactivity. Increasing the period of coking at final temperatures in the 650 and 750 C range, produced insignificant hardening of the formed coke. An objective evaluation of the effect of final temperature can be performed by a series of tests which characterize the resistivity of the formed coke to impact and abrasion and the fine structure of the matter in coke. 9 references.

Energy Technology Data Exchange (ETDEWEB)

The phase transformations and properties of a precipitation-hardened Ni-Cr-based alloy are investigated as a function of C, B, Nb, and Cr contents. It is found that the primary role of Nb consists in the formation of an independent phase, delta-Ni3Nb, a part of a gamma/gamma-prime-delta eutectoid (for high C and B concentrations) and in stimulating the gamma-sigma reaction consecutively with the gamma double prime-delta reaction (for low C and B concentrations). In both cases, the long-term strength characteristics of the Nb-alloyed system are relatively low. The substitution of boron for carbon contributes to a reduction in the number of nucleation sites for topologically close-packed phases and to the formation of more stable (with respect to excess compounds) M3B2 and MB2 borides. The high-boron material exhibits better properties and phase stability under mechanical and thermal loading. 13 references.

Energy Technology Data Exchange (ETDEWEB)

Problems can sometimes occur during the construction of cast in-situ concrete piles. These foundations are formed by drilling a substantial hole into the ground and subsequently filling it with steel reinforcement and wet concrete. Several well-documented cases exist where concrete has not filled the hole and substantial voids have been left in the apparently completed pile. A theory has been developed by which it is possible to identify the nature, size and position of a finite defect within a suspect pile. The technique is based on the concept of receptances, and requires information obtained from vibration tests performed on piles after the concrete has hardened, and the nominal dimensions and material properties of the pile. The application of the theory is demonstrated using data relating to a pile with a known defect. The theory described in this paper ignores the effect of the surrounding soil; this can be included by further development of the theory.

International Nuclear Information System (INIS)

The examination of the high-temperature properties of the alloy Alloy 800HT has shown that both the creep performance and the microstructure of the material can be purposefully set by the initial heat treatment. At the high temperatures applied, (700-900 C), a rapid softening process sets in induced by carbide precipitation, stabilization, and coarsening. This softening process causes creep velocities strongly accelerating as a function of duration of the heat treatment prior to the creep test. The identified cause of the softening effect is a change in particle size that could be verified by SEM and TEM. It is shown that two different carbide precipitate size classes are responsible for the softening effect. While the precipitates dectable by TEM become effective primarily via interactions with dislocations, the carbide precipitates detectable only by SEM contribute to a hardening of the grain boundaries and the matrix.(orig./CB)

Energy Technology Data Exchange (ETDEWEB)

The performance of advanced ceramics under cavitation loading in distilled water was studied by using a laboratory test with vibration-induced cavitation following the pattern of the ASTM standard G32-92. The hardened and tempered martensitic steel 100Cr6 was used as a reference. The aim was to identify mechanisms and the effects of important microstructural parameters on damage of polished Al{sub 2}O{sub 3}, Al{sub 2}O{sub 3}-ZrO{sub 2}, ZrO{sub 2} and SiC ceramics. Results showed that surface damage of brittle ceramics was mainly dominated by intergranular fracture, followed by detachment of single grains or fragments of them. Both incubation time and erosion rate were affected by the amount of initial surface cavities, grain sizes and secondary phases at grain boundaries. (orig.)

Energy Technology Data Exchange (ETDEWEB)

This report consists of a broad overview of activities at Los Alamos National Laboratory (LANL). The following topics are discussed: The growth of the waste management group; what we do today; the mission of the waste management group; the liquid waste treatment section; the radioactive liquid waste project office; the chemical waste section; the radioactive waste section; and the technical support section.

International Nuclear Information System (INIS)

In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).

International Nuclear Information System (INIS)

By the example of CH2Cl2, CF2Cl2, CHF2Cl, C2F6, C2H6, SF6 and C6H12 we have investigated the isobaric thermal conductivity jump at crystal-liquid phase transition. It is shown that the reduction in the thermal conductivity at melting derives from the degree of orientational ordering of the crystals at pre-melting point.

Energy Technology Data Exchange (ETDEWEB)

This articles deals with an approach that has given some key information about the mechanisms of the liquid phase oxidation of butane to acetic acid. This procedure has been developed over the last 34 years; however, much of what will be discussed represents a synthesis of previous insights. Many of the observations are relatively recent and have not been previously published. In principle, this approach should be applicable to many oxidation processes. (orig.)

UK PubMed Central (United Kingdom)

For rapid and low-cost detection of multidrug-resistant (MDR) Mycobacterium tuberculosis, we applied the nitrate reductase assay (NRA) using a liquid medium directly to sputum samples....Full Text Available

International Nuclear Information System (INIS)

Radial distribution functions of liquid sodium and caesium at 100"0C have been calculated by the method of molecular dynamics with interionic pair potentials derived from Heine-Abarenkov-Shaw type model potential. The results were found to be in good agreement with recent experimental data. (Auth.).

International Nuclear Information System (INIS)

To the crushed ore leaching is applied. The resulting solid-liquid mixture is fed to a hydro-cyclon grading facility; here the superfine grain is separated before the concentrated mixture can be filtered or centrifuged. The grading is done in several steps. From the liquid, ultimately ridded of the solid, uranium compounds are precipitated and the yellow cake is obtained. (DG).

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Reported on here are studies of various methods for liquefying coal. Hydropyrolysis as an alternative method for producing liquid hydrocarbons and a carbon enriched char is discussed. Other methods described involve supercritical gas extraction of coal and use of natural gas as a hydrogenating agent. Relevant waste water treatments are discussed as well. 65 refs., 9 figs.

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We describe a liquid hydrogen droplet as an optical cavity via whispering gallery modes. We show that the droplet leads to an ultrahigh-cavity-Q value of 2.5x10{sup 9} in visible region. We show also that the high-Q droplet results in a huge Raman nonlinearity, generating a stimulated Raman comb series covering whole visible region.

International Nuclear Information System (INIS)

The droplet concentration profile in a liquid film-mist two-phase flow in a developing flow region of a horizontal rectangular channel was analyzed theoretically and experimentally. The effects of the mean settling velocity of droplets v sub(f) and the turbulent diffusion coefficient epsilon sub(p) on the droplet concentration profile were investigated by the theoretical analysis. The calculated results of the droplet concentration profile using the proper values of v sub(f) and epsilon sub(p) agreed with the experimental results. (author).

International Nuclear Information System (INIS)

It is desirable to avoid vibration problems by following appropriate guidelines and specifications at the design stage. Accordingly, design specifications were developed to prevent tube failures due to vibration in nuclear steam generators and liquid heat exchangers. These specifications are outlined in this report. (author). 14 refs., 2 figs.

British Library Electronic Table of Contents (United Kingdom)

The interaction between gravity convection and Marangoni convection in a horizontal rectangular channel filled with a liquid containing a surfactant and a drop of another liquid is numerically investigated. For large Schmidt numbers the occurring oscillatory regime of solutal convection is analyzed. In the model with a surface phase the effect of the adsorption and desorption processes on the convective flow structure is determined. The corresponding initial and boundary value problem is solved using a difference method.

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Explosives have been used in the removal of offshore wellhead devices for a number of years. In 1975, the first liquid explosives were run to remove wellheads and have proved to be a safe and reliable method of severing and salvaging the wellhead equipment from most depths of water. Methods of explosive wellhead removal and the areas of safety, reliability, and economics are discussed.

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The apex dimensions and length are calculated as a function of current for the ion-emitting jet in liquid-metal ion sources (LMIS). The results agree well with observations. Since the final expressions are analytical, they give more insight into the fundamental mechanisms involved than do numerical calculations. Some implications of the model are discussed concerning focused ion beam (FIB) systems employing LMIS. (author).

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In a breeder-type nuclear power plant, liquid metal is used as a coolant due to the high heat capacity factor. Also, some proposals for fusion reactor blanket design include liquid metal as a possible coolant. In both cases the understanding of natural circulation of liquid-metal flow behavior is an integral part of the thermal hydraulic analysis, especially under two-phase flow conditions. Experimental investigations have been conducted to study a liquid metal two-phase natural circulation flow system. A lead-bismuth (PbBi) eutectic mixture is used as a working fluid in a heated metal walled natural circulation loop. Gas injection induces natural circulation through the gas-lift mechanism. A real-time neutron radiography system is used to visualize the two-phase mixture, specifically the interface and the flow regime. Measurements of void fraction, void fluctuation and bubble propagation are performed.

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A visual study of film boiling using photographic and high speed motion-picture methods was carried out to determine the flow regime transition criteria in the post-CHF region. An idealized inverted annular flow was obtained by introducing a liquid jet of Freon 113 through a nozzle, precisely centered with respect to the internal diameter of the test section, with an annular gas flow. The respective ranges for liquid and gas exit velocities were 0.05 to 0.5 and 0.03 to 7.9 m/s. Nitrogen and helium were used in the study. For the present configuration, there are four basic flow regimes. Beginning from the nozzle exit, there is a smooth, inverted annular flow section with liquid in the core and gas in the annulus; followed by the rough wavy section with an intact liquid core, the agitated and the dispersed flow regimes. For a given liquid jet velocity, the axial extent of each flow ...