WorldWideScience
2

Development of large scale parallel visco-elastic analysis system with mesoscopic material model  

International Nuclear Information System (INIS)

We develop a large scale parallel viscous-elastic analysis program incorporating a mesoscopic self-consistent model developed by Laws. In the model, macroscopic elastic constants are treated as variables depending on the shape and statistical properties of pre-existing microscopic pores and change due to neutron irradiation. We apply this program to the visco-elastic analysis of nuclear graphite structures under neutron irradiation environment in High Temperature Gas-cooled Reactor (HTGR), as an example problem. Furthermore the calculated results by this parallel computational program are compared with those by one of commercial finite element analysis codes, FINAS, for validating elastic and thermal stress analysis function. (author)

2000-09-01

3

A Four-Dimensional Probabilistic Atlas of the Human Brain  

UK PubMed Central (United Kingdom)

The authors describe the development of a four-dimensional atlas and reference system that includes both macroscopic and microscopic information on structure and function of the human brain in persons...Full Text Available

2001-09-01

4

Large eddy simulation of pulsating pool fire  

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: General simulation objectives of any fire analysis are macroscopic in nature and deals with the grass data in respect of fire/smoke spread, structural behaviour, environmental conditions etc. However, the accuracy of predicting such macroscopic parameters is a strong function of several other microscopic parameters which govern the overall macroscopic behaviour. Some of the microscopic parameters of interesting such analysis could be buoyancy induced stable/unstable flows, relative flame behaviour, baroclinic velocity distribution etc. Only the field based fire modelling approach is capable of calculating several of these by way of detailed CFD based field modelling. One of the best known tool that could be employed for such studies is the Fire Dynamics simulator (FDS) from NIST with its popular LES based fire modelling ...

2005-07-01

5

Microscopic analysis of the /sup 88/Sr(p,p') reaction at E/sub p/ = 201. 5 MeV  

Energy Technology Data Exchange (ETDEWEB)

Differential cross sections for 201.5 MeV proton scattering form /sup 88/Sr were measured. From the analysis of the elastic data, no unique optical-model potential could be obtained, but the radial moments are well determined. In a macroscopic analysis of the collective states it turns out that if the optical potential and transition potential are chosen consistently, unambiguous potential deformation lengths can be obtained even though the optical potential is not unique. Taking into account the range and density dependence of the underlying effective interaction reliable neutron deformation lengths can be obtained. For inelastic transitions of various character microscopic distorted-wave calculations with a density-dependent interaction based on the Paris potential were performed. The nuclear structure was taken from one broken-pair calculations in a large model space, calibrated by (e,e') ...

1988-04-25

6

Microscopic analysis of the "8"8Sr(p,p') reaction at E_p = 201.5 MeV  

International Nuclear Information System (INIS)

Differential cross sections for 201.5 MeV proton scattering form "8"8Sr were measured. From the analysis of the elastic data, no unique optical-model potential could be obtained, but the radial moments are well determined. In a macroscopic analysis of the collective states it turns out that if the optical potential and transition potential are chosen consistently, unambiguous potential deformation lengths can be obtained even though the optical potential is not unique. Taking into account the range and density dependence of the underlying effective interaction reliable neutron deformation lengths can be obtained. For inelastic transitions of various character microscopic distorted-wave calculations with a density-dependent interaction based on the Paris potential were performed. The nuclear structure was taken from one broken-pair calculations in a large model space, calibrated by (e,e') data. In ...

7

Anomalous properties of the local dynamics in polymer glasses  

CERN Document Server

The emergence of nanoscience has increased the importance of experiments able to probe the very local structure of materials, especially for disordered and heterogeneous systems. This is technologically important; for example, the nanoscale structure of glassy polymers has a direct correlation with their macroscopic physical properties. We have discovered how a local, high frequency dynamic process can be used to monitor and even predict macroscopic behavior in glassy polymers. Polyvinylethylenes vitrified by different chemical and thermodynamic pathways exhibit different densities in the glassy state. We find that the rate and amplitude of a high frequency relaxation mode (the Johari-Goldstein process involving local motion of segments of the chain backbone) can either correlate or anti-correlate with the density. This implies that neither the unoccupied (free) volume nor the configurational entropy ...

2008-01-01

8

Polysulfone/Metal Nanocomposites by Simultaneous Photoinduced Crosslinking and Redox Reaction  

British Library Electronic Table of Contents (United Kingdom)

Abstract A diacrylate polysulfone oligomer is synthesized and used as the acrylic oligomer for the in situ synthesis of noble metal/PSU nanocomposites through UV-induced simultaneous radical polymerization of acrylic functionalities and NP formation by reduction of their precursors. Thus, silver or gold NPs are formed in situ during polymer network formation. FESEM analysis of the morphology of the cured systems demonstrates that the nanoparticles of the noble metals are homogeneously distributed in the network without macroscopic agglomeration.

2011-01-01

9

Data interpretation in nuclear forensics  

International Nuclear Information System (INIS)

Nuclear Forensics is a key element in the response process which is initiated after detection of illicit nuclear or other radioactive material. Credible nuclear forensics relies on appropriate sampling procedures, on validated analytical methods and on thorough data analysis and interpretation. Nuclear forensics aims at providing clues on the history and the potential origin of the material. Elemental and isotopic composition of the material, as well as its macroscopic and microscopic appearance reflect the technological processes used for the fabrication of the material. The nuclear forensic analysis first of all results in measurement data. Through appropriate processing of these data information on the nature and the history of the material can be obtained. A number of data evaluation techniques serving this purpose are conceivable and have been applied. On the one side, statistical methods like principal component ...

10

Nuclear fuel behavior at an atomic scale: the contributions of the ab initio calculations and the synchrotron radiation; Comportement du combustible nucleaire a l'echelle atomique: les apports des calculs ab initio et du rayonnement synchrotron  

Energy Technology Data Exchange (ETDEWEB)

This paper presents fundamental researches based on the electronic structure calculations and X absorption spectroscopy, allowing the knowledge on nuclear fuels at an atomic scale. They bring a better understanding of these material behavior to accurate the macroscopic simulation. The calculation methods, the experimental techniques of validation and the ab initio calculations results are detailed. (A.L.B.)

2000-07-01

11

Reaction with glutathione. A possible mechanism involved in rodent brain retention of a "9"9"mTc SNS/S complex containing a pendant ester functionality  

International Nuclear Information System (INIS)

The synthesis, characterization of M"vO([CH_3CH_2N(CH_2CH_2S)_2](p-S-Ph-COOCH_2-CH_3)) (M:"9"9"mTc: I, Re: II) is presented in this work, where a pendant ester function is attached to the monothiolate ligand. Chemical structure of I is established after chromatographic comparison with II, synthesized in macroscopic amounts. Complex II is fully characterized by classical methods of analysis showing that the compound adopts a distorted trigonal bipyramidal configuration around the metal. The two sulfur atoms of the tridentate ligand and the oxo group form the basal plane, while the remaining nitrogen atom of the tridentate ligand and the sulfur atom of the monothiolate ligand occupy the apices of the bipyramid. In vitro challenge experiments with glutathione (GSH) in neutral aqueous medium demonstrate, that I suffers nucleophilic attack by GSH and thereby transformation to a more hydrophilic daughter metal compound. Formation ...

1998-08-01

12

A study of kerf characteristics in abrasive waterjet machining of graphite/epoxy composite  

Energy Technology Data Exchange (ETDEWEB)

Kerf geometry, kerf wall features, and cutting front characteristics of an Abrasive Waterjet (AWJ) machined Graphite/Epoxy (Gr/Ep) laminate were studied. A macroscopic analyses suggests that geometrical features associated with AWJ machining of Gr/Ep laminates are influenced by three macro regions along the cutting depth. The presence of these regions, including initial damage at jet entry, smooth cutting, and rough cutting near the jet exit, depends on the operating conditions. Design of experiments and analysis of variance were used to determine the effect of cutting parameters on kerf characteristics and to develop empirical models for kerf profile and features of the three distinct macroscopic regions. Cutting front analysis revealed that the mechanisms of material removal in AWJ machining of Gr/Ep do not change over the jet penetration depth. In general, high quality uniform cuts may be obtained by ...

1996-04-01

13

An influence of ion bombardment on plasma nitriding process of Ti6Al14V alloy at 843 K temperature  

International Nuclear Information System (INIS)

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

2004-06-20

15

Analyses of steel liners on concrete structures  

Science.gov (United States)

A post-accident-heat-removal structural effects analysis for the steel liner in the FFTF concrete containment structure is presented. (JWR)

1975-06-01

16

Hydrogen-plasticity interactions in pearlitic steel: a fractographic and numerical study  

Energy Technology Data Exchange (ETDEWEB)

A fractographic and numerical approach is presented to analyze hydrogen-plasticity interactions in pearlitic steel and to elucidate the main hydrogen transport mechanism in this material under triaxial stress states produced by notches. Fractographic analysis showed that the microdamage produced by the hydrogen was clearly detectable by scanning electron microscopy (SEM), through a specific microscopic topography associated with hydrogen effects (tearing topography surface or TTS). Numerical computations obtained by using an elastic-plastic finite element program gave the progressive spreading of the plastic zone, closely associated with the movement of dislocations. In the majority of cases, the plastic zone (PZ) clearly exceeds the hydrogen affected region (TTS) and has no relation with it. In some tests, however, the hydrogen-induced micro-damage surpasses the only region in which there is dislocation movement, and in this case the net ...

1996-11-30

17

High temperature structural silicides  

Energy Technology Data Exchange (ETDEWEB)

Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi{sub 2}-based materials, which are borderline ceramic-intermetallic compounds. MoSi{sub 2} single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi{sub 2} possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi{sub 2}-Si{sub 3}N{sub 4} composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi{sub 2}-based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing.

1997-03-01

18

Experiments on determination of damage effect ions "2"2Ne (172 MeV) on UO_2 monocrystals  

International Nuclear Information System (INIS)

Shadow effect was used for investigating damage of uranium dioxide monocrystal. The dependence of shadow minimum parameters on fluence of "2"2Ne ions with 172 MeV energy was followed when detecting fission fragments. Ion dose responsible for sufficient microdamage of lattice structure, included into the classification of heavy ion damage effect on monocrystals was determined. The problem of radiation intensity effect on the character of occurred damages was studied. It was established that macroscopic sample failure, caused by generation of considerable mechanical stresses in monocrystal under beam effect could be observed along with microdamages of lattice structure at ion flux density >10"1"2 cm"-"2Xs"-"1.

19

Wetting failure and contact line dynamics in a Couette flow  

CERN Document Server

Liquid-liquid wetting failure is investigated in a two-dimensional Couette system with two immiscible fluids of arbitrary viscosity. The problem is solved exactly using a sharp interface treatment of hydrodynamics (lubrication theory) as a function of the capillary number, viscous ratio and separation of scale, i.e. slip length versus macroscopic scale of the system. The existence of critical velocities, above which no stationary solutions are found, is analyzed in detail in terms of the relevant parameters of the system. Comparisons with existing analysis for other geometries are also carried out. A numerical method of analysis is also presented, based on diffuse interface models obtained from multiphase extensions of the lattice Boltzmann equation (LBE). Sharp interface and diffuse interface models are quantitatively compared face to face indicating the correct limit of applicability of the diffuse interface models.

2008-01-01

20

Time-resolved triple-axis spectroscopy - a new method for real-time neutron scattering  

International Nuclear Information System (INIS)

A new method for kinetic experiments with neutrons is described. This method combines the conventional triple-axis neutron spectroscopy with relaxation-type experiments. Whereas the former method yields information about the microscopic dynamics of solids, the latter provides macroscopic relaxation times. The combination of both methods allows to determine the microscopic mechanism of relaxation processes. The time-resolved triple-axis spectroscopy is limited to reversible processes and to time scales from 10"-"3 to 10"4 s. Typical applications are the kinetics of phase transformations (structural and dynamical changes), kinetics of domain distributions, kinetics of (spinodal) decomposition, reversible solid state reactions, time-dependent occupation of phonon states or phonon lifetimes. (orig.).

1990-04-01

21

Asymmetrical mechanical behavior of a precipitation hardened beta titanium alloy  

International Nuclear Information System (INIS)

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

22

Influence of carbonization conditions on micro-pore structure of foundry formed coke produced with char  

Energy Technology Data Exchange (ETDEWEB)

There are few studies on coke's micro-pore structure in recent years, however, micro-pore structure of foundry coke determines its macroscopically quality index and reactivity in cupola furnace. Effect of such factors on micro-pore structure were investigated under different carbonization conditions with certain ratio of raw materials and material forming process in this article as charging temperature (A); braised furnace time (B); heating rate of the first stage (C)and the second stage (D) and holding time of ultimate temperature (E). Research showed that charging temperature was the most influential factor on the coke porosity, pore volume, pore size and specific surface area. It is suggested that formation of plastic mass and releasing rate of volatile during carbonization period are two main factors on microstructure of foundry coke while charging temperature contributes most to the above ...

2009-07-01

23

Improvements on burnup chain model and group cross section library in the SRAC system  

Energy Technology Data Exchange (ETDEWEB)

Data and functions of the cell burnup calculation of the SRAC system were revised to improve mainly the accuracy of the burnup calculation of high conversion light water reactors (HCLWRs). New burnup chain models were developed in order to treat fission products (FPs) and actinide nuclides in detail. Group cross section library, SRACLIB-JENDL2, was generated based on JENDL-2 nuclear data file. In generating this library, emphasis was placed on FPs and actinides. Also revised were the data such as the average energy release per fission for various actinides. These improved data were verified by performing the burnup analysis of PWR spent fuels. Some new functions were added to the SRAC system for the convenience to yield macroscopic cross sections used in the core burnup process. (author).

1992-01-01

24

Expression of suppressor of cytokine signaling 1 and 3 in ligature-induced periodontitis in rats  

British Library Electronic Table of Contents (United Kingdom)

Objective: : Evaluate expression of inducible negative regulators of JAK/STAT pathway and their target proteins during the course of ligature-induced experimental periodontal disease in rats. Design: : Rats were sacrificed 07, 15 and 30days after disease induction for histological evaluation of periodontal inflammation and macroscopic analysis of alveolar bone loss. SOCS expression and the activation status of STAT1 and STAT3 were evaluated in gingival biopsies by real time PCR and Western blot. Results: : Ligature-induced model presented significant progressive bone loss from 7 to 30days. Inflammation was evident and similar for 07 and 15days; however, a decrease on severity at the end of the experimental period was observed. There was a significant (p<0.05) increase on SOCS1 and SOCS3 ge...

2011-01-01

25

FEBEX II Project Final report on thermo-hydro-mechanical laboratory tests  

International Nuclear Information System (INIS)

The results of the thermo-hydro-mechanical (THM) study of the FEBEX bentonite performed during FEBEX II are presented. The laboratory test program continued in part with the works carried out during FEBEX I, particularly in activities related to tests aimed to the calibration of the models, the acquisition of parameters by back-analysis and the improvement of the knowledge on the behaviour of expansive clays. But the program has also included tests on new areas: investigations about the influence of the microstructure changes in bentonite, of temperature and of the solute concentration on the behaviour of clay. Besides, several tests were proposed in order to understand the unexpected behaviour observed in the mock-up test, towards the end of year 2. Temperature effects on water retention curves in confined and unconfined conditions were determined, and swelling pressure, hydraulic conductivity and swelling and consolidation strains as a function of temperature ...

26

A novel CFD/structural analysis of a cross parachute  

Energy Technology Data Exchange (ETDEWEB)

A novel CFD/structural analysis was performed to predict functionality of a cross parachute under loadings near the structural limits of the parachute. The determination of parachute functionality was based on the computed structural integrity of the canopy and suspension lines. In addition to the standard aerodynamic pressure loading on the canopy, the structural analysis considered the reduction in fabric strength due to the computed aerodynamic heating. The intent was to illustrate the feasibility of such an analysis with the commercially available software PATRAN.

1993-12-31

28

Multiscale modeling of transdermal drug delivery  

Science.gov (United States)

This study addresses the modeling of transdermal diffusion of drugs, to better understand the permeation of molecules through the skin, and especially the stratum corneum, which forms the main permeation barrier of the skin. In transdermal delivery of systemic drugs, the drugs diffuse from a patch placed on the skin through the epidermis to the underlying blood vessels. The epidermis is the outermost layer of the skin and can be further divided into the stratum corneum (SC) and the viable epidermis layers. The SC consists of keratinous cells (corneocytes) embedded in the lipid multi-bilayers of the intercellular space. It is widely accepted that the barrier properties of the skin mostly arises from the ordered structure of the lipid bilayers. The diffusion path, at least for lipophilic molecules, seems to be mainly through the lipid bilayers. Despite the advantages of transdermal drug delivery compared to other drug delivery routes such as oral dosing and ...

2006-01-01

29

Skeletal remodeling dynamics: New approaches with imaging instrumentation  

Energy Technology Data Exchange (ETDEWEB)

This report of progress and future objectives timetable is based on an included schematic of goals and objectives and the project abstract which is included as Appendix 1. Five matters are summarized in the order of (1) novel methods of calcified bone confocal microscopy and reconstruction image analysis of decalcified beagle and human cortical bone serial sections, (2) macroscopic cross-correlation of beagle and human cortical and cancellous bone fractions with CT analysis, (3) guidance to the most radiobiologically important skeletal regions of interest with the just completed {sup 90}Sr bone tumor map from life time beagle studies, (4) deposition patterns of radioactive agents that participate in apatite crystal nucleation processes in bone and leave radiation-excited electrons trapped in bone mineral, and (5) the budget period timetable. The discovery that beta particles from {sup 166}Ho (T{sub {1/2}} =26 hr, {beta}{sub ...

1991-12-01

30

Failure analysis of CO_2 anti-freezing heater at Daya Bay Nuclear Power Station  

International Nuclear Information System (INIS)

In this paper, an investigation was performed on a failure pressure vessel, which was as an anti-freezing heater for General Gas Storage and Distribution (SGZ) system. Evident and serious deformation was observed on the body of the vessel. A metallurgical investigation was conducted to establish the mechanism and cause of deformation of the anti-freezing heater at Daya Bay PWR station in China. The investigation, which was performed on specimens cut from the most serious area deformed of the vessel, included macroscopic examination and microscopy examination. The results of the examinations showed that some lamellar pearlite in the microstructure were already spheroidized. It was confirmed that the vessel was operated at high temperature. Stress analysis for the vessel was conducted. And it was confirmed that, in ideal conditions, the vessel would be deformed at around 420 C. The overall results of the investigation showed that the failure of ...

2002-09-23

31

Structural analysis and stress evaluation system for steel structures: ADAMS  

Energy Technology Data Exchange (ETDEWEB)

In order to perform the structural analysis and stress evaluation for frame structures in the nuclear power plants, ADAMS (AIJ Design Analysis and Modules System) has been developed by the addition of the following functions to the ICES-STRUDL system. 1. Load combination and stress evaluation on the basis of specifications for designing steel structure (issued by the Architecture Institute of Japan). 2. Combination of load and stress evaluation of piping support on the basis of the regulations of Ministry of International Trade and Industry. 3. Addition of other functions than that described above. ADAMS enables structural analysis and stress evaluation exactly and efficiently not only for a large scale structure such as the pipe whip protection structure installed inside of the primary containment ...

1980-11-01

32

The magnetic resonance and its agro-industry applications; a review  

International Nuclear Information System (INIS)

The electromagnetic properties that present hydrogen and other nucleus of agro-alimentary products, have allowed widely use of magnetic resonance (MR) to study the composition and internal structure of these biological materials in a micro and macroscopic scale, in a nondestructive way. In this paper the physical principles, basic equipment to measure the MR signals and the MR imaging of any biological sample, are explained. It is also shown a review of the main agro-alimentary applications, emphasizing in the use of this principle to examine the internal quality of fruits and vegetables. In these products, the MR has been used to detect and follow the evolution of different factors that determine the internal quality after harvesting, during storage and after post harvesting processes. The main studies that have been conducted with MR in harvested products are about physiological disorders that take place during storage and conservation of ...

33

Micromechanical modeling of ferrite-pearlite steels using finite element unit cell models  

Energy Technology Data Exchange (ETDEWEB)

An axisymmetric unit cell model based on a regular array of second-phase particles arranged on a BCC lattice is used to study deformation mechanisms of ferrite-pearlite structural steels. Microstructural characteristics of the steels were parameterized by the pearlite volume fraction, the aspect ratio of the pearlite particles, and the neighboring factor, which represents the ratio of interparticle spacing in the longitudinal direction to that in the transverse direction. FE analyses were carried out to investigate the macroscopic and microscopic response of unit cells with morphological features based on idealizations of the microstructures of the actual steels. Tensile properties of each constituent phase were obtained experimentally and used in the analyses. As compared to traditional axisymmetric models, the BCC tell model appears to be able to capture more realistically the behavior of the materials, and it accurately estimates the tensile ...

2000-11-01

34

Generalized Gas Dynamic Equations for Microflows  

CERN Document Server

n an early approach, we proposed a kinetic model with multiple translational temperature [K. Xu, H. Liu and J. Jiang, Phys. Fluids {\\bf 19}, 016101 (2007)], to simulate non-equilibrium flows. In this paper, instead of using three temperatures in $x-$, $y-$, and $z$-directions, we are going to further define the translational temperature as a second-order symmetric tensor. Based on a multiple stage BGK-type collision model and the Chapman-Enskog expansion, the corresponding macroscopic gas dynamics equations in three-dimensional space will be derived. The zeroth-order expansion gives the 10 moment closure equations of Levermore [C.D. Levermore, J. Stat. Phys {\\bf 83}, pp.1021 (1996)]. To the 1st-order expansion, the derived gas dynamic equations can be considered as a regularization of Levermore's 10 moments equations. The new gas dynamic equations have the same structure as the Navier-Stokes equations, but the stress strain relationship in ...

2008-01-01

35

Transient / Structural Analysis of a Combustor under Explosive Loads  

Science.gov (United States)

Ultimate Compressive Strength = 3000.0 psi. 3.0 Failure Criteria. The structural criteria used to evaluate the combustor components was chosen ...

36

Structure and function of an acetylcholine receptor.  

UK PubMed Central (United Kingdom)

Structural analysis of an acetylcholine receptor from Torpedo californica leads to a three-dimensional model in which a "monomeric" receptor is shown to contain subunits arranged around a central ionophoretic...Full Text Available

1982-01-01

37

High resolution electron microscopy of interfaces in fcc materials  

Energy Technology Data Exchange (ETDEWEB)

Modern high-resolution electron microscopy (HREM) instruments, which are capable of a point-to-point resolution of better than 0.2 nm, have allowed atomic-scale observations of a variety of internal interfaces. The application of the HREM technique to fcc model systems for the purpose of addressing a number of interface issues will be examined in this paper. Atomic structure observations for heterophase interfaces of metal/metal and metal/metal-oxide systems as well as HREM studies of grain boundaries in NiO and Au will be discussed with emphasis on generic structural features and the role of the interface plane. Comparisons between observed interface structures and atomistic computer modeling results have shown agreements for some interfaces, as well as certain differences in others. A number of structural features are common to both metal and oxide grain boundaries, as well as certain heterophase ...

1990-08-01

38

Dislocation plasticity and complementary deformation mechanisms in polycrystalline Mg alloys  

Energy Technology Data Exchange (ETDEWEB)

Deformation mechanisms of Mg-Al-Zn (AZ31) alloys were investigated by performing tensile test at room temperature. In fine grain Mg alloys deformed at room temperature, nonbasal slip systems were found to be active as well as basal slip systems because of grain-boundary compatibility effect. Slip-induced grain-boundary sliding occurred as a complementary deformation mechanism to give rise to c-axis component of strain. With increasing grain size, the activation of the nonbasal slip systems was limited near grain boundaries. Instead of grain-boundary sliding, twinning occurred as a complementary deformation mechanism in large grained samples. Orientation analysis of twins indicated that twinning is induced by stress concentration due to the pile up of basal dislocations. The grain-size dependence on deformation mechanism was found to affect yielding behavior both microscopically and macroscopically which can influence various mechanical ...

2004-07-01

40

Structural aspects of lithium ions hydration in aqueous solutions of electrolytes  

International Nuclear Information System (INIS)

Analysis of results of an investigation into the structure of lithium salt aqueous solutions is presented. An anomaly in lithium ion behaviour in solutions at the structural level is noted. 40 refs., 3 tabs.

41

Coupling of Pressure-Induced Structural Shifts to Spectral Changes in a Yellow Fluorescent Protein  

UK PubMed Central (United Kingdom)

AbstractX-ray diffraction analysis of pressure-induced structural changes in the Aequorea yellow fluorescent protein Citrine reveals the structural basis for the continuous...Full Text Available

2009-09-16

42

Response of seismic-isolated structures under long-period motions  

International Nuclear Information System (INIS)

In the past decade, considerable progress has been made on reducing the seismic response of structures through seismic isolation. Application of seismic-isolation techniques to nuclear power facilities is currently being investigated. This paper presents an analysis of the effect of long period motions on a seismic-isolated nuclear structure. Preliminary analysis indicates that long-period earthquake motions increase structural accelerations and relative displacements between the upper and lower mats. Relative displacement between the mats can be represented by spectral displacement at the frequency of the structure, and can be effectively reduced by increasing viscous damping in the isolator. The isolated structure behaves as a system with one degree of freedom. Future analysis of seismic effects on seismic-isolated ...

1991-08-18

43

Structural integrity evaluation of FTL in-pool piping  

Energy Technology Data Exchange (ETDEWEB)

HANARO fuel test loop will be equipped in HANARO to obtain the development betterment of advanced fuel and materials through the irradiation test. The object of this study is to evaluate the structural integrity of FTL in-pool piping by investigating a dynamic analysis of the loop containing a postulated rupture section. The method to perform the dynamic analysis and structural integrity evaluation caused by the pipe whip in water environment can be a reference for a similar structural integrity evaluation. (author). 7 refs., 39 tabs., 34 figs.

1998-05-01

44

Magnetization and magnetostriction curves for highly magnetostrictive materials  

Energy Technology Data Exchange (ETDEWEB)

The macroscopic behavior of magnetostrictive materials results from domain evolutions occurring at a microscopic scale. The author shows how to compute magnetization and magnetostriction curves by appraising the behavior of the underlying microstructures. The method hinges on an averaging device (Young measures), which allows one to pass from the microscopic to the macroscopic scale. He takes into account the kinematical constraints on the accommodation of elastic effects, and he highlights the role of material symmetry in the selection of energetically optimal microstructures.

1994-12-31

45

Probabilistic Seismic Risk Analysis of a Wolsung NPP Containment Building for Near Fault Ground Motions  

Energy Technology Data Exchange (ETDEWEB)

In this study, a probabilistic seismic risk analysis of the Wolsung NPP containment building was performed by a seismic hazard analysis and a seismic fragility analysis based on the nonlinear dynamic time-history analyses. The conventional seismic fragility analysis of the safety related structures in a NPP have been performed by using the linear elastic analysis results. The probabilistic seismic risk of the containment building was 5.19e-8.

2006-07-01

46

Probabilistic Seismic Risk Analysis of a Wolsung NPP Containment Building for Near Fault Ground Motions  

International Nuclear Information System (INIS)

In this study, a probabilistic seismic risk analysis of the Wolsung NPP containment building was performed by a seismic hazard analysis and a seismic fragility analysis based on the nonlinear dynamic time-history analyses. The conventional seismic fragility analysis of the safety related structures in a NPP have been performed by using the linear elastic analysis results. The probabilistic seismic risk of the containment building was 5.19e-8.

2006-05-25

47

Can intensity-modulated radiation therapy of the paraaortic region overcome the problems of critical organ tolerance?  

International Nuclear Information System (INIS)

Background and purpose: the recent RTOG guidelines for future clinical developments in gynecologic malignancies included the investigation of dose escalation in the paraaortic (PO) region which is, however, very difficult to target due to the presence of critical organs such as kidneys, liver, spinal cord, and digestive structures. The aim of this study was to investigate intensity-modulated radiotherapy's (IMRT) possibilities of either increasing, in a safe way, the dose to 50-60 Gy in case of macroscopic disease or decreasing the dose to organs at risk (OR) when treatment is given in an adjuvant setting. Material and methods: the dosimetric charts of 14 patients irradiated to the PO region at the department of radiation oncology, university hospital of Liege, Belgium, in 2000 were analyzed in order to compare six-field conformal external-beam radio-therapy (CEBR) and five-beam IMRT approaches. Both CEBR and IMRT investigations were planned to ...

2005-03-01

48

Floating production and storage vessels - design analysis and operational issues: a handbook produced to accompany the Bentham Technical Training Courses  

Energy Technology Data Exchange (ETDEWEB)

These ten chapters present an overview of floating production, storage and offloading (FPSO) vessels, and examines deep water developments; hydrostatic stability; production, storage and offloading systems; the configuration and structure of flexible risers and umbilicals; the structural and global dynamic analysis of flexible riser and umbilicals; verification of FPSO structural integrity; vessel global loading and rigid body response; environmental loading and vessel response; and mooring systems. (UK)

1998-07-01

49

Modeling of ablation by photospallation using the computer program PUFF/DFRACT  

Energy Technology Data Exchange (ETDEWEB)

In general, macroscopic material failure is a manifestation of irreversible changes at the microscopic level. Many tissues, which may appear to be macroscopically homogeneous, are, at a fundamental microscopic level, a composite material. For example, cornea is composed of a hyaluronic acid matrix in which layers of collagen fibers are overlaid in a crossing pattern. The points where the collagen fibers intersect are potential nucleation sites for microscopic defects, which under the action of tensile stress, nucleate, grow and coalesce to form macroscopic failure planes, or spall planes. Using a model based on microstructural evolution, this paper examines the failure process during photoablation. Specifically, the paper describes a physically motivated, micromechanical model based on the nucleation and growth of spherical voids. This model is then used to simulate photoablation of cornea. Potential for using this model to ...

1995-03-01

50

System reliability of timber structures with ductile behaviour  

British Library Electronic Table of Contents (United Kingdom)

The present paper considers the evaluation of timber structures with the focus on robustness due to connection ductility. The robustness analysis is based on the structural reliability framework applied to a simplified mechanical system. The structural timber system is depicted as a parallel system. An evaluation method of the ductile behaviour is introduced. For different ductile behaviours, the system reliability is estimated based on Monte Carlo simulation. A correlation between the strength of the structural elements is introduced. The results indicate that the reliability of a structural timber system can be significantly increased due to the ductile behavior.

2011-01-01

51

Effects of scale in predicting global structural response  

Science.gov (United States)

In the course of previous composite structures test programs, the need for and the feasibility of developing analyses for scale-up effects has been demonstrated. The analysis techniques for scale-up effects fall into two categories. The first category pertains to developing analysis methods independently for a single, unique failure mode in composites, and using this compendium of analysis methods together with a global structural model to identify and predict the response and failure mode of full-scale built-up structures. The second category of scale-up effects pertains to similitude in structural validation testing. In this latter category, dimensional analysis is used to develop scale-up laws that enable extrapolation of sub-scale component test data to full-scale structures. This viewgraph ...

1994-07-01

52

In vivo monitoring system for structure-function relationship analysis of the antibacterial peptide apidaecin.  

UK PubMed Central (United Kingdom)

A unique antibacterial peptide derivative found in immune honeybee lymph, apidaecin 1b (AP1), was randomly mutagenized and characterized by a newly established system to analyze in vivo its structure-function...Full Text Available

1994-10-01

53

Crystal structure of the human adenovirus proteinase with its 11 amino acid cofactor.  

UK PubMed Central (United Kingdom)

The three-dimensional structure of the human adenovirus-2 proteinase complexed with its 11 amino acid cofactor, pVIc, was determined at 2.6 A resolution by X-ray crystallographic analysis. The fold...Full Text Available

1996-04-15

54

An analysis by low-angle neutron scattering of the structure of the acetylcholine receptor from Torpedo californica in detergent solution.  

UK PubMed Central (United Kingdom)

The acetylcholine receptor from the electric tissue of Torpedo californica is a large, integral membrane protein containing four different types of polypeptide chains. The structure of the purified...Full Text Available

1979-12-01

55

Peptides of human bronchial mucus glycoproteins. Size determination by electron microscopy and by biosynthetic experiments.  

UK PubMed Central (United Kingdom)

Secreted human bronchial mucins, directly collected from macroscopically healthy bronchial mucosa, were prepared in the presence of six proteinase inhibitors, and analysed by electron microscopy. These...Full Text Available

1987-11-15

57

Energy Finite Element Analysis ... - NASA Technical Reports Server  

Science.gov (United States)

structures made out of composite laminates and/or composite sandwich panels. A Spectral Finite Element Method (SFEM) [19, 20] is used for evaluating the ...

59

Design of Damage-Tolerant Composite Sandwich Panels with Tear Straps  

Science.gov (United States)

The objectives of the Phase-I research address the development of mechanics- based structural integrity analysis methodologies for composite sandwich panels ...

60

Residual stress measurements on a stress relieved Zircaloy-4 weld by neutron diffraction  

Energy Technology Data Exchange (ETDEWEB)

The macroscopic stress distribution across an annealed Zircaloy-4 gas tungsten arc weld was measured by neutron time-of-flight diffraction at the SMARTS diffractometer at Los Alamos National Laboratory. The stresses after annealing are about 40% lower than those in the same weld prior to heat treatment. The intergranular strains in the reference coupons, which give the macroscopic stress free lattice spacings, are consistent with the difference in cooling the strongly textured plate and the weakly textured weld.

2006-12-15

61

MACROSCOPIC ONTOLOGY IN EVERETTIAN QUANTUM MECHANICS  

British Library Electronic Table of Contents (United Kingdom)

Abstract Simon Saunders and David Wallace have proposed an attractive semantics for interpreting linguistic communities embedded in an Everettian multiverse. It provides a charitable interpretation of our ordinary talk about the future, and allows us to retain a principle of bivalence for propositions and to retain the law of excluded middle in the logic of propositions about the future. But difficulties arise when it comes to providing an appropriate account of the metaphysics of macroscopic objects and events. I evaluate various metaphysical frameworks which might be combined with the Saunders-Wallace semantics. I conclude that the most appropriate metaphysics to underwrite the semantics renders Everettian quantum mechanics a theory of non-overlapping worlds.

2011-01-01

62

Investigation of the dc vacuum breakdown mechanism  

Science.gov (United States)

Breakdowns occurring in rf accelerating structures will limit the ultimate performance of future linear colliders such as the Compact Linear Collider (CLIC). Because of the similarity of many aspects of dc and rf breakdown, a dc breakdown study is underway at CERN to better understand the vacuum breakdown mechanism in a simple setup. Measurements of the field enhancement factor ? show that the local breakdown field is constant and depends only on the electrode material. With copper electrodes, the local breakdown field is around 10.8GV/m, independent of the gap distance. The ? value characterizes the electrode surface state, and the next macroscopic breakdown field can be well predicted. In breakdown rate experiments, where a constant field is applied to the electrodes, clusters of consecutive breakdowns alternate with quiet periods. The occurrence and lengths of these clusters and quiet periods depend on the evolution of ?. The application of ...

2009-09-01

63

Structures in the Universe and Origin of Galaxies  

CERN Document Server

The analysis of images (of obtained in various ranges of the lengths of waves) of luminous objects in the Universe by means of a method of multilevel dynamic contrasting led author to the conclusions: a) the structures of all observable galaxies represents a complicated constructions which have the tendency to self-similarity and made of separate (basic) blocks, which are a coaxially tubular structures and a cartwheel-like structures; b) the majority of observable objects in the Universe are luminous butt-ends of almost invisible (of almost completely transparent) of filamentary formations which structures are seen only near to their luminous butt-ends; c) the result of analysis of images of cosmic objects show the structure of many pairs of cooperating galaxies point to opportunity of their formation at butt-ends generated in a place of ...

2005-01-01

64

Research of structural concept to heat-resistant airframe of HOPE. HOPE tainetsu kozo gainen no kenkyu  

Energy Technology Data Exchange (ETDEWEB)

This paper states the concept of a heat-resistant structure of the HOPE airframe having a 10 ton weight when lifting off and also the research situation of heat-resistant structural materials. To study the structure, established are design conditions for lift-off, reentry to the atmosphere and landing. As to the load condition, the load at the time of lift-off is most critical. Relating to the temperature environment condition, thermal analysis is made of the time when a HOPE is on the orbit (low-temperature range) and reenters the atmosphere (high-temperature range), when the temperature environment is critical. The analysis shows that the temrerature environment is in a {minus}80-1700{degree}C (range). The heat-resistant structural materials are developed so as to meet these conditions. The paper describes distribution of the airframe surface temperature by ...

1991-11-05

65

Validation of immune function testing during a 4-week oral toxicity study with FK506.  

Science.gov (United States)

Assessment of the immune system's capability to respond to antigens with the generation of specific antibodies, whilst under the influence of a test article, is required in toxicity tests according to the European guideline for repeated dose toxicity testing of medicinal products. The purpose of this study in rats was to validate methodology for the determination of Keyhole Limpet Haemocyanin (KLH)-specific antibodies under the influence of an immunologically active compound. The immunosuppressant FK506, commercially available as Prograf, was administered orally (gavage) to five rats per sex per group at dosages of 0.5mg/kg per day or 3mg/kg per day, for a period of 4 weeks. On days 14 and 22, KLH was administered subcutaneously, with an adjuvant (AluGel), to the two treated groups and a control (i.e. without FK506 treatment) approximately 1h following administration of FK506. Terminal investigations included haematology parameters, titration of KLH-specific antibodies in serum ...

2004-04-01

66

Isospin dependence of nuclear deformations  

International Nuclear Information System (INIS)

11-MeV neutrons were elastically and inelastically scattered from eight single-closed-shell nuclei: three proton-vibrational nuclei with N = 50 ("8"8Sr, "9"0Zr, "9"2Mo) and five even-even neutron-vibrational nuclei ("1"1"6"-"1"2"4Sn) with Z = 50. Detection methods involving electronic discrimination against #gamma# rays, and time-of-flight techniques were used to measure the energy of the scattered neutrons. Data were taken from 15"0 to 150"0 in 5"0 intervals. Measured differential cross sections were normalized to the zero-degree neutron flux and corrected. An optical model (OM) analysis was used to fit the elastic data with the code GENOA, and potential parameters were obtained for each nucleus. The observed low-lying electric quadrupole (2"+) and octupole (3"-) states were collective in nature; the macroscopic or collective model for inelastic scattering was used to generate the differential cross-section angular distributions with the ...

67

A spatial sensitivity analysis technique for neutron and gamma-ray measurements  

International Nuclear Information System (INIS)

In the fields of medical imaging, geophysical well logging, and industrial radiography, it is often of interest to characterize the spatially distributed sensitivities of neutron and gamma-ray measurement devices to the physical properties of the materials being examined. For instance, one may wish to know how the count rate in a detector varies in response to small changes in the local density of the irradiated object as a function of position. Experimental determination of such sensitivity functions is often impractical. Consequently, we have developed a general three-dimensional Monte Carlo numerical technique that allows us to directly compute the differential sensitivity of an arbitrary integral response parameter, such as a time- or energy-discriminated count rate, with respect to the spatial distribution of macroscopic cross sections and sources in the irradiated medium. Sensitivities to object density, porosity, etc., can easily be derived from these ...

1992-09-08

68

Web-based post-processing visualization system for finite element analysis  

British Library Electronic Table of Contents (United Kingdom)

In this paper, we propose and implement a website of post-processing system for finite element analysis (WebDFEA). Finite element analysis is a computer-aided engineering tool and is popular for static/dynamic structure analysis. It includes three processing systems where post-processing system is to graphically demonstrate the analysis result of a structure model analyzed by finite element method. WebDFEA performs as a website. It is cross-platform because it can auto-detect a client computer platform and auto-download proper OpenGL API for drawing computer graphics. It can draw precise graphics on webpage which can be free controlled by the mouse as a manner in professional software. A database server is involved to store finite element model data and its analysis result. The graphic use...

2011-01-01

69

Seismic stability analysis of the spent fuel storage structures for increase of storage capacity at Wolsung NPP  

Energy Technology Data Exchange (ETDEWEB)

This paper introduces the method of seismic stability analysis for the increase of fuel storage capacity of wet storage stacks by one or two more stack floor at Wolsung Nuclear Unit 2,3,4, which had been originally licensed assuming 16 tray stack-o-storage. As a basic procedure, tipping and sliding stability of the structure is checked at first thru seismic analysis and the resultant load from dynamic analysis is applied for static stress analysis, and the result of which is reviewed for compatability with applicable standard. As a result, sliding and overturning are not expected under design basis earthquakes for increased storage cases of 17 tray and 18 tray stacks. And it is anticipated the result of stress analysis will be acceptable.

2003-07-01

70

Seismic stability analysis of the spent fuel storage structures for increase of storage capacity at Wolsung NPP  

International Nuclear Information System (INIS)

This paper introduces the method of seismic stability analysis for the increase of fuel storage capacity of wet storage stacks by one or two more stack floor at Wolsung Nuclear Unit 2,3,4, which had been originally licensed assuming 16 tray stack-o-storage. As a basic procedure, tipping and sliding stability of the structure is checked at first thru seismic analysis and the resultant load from dynamic analysis is applied for static stress analysis, and the result of which is reviewed for compatability with applicable standard. As a result, sliding and overturning are not expected under design basis earthquakes for increased storage cases of 17 tray and 18 tray stacks. And it is anticipated the result of stress analysis will be acceptable.

2003-05-29

71

Structure of unilamellar vesicles: Numerical analysis based on small-angle neutron scattering data  

International Nuclear Information System (INIS)

The structure of polydispersed populations of unilamellar vesicles is studied by small-angle neutron scattering for three types of lipid systems, namely, single-, two-and four-component vesicular systems. Results of the numerical analysis based on the separated-form-factor model are reported.

2006-12-01

72

Structure of an accelerator island with one step on double period of conserving area mapping  

International Nuclear Information System (INIS)

The structure of the P-2, S-1 accelerator mode with one step, S-1, on double period, P-2 for systems, described by the Harper mapping as well as by standard mapping, is analyzed. Detailed analysis of stability criteria is given and comparison with the results of numerical analysis is performed. Three-period compression of the P-2, S-1 island is revealed in the standard mapping. Refs. 7, figs. 7.

73

Structure analysis of ferrite in deformed pearlitic steel by means of X-ray diffraction method with synchrotron radiation  

Energy Technology Data Exchange (ETDEWEB)

Structure of ferrite in drawn pearlitic steel containing 0.9 mass% C was investigated with X-ray diffraction technique using synchrotron radiation. In the detailed analysis of diffraction peaks of ferrite during the drawing process, it was experimentally revealed that the transformation of ferrite from bcc to bct due to the supersaturation of carbon in ferrite of heavily drawn pearlitic steel.

2004-07-15

74

Structure analysis of ferrite in deformed pearlitic steel by means of X-ray diffraction method with synchrotron radiation  

International Nuclear Information System (INIS)

Structure of ferrite in drawn pearlitic steel containing 0.9 mass% C was investigated with X-ray diffraction technique using synchrotron radiation. In the detailed analysis of diffraction peaks of ferrite during the drawing process, it was experimentally revealed that the transformation of ferrite from bcc to bct due to the supersaturation of carbon in ferrite of heavily drawn pearlitic steel.

2004-07-01

75

Structural analysis of a binary metallic glass model. I. - The Pd/sub 80/Si/sub 20/ alloy  

Energy Technology Data Exchange (ETDEWEB)

In the first paper of this series devoted to a structural analysis of a binary metallic glass model, we study a Pd/sub 80/Si/sub 20/ sample obtained by numerical relaxation. We discuss the reproducibility of the method and make a comparison with the experimental interference functions. Then we undertake a microscopic structural analysis from several point of view: we first study the number of neighbours of each type for each type of atoms; secondly, we analyse the structure by means of the radical plane method; at last, we show that it is possible to generalize the five fundamental characteristic units introduced by Bernal, so that we can define the environment of any Si atom without any ambiguity. All these methods reveal a certain tendency towards a prismatic environment for the metalloids.

1985-02-01

76

Reliability-based robustness analysis for a Croatian sports hall  

British Library Electronic Table of Contents (United Kingdom)

This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness and a simplified mechanical system modelling of a timber truss system. A complex timber structure with a large number of failure modes is modelled with only a few dominant failure modes. First, a component based robustness analysis is performed based on the reliability indices of the remaining elements after the removal of selected critical elements. The robustness is expressed and evaluated by a robustness index. Next, the robustness is assessed using system reliability indices where the probabilistic failure model is modelled by a series system of parallel systems.

2011-01-01

77

Applications of environmental scanning electron microscopy (ESEM) in the study of novel drying latex films  

Energy Technology Data Exchange (ETDEWEB)

We have employed Environmental Scanning Electron Microscopy (ESEM) and Energy Dispersive X-ray (EDX) analysis to study the microstructural evolution of acrylic latex stabilised with a novel polysaccharide derived from agricultural waste. The analysis revealed that the micro structure of the latex in the 'wet' state consists of individual particles and clusters. Upon evaporation a discontinuous film is formed, with voids present within its structure, which is inconsistent with the conventional descriptions of film formation. Further ESEM examination of 'dry' specimens revealed that aging resulted in the formation of dendritic structures on the surfaces of the latex films, which EDX analysis confirmed to have been formed via crystallisation of salt. The experimental evidence suggests that the clusters, which are part of the ...

2008-08-15

78

Airbags to Martian Landers: Analyses at Sandia National Laboratories  

Energy Technology Data Exchange (ETDEWEB)

A new direction for the national laboratories is to assist US business with research and development, primarily through cooperative research and development agreements (CRADAs). Technology transfer to the private sector has been very successful as over 200 CRADAs are in place at Sandia. Because of these cooperative efforts, technology has evolved into some new areas not commonly associated with the former mission of the national laboratories. An example of this is the analysis of fabric structures. Explicit analyses and expertise in constructing parachutes led to the development of a next generation automobile airbag; which led to the construction, testing, and analysis of the Jet Propulsion Laboratory Mars Environmental Survey Lander; and finally led to the development of CAD based custom garment designs using 3D scanned images of the human body. The structural analysis of these ...

1994-03-01

79

Classical fracture mechanics methods  

International Nuclear Information System (INIS)

Comprehensive Structural Integrity is a reference work which covers all activities involved in the assurance of structural integrity. It provides engineers and scientists with an unparalleled depth of knowledge in the disciplines involved. The new online Volume 11 is dedicated to the mechanical characteristics of materials. This paper contains the chapter 11.02 of this volume and is structured as follows: Test techniques; Analysis; Fracture behavior; Fracture toughness tests for nonmetals.

80

The Department of Energy (DOE) research program in structural analysis of vertical-axis wind turbines  

Science.gov (United States)

The Darrieus-type Vertical Axis Wind Turbine (VAWT) presents a variety of unusual structural problems to designers. The level of understanding of these structural problems governs, to a large degree, the success or failure of today's rotor designs. A survey is presented of the technology available for rotor structural design with emphasis on the DOE research program now underway. Itemizations are included of the major structural issues unique to the VAWT along with discussion of available analysis techniques for each problem area. It is concluded that tools are available to at least approximately address the most important problems. However, experimental data for confirmation is rather limited in terms of volume and the range of rotor configurations tested.

1982-01-01

81

Structural fuzzy reliability analysis and its applications in strength problems for ships  

Energy Technology Data Exchange (ETDEWEB)

In the universe there are two different kinds of uncertain phenomena: stochastic and fuzzy or vague. Both uncertain phenomena have been found in structural problems. Therefore, rational decisions concerning the design of marine structures cannot be made without resorting to the methods which can take the uncertainties into account. The fundamental concept of structural fuzzy reliability problems and the methods to give the fuzzy solution are introduced in the paper. Based on the principle of fuzzy decision-making the method to obtain the crisp solution of structural fuzzy reliability analysis is proposed by means of the Bound Search method. Illustrative numerical examples, ship bottom plates under slamming impact pressures are solved. The influence of variation of allowable tolerances in the fuzzy reliability indexes is discussed.

1995-12-31

82

Symmetries in nuclei near the centre of the f{sub 7/2} shell  

Energy Technology Data Exchange (ETDEWEB)

High-spin states in the mirror pair nuclei {sup 49}Cr and {sup 49}Mn and their cross-conjugate partners, the mirror pair {sup 47}V and {sup 47}Cr have been investigated using experimental {gamma}-ray spectroscopic techniques. The combination of high-efficiency EUROBALL cluster Germanium detectors and clean exit-channel gating afforded by a 31-element silicon ball used in conjunction with a 15-detector neutron wall allowed a revision and extension to the energy level schemes of all four nuclei up to J{sup {pi}}=31{sup -}/2. The difference in excitation energy between states of equivalent spin in the parent nucleus and its analogue partner have thus been established for both mirror pairs up to the f{sub 7/2}-shell band terminating state for the first time. This difference is assumed to be due almost entirely to the Coulomb effect and is therefore called the Coulomb energy difference (CED). The variation in the CED with spin has been interpreted as reflecting the change in the way the ...

1998-10-01

83

Can intensity-modulated radiation therapy of the paraaortic region overcome the problems of critical organ tolerance?  

Energy Technology Data Exchange (ETDEWEB)

Background and purpose: the recent RTOG guidelines for future clinical developments in gynecologic malignancies included the investigation of dose escalation in the paraaortic (PO) region which is, however, very difficult to target due to the presence of critical organs such as kidneys, liver, spinal cord, and digestive structures. The aim of this study was to investigate intensity-modulated radiotherapy's (IMRT) possibilities of either increasing, in a safe way, the dose to 50-60 Gy in case of macroscopic disease or decreasing the dose to organs at risk (OR) when treatment is given in an adjuvant setting. Material and methods: the dosimetric charts of 14 patients irradiated to the PO region at the department of radiation oncology, university hospital of Liege, Belgium, in 2000 were analyzed in order to compare six-field conformal external-beam radio-therapy (CEBR) and five-beam IMRT approaches. Both CEBR and IMRT investigations were ...

2005-03-01

84

Reflected-shock initiation of explosives  

Energy Technology Data Exchange (ETDEWEB)

In a study of initiations caused by reflected shock from a high-impedance boundary, attempts to establish sufficient conditions for initiative are described. Shock polar analysis is used to discover the ranges of various flow regimes, general shock structures and pressure estimates of states behind the reflected wave. Using this knowledge, wave structure growth rates from hydrocode simulations are estimated and standard-shock initiation criteria are used; experiments are designed in which the initiation from a reflected-shock wave structure appears likely. Two experiments are described in which a reflected-shock wave from a uranium surface initiated PBX 9502. The experimental evidence is in good agreement with the assumptions and results of the analysis.

1993-08-01

85

Nastran nonlinear dynamic transient accident analysis for FFTF reactor component  

International Nuclear Information System (INIS)

A nonlinear dynamic transient analysis merging hand calculations and the NASTRAN structural analysis computer code was conducted for a Fast Flux Test Facility in-reactor test assembly during an extremely unlikely design basis accidental event which is considered a Hypothetical Core Disruptive Accident (HCDA). The finite element modeling of the problem took advantage of NASTRAN's versatility to create loads and nonlinear elements not previously found in NASTRAN's library. The structural criteria for the test assembly to withstand an HCDA stipulates that the test assembly and its spoolpiece shall remain integral with the reactor head such that missiles are not generated.

1976-11-15

86

Generalization of proposed tendon friction correlation and its application to PCCV structural analysis  

Energy Technology Data Exchange (ETDEWEB)

The present paper dealt with the extension of tendon friction coefficient correlation as a function of loading end load and circumferential angle, proposed in the former paper. The extended correlation further included the effects of the number of strands contacted with sheath, tendon diameter, politicization of tendon and tendon local curvature. The validity of the correlation was confirmed by several published measured data. The structural analysis of middle cylinder part of 1/4 PCCV (Prestressed Concrete Containment Vessel) model was conducted using the present friction coefficient correlation. The results were compared with the analysis using constant friction coefficient, focused on the tendon tension force distribution. (author)

2000-12-01

87

Synthesis, Herbicidal Activities and Comparative Molecular Field Analysis Study of Some Novel Triazolinone Derivatives  

British Library Electronic Table of Contents (United Kingdom)

A series of novel triazolinones were synthesized and their structures were characterized by 1H NMR, elemental analysis and single-crystal X-ray diffraction analysis. The herbicidal activities were evaluated against Echinochloa crusgalli (L.) Beauv., Digitaria adscendens, Brassica napus and Amaranthus retroflexus. The herbicidal activity data indicated that the title compounds had higher activities with substituted benzyl group moieties than with other groups such as sulfonyl, alkyl, etc. To further investigate the structure-activity relationship, comparative molecular field analysis was performed on the basis of herbicidal activity data. Both the steric and electronic field distributions of comparative molecular field analysis are in good agreement in this work. The results showed that a b...

2009-01-01

88

Structural integrity evaluation of fuel test loop submerged in water subjected to postulated pipe rupture  

Energy Technology Data Exchange (ETDEWEB)

The structural integrity of the Fuel Test Loop(FTL) in a Korean experimental reactor is evaluated when the FTL, submerged in a water environment, is subjected to a postulated pipe rupture. The analyses are performed under static and dynamic conditions, imposing the thrust force history at each postulated pipe rupture section. Through analysis the following results are found: 1) A double ended guillotine can not be expected based on the toughness of the material, 2) the structural integrity of the chimney surrounding the FTL would not impede the structural integrity by the pipe whip. All analyses are performed by finite element methods.

2000-02-01

89

Safety assessment and life time management of nuclear power plants: from reasonable design to reliable structural health monitoring  

International Nuclear Information System (INIS)

Nowadays the safety of Nuclear Power Plants is becoming more and more significant. Therefore consideration of severe accidents shall be included in both design and operating process of Nuclear Power Plants. In particular ground motion forms one of the important natural hazards. For structural analysis both linear-elastic and non-linear methods are specified by the engineering codes for earthquake resistance design. However, time history analysis is required for investigation of non-linear structural behaviour. Moreover, non-linearities are often caused by the presence of damage. This can be detected by means of structural health monitoring and subsequently system identification. In this paper the advantages of both dynamic time history analysis and damage detection by means of wavelet analysis are discussed. First, the non-linear behaviour ...

2005-06-15

90

Study of technetium chemistry. Pt.10: Qsar analysis of "9"9Tc"m-labelled N_2S_2 analogues of brain imaging agents  

International Nuclear Information System (INIS)

Quantitative structure activity relationship (QSAR) analysis of the correlations between initial brain uptake and structure parameters, for example lipophilicity F_r, molar refractivity MR and electronic parameters #sigma#_1 of the "9"9Tc"m-N_2S_2 complexes have been studied with multiple regression analysis method. The main structural factors which affect the initial brain uptake of this kind of brain imaging agents have been discussed. The results may give some theoretical information for designing new brain imaging agents

1998-02-01

91

Structure design of human factor data management system for Daya Bay NPP  

International Nuclear Information System (INIS)

Collection, analysis and quantification of human factor data are important compositions of human reliability analysis (HRA) and probabilistic risk assessment (PRA). Various human factor databases have been set up, but there are comparatively little human factor data management systems which can be uses for collection, classification, analysis, calculation and predication of the human factor data. Therefore, the human factor data management system for Daya Bay NPP is developed, with the following three modules and four databases: original data module, computing module, introduced data module, and basic database, other data source of the plant, external database and introduced database. The foundational problems about human factor data and the systemic structure and function are described. The data structure in the database is also discussed, because it is of the most importance in ...

2000-04-01

92

Application of unified Lyapunov control algorithm and mathematical demonstration for structure control  

British Library Electronic Table of Contents (United Kingdom)

This paper presents a new algorithm which is applicable in designing a smart damping system for vibration mitigation. The algorithm, which is extended into a unified system from Lyapunov stability theory, enables us to decrease the errors by its increased stability. The validity of this design method was proved in the experiment on a control model of three-storied building structure. Smart damper was used for MR (Magneto-Rheological fluid) damper in the experiment, and its control effectiveness was evaluated. In order to make a more accurate control model mathematically, we updated the model on the basis of the analysis of dynamic characteristics of structure and of the mathematical analysis of a lumped mass model, and then employed a state space model redefined by structural property matr...

2011-01-01

93

Structure of human insulin monomer in water/acetonitrile solution  

Energy Technology Data Exchange (ETDEWEB)

Here we present evidence that in water/acetonitrile solvent detailed structural and dynamic information can be obtained for important proteins that are naturally present as oligomers under native conditions. An NMR-derived human insulin monomer structure in H{sub 2}O/CD{sub 3}CN, 65/35 vol%, pH 3.6 is presented and compared with the available X-ray structure of a monomer that forms part of a hexamer (Acta Crystallogr. 2003 Sec. D59, 474) and with NMR structures in water and organic cosolvent. Detailed analysis using PFGSE NMR, temperature-dependent NMR, dilution experiments and CSI proves that the structure is monomeric in the concentration and temperature ranges 0.1-3 mM and 10-30 deg. C, respectively. The presence of long-range interstrand NOEs, as found in the crystal structure of the monomer, provides the evidence for conservation of the ...

2008-01-15

94

Sub-barrier fusion reactions for synthesis of "2"9"8114  

International Nuclear Information System (INIS)

Favorable reaction channels are searched for in order to obtain the superheavy element "2"9"8114. The interaction energy is supposed to comply with the adiabatic hypothesis. Concerning the deformation energy, a very complete binary macroscopic-microscopic energy method is used to perform calculations. Deformed two-center shell model provides the energy level schemes for shell effects. Yukawa-plus-exponential model gives the macroscopic (liquid drop) part of the total energy. The mass tensor is obtained by the Werner-Wheeler irrotational flow hypothesis. Finally the minimization of the multidimensional action integral produces the highest penetrability values. Kr-projectile reactions provide the best pairs, although generally the presentabilities are very low. (author)

2005-01-01

95

Coherent spontaneous radiation of Frenkel excitons  

International Nuclear Information System (INIS)

We have constructed a mathematical model that describes the coherent spontaneous radiation of a macroscopically filled exciton mode. We have demonstrated qualitatively ways in which a coherent subsystem of excitons can be formed. When this occurs under the influence of an external coherent source, exciton free induction occurs, while in the case of a spontaneous transition of the excitons to a coherent state through freezing of the reservoir of intermolecular interactions superradiance occurs. We have concluded that superradiance in the system of Frenkel excitons is possible under the influence of the non-Dicke mechanisms of self-induction of correlations, when the dipole transition moments of the individual atoms are coupled into a single macroscopic effective spin through their electrostatic interaction, this being analogous to the ordering of magnetic dipole moments in a ferromagnet.

1988-01-01

96

Reliability analysis of the downstream face of a rockfill dam. Introductory work  

Energy Technology Data Exchange (ETDEWEB)

Reliability analysis is now being used to a large extent for several civil engineering structures. Such analysis has not been used for rockfill dams, the most common dams in Norway. Following work on reliability analysis for breakwaters, reliability analysis was then used to investigate the ability of the stone material on the upstream face of a rockfill dam to withstand wind generated waves. An attempt is made to follow up this work by including discharge overtopping on a rockfill dam in a reliability analysis. This report primarily goes through previous work on the required weight of protective stones on the downstream face of the dam for specified discharges over the dam and also deals with the probability formulation of extreme floods. A failure function with partial coefficients is formulated. But for reasons of economy the calibration of the partial ...

1995-02-01

97

Thermodynamic and structural analysis of microtubule assembly: the role of GTP hydrolysis.  

UK PubMed Central (United Kingdom)

Different models have been proposed that link the tubulin heterodimer nucleotide content and the role of GTP hydrolysis with microtubule assembly and dynamics. Here we compare the thermodynamics of...Full Text Available

1997-03-01

98

Teaching electron diffraction and imaging of macromolecules.  

UK PubMed Central (United Kingdom)

Electron microscopic analysis can be used to determine the three-dimensional structures of macromolecules at resolutions ranging between 3 and 30 A. It differs from nuclear magnetic resonance spectroscopy...Full Text Available

1993-05-01

99

Systems-level analysis of microbial community organization through combinatorial labeling and spectral imaging  

UK PubMed Central (United Kingdom)

Microbes in nature frequently function as members of complex multitaxon communities, but the structural organization of these communities at the micrometer level is poorly understood because of limitations...Full Text Available

2011-03-08

100

Structural analysis of a hepatitis B virus genome integrated into chromosome 17p of a human hepatocellular carcinoma.  

UK PubMed Central (United Kingdom)

Hepatitis B virus (HBV) is clearly a factor in the development of hepatocellular carcinoma, but its mechanism of action remains obscure. One possibility is that the HBV integration event alters the...Full Text Available

1988-11-01

101

Structural Characterization and Expression Analysis of the SERK/SERL Gene Family in Rice (Oryza sativa)  

UK PubMed Central (United Kingdom)

Somatic embryogenesis (SE) is the developmental restructuring of somatic cells towards the embryogenic pathway and forms the basis of cellular totipotency in angiosperms. With the availability of full-length...Full Text Available

2009-01-01

102

Structural Analysis of the Danish Windmill Industry.  

Science.gov (United States)

Most Danish windmill manufacturers have experienced a grave economic crisis during the last three years. In 1987, the total windmill industry in this country ran at a loss of 40 million Danish crowns where the turnover was 550 million crowns. Danish firms...

1988-01-01

103

Potential of cattails as an energy source. Final report  

Energy Technology Data Exchange (ETDEWEB)

Research on the feasibility of growing cattails as an energy crop is described. The following topics are included: productivity in natural strands, germination requirements for seed, establishing stands by seeding, rhizome dormancy and development, harvesting and stand establishment, and analysis of canopy structure and radiation profiles in a natural community. (MHR)

1980-01-01

104

Large-scale Analysis of Thermo-stable, Mammalian Proteins Provides Insights into the Intrinsically Disordered Proteome  

UK PubMed Central (United Kingdom)

Intrinsically disordered proteins are predicted to be highly abundant and play broad biological roles in eukaryotic cells. In particular, by virtue of their structural malleability and propensity...Full Text Available

2009-01-01

105

Ixodes scapularis tick serine proteinase inhibitor (serpin) gene family; annotation and transcriptional analysis  

UK PubMed Central (United Kingdom)

BackgroundSerine proteinase inhibitors (Serpins) are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in...Full Text Available

106

Functional and Structural Analysis of a Key Region of the Cell Wall Inhibitor Moenomycin  

UK PubMed Central (United Kingdom)

Moenomycin A (MmA) belongs to a family of natural products that inhibit peptidoglycan biosynthesis by binding to the peptidoglycan glycosyltransferases (PGTs), the enzymes that make the glycan...Full Text Available

2010-07-16

107

Evidence for nonrandom hydrophobicity structures in protein chains.  

UK PubMed Central (United Kingdom)

The question of whether proteins originate from random sequences of amino acids is addressed. A statistical analysis is performed in terms of blocked and random walk values formed by binary hydrophobic...Full Text Available

1996-09-03

108

Comparative Structural Analysis of Lipid Binding START Domains  

UK PubMed Central (United Kingdom)

BackgroundSteroidogenic acute regulatory (StAR) protein related lipid transfer (START) domains are small globular modules that form a cavity where lipids and lipid hormones bind....Full Text Available

109

An Analysis of the Subunit Structure of the Crystalloid Protein Complex from Castor Bean Endosperm 1  

UK PubMed Central (United Kingdom)

Chromatographic and electrophoretic studies have shown that the subunits of the crystalloid protein, isolated from mature castor bean (Ricinus communis L. cv Hale) seed endosperm protein...Full Text Available

1983-06-01

110

Vibration signature analysis of AFM images  

Energy Technology Data Exchange (ETDEWEB)

Vibration signature analysis has been commonly used for the machine condition monitoring and the control of errors. However, it has been rarely employed for the analysis of the precision instruments such as an atomic force microscope (AFM). In this work, an AFM was used to collect vibration data from a sample positioning stage under different suspension and support conditions. Certain structural characteristics of the sample positioning stage show up as a result of the vibration signature analysis of the surface height images measured using an AFM. It is important to understand these vibration characteristics in order to reduce vibrational uncertainty, improve the damping and structural design, and to eliminate the imaging imperfections. The choice of method applied for vibration analysis may affect the results. Two methods, the data dependent systems (DDS) ...

1995-12-31

111

CFD analysis on the flow distribution of steam generator of SMART-P  

Energy Technology Data Exchange (ETDEWEB)

The Computational Fluid Dynamics(CFD) study was conducted to assess the new design concept introduced to solve the issues on the flow deviation between SG cassettes and the supporting structure design of the flow distributing plate subjected to the flow induced vibration. Flow field from MCP to the bottom of SG was modeled for 2-dimensional(2D) CFD analysis and then sensitivity analysis on major design parameters was conducted using commercial CFD code, Fluent. The cases for detailed 3D analysis were selected based on the result of 2D analysis and the detailed 3-dimensional(3D) analysis was conducted for these selected cases using Fluent code. Flow field was modeled by RNG model and wall function, 2nd upwind scheme, porous model, structured or hybrid grid. The analysis result shows that the maximum deviation of flow ...

2003-12-01

112

Uncertainty analysis in fusion activation calculations: Application to the waste disposal assessment of HYLIFE-II structure  

International Nuclear Information System (INIS)

A computational procedure is proposed to perform uncertainty analysis for the calculation of the isotopic inventory and radiological quantities obtained as a linear function of it, due to uncertainties in the activation cross sections. The method is applied to determine the uncertainty of the calculated shallow burial index (SBI) from activated type 304 stainless steel (SS) in the most neutron-exposed zone of the HYLIFE-II vessel structure. Results are obtained by means of an element-by-element study. Some other types of steel are also investigated for comparison purposes. The SS304 is confirmed to be the most promising steel option. 16 refs., 2 tabs.

1996-06-16

113

Measurement and analysis of temperature, strain and stress of foundation mat concrete in nuclear and thermal power stations  

International Nuclear Information System (INIS)

The problems of the thermal stress in concrete structures are roughly divided into the initial stress due to setting heat and the stress due to external temperature after hardening. The initial stress exists in every concrete structure, and it is usually neglected in beams and columns, but it must be taken into account in case of the foundation mat structures in nuclear power stations, for example. In this paper, (1) the results of measurement of temperature, strain and stress in each lift at the time of and after placing concrete in the foundation mat of a nuclear power station and the comparison of them with the results of analysis, (2) the results of measurement of the temperature and stress in a foundation mat, which was carried out to rationalize the design method for the raft type foundation mats in thermal power stations, and (3) the results of examination on the analysis ...

114

Structural relaxation and crystallization in the Fe-Cr-Si-B and Fe-Cu-Cr-Si-B amorphous alloys  

International Nuclear Information System (INIS)

Structural relaxation, crystallization and optimisation processes in soft magnetic amorphous alloys based on iron are examined by applying different experimental techniques: X-ray diffraction analysis, high-resolution electron microscopy, measurements of magnetic and electric properties (permeability, after-effect resistivity). The presented results are discussed in terms of annealing out of microvoids, formation of nanocrystalline phase and changes of effective magnetostriction constant. (author)

2001-09-23

115

Seismic analysis of the Par Pond Dam: Study of slope failure and liquefaction. Technical evaluation report  

Energy Technology Data Exchange (ETDEWEB)

Stability concerns of the Par Pond Dam, an embankment structure in the Savannah River Site complex, resulted in a comprehensive evaluation of the state of its integrity. Specifically, excessive seepage through the embankment, slope failure due to an earthquake event as well as liquefaction potential of the embankment and the foundation are addressed and the potential of failure is evaluated. Lastly, remedial benefits of the addition of a berm structure are also assessed.

1994-07-01

116

Radiation damage on amorphous metals. [Helium ion, neutron and gamma ray irradiation  

Energy Technology Data Exchange (ETDEWEB)

The structural variations of amorphous metals, such as Pd/sub 80/Si/sub 20/, with irradiation of helium ion, neutron, and gamma ray have been mainly pursued by the method of X-ray diffraction and thermal analysis. It should be noticed that the amorphous metals show a radiation resistance, that is, no remarkable structural changes under helium ion, neutron, and gamma ray irradiation.

1982-04-01

117

LC-MS analysis in the e-beam and gamma radiolysis of metoprolol tartrate in aqueous solution: Structure elucidation and formation mechanism of radiolytic products  

British Library Electronic Table of Contents (United Kingdom)

E-beam and gamma products from the radiolysis of aqueous solutions of (+-)-metoprolol tartrate, saturated in nitrogen, are analyzed by HPLC with on-line mass and UV detectors. The structures of 10 radiolytic products common to e-beam and gamma irradiations are elucidated by comparing their fragmentation pattern to that of (+-)-metoprolol. Two of the radiolytic products are also metabolites. Different routes for the formation of the radiolytic products are proposed.

2006-01-01

118

Complex fractal dimensions describe the hierarchical structure of diffusion-limited-aggregate clusters  

Energy Technology Data Exchange (ETDEWEB)

We analyze large diffusion-limited aggregates and uncover a {ital discrete} scaling invariance in their inner structure, which can be quantified by the introduction of a set of {ital complex} fractal dimensions. We provide a theoretical framework and prediction of their values based on renormalization group theory and a previous wavelet analysis. {copyright} {ital 1996 The American Physical Society.}

1996-01-01

119

Search Efficiency in Indexing Structures for Similarity Searching  

CERN Document Server

Similarity searching finds application in a wide variety of domains including multilingual databases, computational biology, pattern recognition and text retrieval. Similarity is measured in terms of a distance function edit distance in general metric spaces, which is expensive to compute. Indexing techniques can be used reduce the number of distance computations. We present an analysis of various existing similarity indexing structures for the same. The performance obtained using the index structures studied was found to be unsatisfactory . We propose an indexing technique that combines the features of clustering with M tree(MTB) and the results indicate that this gives better performance.

2004-01-01

120

Proton and deuteron spin structure function measurements in the resonance region  

Energy Technology Data Exchange (ETDEWEB)

The RSS collaboration has measured the spin structure functions of the proton and the deuteron at Jefferson Lab using the Hall C HMS spectrometer, a polarized electron beam and a polarized solid target. The asymmetries A and A were measured in the region of the nucleon resonances (0.82 GeV < W < 1.98 GeV) at an average four momentum transfer of Q2 = 1.3 GeV2. The extracted spin structure functions and their kinematic dependence will make a significant contribution in the study of higher-twist effects and polarized duality tests. A description of the experiment and the latest findings of the analysis will be presented.

2003-07-01

121

Polycrystalline thin films -- Structure, texture, properties and applications III. Materials Research Society symposium proceedings: Volume 472  

Energy Technology Data Exchange (ETDEWEB)

The symposium, Polycrystalline Thin Films - Structure, Texture, Properties, and Applications III, was held at the 1997 Materials Research Society Spring Meeting on March 31--April 4 in San Francisco, California. The topics and investigations were interdisciplinary in nature, and ranged from fundamental to technological. Specifically, the work presented in this volume includes film growth, texture and structural evolution, phase transformation, characterization of grain boundaries and interfaces, stress analysis, and works on polycrystalline Si and SiGe films and devices. Fifty four papers were processed separately for inclusion on the data base.

1997-07-01

122

Polycrystalline thin films -- Structure, texture, properties and applications III. Materials Research Society symposium proceedings: Volume 472  

International Nuclear Information System (INIS)

The symposium, Polycrystalline Thin Films - Structure, Texture, Properties, and Applications III, was held at the 1997 Materials Research Society Spring Meeting on March 31--April 4 in San Francisco, California. The topics and investigations were interdisciplinary in nature, and ranged from fundamental to technological. Specifically, the work presented in this volume includes film growth, texture and structural evolution, phase transformation, characterization of grain boundaries and interfaces, stress analysis, and works on polycrystalline Si and SiGe films and devices. Fifty four papers were processed separately for inclusion on the data base.

123

On endogenous order of moves in a trade embargo game  

International Nuclear Information System (INIS)

Hung and Quyen's model (analysis of strategic interactions between players in the game theoretic framework) is first recapitulated. Solutions to the embargo game with the seller acting as the Stackelberg leader in both periods. Then the timing coordination issue is discussed and perfect equilibrium outcomes under different structures of leader-follower in the game are compared. Numerical simulations show that the structure corresponding to alternated leadership from one period to the other yields the perfect equilibrium outcome that is Pareto improving with respect to the structure where the buyer is first mover in both periods and Pareto dominant for some specific values of the parameters embedded in the game.

124

Scour and accretion in sub-sea structures  

Energy Technology Data Exchange (ETDEWEB)

Analytical means have been developed to predict scour and accretion in sub-sea structures. Such structures can be very large and can have a large density of piping and structural members. They introduce a blocking and a shielding in the flow at the sea bottom leading to variable velocities and turbulence in the interior of the structure. This changes the transport capacity of the flow and result in general erosion where the transport capacity is increased and in accretion where the transport capacity is decreased. In addition there may occur the so-called tunnel erosion for structures built on concrete mats or similar. This type of erosion undermines the foundation of the sub-sea structure. Analytical models are developed and programmed to analyse the above phenomena. The internal flow variations are found by means of the LICengineering shielding programme and ...

1997-09-01

125

Weibel and Two-Stream Instabilities for Intense Charged Particle Beam Propagation through Neutralizing Background Plasma  

Energy Technology Data Exchange (ETDEWEB)

Properties of the multi-species electromagnetic Weibel and electrostatic two-stream instabilities are investigated for an intense ion beam propagating through background plasma. Assuming that the background plasma electrons provide complete charge and current neutralization, detailed linear stability properties are calculated within the framework of a macroscopic cold-fluid model for a wide range of system parameters.

2004-04-09

126

Relativistic effects on chaos. Loss mechanism of runaway electrons in a tokamak  

Energy Technology Data Exchange (ETDEWEB)

The relativistic motion of an electron is numerically analyzed in a tokamak having macroscopic magnetic turbulence. Stochasticity induced by the relativistic motion overwhelms the phase averaging effect, which provides a tokamak with an effective loss mechanism for the avoidance/suppression of runaway electron generation at a major disruption. On the other hand, electrons in the KAM (Kolmogorov-Arnold-Moser) region will be observed as a runaway snake. (author)

2001-12-01

127

Heat treatment effect on impact strength of 40Kh steel  

Energy Technology Data Exchange (ETDEWEB)

The paper presents results of studies on the effect of heat treatment on strength and pattern of 40Kh steel impact failure. Loading levels corresponding to macroscopic spalling microdamage initiation in the material are determined for three initial states. Metallographic study on the spalling failure pattern for 40Kh steel in different initial states and data on microhardness measurement are presented.

1984-01-01

128

Effect of ultrasonic waves on boiling heat transfer. 2  

International Nuclear Information System (INIS)

This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic steam induced by ultrasonics is a major contribution to heat transfer augmentation. (author).

1993-05-01

129

Effect of ultrasonic waves on boiling heat transfer  

Energy Technology Data Exchange (ETDEWEB)

This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic stream induced by ultrasonics is a major contribution to heat transfer augmentation. (author).

1993-07-01

130

EPA (ENVIRONMENTAL PROTECTION AGENCY) MACROSCOPIC PLANNING MODEL (EPAMAC) FOR STORMWATER AND COMBINED SEWER OVERFLOW CONTROL: APPLICATION GUIDE AND USER'S MANUAL  

Science.gov (United States)

A simplified stormwater management model has been developed to provide an inexpensive, flexible tool for planning and preliminary sizing of stormwater facilities. The model was developed to be part of a methodology for use in the management of stormwater that utilizes both simple...

131

(Photoexcited charge pair escape and recombination)  

Science.gov (United States)

Progress in four research areas on this project are summarized under the following topics: (1) Geminate charge pair recombination in hexane; (2) Fast current measurements resulting from excitation of charge transfer (CT) states; (3) Measurement of the dipole moment of excited states by DC conductivity; and (4) Charge separation at macroscopic interfaces between electron donor and acceptor solids. In a final section, personnel who have contributed to the project during the past budget period are described.

1990-01-01

132

Thermal stresses in the space shuttle orbiter: Analysis versus test  

International Nuclear Information System (INIS)

Significant temperature differences occur between the internal structure and the outer skin of the Space Shuttle Orbiter as it returns from space. These temperature differences cause important thermal stresses. A finite element model containing thousands of degrees of freedom is used to predict these stresses. A ground test was performed to verify the prediction method. The analysis and test results compare favorably. (orig.).

133

Synthesis and physicochemical properties of iron (2) perrhenates  

Energy Technology Data Exchange (ETDEWEB)

By dissolution of iron (2) carbonate in rhenium acid iron (2) perrhenate of the Fe(ReO/sub 4/)/sub 2/x4H/sub 2/O composition is obtained. By the method of thermal analysis the limits of tetra-, dihydrate and anhydrous iron (2) perrhenate stability are revealed. By means of X ray phase and IR spectroscopic analysis methods modification of structure in the process of synthesized salt dehydration is shown.

1983-01-01

134

Nucleotide sequence and genetic analysis of a 13.1-kilobase-pair Pseudomonas denitrificans DNA fragment containing five cob genes and identification of structural genes encoding Cob(I)alamin adenosyltransferase, cobyric acid synthase, and bifunctional cobinamide kinase-cobinamide phosphate guanylyltransferase.  

UK PubMed Central (United Kingdom)

A 13.1-kb DNA fragment carrying Pseudomonas denitrificans cob genes has been sequenced. The nucleotide sequence and genetic analysis revealed that this fragment contained five different cob genes named...Full Text Available

1991-10-01

135

Structure analysis of cation selective Cr-goethite as protective rust of weathering steel  

International Nuclear Information System (INIS)

We have performed extended X-ray absorption fine structure (EXAFS) analysis for artificial Cr-goethite to elucidate the local structure around Cr in Cr-goethite. The spectra were obtained using synchrotron radiation X-rays at the Photon Factory in Tsukuba. The first shell contributions were isolated by Fourier filtering EXAFS data, and the inverse Fourier transformed single-shell data were analyzed using a curve fitting method. The results show that Cr is coordinated with (7#+-#1)O"2"- ions. The protective characteristics of the Cr-goethite protective rust layer on weathering steel can be interpreted in terms of the O"2"- coordination around Cr"3"+ resulting in the creation of negative fixed charge in the Cr-goethite particles. (author)

2005-02-01

136

Offshore platforms and pipelines  

Energy Technology Data Exchange (ETDEWEB)

This book discusses problems and topics important for the design and construction of fixed offshore platforms used for drilling and producing petroleum from beneath the sea. A general description of offshore platforms serves as an introduction to the whole problem of offshore structures. A chapter on the hydrodynamic analysis of fixed offshore platforms gives the basis for the layout and construction of such structures. A guide to soil investigation methods essential for the geotechnical analysis of foundation designs for all types of offshore structures concentrates on the instrumentation equipment actually used. Detailed information is given on pile foundations with special emphasis on steel jacket platforms. The behaviour of gravity platforms during the final construction stage is analysed. The basis for the design of subsea pipelines and their stability is treated as well as the ...

1986-01-01

137

Filler metal development for Hastelloy alloy XR. Filler metal for hastelloy alloy XR structure with thick wall  

Energy Technology Data Exchange (ETDEWEB)

In order to develop the filler metal for Hastelloy alloy XR structure with thick wall, the weldability and high temperature strength properties of Hastelloy alloy XR weldment were investigated using the filler metals, which were alloy-designed on the basis of multiple regression analysis. The former was examined through the chemical analysis in the deposited metal, bend test, FISCO cracking test, optical microscopy and hardness measurement. The latter was investigated by means of tensile and creep test. It was found from these results that the crack susceptibility in the weldment was apparent to be lowered without degrading the high temperature strength properties. Therefore, it is concluded that these filler metals possess excellent performance as the filler metal for Hastelloy alloy XR structure with thick wall. (author).

1991-11-01

138

Bioinformatic analysis of BBTV satellite DNA in Hainan  

British Library Electronic Table of Contents (United Kingdom)

Banana bunchy top virus (BBTV), family Nanaviridae, genus Babuvirus, is a single stranded DNA virus (ssDNA) that causes banana bunchy top disease (BBTD) in banana plants. It is the most common and most destructive of all viruses in these plants and is widespread throughout the Asia-Pacific region. In this study we isolated, cloned and sequenced a BBTV sample from Hainan Island, China. The results from sequencing and bioinformatics analysis indicate this isolate represents a satellite DNA component with 12 DNA sequences motifs. We also predicted the physical and chemical properties, structure, signal peptide, phosphorylation, secondary structure, tertiary structure and functional domains of its encoding protein, and compare them with the corresponding quantities in the replication initiatio...

2011-01-01

139

Sensitivity analysis: Interaction of DOE SNF and packaging materials  

International Nuclear Information System (INIS)

A sensitivity analysis was conducted to evaluate the technical issues pertaining to possible destructive interactions between spent nuclear fuels (SNFs) and the stainless steel canisters. When issues are identified through such an analysis, they provide the technical basis for answering what if questions and, if needed, for conducting additional analyses, testing, or other efforts to resolve them in order to base the licensing on solid technical grounds. The analysis reported herein systematically assessed the chemical and physical properties and the potential interactions of the materials that comprise typical US Department of Energy (DOE) SNFs and the stainless steel canisters in which they will be stored, transported, and placed in a geologic repository for final disposition. The primary focus in each step of the analysis was to identify any possible phenomena that could potentially compromise the ...

1999-06-06

140

Synthesis and characterization of MnV{sub 2}O{sub 6} as a high capacity anode material for a lithium secondary battery  

Energy Technology Data Exchange (ETDEWEB)

Crystalline MnV{sub 2}O{sub 6} has been synthesized by a polymer gellation method and investigated for its physical and electrochemical properties as an anode material for Li secondary battery. The physical characterization was carried out by thermal analysis (TG/DTA), FT-IR and SEM. Structural analysis by powder XRD and spectroscopic analysis by XANES showed that the synthesized compound is MnV{sub 2}O{sub 6} with brannerite structure. The Li insertion of MnV{sub 2}O{sub 6} anode during the first charge showed a large capacity of about 1400 mAh/g, accompanied by irreversible structural transformation into amorphous material. Despite its structural transformation to amorphous during the first lithiation, subsequent cycles showed a capacity of about 800 mAh/g. This paper presents the advantage of this material over existing anode material and ...

2001-01-02

141

Seismic evaluation and upgrading of critical tower pile foundations in liquefiable soils  

Energy Technology Data Exchange (ETDEWEB)

BC Hydro has been assessing and upgrading its facilities and implementing response alternatives to potential damage resulting from a major earthquake. This paper reviews the utility`s seismic evaluation of its overhead transmission system, focusing on the Lower Mainland area where most of the tall critical river-crossing towers are located. The paper gives an overview of the geologic environment of the Lower Mainland and outlines the criteria used for assessing existing structures for their ability to withstand design seismic loads. It then describes the investigation and analysis methods used in the assessment, including geotechnical field tests, ground response analysis, determination of soil liquefaction potential, and dynamic analysis of structures and piles. Options for seismic upgrades are discussed and illustrated by the case of the Pitt River crossing, where tower ...

1995-12-31

142

Research and development on next generation reactor (phase I)  

Energy Technology Data Exchange (ETDEWEB)

The objective of the study is to improve the volume of nuclear power plant which adopts passive safety system concept. The passive safety system reactor is characterized by excellent safety and reliability. But the volume of NSSS (Nuclear Steam Supply System) of the passive safety system reactor is so small that it should be upgraded for commercial operation. For volume upgrade, detailed analyses are performed as follows; core design, hydraulics, design and mechnical structures, and safety analysis. In addition to above analysis, some investigations must be supplied as follows: power density vs. DNB margin decrease, outlet temperature vs. EPRI-URD, additional tests for upgraded reactor, dynamic analysis of mechanical vibration according to expanded reactor vessel and expanded in-core structures, and Merit loss of passive safety system reactor according to design margin decrease. ...

1994-10-01

143

Naturally fractured tight gas reservoir detection optimization  

Energy Technology Data Exchange (ETDEWEB)

During this quarter, work began on the regional structural and geologic analysis of the greater Green River basin (GGRB) in southwestern Wyoming, northwestern Colorado and northeastern Utah. The ultimate objective of the regional analysis is to apply the techniques developed and demonstrated during earlier phases of the project to sweet-spot delineation in a relatively new and underexplored play: tight gas from continuous-type Upper Cretaceous reservoirs of the GGRB. The primary goal of this work is to partition and high-grade the greater Green River basin for exploration efforts in the Cretaceous tight gas play. The work plan for the quarter of January 1, 1998--March 31, 1998 consisted of three tasks: (1) Acquire necessary data and develop base map of study area; (2) Process data for analysis; and (3) Initiate structural study. The first task and second tasks were completed during ...

1998-09-30

144

NAME=\\  

Wastenet

...the School, the research group structure was recently revised and now comprises the following teams: Drug Design and Analysis Pharmaceutics Pharmacy Practice and Policy Pharmacological and Biomedical Science The current structure was designed to take into account the future development of research in the academic area. The ...Discovery, Molecular Modelling, Pharmacology and Molecular Biology) and international recognition (Biological Sciences), which have now been re-organised into the Drug Design and Analysis and Pharmacological and Biomedical Sciences teams. The reorganisation also aimed to improve the research reputation of the other teams. The improvements in ... Email to a friend Print Within this area Drug design and analysis Pharmaceutics Pharmacy practice and policy Pharmacological and biomedical sciences Projects Publications Staff Considering a course? Research Degrees ...

145

A quantitative structural analysis of the low temperature phase of lithium-7  

International Nuclear Information System (INIS)

Calculations in "7Li have been carried out for the differential coherent elastic scattering cross-section of thermal neutrons at a fixed scattering angle #theta#_0(148"o) and varying the energy of incident neutrons (or corresponding d-spacings). The results are reported, as variations of the ratio #SIGMA#_0"c"o"h (#theta#_0, d)/#SIGMA#_0"c"o"h (#theta#_0) with d-spacing, at atmospheric pressure and at two temperatures, 80 and 20 K. The calculations at 80 K correspond to BCC lithium whereas at 20 K all the possible crystallographic structures of polytype lithium (BCC, 9R, HCP and FCC) were considered. On comparing our results with the time-of-flight (TOF) measurements of Berliner et al. (Physical Review, B40, 12086, 1989) we find that up to 80 K lithium-7 does not undergo any martenistic transformation whereas the structural state at 20 K can be described by the co-existence of the original BCC phase with 9R, HCP and FCC closed packed ...

146

The structure of molecular clouds - III. A link between cloud structure and star formation mode  

British Library Electronic Table of Contents (United Kingdom)

Abstract We analyse extinction maps of nearby giant molecular clouds to forge a link between driving processes of turbulence and modes of star formation. Our investigation focuses on cloud structure in the column density range above the self-shielding threshold of 1-mag AV and below the star formation threshold - the regime in which turbulence is expected to dominate. We identify clouds with shallow mass distributions as cluster forming. Clouds that form stars in a less clustered or isolated mode show a steeper mass distribution. Structure functions prove inadequate to distinguish between clouds of different star formation mode. They may, however, suggest that the turbulence in the average cloud is governed by solenoidal forcing. The same is found using the -variance analysis which also in...

2011-01-01

147

Systematic view of optical absorption spectra in the actinide series  

International Nuclear Information System (INIS)

In recent years sufficient new spectra of actinides in their numerous valence states have been measured to encourage a broader scale analysis effort than was attempted in the past. Theoretical modelling in terms of effective operators has also undergone development. Well established electronic structure parameters for the trivalent actinides are being used as a basis for estimating parameters in other valence states and relationships to atomic spectra are being extended. Recent contributions to our understanding of the spectra of 4+ actinides have been particularly revealing and supportive of a developing general effort to progress beyond a preoccupation with modelling structure to consideration of the much broader area of structure-bonding relationships. We summarize here both the developments in modelling electronic structure and the interpretation of apparent trends in bonding. ...

1985-09-01

148

Systematic view of optical absorption spectra in the actinide series  

Energy Technology Data Exchange (ETDEWEB)

In recent years sufficient new spectra of actinides in their numerous valence states have been measured to encourage a broader scale analysis effort than was attempted in the past. Theoretical modelling in terms of effective operators has also undergone development. Well established electronic structure parameters for the trivalent actinides are being used as a basis for estimating parameters in other valence states and relationships to atomic spectra are being extended. Recent contributions to our understanding of the spectra of 4+ actinides have been particularly revealing and supportive of a developing general effort to progress beyond a preoccupation with modelling structure to consideration of the much broader area of structure-bonding relationships. We summarize here both the developments in modelling electronic structure and the interpretation of apparent trends in bonding. ...

1985-01-01

149

Self-consistent electronic structure of transition-metal surfaces: The Mo (001) surface  

International Nuclear Information System (INIS)

A self-consistent pseudopotential method together with a mixed-basis set of plane waves and Gaussian orbitals are used to determine the electronic structure of the (001) surface of molybdenum. The pseudopotential is derived from a self-consistent calculation of the atomic levels and wave functions, and is tested for bulk molybdenum. The resulting bulk band structure and density of states are compared with existing augmented-plane-wave APW calculations. The same potential is applied to investigate the electronic structure of an uncontracted Mo (001) surface. A complete analysis of the surface states is given in terms of their distribution in the two-dimensional surface Brillouin zone, charge-density distribution, and the local density of states. The results are in very good agreement with recent photoemission measurements.

150

Numerical methods for thermal-hydraulics and structure in nuclear engineering  

International Nuclear Information System (INIS)

Designs of nuclear reactor plants aim for high performance under safety consideration. Because of large scale and high pressure/temperature conditions, data from costly mockup tests have been required to verify simulation codes of systems and components. Establishment of design by analysis (DBA) in nuclear engineering is required for development of next generation nuclear reactors. Recent powerful computers and simulation technique enable numerical analyses to predict realistic behaviors of thermo-fluid flow, structure and do on. The present report describes resent simulation results of complex gas-liquid two-phase flow, large scale structure dynamics and fluid-structure interaction. (author)

2008-06-01

151

Impact of different cultivation and induction regimes on the structure of cytosolic inclusion bodies of TEM1-b-lactamase  

British Library Electronic Table of Contents (United Kingdom)

The enzyme TEM1-b-lactamase has been used as a model to study the impact of different cultivation and induction regimes on the structure of cytosolic inclusion bodies (IBs). The protein has been heterologously expressed in Escherichia coli in fed-batch cultivations at different temperatures (30, 37, and 40degreeC) as well as induction regimes that guaranteed distinct product formation rates and ratios of soluble to aggregated protein. Additionally, shake flask cultivations at 20, 30, and 37degreeC were performed. IBs were sampled during the whole bioprocess and structural analysis was performed by attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy. This work clearly demonstrates that the tested production regimes and rates had no impact on the IB structure, wh...

2008-01-01

152

Design of Reactor Head Structure Assembly Using Axiomatic Design  

Energy Technology Data Exchange (ETDEWEB)

The Reactor Head Structure Assembly(RHSA) is the structure located on the reactor assembly. The purpose of the assembly is providing interface location for cables, preventing pipe whips, prohibiting instruments from becoming missiles, and restraining CEDMs' horizontal motion. On the RHSA, Reactor Disconnect Panels(RDP) are installed. The installation location of RDP is to be decided to minimize the geometric interface with other components. Since the neighborhood of RHSA is crowded due to many connectors and cables, it is necessary to find the good design of RHSA to make an intricate situation attenuated and the required function maintained. The geometric shape and overall configuration of RHSA are determined by axiomatic design approach. The FRs of RHSA are specified and the corresponding DPs are found to satisfy FRs in sequence. The finite element analysis is carried out based on the result of the axiomatic ...

2007-07-01

153

Propagation of guided waves in aircraft structure  

International Nuclear Information System (INIS)

The potential of ultrasonic guided modes for use in global structural health monitoring of aging metallic aircraft can only be realized if the modes selected are able to propagate over a reasonable distance. This work studies the propagation of different modes through fuselage structure by means of mode analysis, finite element modeling and experimental measurement. Beginning with the case of a simple skin panel, the paper examines propagation across a set of structural features representing a typical monocoque fuselage and considers the effect of overlying sealant layers, bonded and sealed joints, paint layers and tapering skin. With the exception of the fundamental symmetric mode at very low frequency, no mode was found that could propagate across all features with an effective attenuation of less than 40 dB/m. This makes global monitoring of a fuselage structure using a sparse ...

2000-05-23

154

Fuzzy reliability analysis of structures by using the method of fuzzy optimization  

Energy Technology Data Exchange (ETDEWEB)

There are two kinds of uncertainties in safety assessment of engineering structures. One is of the nature of randomness, and the other fuzziness. Fuzzy uncertainties exist in defining certain structural performances, conditions, parameters, and their interrelationships. The theory of fuzzy sets should be employed to cope with the fuzzy uncertainties. In this paper, a general definition for structural failure considering the fuzzy uncertainties is introduced firstly. Failure of the structure is modelled by a fuzzy event, and described by the membership function. The limit state surface is then replaced by a fuzzy limit state zone, in which every point represents a state belonging to the failure with a certain degree of membership. Then a fuzzy optimization problem for solving the reliability index is formulated. In classical structural reliability theory, the reliability index is ...

1996-12-31

155

WIPS: computer code for whip and impact analysis of piping systems. Summary report  

Energy Technology Data Exchange (ETDEWEB)

WIPS (Whip and Impact of Piping Systems) is a special purpose computer code for the structural analysis of pipe whip dynamic effects following a postulated pipe rupture. WIPS has been developed primarily to provide support for the pipe whip analysis procedures described in Section 3.6.2 of the US Nuclear Regulatory Commission Standard Review Plan. This report summarizes the purpose and scope of the WIPS development effort, identifying those clauses in the Standard Review Plan which refer to pipe whip analysis, and indicating how the WIPS code can be used to provide supporting data. Detailed information on use of the code is contained in accompanying reports which cover: (1) user instructions; (2) theory; (3) programming procedures; and (4) verification examples.

1984-06-01

156

Pre-test report on international round robin analysis of BARC containment (BARCOM) test model  

International Nuclear Information System (INIS)

BARC has organized an international round robin analysis program to carry out the ultimate load capacity assessment of BARC containment (BARCOM) test model. The test model located in BARC facilities Tarapur, is a 1:4 scale representation of 540 MWe pressurized heavy water reactor (PHWR) pre-stressed concrete inner containment structure of Tarapur Atomic Power Station (TAPS) unit 3 and 4. The features of the BARCOM test model and the constitutive data for the pre-test analysis along with the comparison of the results submitted by various participants are described in this pre-test report of the round robin analysis of BARCOM test model

2009-01-01

157

Hot Cell Facility (HCF) Safety Analysis Report  

Energy Technology Data Exchange (ETDEWEB)

This Safety Analysis Report (SAR) is prepared in compliance with the requirements of DOE Order 5480.23, Nuclear Safety Analysis Reports, and has been written to the format and content guide of DOE-STD-3009-94 Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Safety Analysis Reports. The Hot Cell Facility is a Hazard Category 2 nonreactor nuclear facility, and is operated by Sandia National Laboratories for the Department of Energy. This SAR provides a description of the HCF and its operations, an assessment of the hazards and potential accidents which may occur in the facility. The potential consequences and likelihood of these accidents are analyzed and described. Using the process and criteria described in DOE-STD-3009-94, safety-related structures, systems and components are identified, and the important safety functions of each SSC are described. Additionally, information which ...

2000-11-01

158

Nanomechanical properties of vimentin intermediate filament dimers  

International Nuclear Information System (INIS)

The cell's cytoskeleton, providing the cell with structure and shape, consists of a complex array of structural proteins, including microtubules, microfilaments and intermediate filaments. Intermediate filaments play a crucial role in mechanotransduction and in providing mechanical stability to cells, in particular under large deformation. By utilizing molecular simulation, here we report a nanomechanical analysis of vimentin intermediate filament dimers, the basic building blocks of intermediate filaments. We describe a detailed analysis of the mechanical properties and associated deformation mechanisms, and find that mechanical stretch induces a transition from alpha-helices to beta-sheets, a phenomenon known as alpha-beta transition. A comparison of the Young's modulus predicted from simulation with experimental measurements is provided, and good agreement is found. We present an ...

2009-10-21

159

Investigation of local-dimensional galvanic distortion on MT data in the central part of Northeastern Japan; Tohoku chiho no MT data ni mirareru kyokushoteki sanjigensei no eikyo  

Energy Technology Data Exchange (ETDEWEB)

Groom-Bailey decomposition analysis was carried out to investigate regional 3-D galvanic distortion on MT data in the central part of Northeastern Japan. Measuring sites were located nearly along the east-west line crossing Northeastern Japan. Three measuring lines (A, B, C) from the north to the south were prepared, and only data on the C line were analyzed in this paper. As a result, twist and shear were estimated to be not zero depending on local distortion in most of the sites. It was thus clarified that this method is not always perfect. This method was effective for regional 2-D structures, however, its application was doubtful to complicated 3-D underground structures in Japan. In order to obtain more accurate results, 2-D analysis using the impedance including no local distortion effect was necessary after the preliminary Groom-Bailey decomposition analysis. The direction of ...

1996-10-01

160

Fiscal 1997 report of the R and D result of industrial science and technology. R and D on synergy ceramics (development of rational energy use technology); 1997 nendo sangyo kagaku gijutsu kenkyu kaihatsu seika hokokusho. Synergy ceramics no kenkyu kaihatsu (energy shiyo gorika gijutsu kaihatsu)  

Energy Technology Data Exchange (ETDEWEB)

For rational use of energy resources, the process technology which allows harmonization and multiplication of conflicting characteristics was developed for development of new ceramic system materials. This paper summarizes the result in fiscal 1997. On a structural reaction process among creation technologies of ultra-reliable structure, study was made on structure control and hot-working technology through atmosphere control in ceramics synthesis. On basic technology for analysis and evaluation, study was made on the effect of particle bridging on strengthening and toughening of ceramic materials. Study was also made on a toughness expression mechanism, FEM model analysis of particle bridging, and crack growth resistance of ceramics. On control of solid solution precipitation, new alumina ceramics with high strength, hardness and wear resistance was obtained by transgranularly ...

1998-03-01

161

An effective method for the linearization of nodal stress components to apply ASME criteria  

Energy Technology Data Exchange (ETDEWEB)

The code of ASME Sec. III prescribes the general rules upon the design of a NSSS (nuclear steam supply system). The code provides further flexibility to the design of the nuclear structures by introducing a design by analysis concept. But it still preserves the conservatisms in design works by imposing strict failure mechanism and controlling material properties in use. A designer should prove the integrity of a structure under consideration by comparing the stress intensity, which was driven from the linearization of stress at concerning section, with the prescribed one. The recent development in computing system has enabled the commercial finite element programs to be a prevailing way to structural analysis field. But only few programs provide the procedure for stress linearization through the post-processing stage. Therefore, the simplified method which uses nodal stresses over ...

2002-02-01

162

The characteristics of coal reservoir pores and coal facies in Liulin district, Hedong coal field of China  

Energy Technology Data Exchange (ETDEWEB)

The composition, rank, coal facies, and coal pore structure characteristics of 15 coal samples were investigated systemically using methods of lithotype analysis, maceral analysis, proximate analysis, mercury porosimetry analysis, and nitrogen adsorption analysis. These samples were directly collected from the working faces of No.4, 8, 9 seams in Liulin district, eastern margin Ordos Basin, China. Four types of paleoenvironment including a wet forest swamp, an intergradation forest swamp, a drained forest swamp, and a fresh-water peat swamp were distinguished by lithotype and merceral analysis. An R-cluster analysis was performed to demonstrate the correlations between the coal facies and the pore structures. The results showed that coal rank is the primary factor affecting the development of ...

2010-02-01

163

Multiscale modeling of skeletal muscle properties and experimental validations in isometric conditions.  

Science.gov (United States)

In this article, we describe an approach to model the electromechanical behavior of the skeletal muscle based on the Huxley formulation. We propose a model that complies with a well established macroscopic behavior of striated muscles where force-length, force-velocity, and Mirsky-Parmley properties are taken into account. These properties are introduced at the microscopic scale and related to a tentative explanation of the phenomena. The method used integrates behavior ranging from the microscopic to the macroscopic scale, and allows the computation of the dynamics of the output force and stiffness controlled by EMG or stimulation parameters. The model can thus be used to simulate and carry out research to develop control strategies using electrical stimulation in the context of rehabilitation. Finally, through animal experiments, we estimated model parameters using a Sigma Point Kalman Filtering technique and dedicated experimental protocols ...

2011-07-15

164

Macroscopic angular momentum states of Bose-Einstein condensates in toroidal traps  

International Nuclear Information System (INIS)

We consider a Bose-Einstein condensate (BEC) of N atoms of repulsive interaction #approx# U_0, in an elliptical trap, axially pierced by a Gaussian-intensity laser beam, forming an effective (quasi-2D) toroidal trap with minimum at radial distance #rho# = #rho#_p. The macroscopic angular momentum states #PSI#_l(#rho#,#theta#) #approx# #sq root#N#PHI#_l(#rho#)e"i"l"#theta# for integer l spread up to #rho# > #rho#_p. The spreading lowers rotational energies, so estimated low metastability barriers can support large l < or approx. l_m_a_x #approx# (NU_0)"1"/"4, < or approx. 10 for typical parameters. The l-dependent density profile module #PHI#_l(#rho#)"2 -#PHI#_0(#rho#)"2 is a signature of BEC rotation. Results are insensitive to off-axis laser displacements #rho#_0, for #rho#_0 #rho#_m_a_x << 1. (author).

165

Unconstrained energy functionals for electronic structure calculations  

Energy Technology Data Exchange (ETDEWEB)

The performance of conjugate gradient schemes for minimizing unconstrained energy functionals in the context of electronic structure calculations is studied. The unconstrained functionals allow a straightforward application of conjugate gradients by removing the explicit orthonormality constraints on the quantum-mechanical wave functions. However, the removal of the constraints can lead to slow convergence, in particular when preconditioning is used. The convergence properties of two previously suggested energy functionals are analyzed, and a new functional is proposed, which unifies some of the advantages of the other functionals. A numerical example confirms the analysis.

1998-04-01

166

Structure functions of nuclei and #pi#-meson production in cumulative region  

International Nuclear Information System (INIS)

The structure functions (SF) of nuclei determined within the framework of the flucton model with rescaling (FMR) are compared with new experimental data of the ITEP on cumulative #pi#-meson yield in a wide range of the scale variable X (1analysis of deep inelastic lepton scattering by nuclei within the FMR framework and experimental data on #pi#"+-meson production on Be, Al, Cu, Ta nuclei in cumulative region has confirmed the hypothesis of limiting fragmentation.

167

Structural transformations of metastable #alpha#''-phase during cold deformation  

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.

168

New developments in the surveillance and diagnostics technology for vibration, structure-borne sound and leakage monitoring systems  

International Nuclear Information System (INIS)

Monitoring and diagnostic systems are of main importance for a safe and efficient operation of nuclear power plants. The author describes new developments with respect to vibration monitoring with a functional extension in the time domain for den secondary circuit, the development of a local system for the surveillance of rotating machines, the structure-borne sound monitoring with improvement of event analysis, esp. the loose part locating, leakage monitoring with a complete system for humidity measurement, and the development of a common platform for all monitoring and diagnostic systems, that allows an efficient access for comparison and cross references.

169

NMR analysis of the structure of synaptobrevin and of its interaction with syntaxin  

Energy Technology Data Exchange (ETDEWEB)

Synaptobrevin is a synaptic vesicle protein that has an essential role in exocytosis and forms the SNARE complex with syntaxin and SNAP-25. We have analyzed the structure of isolated synaptobrevin and its binary interaction with syntaxin using NMR spectroscopy. Our results demonstrate that isolated synaptobrevin is largely unfolded in solution. The entire SNARE motif of synaptobrevin is capable of interacting with the isolated C-terminal SNARE motif of syntaxin but only a few residues bind to the full-length cytoplasmic region of syntaxin. This result suggests an interaction between the N- and C-terminal regions of syntaxin that competes with core complex assembly.

1999-07-15

170

Fractal analysis of deformation-induced dislocation patterns  

Energy Technology Data Exchange (ETDEWEB)

The paper reports extensive analyses of the fractal geometry of cellular dislocation structures observed in Cu deformed in multiple-slip orientation. Several methods presented for the determination of fractal dimensions are shown to give consistent results. Criteria are formulated which allow the distinguishing of fractal from non-fractal patterns, and implications of fractal dislocation patterning for quantitative metallography are discussed in detail. For an interpretation of the findings a theoretical model is outlined according to which dislocation cell formation is associated to a noise-induced structural transition far from equilibrium. This allows relating the observed fractal dimensions to the stochastic properties of deformation by collective dislocation glide.

1999-06-22

171

Electron microscopy analysis of grain boundary structure and composition in superplastically deformed Al-Mg alloys  

Energy Technology Data Exchange (ETDEWEB)

Evaluation of grain boundary composition and structure in superplastically deformed AA5083-based alloys (Al-4.5Mg-1.6Mn-0.2Zr) was carried out in a field-emission gun transmission electron microscope (FEG-TEM). During superplastic deformation at high homologous temperatures materials undergo extensive grain boundary sliding (GBS) which creates a flow of defects in the near-boundary region. Recent literature has shown that the grain-boundary composition in Al-Mg alloys is not necessarily the same as the matrix, and that these differences can have an effect on GBS.

1996-12-31

172

Analysis on uranium resource situations and metallogenic potential of Heyuan mineralization belt of Guangdong province  

International Nuclear Information System (INIS)

Heyuan mineralization belt is a structure-magmatic activities belt which is charcterized by strong plastic deformation and shearing. The squeeze (overthrust) structure is formed early. Later stretch produced slide shovel-shaped normal fault which control the red basin and uranium mineralization. Comprehensive study shows that this area is of favorable uranium metallogenic condition due to the rich uranium source and higher degree of geology work, it is a target for the new round resources exploration. (authors)

2008-03-01

173

Investigation of the electronic structure of base adducts derived from tris(#eta#"5-cyclopentadienyl)-lanthanide(III) and related compound types  

International Nuclear Information System (INIS)

The purpose of this work is the elucidation of the f"n electronic structure of neutral mono base adducts derived from tris(#eta#"5-cyclopentadienyl)-lanthanide(III) (Cp_2Ln). The available data on related compounds like bis adducts and anionic mono adducts of the same moiety was also analyzed. The first aim was to derive the experimental crystal field splitting pattern from optical, magnetooptical and magnetochemical measurements and to reproduce it using an empirical Hamiltonian operator. The eigenvalues and eigenvectors obtained in this manner were used for a quantitative interpretation of the magnetochemical, EPR- and NMR-spectroscopic properties. For the latter subject it was necessary to develop an own procedure for the NMR analysis of paramagnetic compounds. This method is based on factor analysis and as demonstrated in the second part of this work, is clearly superior to all previous procedures. (orig.).

174

Genetic structure of gilthead seabream, Sparus aurata, in the Central Mediterranean Sea  

British Library Electronic Table of Contents (United Kingdom)

The gilthead seabream, Sparus aurata, represents an important economic resource for Mediterranean aquaculture. In spite of its wide geographic distribution and economic importance, only recently studies have been carried out on the genetic composition of natural populations, which have revealed a picture of a heterogeneous degree of genetic differentiation among S. aurata populations. In this study an allozyme analysis of samples from six different collecting sites along the Italian and Croatian coasts was carried out, covering an area in the Central Mediterranean sea that has yet to be investigated through gene-enzyme systems. Data on 26 gene loci, 10 of which are polymorphic, indicate a slight but significant genetic structure (FST = 0.0167) of the species. A hierarchical analysis of pop...

2006-01-01

175

Analysis of installation damage tests for LRFD calibration of reinforced soil structures  

British Library Electronic Table of Contents (United Kingdom)

North American design codes are now committed to the development of load and resistance factor design (LRFD) for reinforced soil structures including internal stability limit states. Reliability-based analysis is required to carry out these calibrations. A framework for LRFD calibration has been proposed by the writers that requires bias statistics for load and resistance terms for each limit state function. In this paper the formulation of the limit state for reinforcement tensile rupture is developed and the component strength-reduction bias statistics identified. The paper describes how to compute bias statistics from project-specific installation damage trials for use in reliability-based design for the reinforcement rupture limit state or using data from multiple sources for LRFD cali...

2011-01-01

176

Why we don`t need quantum planetary dynamics, or on decoherence and the correspondence principle for chaotic systems  

Energy Technology Data Exchange (ETDEWEB)

Violation of correspondence principle may occur for very macroscopic byt isolated quantum systems on rather short timescales as illustrated by the case of Hyperion, the chaotically tumbling moon of Saturn, for which quantum and classical predictions are expected to diverge on a timescale of approximately 20 years. Motivated by Hyperion, we review salient features of ``quantum chaos`` and show that decoherence is the essential ingredient of the classical limit, as it enables one to solve the apparent paradox caused by the breakdown of the correspondence principle for classically chaotic systems.

1995-08-01

177

Quantum Darwinism in quantum Brownian motion: the vacuum as a witness  

CERN Document Server

We study quantum Darwinism -- the redundant recording of information about a decohering system by its environment -- in zero-temperature quantum Brownian motion. An initially nonlocal quantum state leaves a record whose redundancy increases rapidly with its spatial extent. Significant delocalization (e.g., a Schroedinger's Cat state) causes high redundancy: many observers can measure the system's position without perturbing it. This explains the objective (i.e. classical) existence of einselected, decoherence-resistant pointer states of macroscopic objects.

2007-01-01

178

Periosteal Ewing's sarcoma  

International Nuclear Information System (INIS)

Periosteal Ewing's sarcoma is an uncommon, but well documented origin of this malignant condition with radiography signs, different from intramedullary growing tumours. Imaging modalities like CT or MRI supply proof of macroscopically intact endosteal cortical surface and free medullary cavity in long bones affected by this periosteal type of malignancy. Definite confirmation is valid after a careful microscopic investigation of the resected specimen. The prognosis of this type of Ewing's sarcoma may be favourable than that of the central type. Early diagnosis and therapy are thus essential. A clinical survey of six observations is given. (orig.).

179

Nuclear Forensics' role in analyzing nuclear trafficking activities  

International Nuclear Information System (INIS)

Nuclear forensics aims at identifying origin and intended use of nuclear material using information inherent to the nuclear material.The information gathered in nuclear forensics include isotopic composition, elemental composition, impurities and age of the material, macroscopic appearance and microstructure. The information so collected helps to solve criminal cases and put the individuals involved in nuclear trafficking in jails. The information also helps to improve safeguards and physical protection measures at place of theft or diversion to prevent future thefts or diversions.

2010-05-10

180

Industrial processing of complex fluids: Formulation and modeling  

Energy Technology Data Exchange (ETDEWEB)

The production of many important commercial materials involves the evolution of a complex fluid through a cooling phase into a hardened product. Textile fibers, high-strength fibers(KEVLAR, VECTRAN), plastics, chopped-fiber compounds, and fiber optical cable are such materials. Industry desires to replace experiments with on-line, real time models of these processes. Solutions to the problems are not just a matter of technology transfer, but require a fundamental description and simulation of the processes. Goals of the project are to develop models that can be used to optimize macroscopic properties of the solid product, to identify sources of undesirable defects, and to seek boundary-temperature and flow-and-material controls to optimize desired properties.

1997-08-01

181

Graphitic nano tubes and aligned nano tubes films  

Energy Technology Data Exchange (ETDEWEB)

Carbon nano tubes are easily produced in macroscopic quantities, however their characterisation and possible applications are still rather limited. We have developed a new method to make aligned nano tube films which open new opportunities, not only for basic research but also for eventual applications. With this method the tubes can be aligned either parallel or perpendicular to the surface. We give a short review of the microscopic properties of single tubes and the bulk properties of the aligned films. (author). 24 refs., 6 figs.

1996-03-01

182

Structural Analysis for Gold Mineralization Using Remote Sensing and Geochemical Techniques in a GIS Environment: Island of Lesvos, Hellas  

International Nuclear Information System (INIS)

Exploration for epithermal Au has been active lately in the Aegean Sea of the eastern Mediterranean Basin, both in the islands of the Quaternary arc and in those of the back-arc region. The purpose of this study was the structural mapping and analysis for a preliminary investigation of possible epithermal gold mineralization, using remotely sensed data and techniques, structural and field data, and geochemical information, for a specific area on the Island of Lesvos. Therefore, Landsat-TM and SPOT-Pan satellite images and the Digital Elevation Model (DEM) of the study area were processed digitally using spatial filtering techniques for the enhancement and recognition of the geologically significant lineaments, as well as algebraic operations with band ratios and Principal Component Analysis (PCA), for the identification of alteration zones. Statistical rose diagrams and a SCHMIDT projection Stereo Net ...

2000-12-01

183

Waste sampling and characterization facility (WSCF)  

Energy Technology Data Exchange (ETDEWEB)

The Waste Sampling and Characterization Facility (WSCF) complex consists of the main structure (WSCF) and four support structures located in the 600 Area of the Hanford site east of the 200 West area and south of the Hanford Meterology Station. WSCF is to be used for low level sample analysis, less than 2 mRem. The Laboratory features state-of-the-art analytical and low level radiological counting equipment for gaseous, soil, and liquid sample analysis. In particular, this facility is to be used to perform Resource Conservation and Recovery Act (RCRA) of 1976 and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 sample analysis in accordance with U.S. Environmental Protection Agency Protocols, room air and stack monitoring sample analysis, waste water treatment process support, and contractor laboratory quality assurance ...

1994-10-01

184

A structured approach to the assessment of the quality culture in nuclear installation  

International Nuclear Information System (INIS)

INSAG has emphasized that safety culture has two general components: the organizational framework and the attitude of the staff. To develop a structured approach to the assessment of safety culture, we propose that the highly formalized nature of nuclear power plant organizations be exploited. The prime coordinating mechanism of NPP organizations is the standardization of work processes, where a work process is defined as a standardized sequence of tasks designed to achieve a specific goal (an example is the maintenance work process). The predictable nature of work processes is exploited by the Work Process Analysis Model (WPAM) to conduct a systematic analysis that identifies the desirable characteristics of work processes and develops performance measures for their strengths and weaknesses. These can provide a set of tangible characteristics of a good safety culture. It is argued in this paper that the ...

1995-04-01

185

Microlocal analysis of asymptotically hyperbolic and Kerr-de Sitter spaces  

CERN Document Server

In this paper we develop a general, systematic, microlocal framework for the Fredholm analysis of non-elliptic problems, including high energy (or semiclassical) estimates, which is stable under perturbations. This framework is relatively simple given modern microlocal analysis, and only takes a bit over a dozen pages after the statement of notation. It resides on a compact manifold without boundary, hence in the standard setting of microlocal analysis, including semiclassical analysis. The rest of the paper is devoted to applications. Many natural applications arise in the setting of non-Riemannian b-metrics in the context of Melrose's b-structures. These include asymptotically Minkowski metrics, asymptotically de Sitter-type metrics on a blow-up of the natural compactification and Kerr-de Sitter-type metrics. The simplest application, however, is to provide a new approach to ...

2010-01-01

186

The fluorescence properties and NMR analysis of protopine and allocryptopine  

International Nuclear Information System (INIS)

The fluorescence properties of protopine and allocryptopine in aqueous and organic environments are described for the first time. The fluorescence of alkaloids and their pH-dependent interconversion to cationic forms (transannular interaction) were studied using steady-state and time-resolved fluorescence techniques. For the analysis of tricyclic base and cis/trans tetracyclic cations of the alkaloids, NMR and X-ray crystallography were used. - Highlights: ? We describe fundamental fluorescence characteristics of alkaloids protopine and allocryptopine. ? We analyzed the pH-dependent transitions and cis/trans isomerization. ? These two alkaloids can be better distinguished by their fluorescence decay characteristics. ? The fluorescence parameters are related to the NMR and crystallographic structural data.

2011-07-01

187

RAPID DAMAGE ASSESSMENT FROM HIGH RESOLUTION IMAGERY  

Energy Technology Data Exchange (ETDEWEB)

Disaster impact modeling and analysis uses huge volumes of image data that are produced immediately following a natural or an anthropogenic disaster event. Rapid damage assessment is the key to time critical decision support in disaster management to better utilize available response resources and accelerate recovery and relief efforts. But exploiting huge volumes of high resolution image data for identifying damaged areas with robust consistency in near real time is a challenging task. In this paper, we present an automated image analysis technique to identify areas of structural damage from high resolution optical satellite data using features based on image content.

2008-07-01

188

Proceedings of the third international conference on containment design and operation. v.1  

International Nuclear Information System (INIS)

The second international conference on containment design and operation included sessions on the following topics: performance and regulatory requirements; radionuclide behaviour; severe accident design and analysis; operation, maintenance, leaking and aging of containment systems; thermal hydraulic behaviour of containment systems; hydrogen mixing and mitigation; design methods and concepts; code validation; structural analysis and response tests; passive safety systems; aerosol behaviour; containment reliability, integrity, and risk assessment; hydrogen deflagration and detonation. Due prominence was given to CANDU and other PHWR reactors. The individual papers have been abstracted separately.

1994-10-19

189

Large scale breeder reactor pump dynamic analyses  

Energy Technology Data Exchange (ETDEWEB)

The lateral natural frequency and vibration response analyses of the Large Scale Breeder Reactor (LSBR) primary pump were performed as part of the total dynamic analysis effort to obtain the fabrication release. The special features of pump modeling are outlined in this paper. The analysis clearly demonstrates the method of increasing the system natural frequency by reducing the generalized mass without significantly changing the generalized stiffness of the structure. Also, a method of computing the maximum relative and absolute steady state responses and associated phase angles at given locations is provided. This type of information is very helpful in generating response versus frequency and phase angle versus frequency plots.

1982-01-01

190

Integrating decision support tools and environmental information systems: a case study on the Province of Milan  

International Nuclear Information System (INIS)

The paper demonstrates an application of advanced decision support tools within the framework of the environmental information system of the Province of Milan. These tools include environmental simulation models, multi criteria analysis, risk analysis and environmental accounting for marketable emission permits. After describing the general structure of the system, three demonstrational case studies are introduced concerning: groundwater pollution management; atmospheric pollution management; urban environmental quality perception and management. In the conclusion, potential use of tools like the ones implemented by the province of Milan within the framework of Local Agenda 21 processes is recalled.

2006-03-01

191

Compression, bend, and impact testing of some tropical wood-polymer composites  

International Nuclear Information System (INIS)

The compressive and bending strengths of a local tropical wood (Kapur-Dryobalanop sp.) were improved significantly by suitable impregnation of polymeric monomers (methylmethacrylate, methylmethacrylate - 5% dioxane and vinyl acetate) into the wood cellular structure and subsequent irradiation to form a wood-polymer composite. Statistical analysis revealed a linear relationship between increase in the strengths and the percentage of polymer impregnated. Fractographic analysis of the impact fractured surfaces under the scanning electron microscope showed the nature of the wood-polymer interface, which could account for the increase in the compressive and bending strengths. (author).

1985-01-01

192

Algorithmic tangent stiffness in elastoplasticity and elastoviscoplasticity: A geometric insight  

British Library Electronic Table of Contents (United Kingdom)

The algorithmic, or consistent, tangent stiffness was introduced to improve the asymptotic convergence rate of the iterative correction algorithm for the evolutive analysis of elastoplastic structures. The original approach is based on a formulation of the elastoplastic law in terms of a plastic multiplier with an analysis which, in general, requires an operator inversion. A geometric description of the method, based on hypersurface theory, is proposed here to provide a clear picture of the algorithmic properties. An estimate of the tangent stiffness associated with finite step elastoplastic and elastoviscoplastic constitutive models is given. It is based on the properties of the projection operator on the elastic domain and avoids operator inversions retaining the beneficial properties of...

2010-01-01

193

A database for QA/QC in neutron activation analysis and gamma-ray spectrometry  

International Nuclear Information System (INIS)

A database has been designed for storing, retrieving and analyzing information about samples, experimental conditions and results obtained by neutron activation analysis and gamma-ray spectrometry. It has been created using Microsoft ACCESS 2002 under a Windows operating system. The database has been designed not only for saving information but also for quality assurance and quality control purposes. The structure of the relational design has been discussed and demonstrated with a new graphical feature of ACCESS 2002 called PIVOTCHART. (author)

2007-04-01

194

Vibration testing of the I-40 bridge before and after the introduction of damage  

Energy Technology Data Exchange (ETDEWEB)

Because the bridges over the Rio Grande were to be razed, the investigators were able to introduce simulated cracks in four stages of increasing length into the structure. This paper summarizes the results of ambient and conventional, measured-input, modal analyses, performed on the undamaged structure. Also summarized are the results of conventional modal analyses performed after each stage of damage had been introduced. These tests were intended to quantify the amount of damage necessary to produce changes in the global dynamic properties of the bridge and to form a data base that can be used by other investigators to develop damage identification algorithms. Conventional modal analysis identified changes in the global dynamic properties of the structure only after the final stage of a damage.

1994-11-01

195

The use of combinatorial topographical libraries for the screening of enhanced osteogenic expression and mineralization  

British Library Electronic Table of Contents (United Kingdom)

Nano- and microstructured surfaces are known to impact on the binding and differentiation of cells, but the detailed basic understanding of the underlying regulatory mechanisms is still scarce, which impedes the rational design of smart biomaterials. Towards a comprehensive analysis of the interplay between topographical parameters such as feature design and lateral and vertical dimensions we here report on a combinatorial screening approach, BioSurface Structure Array (BSSA) of test squares each with a distinct topography. Using such BSSA libraries of 504 topographically distinct surface structures, we have identified combinations of size, gap and height of structures which enhance mineralization as well as the expression of osteogenic markers of a preosteoblastic murine cell line. This g...

2009-01-01

196

The cybernetics of viability: an overview  

British Library Electronic Table of Contents (United Kingdom)

A three-level approach to viability is developed, considering (1) living systems, (2) a niche, understood as the area within the reach of their actions, and (3) an environment. A systematic analysis of the interrelations between these levels shows that living systems emerge with matter/energy processing systems. These can add controller structures when producing excess energy. A three-sensor controller structure enables a living system to deal with unfavourable and scarce environments. Further evolution of these controller structures offers improved ways to act on niches. Maintaining niches in scarce environments can require technology or economy. So social systems emerge, which are understood as aggregates of living systems. Basic patterns of interactions within social systems are analyse...

2011-01-01

197

Structure and properties of a metastable #beta#-alloy aged after plastic deformation  

International Nuclear Information System (INIS)

Phase and structural transformations in a multicomponent (5.05 mas.% Mo-4.95V-3.00Cr-3.05Al) metastable #beta#-titanium alloy on aging after plastic deformation are studied using methods of electron microscopy and X-ray diffraction analysis. The alloy is deformed by twinning in a #left brace#332#right brace# system, and even at initial stages the formation of a twin skeleton takes place in the structure, on further loading the deformation of the skeleton is by secondary twinning resulting in a high plasticity of the alloy. On annealing mechanical twins transform into #alpha#-phase - a ductile twin skeleton is replaced by a rigid skeleton of #alpha#-phase plates. The aging enhances the yield strength of the alloy but decreases sharply its plasticity

2004-12-01

198

Structural analysis and modifications-2 tankers for offshore FPSO and FSO service  

British Library Electronic Table of Contents (United Kingdom)

This paper addresses the unique structural requirements for successful conversion of tankers for floating production storage and offloading (FPSO) or floating storage and offloading (FSO) service. A description is given of the steps undertaken during two recent and very different conversions of a highly optimized 1980s VLCC to FPSO service, and a typical robust 1970s ULCC to FSO service. The paper describes the steps needed for ensuring the FPSO or FSO requirements are successfully met during conversion of the two tankers - each having its own history, e.g. date of build, original design, material choices, class society, voyage history and repairs. Firstly, the paper describes the procedure and results of an early initial structural assessment procedure on the basis of an American Bureau o...

2008-01-01

199

Safety philosophy and concepts for large liquid metal breeder reactor power plants  

International Nuclear Information System (INIS)

This paper addresses the unique related aspects of the LMFBR concept which are of significance to containment design and structural analysis. Topics covered include: Primary boundary integrity assurance; Effects of sodium spills on integrity of structures; Provisions being considered for containment of melted cores; Fuel handling accidents. Specific reference is made to the FFTF and the Clinch River Breeder Reactor Project designs and methods of treatment of the above problems. In particular, the part played by tests, such as those carried out on a simulated FFTF model, and the planned structural reliability and related programs are considered. Where practicable, these topics are addressed in a manner which places FFTF and CRBR in context with other LMFBR's and point to a possible direction for future American LMFBR designs. (Auth.).

200

Electronic structure, charge distribution and X-ray emission spectra of V_3Si  

International Nuclear Information System (INIS)

Cluster calculations of the electronic structure and charge distribution in V_3Si have been performed using two different molecular orbital methods: a semiempirical LCAO and the MS X#alpha# model. The results are compared with X-ray emission spectra and band structure calculations. An analysis of the calculated electronic distribution reveals a charge transfer from Si-atoms to V-atoms, the additional charge on a V-atom being 0.6e (LCAO) and 0.4e (MS X#alpha# method). The results are in good agreement with experiment, which indicates that the cluster approach is adequate for the description of charge distributions and spectra characteristics of the A-15 compounds. (author).

201

Dynamic neuronal ensembles: Issues in representing structure change in object-oriented, biologically-based brain models  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the structure of dynamic neuronal ensembles (DNEs). DNEs represent a new paradigm for learning, based on biological neural networks that use variable structures. We present a computational neural element that demonstrates biological neuron functionality such as neurotransmitter feedback absolute refractory period and multiple output potentials. More specifically, we will develop a network of neural elements that have the ability to dynamically strengthen, weaken, add and remove interconnections. We demonstrate that the DNE is capable of performing dynamic modifications to neuron connections and exhibiting biological neuron functionality. In addition to its applications for learning, DNEs provide an excellent environment for testing and analysis of biological neural systems. An example of habituation and hyper-sensitization in biological systems, using a neural circuit from a snail is presented and ...

1996-12-31

202

The crystal structure Escherichia coli Spy.  

Science.gov (United States)

Escherichia coli spheroplast protein y (EcSpy) is a small periplasmic protein that is homologous with CpxP, an inhibitor of the extracytoplasmic stress response. Stress conditions such as spheroplast formation induce the expression of Spy via the Cpx or the Bae two-component systems in E. coli, though the function of Spy is unknown. Here, we report the crystal structure of EcSpy, which reveals a long kinked hairpin-like structure of four ?-helices that form an antiparallel dimer. The dimer contains a curved oval shape with a highly positively charged concave surface that may function as a ligand binding site. Sequence analysis reveals that Spy is highly conserved over the Enterobacteriaceae family. Notably, three conserved regions that contain identical residues and two LTxxQ motifs are placed at the horizontal end of the dimer structure, stabilizing the overall fold. CpxP also contains the conserved ...

2010-11-01

203

Study on reactor building structure using ultrahigh strength materials - Part 9: Summary of the study  

International Nuclear Information System (INIS)

Considerations for longevity of nuclear facilities and ease of decommissioning are of great importance for future nuclear power plants. To this end, a concept of an optimal structural concept for nuclear reactor buildings has been studied: the main feature of this concept is to utilize large-sized, light weight prefabricated members with ultrahigh strength materials. The following two items have been selected to study the prospective structure: (1) Applicability of ultrahigh strength materials for reinforced concrete shear walls (2) Construction using large sized prefabricated members As the first step (1), material and structural tests using ultrahigh strength materials, and the subsequent analysis of those tests for reinforced concrete shear walls, has been conducted. The positive results of this study show a bright future for the use of ultrahigh strength materials for the reinforced concrete shear ...

1993-08-15

204

Structural and transport properties of illitized samples from drillhole OL-KR12 in Olkiluoto. Porosity, diffusion coefficient, permeability and tomographic imaging  

Energy Technology Data Exchange (ETDEWEB)

Six illitized samples from drillhole OL-KR12 in Olkiluoto were analyzed by helium gas methods for their diffusion coefficient, permeability and porosity. The diffusion coefficients measured varied in the range 2.1 x 10-10 - 3.5 x 10-8 m2/s, permeabilities in the range 6 x 10-21 - 5.8 x 10-16 m2, and porosities in the range 0.2 6.2%. Variations observed in these quantities were concluded to arise from the heterogeneous structure of the sample rock. A 4 mm x 4 mm x 4 mm subsample was sawed from each of the six samples for structural analysis by x-ray microtomography. The three-dimensional structure of tomographic reconstructions, and thereby that of the samples themselves, was analyzed visually, which confirmed their heterogeneity. Samples represent altered rock whose structure and thereby transport properties vary significantly depending on the local alteration history of the rock. ...

2009-10-15

205

Preliminary Guideline for the High Temperature Structure Integrity Assessment Procedure Part I. High Temperature Structure Design Guide  

Energy Technology Data Exchange (ETDEWEB)

A preliminary guideline for the design and evaluation of LMR high temperature structure is presented based upon ASME B and PV Code, Section III, Subsection NH. The main contents of this guideline are the materials, general design, vessel, piping, core support structure, pumps, valves, fabrication, examination, and testing for the class 1 components. The ratcheting evaluation, enhanced creep assessment, welds design and evaluation, inelastic analysis approach, piping design alternatives, and bellows design method are described in appendices. A user of this guideline should follow the essential procedures and may refer to other pertinent codes, standards, laws, regulations, or other pertinent documents when this guideline does not lead to proper design of the structure. While this guideline adopts major procedures of Subsection NH, it refers to the RCC-MR and/or DDS in some amount for the items where ...

2007-02-15

206

Novel recombinant insulin analogue with flexible C-terminus in B chain. NMR structure of biosynthetic engineered A22^G-B31^K-B32^R human insulin monomer in water/acetonitrile solution  

British Library Electronic Table of Contents (United Kingdom)

A tertiary structure of recombinant A22^G-B31^K-B32^R-human insulin monomer (insulin GKR) has been characterized by ^1H, ^1^3C NMR at natural isotopic abundance using NOESY, TOCSY, ^1H/^1^3C-GHSQC, and ^1H/^1^3C-GHSQC-TOCSY spectra. Translational diffusion studies indicate the monomer structure in water/acetonitrile (65/35vol.%). CSI analysis confirms existence of secondary structure motifs present in human insulin standard (HIS). Both techniques allow to establish that in this solvent recombinant insulin GKR exists as a monomer. Starting from structures calculated by the program CYANA, two different refinement protocols used molecular dynamics simulated annealing with the program AMBER; in vacuum (AMBER_VC), and including a generalized Born solvent model (AMBER_GB). From these calculation...

2011-01-01

207

Focused ion beam machined nanostructures depth profiled by macrochannelling ion beam analysis  

International Nuclear Information System (INIS)

High aspect ratio sub-#mu#m periodic structures fabricated by focused ion beam (FIB) lithography have been characterised by Rutherford backscattering spectrometry (RBS) using the macrochannelling technique. The technique overcomes the limitations of complementary techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM), which can provide images with sub-#mu#m resolution of just the surface features and not of the deep sub-surface structures, without destructive cross sectioning of the sample. Here RBS macrochannelling with a 2 MeV He"+ ion beam is used to analyse a diffraction grating fabricated by FIB milling an array of 100 nm wide trenches in a 300 nm thick Ag film on a Si substrate. Using the surface structure imaged by SEM and AFM as a starting point, a numerical model for the RBS spectrum from the grating is fitted to the experimental spectrum as a function of the sub-surface ...

2006-08-01

208

Raman spectroscopic studies of carbon in extra-terrestrial materials  

International Nuclear Information System (INIS)

The measurements obtained here indicate ways in which micro-Raman spectroscopy can be used to elucidate structural characteristics and distribution of carbon in meteorites and interplanetary dust particles (IDPs). Existing information about structurally significant aspects of Raman measurements of graphite is combined with structurally relevant findings from the present micro-Raman studies of carbons prepared by carbonization of polyvinylidine chloride (PVDC) at various temperatures and natural material, as well as several acid residues from the Allende and Murchison meteorites in order to establish new spectra-structure relationships. Structural features of many of the materials in this study have been measured by x ray analysis and electron microscopy: thus, their structural differences can be directly correlated with differences in the ...

1990-04-01

209

Wind turbine fault diagnosis based on Morlet wavelet transformation and Wigner-Ville distribution  

British Library Electronic Table of Contents (United Kingdom)

Based on the Morlet wavelet transformation and Wigner-Ville distribution (WVD), we present a wind turbine fault diagnosis method in this paper. Wind turbine can be damaged by moisture absorption, fatigue, wind gusts or lightening strikes. Due to this reason, there is an increasing need to monitor the health of these structures. Vibration analysis is the best-known technology applied in wind turbine condition monitoring, in which the time-frequency analysis techniques such as Wigner-Ville distribution (WVD) are widely used. Theoretically WVD has an infinite resolution in time-frequency domain. For early wind turbine fault signals, however, there are two main difficulties in WVD analysis. One is strong noise signals in the background and the other is cross terms in WVD itself. In this paper,...

2010-01-01

210

Nuclear structure studies via neutron interactions  

Energy Technology Data Exchange (ETDEWEB)

Research preformed consisted of: (1) publication of an experimental paper for the n + {sup 40}Ar high resolution total cross section and submission of a theoretical paper dealing with the prediction of the average parameters deduced from the the data; (2) preliminary R-matrix analysis of the neutron total cross section data for the n + {sup 208}Pb systems, up to an energy of 1.7 MeV; (3) completed the analysis of neutron total cross section of data for n + {sup 54}Fe up to energy of 500 keV, with j{sup {pi}} values confirmed, in most cases, by differential scattering data; (4) analysis of total cross section data for the n + {sup 88}Sr system up to an energy of 175 keV; (5) development of a graphical interface for the code RFUNC, used to calculate the differential scattering cross sections, for comparison with measurements.

1991-03-01

211

Multiscale morphology analysis and its application to fault diagnosis  

Science.gov (United States)

A novel approach to fault diagnosis is proposed using multiscale morphology analysis to extract impulsive features from the signals with strong background noise. Multiscale morphology is applied to one-dimensional signal by defining both the length and height scales of structuring elements (SEs). A local-peak-value based adaptive algorithm is also introduced. The new approach makes the selection of SEs more transparent and is independent of empirical rules. Both simulated impulsive and vibration signals of two defective roller bearings are employed to validate the proposed algorithm. The roller bearing faults presented in the validation include both inner and outer race faults. The test results show that the multiscale morphology analysis is effective and robust to extract morphological features.

2008-04-01

212

Multi-Dimensional Analysis for Sodium Hot Pool using MARS-LMR in Steady State  

International Nuclear Information System (INIS)

DBEs (Design Basis Event) of KALIMER-600 (Korea Advanced Liquid Metal Reactor) were analyzed in one dimension by KAERI (Korea Atomic Energy Research Institute). KALIMER-600 is the pool type SFR (Sodium cooled Fast Reactor), thereby the sodium of primary system is prohibited movement to out of a reactor vessel. There are many contacting and including compositions in the sodium hot pool, such as IHX (Intermediate Heat eXchanger), DHX (Decay Heat eXchanger), Pump, UIS (Upper Internal Structure), and core. Moreover, the complex phenomena are occurred in sodium hot pool during steady and transient states. Therefore, the one dimensional analysis is modified to the multi-dimensional analysis through modification of sodium hot pool from one to three dimensions

2010-10-01

213

JMassBalance: mass-balanced randomization and analysis of metabolic networks  

British Library Electronic Table of Contents (United Kingdom)

Summary: Analysis of biological networks requires assessing the statistical significance of network-based predictions by using a realistic null model. However, the existing network null model, switch randomization, is unsuitable for metabolic networks, as it does not include physical constraints and generates unrealistic reactions. We present JMassBalance, a tool for mass-balanced randomization and analysis of metabolic networks. The tool allows efficient generation of large sets of randomized networks under the physical constraint of mass balance. In addition, various structural properties of the original and randomized networks can be calculated, facilitating the identification of the salient properties of metabolic networks with a biologically meaningful null model. Availability and Imp...

2011-01-01

214

Development of a petrographic technique for the quality control of concrete mixes used in mines. Final report; Mise au point d`une technique petrographique pour le controle de qualite des betons miniers. Rapport final  

Energy Technology Data Exchange (ETDEWEB)

Petrographical analysis is a microscopical analytical tool which allows definition of the exact nature of the components of different concrete mixes, as well as definition of internal structures and alteration processes. In order to improve the precision and the swiftness of the petrographical analysis, an automated image analysis system has been developed. In the next stage of this study, which consisted in the testing of new concrete mixes containing fluidised bed ashes, petrography has been used, not only to identify the nature of the mix components, but also assess the behaviour of these new concrete mixes when exposed to aggressive conditions.

1997-11-01

215

Buckling analysis of structural steel frames with inelastic effects according to codes  

British Library Electronic Table of Contents (United Kingdom)

Steel building frames are often analyzed for stability in an elastic way, while most of their columns behave inelastically at the buckling stage. Most column design provisions allow for inelastic behavior, but overall inelastic stability analysis is rarely performed. In this study the analysis philosophy is centered on the overall frame stability and its true safety factor. As many columns show inelastic behavior at the buckling stage, the proposed procedure takes due consideration of this fact. Once the overall buckling factor for the frame is obtained, individual column effective length factors, and their true slenderness ratios are computed, and used in the design relationships. This procedure circumvents the use of design nomographs and numerous formulas proposed in the past to allevia...

2009-01-01

216

SIMS analysis of silicon on insulator structures formed by high-dose O/sup +/ implantation into silicon  

Energy Technology Data Exchange (ETDEWEB)

Silicon on insulator (SOI) structures are promising candidates for the fabrication of VLSI circuits with very high packing densities. The preparation of such structures can now be achieved by high dose implantation of reactive ion species such as oxygen to produce buried layers of SiO/sub 2/ in silicon. In this paper we report experiments to depth profile these layered structures by SIMS. SOI samples have been prepared by implanting (100) silicon wafers with 400 keV molecular oxygen ions at a dose of 1.8x10/sup 18/ O/sup +/ cm/sup -2/. During the implantation the wafers were maintained at temperatures between 325 and 600/sup 0/C, using beam heating, which achieved in situ-annealing and ensured that the top silicon layer remained single crystal. Analysis was carried out on an Atomika DIDA-II spectrometer using 10 keV Ar/sup +/ ions with a low current density of less than 1 mA cm/sup -2/. During ...

1983-12-15

217

Crystal field analysis of the energy level structure of Cs{sub 2}NaAlF{sub 6}:Cr{sup 3+}  

Energy Technology Data Exchange (ETDEWEB)

An analysis of the energy level structure of Cr{sup 3+} ions in Cs{sub 2}NaAlF{sub 6} crystal is performed using the exchange charge model (ECM) together with the crystal field analysis/microscopic spin Hamiltonian (CFA/MSH) computer package. Utilizing the crystal structure data, our approach enables modelling of the crystal field parameters (CFPs) and thus the energy level structure for Cr{sup 3+} ions at the two crystallographically inequivalent sites in Cs{sub 2}NaAlF{sub 6}. Using the ECM initial adjustment procedure, the CFPs are calculated in the crystallographic axis system centred at the Cr{sup 3+} ion at each site. Additionally the CFPs are also calculated using the superposition model (SPM). The ECM and SPM predicted CFP values match very well. Consideration of the symmetry aspects for the so-obtained CFP datasets reveals that the latter axis system matches the ...

2006-06-07

218

Crystal field analysis of the energy level structure of Cs2NaAlF6:Cr3+  

International Nuclear Information System (INIS)

An analysis of the energy level structure of Cr3+ ions in Cs2NaAlF6 crystal is performed using the exchange charge model (ECM) together with the crystal field analysis/microscopic spin Hamiltonian (CFA/MSH) computer package. Utilizing the crystal structure data, our approach enables modelling of the crystal field parameters (CFPs) and thus the energy level structure for Cr3+ ions at the two crystallographically inequivalent sites in Cs2NaAlF6. Using the ECM initial adjustment procedure, the CFPs are calculated in the crystallographic axis system centred at the Cr3+ ion at each site. Additionally the CFPs are also calculated using the superposition model (SPM). The ECM and SPM predicted CFP values match very well. Consideration of the symmetry aspects for the so-obtained CFP datasets reveals that the latter axis system matches the symmetry-adapted axis system related directly to the ...

2006-06-07

219

Thermal reactor safety  

International Nuclear Information System (INIS)

Information is presented concerning new trends in licensing; seismic considerations and system structural behavior; TMI-2 risk assessment and thermal hydraulics; statistical assessment of potential accidents and verification of computational methods; issues with respect to improved safety; human factors in nuclear power plant operation; diagnostics and activities in support of recovery; LOCA transient analysis; unresolved safety issues and other safety considerations; and fission product transport.

1990-09-01

220

Thermal reactor safety  

Energy Technology Data Exchange (ETDEWEB)

Information is presented concerning new trends in licensing; seismic considerations and system structural behavior; TMI-2 risk assessment and thermal hydraulics; statistical assessment of potential accidents and verification of computational methods; issues with respect to improved safety; human factors in nuclear power plant operation; diagnostics and activities in support of recovery; LOCA transient analysis; unresolved safety issues and other safety considerations; and fission product transport.

1980-06-01

221

The implementation of SOMO (SOlution MOdeller) in the UltraScan analytical ultracentrifugation data analysis suite: enhanced capabilities allow the reliable hydrodynamic modeling of virtually any kind of biomacromolecule  

UK PubMed Central (United Kingdom)

The interpretation of solution hydrodynamic data in terms of macromolecular structural parameters is not a straightforward task. Over the years, several approaches have been developed to cope...Full Text Available

2010-02-01

222

The controllability analysis of the purification system for heavy water reactors  

International Nuclear Information System (INIS)

The heavy water reactor such as Wolsung No.1 and No.2 has a purification system to purify the reactor coolant. The control system regulates the coolant temperature to protect the ion exchanger. After the fuel exchanges of operating plant, the increase of the coolant pressure makes the purification temperature control difficult. In this paper, the controllability of the control dynamics of the purification system was analysed and the optimal parameters were proposed. To reduce the effects of the flow disturbance, the feedforward control structure was proposed and analysed.

2001-10-01

223

Synthesis, Characterization, and Biological Activity Studies of Copper(II) Mixed Compound with Histamine and Nalidixic Acid  

UK PubMed Central (United Kingdom)

A mixed copper complex with deprotonated nalidixic acid (nal) and histamine (hsm) was synthesized and characterized by FTIR, UV-Vis, elemental analysis, and conductivity. The crystal structure of [Cu(hsm)(nal)H2O]Cl·3H2O...Full Text Available

2009-01-01

224

Offshore and arctic operations symposium - 1987  

Energy Technology Data Exchange (ETDEWEB)

This book presents the papers given at a conference on offshore platforms. Topics considered in this book include risk assessment, crack propagation, fracture control, stress corrosion, the reliability of pile foundations, the thermal conductivity of offshore pipeline coating material, economic analysis, hydrodynamics, simulation, Arctic structure design, composite materials, buoys, deep water drilling, corrosion protection, pollution control equipment, and subsea exhaust gas compressors.

1987-01-01

225

Inertinite of fossil coal and molecular paleontology  

British Library Electronic Table of Contents (United Kingdom)

The etching method developed made it possible to observe under the microscope the finest components of the anatomical structure of coal-forming plants. The dependence of the effectiveness of etching of tissues on the concentrations of geopolymers (protocellulose and protolignin) in them was found. The study of tissues of this kind by the methods of local analysis (for example, X-ray microanalysis) allowed us to obtain the characteristics of the above geopolymers and to use them for the identification of the primary biochemical composition of fossil organic matter.

2011-01-01

226

ELECTRON MICROSCOPE PREPARATIONS OF RADIOACTIVELY LABELED AEROSOLS  

Science.gov (United States)

A method is described to smear extremely thin layers of nuclear emulsion on labeled electron microscope preparations and to measure the thicknesses of these layers, Without further separation, preparation and emulsion can be observed after exposure and development in an electron microscope. The source of the tracks formed in the emulsion can be exactly identified and the size and structure determined. This method finds applications in dust research and also in the analysis of medical and biological sections. Further information can be obtained about properties of different emulsions. (auth)

1963-04-01

227

Campylobacter jejuni Fatty Acid Synthase II: Structural and functional analysis of ?-hydroxyacyl-ACP dehydratase (FabZ)  

UK PubMed Central (United Kingdom)

Fatty acid biosynthesis is crucial for all living cells. In contrast to higher organisms, bacteria use a type II fatty acid synthase (FAS II) composed of a series of individual proteins, making...Full Text Available

2009-03-06

228

Analysis of Computer Experiments with Multiple Noise Sources  

DEFF Research Database (Denmark)

In this paper we present a modeling framework for analyzing computer models with two types of variations. The paper is based on a case study of an orthopedic surgical unit, which has both controllable and uncontrollable factors. Our results show that this structure of variation can be modeled effectively with linear mixed effects models and generalized additive models. Copyright (C) 2009 John Wiley & Sons, Ltd.

2010-01-01

229

Gastric stromal tumors. CT findings; Tumori stromali gastrici. Aspetti con Tomografia Computerizzata  

Energy Technology Data Exchange (ETDEWEB)

Gastric stromal tumors are an ill-defined group of lesions arising from muscle wall cells and characterized by extremely variable biological patterns. Thanks to modern immunohistochemical and ultrastructural techniques, four main classes of these lesions have been identified, namely: (1) tumors with differentiation toward smooth muscle cells; (2) tumors with differentiation toward neural elements; (3) tumors with differentiation toward neural elements; (3) tumors with dual differentiation toward either cell type. It was investigated the yield of CT in diagnosing and characterizing gastric stromal tumors. It was retrospectively reviewed the CT findings of 38 patients (15 men and 23 women; mean age 51 years) with pathologically proven gastric stromal tumors, namely 31 of myoid origin, 4 of neural origin, 2 with both muscle and neural differentiation, 1 lacking differentiation with either cell type. The myoid tumors involved gastric fundus in 9/13 and 5/7 benign lesions and lesions with ...

2000-02-01

230

Wiener Reconstruction of Large-Scale Structure from Peculiar Velocities  

CERN Document Server

We present an alternative, Bayesian method for large-scale reconstruction from observed peculiar velocity data. The method stresses a rigorous treatment of the random errors and it allows extrapolation into poorly sampled regions in real space or in k-space. A likelihood analysis is used to determine the fluctuation power spectrum, followed by a Wiener Filter (WF) analysis to obtain the minimum-variance mean fields of velocity and mass density. Constrained Realizations (CR) are then used to sample the statistical scatter about the WF mean field. The WF/CR method is applied as a demonstration to the Mark III data with 1200 km/s, 900 km/s, and 500 km/s resolutions. The main reconstructed structures are consistent with those extracted by the POTENT method. A comparison with the structures in the distribution of IRAS 1.2Jy galaxies yields a general agreement. The reconstructed velocity field is decomposed ...

1999-01-01

231

Micromachining using a focused ion beam miller  

International Nuclear Information System (INIS)

Full text: The focused ion beam (FIB) miller is becoming well established as a machine for the structural analysis of materials and for the rapid preparation of transmission electron microscope specimens. It has also been used for some time in the semiconducting materials industry for the analysis, repair and redesign of device materials. However, one emerging technique is the use of the FIB for micromachining. The FIB software can also be used to manufacture and machine components. This process can occur through converting software, typically in the form of bitmaps or TIF files, to proprietary 'stream' files. These files allow, often complex, patterns to be generated and milled into the specimen and thus the generation of micro-electromechanical systems. Frequently, this involves largely two-dimensional patterns and structures, however, more complex patterns and file types can be generated which allow, ...

2002-02-01

232

A non-linear approach to the structure-mobility relationship in protein main chains  

Energy Technology Data Exchange (ETDEWEB)

A correlation investigation was carried out on the series of atomic coordinates (MPV) and temperature factor (T {sub f}), respectively for human hemoglobin and HIV-1 protease protein main chains. The MPV series revealed resemblances to the corresponding T {sub f} series. Each minor or major peak in a series had a corresponding peak in the related series. This brings a qualitative evidence for the connection of the two parameters. The series were further subjected to spectral and detrended fluctuation analysis which all revealed long-range correlation properties. This combined analysis revealed that the data were controlled both by the correlation of stationary fluctuation and trends or non-stationary contribution to correlation. The correlation of all MPV series was found to be much less sensitive to ligand binding than the corresponding T {sub f} series. Thus the long-range correlation properties of the protein main chain ...

2007-05-15

233

A non-linear approach to the structure-mobility relationship in protein main chains  

International Nuclear Information System (INIS)

A correlation investigation was carried out on the series of atomic coordinates (MPV) and temperature factor (T _f), respectively for human hemoglobin and HIV-1 protease protein main chains. The MPV series revealed resemblances to the corresponding T _f series. Each minor or major peak in a series had a corresponding peak in the related series. This brings a qualitative evidence for the connection of the two parameters. The series were further subjected to spectral and detrended fluctuation analysis which all revealed long-range correlation properties. This combined analysis revealed that the data were controlled both by the correlation of stationary fluctuation and trends or non-stationary contribution to correlation. The correlation of all MPV series was found to be much less sensitive to ligand binding than the corresponding T _f series. Thus the long-range correlation properties of the protein main chain structure and ...

2007-05-01

234

Stability study of a gyrotron-traveling-wave amplifier based on a lossy dielectric-loaded mode-selective circuit  

Science.gov (United States)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The ...

2009-07-15

235

Stability study of a gyrotron-traveling-wave amplifier based on a lossy dielectric-loaded mode-selective circuit  

International Nuclear Information System (INIS)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE01 mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The ...

2009-07-01

236

Seismic tomography inversion in the case that sources and receivers are distributed out of a 2-D plane; Shingen jushinten ga nijigen heimennai ni nai baai no danseiha tomography kaiseki ni kansuru kosatsu  

Energy Technology Data Exchange (ETDEWEB)

In the case where sources and receivers are not distributed on a 2-D plane, seismic tomography inversion was studied. In tomography experiments, the existing wells are generally used. In such case, sources and receivers are frequently not distributed on a 2-D plane. The 2.5-D analysis method including 2-D structure and 3-D ray-tracing was thus developed. This method is featured by less memory necessary for ray-tracing calculation, and the same algorithm for velocity determination as 2-D analysis method. In previous methods, since analysis is generally carried out by projecting sources and receivers on a certain assumed 2-D plane, it can derive correct results in the case of constant velocity and straight ray, however, in the other case, it derives incorrect results. Application of 3-D tomography requires a large amount of memory, and falls into poor convergence because of various parameters. The 2.5-D ...

1996-10-01

237

Reliability analysis of pipe whip impacts  

Energy Technology Data Exchange (ETDEWEB)

A probability-based approach is presented as the integration of probabilistic methods and deterministic modelling based on the finite element method. An existing finite element software package was linked to an existing probabilistic package to analyse the complex mechanics that occur during the transient non-linear analysis of impact problems. This methodology is applied to a pipe whip analysis of a group-distribution-header, which results from a guillotine break, and subsequent impact with the adjacent building wall; this is a postulated accident for the Ignalina Nuclear Power Plant RBMK-1500 reactors. The uncertainties of material properties, component geometry data and loads were taken into consideration. The probabilities of failure of the impacted header and of the header support-wall were estimated given uncertainties in material properties, geometrical parameters and loading. The software ProFES was used for the probabilistic ...

2005-08-01

238

On the analysis and evaluation of enhanced creep behavior of LMFBR structure  

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 ...

2003-03-01

239

Jacobi stability of the vacuum in the static spherically symmetric brane world models  

International Nuclear Information System (INIS)

We analyze the stability of the structure equations of the vacuum in the brane world models, by using both the linear (Lyapunov) stability analysis, and the Jacobi stability analysis, the Kosambi-Cartan-Chern theory. In the brane world models the four-dimensional effective Einstein equations acquire extra terms, called dark radiation and dark pressure, respectively, which arise from the embedding of the three-brane in the bulk. Generally, the spherically symmetric vacuum solutions of the brane gravitational field equations have properties quite distinct as compared to the standard black hole solutions of general relativity. We close the structure equations by assuming a simple linear equation of state for the dark pressure. In this case the vacuum is Jacobi stable only for a small range of values of the proportionality constant relating the dark pressure and the dark radiation. The unstable trajectories ...

2008-05-15

240

Correlation between ion beam parameters and physical characteristics of nanostructures fabricated by focused ion beam  

International Nuclear Information System (INIS)

We report a study of the physical characteristics of the pillars of C, Pt and W grown by 10-30 keV Ga focused ion beam (FIB) as a function of Ga ion flux, and present a quantitative analysis of the elements using energy-dispersive analysis of X-rays (EDAX). All the FIB grown pillars exhibit a rough morphology with whisker like protrusions on the cylindrical surface and broadening of the base as compared to the nominal size. For a constant fluence, the height of the pillar initially increases and then reduces after going through a maximum as a function of ion flux in all the cases. The compositional analysis shows good metallic quality for Pt structures but reveals significant contamination of Ga in C and Ga and C in W structures at higher ion fluxes. Explanation to all these observations has been sought in the light of secondary ion and electron effects and the different processes ...

2008-04-01

241

Sound transmission loss of composite sandwich panels  

Science.gov (United States)

Light composite sandwich panels are increasingly used in automobiles, ships and aircraft, because of the advantages they offer of high strength-to-weight ratios. However, the acoustical properties of these light and stiff structures can be less desirable than those of equivalent metal panels. These undesirable properties can lead to high interior noise levels. A number of researchers have studied the acoustical properties of honeycomb and foam sandwich panels. Not much work, however, has been carried out on foam-filled honeycomb sandwich panels. In this dissertation, governing equations for the forced vibration of asymmetric sandwich panels are developed. An analytical expression for modal densities of symmetric sandwich panels is derived from a sixth-order governing equation. A boundary element analysis model for the sound transmission loss of symmetric sandwich panels is proposed. Measurements of the modal density, total loss factor, ...

2009-01-01

242

The Structure of Sucrose Phosphate Synthase from Halothermothrix orenii Reveals Its Mechanism of Action and Binding Mode  

Energy Technology Data Exchange (ETDEWEB)

Sucrose phosphate synthase (SPS) catalyzes the transfer of a glycosyl group from an activated donor sugar, such as uridine diphosphate glucose (UDP-Glc), to a saccharide acceptor D-fructose 6-phosphate (F6P), resulting in the formation of UDP and D-sucrose-6'-phosphate (S6P). This is a central regulatory process in the production of sucrose in plants, cyanobacteria, and proteobacteria. Here, we report the crystal structure of SPS from the nonphotosynthetic bacterium Halothermothrix orenii and its complexes with the substrate F6P and the product S6P. SPS has two distinct Rossmann-fold domains with a large substrate binding cleft at the interdomain interface. Structures of two complexes show that both the substrate F6P and the product S6P bind to the A-domain of SPS. Based on comparative analysis of the SPS structure with other related enzymes, the donor substrate, nucleotide diphosphate glucose, ...

2008-01-01

243

Structural studies of the O-antigenic polysaccharide from Escherichia coli O177  

British Library Electronic Table of Contents (United Kingdom)

The structure of the O-antigen polysaccharide (PS) from Escherichia coli O177 has been determined. Component analysis together with 1H and 13C NMR spectroscopy experiments was used to determine the structure. Inter-residue correlations were determined by 1H,13C-heteronuclear multiple-bond correlation and 1H,1H-NOESY experiments. PS is composed of tetrasaccharide repeating units with the following structure: 2)-a-l-Rhap-(13)-a-l-FucpNAc-(13)-a-l-FucpNAc-(13)-b-d-GlcpNAc-(1 An a-l-Rhap residue is suggested to be present at the terminal part of the polysaccharide, which on average is composed of 20 repeating units, since the 1H and 13C chemical shifts of an a-linked rhamnopyranosyl group could be assigned by a combination of 2D NMR spectra. Consequently, the biological repeating unit has a 3-...

2011-01-01

244

Structural acceptance criteria for the evaulation of existing double-shell waste storage tanks located at the Hanford site, Richland, Washington  

Energy Technology Data Exchange (ETDEWEB)

The structural acceptance criteria contained herein for the evaluation of existing underground double-shell waste storage tanks located at the Hanford Site is part of the Life Management/Aging Management Program of the Tank Waste Remediation System. The purpose of the overall life management program is to ensure that confinement of the waste is maintained over the required service life of the tanks. Characterization of the present condition of the tanks, understanding and characterization of potential degradation mechanisms, and development of tank structural acceptance criteria based on previous service and projected use are prerequisites to assessing tank integrity, to projecting the length of tank service, and to developing and applying prudent fixes or repairs. The criteria provided herein summarize the requirements for the analysis and structural qualification of the existing double-shell tanks for ...

1995-09-01

245

Seismic response of pile-supported structure considering nonlinearity of superstructure and pile, and liquefaction of surrounding ground; Shuhen jiban no ekijoka oyobi kui no hisenkeisei wo koryoshita kui shiji tatemono no jishin oto kaiseki  

Energy Technology Data Exchange (ETDEWEB)

Recent earthquake disasters have revealed the importance of countermeasures against soil Liquefaction in seismic design. In particular, the 1995 Hyogoken Nanbu earthquake caused several types of severe damages to pile foundations. This paper describes an analysis method for soil liquefaction using simple parameters such as SPT-N values and seismic response analyses for the pile-supported structure to consider soil-structure interaction effects and soil non-linearity using a modified Penzien model. It is important to find a way to determine the region of surrounding soil whose behavior is identical to that of piles. This paper adopts the thin layer element method to systematically determine the volume of the surrounding soil. The responses of pile-supported structure are similar, whether soil liquefaction and nonlinearity of pile are considered or not. However, the bending moment of pile become large as ...

2000-01-10

246

Reaction mechanisms of MnMoO{sub 4} for high capacity anode material of Li secondary battery  

Energy Technology Data Exchange (ETDEWEB)

Crystalline MnMoO{sub 4} was synthesized using a conventional solid reaction method and investigated for its physical and electrochemical properties as an anode material for Li secondary battery. The reversible amount of Li insertion/removal of MnMoO{sub 4} anode during the first cycle was about 800 mA h/g, accompanied by irreversible structural transformation into amorphous material. The amorphization during the first Li insertion was investigated by structural analysis using XRD of electrode. The charge compensation during Li insertion/removal was examined by measurement of X-ray Absorption Near Edge Structure (XANES) spectroscopy. Despite its irreversible structural transformation to amorphous during the first lithiation, subsequent cycles showed a reasonable cyclability. This paper presents the electrochemical properties of MnMoO{sub 4} and discusses the mechanism underlying the ...

2002-02-02

247

On the change of pore distribution in the course of coking and its effect on the gap tensile strength and the modulus of elasticity of coke. Zur Veraenderung der Porenverteilung im Verlauf der Verkokung und deren Auswirkung auf die Spaltzugfestigkeit und den Elastizitaetsmodul von Koksen  

Energy Technology Data Exchange (ETDEWEB)

A model describes the effect of changes to the pore structure on the mechanical properties of semi-coke during coking. The gap tensile experiment makes it possible to determine the mechanical properties of the coke and semi-coke; a theoretical analysis is valid for the deformation of samples in the gap tensile test, by which the gap tensile strength of the coke can be determined, and by which a method for the simultaneous determination of the effective modulus of elasticity was developed. The effect of the pore structure on the mechanical properties is given in semi-empirical equations. The main point here is to check whether a pore in the coke can be regarded as a Griffith crack, and whether the interaction of pores can be neglected. A model which takes the pore distribution into account was also developed and tested. A model for the change of pore structure during coking, which includes the ...

1984-01-01

248

Effect of Temperature on the Local Structure of Kaolinite Intercalated with Potassium Acetate  

International Nuclear Information System (INIS)

Kaolinite intercalated with potassium acetate is of great interest in the areas of environmental remediation and industrial application; however, its exact atomic structure and the changes which occur when heated have remained largely elusive. Here, neutron pair distribution function analysis is used to investigate the local structural characteristics of this complex material, revealing that hydrated potassium acetate exists as a single layer in the interlamellar spacing of kaolinite. Furthermore, the potassium ions within the intercalated complex are most likely associated with the resonance structure of the acetate molecules, and upon heating (and decomposition of the carbon containing molecules), these ions become strongly associated with the negative charge located on the oxygen atoms in the alumina layers of dehydroxylated kaolinite. Several possible orientations of hydrated potassium acetate ...

2011-01-25

249

Data processing for the mise-a-la-masse survey; Ryuden den`iho tansa no data shori  

Energy Technology Data Exchange (ETDEWEB)

Data processing method was studied for mise-a-la-masse survey. Mise-a-la-masse method using wells as current sources measures resultant ground surface potential difference, and detects underground local resistivity anomaly. To extract resistivity anomaly largely different from surroundings, the anomaly is extracted as difference between the estimated value of regular resistivity structure (background) and potential difference or apparent resistivity. The following three approximations were attempted to estimate the background: the theoretical equation assuming isotropic homogeneous resistivity structure, that assuming horizontal multi-layered structure and the exponential function of distance from linear electrode for apparent resistivity, and these were compared with each other by numerical model experiment. The data processing method which determines the resistivity structure of the background and the ...

1996-10-01

250

Aeroelastic Analysis of Rotor Blades Using Cfd/csd Coupling in Hover Mode  

Science.gov (United States)

A computational fluid dynamics (CFD) is coupled with a computational structural dynamics (CSD) to simulate the unsteady rotor flow with aeroelasticity effects. An unstructured upwind Navier-Stokes solver was developed for this simulation, with 2nd order time-accurate dual-time stepping method for temporal discretization and low Mach number preconditioning method. For turbulent flows, both the Spalart-Allmaras and Menter's SST model are available. Mesh deformation is achieved through a fast dynamic grid method called Delaunay graph map method for unsteady flow simulation. The rotor blades are modeled as Hodges & Dowell's nonlinear beams coupled flap-lag-torsion. The rotorcraft computational structural dynamics code employs the 15-dof beam finite element formulation for modeling. The structure code was validated by comparing the natural frequencies of a rotor model with UMARC. The flow and structure ...

2010-01-01

251

ANALYSIS OF OIL-BEARING CRETACEOUS SANDSTONE HYDROCARBON RESERVOIRS, EXCLUSIVE OF THE DAKOTA SANDSTONE, ON THE JICARILLA APACHE INDIAN RESERVATION, NEW MEXICO  

Energy Technology Data Exchange (ETDEWEB)

An additional 450 wells were added to the structural database; there are now 2550 wells in the database with corrected tops on the Juana Lopez, base of the Bridge Creek Limestone, and datum. This completes the structural data base compilation. Fifteen oil and five gas fields from the Mancos-ElVado interval were evaluated with respect to the newly defined sequence stratigraphic model for this interval. The five gas fields are located away from the structural margins of the deep part of the San Juan Basin. All the fields have characteristics of basin-centered gas and can be considered as continuous gas accumulations as recently defined by the U.S. Geological Survey. Oil production occurs in thinly interbedded sandstone and shale or in discrete sandstone bodies. Production is both from transgressive and regressive strata as redefined in this study. Oil production is both stratigraphically and structurally ...

2000-01-21

252

Nanoelectrospray high capacity ion trap multiple stage mass spectrometry for the structural analysis of human brain gangliosides  

International Nuclear Information System (INIS)

Full text: A novel protocol based on electrospray ionization (ESI) multiple stage high capacity ion trap (HCT) mass spectrometry (MS) was developed for glycosphingolipidomic surveys. The method was optimized for detailed structural elucidation of human brain gangliosides and particularly applied to human hippocampus-associated structures. The multiple stage MS experiments allowed for a complete structural characterization of GM1 ganglioside species, which was achieved by elucidation of the oligosaccharide sequence, identification of the GM1 a structural isomer from the data upon sialic acid localization along the sugar backbone and determination of the d18:1/18:0 of fatty acid/sphingoid base composition of the ceramide moiety. The methodology developed here is of general practical applicability for glycolipids and represents a step forward in the implementation of the advanced and most modern MS methods ...

2006-10-25

253

Experimental studies of the turbulence structures of impinging reacting jets using time-resolved particle image velocimetry visualisation, hot wire anemometry and acoustic signal processing  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the turbulence structures of premixed impinging jets are investigated by three different experimental techniques: time-resolved particle image velocimetry (TPIV) visualisation, hot wire anemometry (HWA) and acoustic signal processing. The focus is on the TPIV, with the other two techniques providing supplementary information. The 2-D velocities of the impinging jets were obtained by TPIV. The contour maps of velocity derivatives were computed to facilitate the visualisation of the turbulence structure of the reactant part of turbulent impinging flames. Particular attention was concentrated on the turbulence structures out of the burner nozzle and their interactions with the combustion process. It was found that the contour plots are effective in visualising time-dependent structures. It is demonstrated that the derivatives of the velocity field are able to reveal many otherwise hidden ...

2000-12-01

254

Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction  

Energy Technology Data Exchange (ETDEWEB)

Low-temperature catalytic pretreatment is a promising approach to the development of an improved liquefaction process- This work is a fundamental study on effects of pretreatments on coal structure and reactivity in liquefaction. The main objectives of this project are to study the coal structural changes induced by low-temperature catalytic and thermal pretreatments by using spectroscopic techniques; and to clarify the pretreatment-induced changes in reactivity or convertibility of coals in the subsequent liquefaction. This report describes the recent progress of our work. Substantial progress has been made in the spectroscopic characterization of structure and pretreatment-liquefaction reactions of a Montana subbituminous Coal (DECS-9), and thermochemical analysis of three mw and reacted bituminous coals. Temperature programmed liquefaction has been performed on three low-rank coals both in the ...

1992-08-01

255

Thermal stability of nanocomposite CrC/a-C:H thin films  

International Nuclear Information System (INIS)

The thermal stability of low-friction Me-C/a-C:H coatings is important for their potential applications in the tool and automotive industry. Recently we showed that CrC _x/a-C:H coatings prepared by unbalanced magnetron sputtering of a Cr target in Ar + CH_4 glow discharges exhibit a nanocomposite structure where metastable fcc CrC nanocrystals are encapsulated by an a-C:H phase. Here, we present the structural evolution of these nanocomposite CrC/a-C:H coatings during annealing. High-temperature X-ray diffraction in vacuum and differential scanning calorimetry (DSC) combined with thermo-gravimetric analysis in Ar atmosphere indicate decomposition of the formed metastable fcc CrC phase and subsequent formation of Cr_3C_2 and Cr_7C_3 and structural transformation of the a-C:H matrix phase towards higher sp"2 bonding contents at temperatures above 450 deg. C. Combined DSC and mass spectrometer ...

2007-05-07

256

Integrated experimental test program on waterhammer pressure pulses and associated structural responses within a feedwater sparger  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the methods and systems as utilized in an integrated experimental thermohydraulic/mechanics analysis test program on waterhammer pressure pulses within a revised feedwater sparger of a Loviisa generation VVER-440-type reactor. This program was carried out in two stages: (1) measurements with a strictly limited set of operating parameters at Loviisa NPP, and (2) measurements with the full set of operating parameters on a test article simulating the revised feedwater sparger. The experiments at Loviisa NPS served as an invaluable source of information on the nature of waterhammer pressure pulses and structural responses. These tests thus helped to set the objectives and formulate the concept for series of tests on a test article to study the water hammer phenomena. The heavily instrumented full size test article of a steam generator feedwater sparger was placed within a pressure vessel simulating the steam generator. The ...

1997-12-31

257

Synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15  

International Nuclear Information System (INIS)

The n=4 Aurivillius phase, Bi5Ti3CrO15, was synthesised by solid state reaction. Rietveld analysis of high resolution neutron diffraction data demonstrated this material to adopt the polar space group A21am at room temperature, transforming to the aristotype I4/mmm structure above 650 oC. This phase transition is coincident with an anomaly in DSC signal and relative permittivity, which are characteristic of a ferroelectric-paraelectric phase transition. Bi5Ti3CrO15 exhibits paramagnetic behaviour at low temperature, with short range antiferromagnetic interactions, but no evidence for long range magnetic ordering. This is considered a consequence of significant disorder of Ti and Cr over the available octahedral sites, as demonstrated by analysis of neutron diffraction data. -- Graphical abstract: We report here the synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15. ...

2011-02-01

258

Synthesis, crystal structure and nonlinear optical property of Rb3V5O14  

International Nuclear Information System (INIS)

The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. The crystal Rb3V5O14 crystallizes in the trigonal system with space P31m (No. 157), a=b=8.7134(12) A, c=5.2807(11) A and ?=90o, ?=90o, ?=120o, Z=1, ?=3.516 g/cm3. It is a layered structure that is very flat and strongly parallel to c. The V5O14 layer structure consists of corner-linked square and triangular pyramids. The layers are separated by Rb+ ions, which fit equally well on the V5O14 layer. The Kurtz powder SHG measurement, using 1064 nm radiation, showed that the second-harmonic generation efficiency of Rb3V5O14 is about two times that of KDP. -- Graphical abstract: The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric ...

2010-12-01

259

Development of an efficient parallel FEM analysis program for large structural problems over several millions of DOF  

International Nuclear Information System (INIS)

In order to predict or to evaluate the structural reliability of a variety of nuclear components under actual changing operating conditions, it is necessary to take the detailed geometrical features of components into consideration on one hand, and thermo-mechanical loading conditions with space and time variations during the lifetime, on the other hand. This consideration leads the authors to develop a super large-scale structural analysis program based on a parallel computational FEM with a variable scale of PC cluster architecture, whose prototype system is presented in a companion paper in this Symposium. Development of the PC cluster technology is one of the most important subjects in large-scale structural simulation, reducing computer costs and thus making simulation more acceptable to the engineering community. This paper presents the developmental status of the parallel FEM solver, ...

2000-09-01

260

Cloning, Expression, Crystallization and Preliminary Crystallographic Analysis of a Pentapeptide-repeat Protein (Rfr23) from the Bacterium Cyanothece 51142l  

International Nuclear Information System (INIS)

A unique feature of cyanobacteria genomes is the abundance of genes that code for hypothetical proteins containing tandem pentapeptide repeats approximately described by the consensus motif A(N/D)LXX. To date, the structures of two pentapeptide-repeat proteins (PRPs) have been determined, with the tandem pentapeptide-repeat sequences observed to adopt a novel type of right-handed quadrilateral ?-helix, or Rfr-fold, in both structures. One structure, Mycobacterium tuberculosis MfpA, is a 183-residue protein that contains 30 consecutive pentapeptide repeats and appears to offer antibiotic resistance by acting as a DNA mimic. The other structure, Cyanothece 51142 Rfr32, is a 167-residue protein that contains 21 consecutive pentapeptide repeats. The function of Rfr32, like the other 35 hypothetical PRPs identified in the genome of Cyanothece, is unknown. In an effort to understand the role of PRPs in ...

2006-01-01

261

Studies on multivariate autoregressive analysis using synthesized reactor noise-like data for optimal modelling  

International Nuclear Information System (INIS)

Studies on the multivariate autoregressive (MAR) analysis are carried out for the choice of the parameters for modelling the data obtained from various sensors optimally. Accordingly, the roles of the parameters on the analysis results are identified and the related ambiguities are reduced. Experimental investigations are carried out by means of synthesized reactor noise-like data obtained from a digital simulator providing simulated stochastic signals of an operating nuclear reactor so that the simulator constitutes a favourable tool for the present studies aimed. As the system is well defined with its known structure, precise comparison of the MAR analysis results with the true values is performed. With the help of the information gained through the studies carried out, conditions to be taken care of for optimal signal processing in MAR modelling are determined. Although the parameters involved are ...

1987-10-01

262

Phase, residual stress, and texture in triode-sputtered tantalum coatings on steel. Final report  

Energy Technology Data Exchange (ETDEWEB)

This work analyzes the unoptimized prototype triode-sputtered, 150 microns thick tantalum coatings deposited with a 2.5 microns niobium underlayer on the bore of a large-diameter A723 steel cylinder. The coating was deposited for wear and erosion protection by Pacific Northwest National Laboratory. The phase determination was based on X ray diffraction analysis, wavelength dispersive X ray fluorescence analysis, energy dispersive X ray analysis, and hardness and electrical resistivity measurements. Both X ray diffraction and radius-of- curvature methods were used to determine residual stresses. A locally developed high-resolution pole figure technique was used to perform texture analysis. The post-firing, debonded coating showed alpha-tantalum, preferred 110 orientation, high surface stresses, tantalum oxides, entrapped krypton sputtering gas, interstitial oxygen, and other impurities. The surface and ...

1998-07-01

263

Electrical biasing and voltage contrast imaging in a focused ion beam system  

Energy Technology Data Exchange (ETDEWEB)

We present two new techniques that enhance conventional focused ion beam (FIB) system capabilities for integrated circuit (IC) analysis: in situ electrical biasing and voltage contrast imaging. We have used in situ electrical biasing to enable a number of advanced failure analysis applications including (1) real time evaluation of device electrical behavior during milling and deposition, (2) verification of IC functional modifications without removal from the FIB system, and (3) ultraprecision control for cross sectioning of deep submicron structures, such as programmed amorphous silicon antifuses. We have also developed FIB system voltage contrast imaging that can be used for a variety of failure analysis applications. The use of passive voltage contrast imaging for defect localization and for navigation on planarized devices will be illustrated. In addition, we describe new, biased voltage contrast ...

1995-09-01

264

ppbar enhancement in B and J/Psi decay  

CERN Document Server

The near-threshold enhancement in the ppbar invariant mass spectrum from the B^+ -> K^+ ppbar decay reported recently by the BaBar Collaboration is studied within the J\\"ulich NNbar model. We illustrate that the invariant mass dependence of the ppbar spectrum close to the threshold can be reproduced by the final state interactions. This explanation is in line with our previous analysis of the ppbar invariant mass spectrum from the J/Psi -> gamma ppbar decay measured by the BES Collaboration. We also comment on a structure found recently in the pi^+ pi^- eta' mass spectrum of the radiative J/Psi decay by the BES Collaboration. In particular we argue that one should be rather cautions in bringing this structure in connection with the enhancement found in the ppbar invariant mass spectrum or with the existence of NNbar bound states.

2006-01-01

265

Use of structural equation modeling to examine the relationships between growth, trade and the environment in developing countries  

British Library Electronic Table of Contents (United Kingdom)

According to the environmental Kuznets curve hypothesis, environmental degradation increases in the early stages of growth, but it eventually decreases as income exceeds a threshold level. It is thus often argued that if international trade increases incomes then it can also have a positive impact on environmental quality. So far, these hypotheses have been widely empirically tested for the developed countries. However, it is still uncertain whether positive effects of international trade on growth and on the environment may also hold in developing countries. One of the major difficulties in testing these relations in developing countries is the poor quality of environment related data. In this analysis this problem is reduced by constructing a structural equation model (SEM) with three la...

2006-01-01

266

Topological Analysis of Large-scale Biomedical Terminology Structures  

British Library Electronic Table of Contents (United Kingdom)

ObjectiveTo characterize global structural features of large-scale biomedical terminologies using currently emerging statistical approaches.DesignGiven rapid growth of terminologies, this research was designed to address scalability. We selected 16 terminologies covering a variety of domains from the UMLS Metathesaurus, a collection of terminological systems. Each was modeled as a network in which nodes were atomic concepts and links were relationships asserted by the source vocabulary. For comparison against each terminology we created three random networks of equivalent size and density.MeasurementsAverage node degree, node degree distribution, clustering coefficient, average path length.ResultsEight of 16 terminologies exhibited the small-world characteristics of a short average path le...

2007-01-01

267

The mechanism of uranium biosorption by Rhizopus arrhizus  

Energy Technology Data Exchange (ETDEWEB)

Biosorption of elements is a little understood phenomenon exhibited by some types of even nonliving microbial biomass. A common fungus Rhizopus arrhizus has been reportd to take up uranium from adqueous solutions to the extent of 180 mg U/sup 6 +//g. The mechanism of uranium sequestering by this type of biomass was studied by using experimental techniques such as electron microscopy, x-ray energy dispersion analysis, IR spectroscopy, and supporting evidence was obtained for a biosorption mechanism consisting of at least three processes. Uranium coordination and adsorption in the cell-wall chitin structure occur simultaneously and rapidly whereas precipitation of uranylhdroxide within the chitin microcrystalline cell-wall structure takes place at a lower rate. Interference of Fe/sup 2/ and Zn/sup 2 +/ coions with uranium biosorption is indicated.

1982-02-01

268

The compatibility of alloy 800 in HTR atmospheres  

International Nuclear Information System (INIS)

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

269

Synthesis and electrochemical properties of lithium ion conductive glass, Li[sub 3]PO[sub 4]-Li[sub 2]S-SiS[sub 2  

Energy Technology Data Exchange (ETDEWEB)

As a continuation of our previous study, further experiments were performed on Li[sub 3]PO[sub 4]-Li[sub 2]S-SiS[sub 2] lithium ion conductive glass. In the present study, we employed a twin roller for quenching process instead of liquid nitrogen. We found that the glass forming region expands by twin roller technique and conductivity up to 1.5x10[sup -3] S/cm was achieved. Structural analysis on the glass revealed that Li[sub 3]PO[sub 4] doping changes the glass structure of Li[sub 2]S-SiS[sub 2], thereby enhancing the electrical conductivity

1994-02-01

270

Structure and electric transport properties of LnSr_2FeTiO_7 (Ln = La, Nd and Gd)  

International Nuclear Information System (INIS)

Three new phases with compositions, LaSr_2FeTiO_7, NdSr_2FeTiO_7 and GdSr_2FeTiO_7, were prepared by the traditional ceramic method. Lazy-Pulverix analysis of the X-ray diffraction data suggests that the phases crystallize in the RP-type (n = 2) structure in the space group, I4/mmm. The cell dimensions along the c-axis decrease with decrease in size of the rare earth ions. Electrical resistivity, as a function of temperature, shows that the materials are insulators and the resistivity decreases with decrease in the size of the rare earth ion, which is attributed to increase in the three-dimensional character. (author)

2011-02-01

271

Structural and optical investigation of sputter deposited hydrophobic chromium oxynitride films  

British Library Electronic Table of Contents (United Kingdom)

Nanocrystalline chromium oxynitride films were deposited by reactive RF magnetron sputtering of metallic chromium target in argon and helium atmospheres. The paper deals with consequence of increase in oxygen partial pressure on structural, hydrophobic and optical properties of chromium oxynitride films. The film stoichiometry changes from CrN and Cr2O3 to only Cr2O3 with increase in oxygen partial pressure as evident from X-Ray Diffraction analysis in both cases. The average crystallite size decreases with increase in oxygen partial pressure for both gas atmospheres. The thickness calculated from transmission data and surface profilometer are in good harmony with each other. The deposited films are hydrophobic by nature and the contact angle of the films varies as a function of surface ro...

2011-01-01

272

Stability of the viscously spreading ring  

CERN Document Server

We study analytically and numerically the stability of the pressure-less, viscously spreading accretion ring. We show that the ring is unstable to small non-axisymmetric perturbations. To perform the perturbation analysis of the ring we use a stretching transformation of the time coordinate. We find that to 1st order, one-armed spiral structures, and to 2nd order additionally two-armed spiral features may appear. Furthermore, we identify a dispersion relation determining the instability of the ring. The theoretical results are confirmed in several simulations, using two different numerical methods. These computations prove independently the existence of a secular spiral instability driven by viscosity, which evolves into persisting leading and trailing spiral waves. Our results settle the question whether the spiral structures found in earlier simulations of the spreading ring are numerical artifacts or genuine ...

2003-01-01

273

Sheathed cold-formed steel housing: A seismic design procedure  

British Library Electronic Table of Contents (United Kingdom)

Nowadays, different research teams are engaged on experimental and theoretical studies having as main aim the evaluation of seismic performance of sheathed cold-formed steel frame structures. Although a relatively large number of experimental and theoretical studies are available, the development of useful tools for the seismic design should be improved. As an attempt to overcome this lack, this paper aims to present a structural design procedure that allows, through the definition of three design nomographs, the screw spacing and all the shear walls components to be obtained on the basis of linear dynamic or nonlinear static seismic analysis. In addition, a procedure for the prediction of the whole pushover response curve of sheathed cold-formed steel shear walls, which can be advantageou...

2009-01-01

274

Probabilistic approach for model and data uncertainties and its experimental identification in structural dynamics: Case of composite sandwich panels  

Science.gov (United States)

This paper deals with the experimental identification and the validation of a non-parametric probabilistic approach allowing model uncertainties and data uncertainties to be taken into account in the numerical model developed to predict low- and medium-frequency dynamics of structures. The analysis is performed for a composite sandwich panel representing a complex dynamical system which is sufficiently simple to be completely described and which exhibits, not only data uncertainties, but above all model uncertainties. The dynamical identification is experimentally performed for eight panels. The experimental frequency response functions are used to identify the non-parametric probabilistic approach of model uncertainties. The prediction of the low- and medium-frequency dynamical responses obtained with the stochastic system is compared with the experimental measurements.

2006-06-01

275

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

Energy Technology Data Exchange (ETDEWEB)

Highly ordered arrays of Ni nanoholes and Fe{sub 20}Ni{sub 80} antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.

2008-07-15

276

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

International Nuclear Information System (INIS)

Highly ordered arrays of Ni nanoholes and Fe20Ni80 antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.

2008-07-01

277

Nuclear structure studies of [sup 187]Ir via on-line nuclear orientation  

Energy Technology Data Exchange (ETDEWEB)

A more complete level scheme is presented here for the decay of [sup 187]Pt, incorporating many new lines and levels up to 2.4 MeV. Emphasis has been placed on the extraction of multipole mixing ratios from nuclear orientation data. Analysis of that data, however, required a more complete understanding of the level structure (including, in particular, branching ratios, conversion coefficients, and level feedings), prompting the collection of new spectroscopy data. The low-lying, positive-parity levels are described in terms of (odd-proton) single-particle Nilsson states coupled to a triaxial core. Multipole mixing ratios are compared to those calculated in the Particle-Plus-Triaxial-Rotor Model. (orig.).

1992-11-01

278

Nuclear structure studies of "1"8"7Ir via on-line nuclear orientation  

International Nuclear Information System (INIS)

A more complete level scheme is presented here for the decay of "1"8"7Pt, incorporating many new lines and levels up to 2.4 MeV. Emphasis has been placed on the extraction of multipole mixing ratios from nuclear orientation data. Analysis of that data, however, required a more complete understanding of the level structure (including, in particular, branching ratios, conversion coefficients, and level feedings), prompting the collection of new spectroscopy data. The low-lying, positive-parity levels are described in terms of (odd-proton) single-particle Nilsson states coupled to a triaxial core. Multipole mixing ratios are compared to those calculated in the Particle-Plus-Triaxial-Rotor Model. (orig.).

279

Magnetic properties of ErPd_2Si_2 from magnetization Moessbauer and neutron diffraction measurements  

International Nuclear Information System (INIS)

Magnetization, neutron diffraction and "1"6"6Er Moessbauer measurements on ErPd_2Si_2 are reported. Below 4.8 K ErPd_2Si_2 orders AF with complex modulated magnetic structures, where the Er moments are aligned along the c-axis. At 1.5 K a squared structure with #mu#_E_r #approx# 7.8(1)#mu#_B is found while a saturation Er moment of 8.2(2)#mu#_B is inferred from the hyperfine field data. The temperature dependence of the Moessbauer spectra in the paramagnetic region is explained in the framework of a relaxation model implying excited crystal field levels. Its analysis is used to estimate the B"m_n CEF parameters. (orig.).

280

Irradiation of polyethylene in the presence of antioxidants  

International Nuclear Information System (INIS)

The radiation induced reactions in LDPE in the presence of phenolic type antioxidants have been studied. It was shown that various antioxidants can influence the polyethylene network formation and the radical yield in different ways. The dependence of network structure on absorbed doses was determined by gel analysis, hot-set test and extraction of antioxidants for samples irradiated with accelerated electrons. It was found that the antioxidants eluted from polyethylene in higher percentage influence polymer crosslinking to a smaller degree. The ESR studies of #gamma#-irradiated blends of polyethylene with antioxidant indicate the presence of alkyl and phenoxyl radicals. The role of antioxidant molecules on radiation induced reactions in polyethylene-antioxidant systems is considered. The correlation between the network structure and the type of additive in polyethylene is also discussed. (author).

281

Investigations of microstructure of thin TbFeCo films by high-resolution electron microscopy  

International Nuclear Information System (INIS)

High-resolution electron microscope observations confirm the presence of small crystallites in thin TbFeCo films protected by Si_3N_4 overcoats. Selected area electron diffraction patterns in top-view projection indicate that the crystals have a face-centered-cubic structure. Microscope analysis reveals grain growth following annealing of these protected thin films at 200 degree C in vacuum, and Kerr measurements yield large reductions in coercivity relative to the room-temperature value. The typical grain size visible in top-view observations increases from about 3 nm in the as-deposited samples to about 30 nm after annealing at 200 degree C for 36 h while the static coercivity, H_c, drops by about 40%. The fcc structure of the crystals is retained after annealing.

282

Importance of level structure in nuclear reaction cross-section calculations. Revision 1  

Science.gov (United States)

It is shown that level-density expressions cannot adequately represent or substitute for level structure information when making calculations of the Hauser-Feshbach type for cross sections or isomer-ratios for nuclei in the first few MeV above their ground state. It is stated that such discrete level information should include both experimentally confirmed and theoretically predicted levels. The utility of discrete level information to optimize level density calculations, to compute isomer ratios, in deriving dipole strength functions, and in the analysis of primary gamma ray spectra is emphasized, especially for nuclei far from the line of stability. 29 refs., 12 figs., 6 tabs. (DWL)

1985-11-07

283

Effects of confinement on the permanent electric-dipole moment of Xe atoms in liquid Xe  

CERN Document Server

Searches for permanent electric-dipole moments (EDM) of atoms provide important constraints on competing extensions to the standard model of elementary particles. Recently proposed experiment with liquid $^{129}$Xe [M.V. Romalis and M.P. Ledbetter, Phys. Rev. Lett. \\textbf{87}, 067601 (2001)] may significantly improve present limits on the EDMs. To interpret experimental data in terms of CP-violating sources, one must relate measured atomic EDM to various model interactions via electronic-structure calculations. Here we study density dependence of atomic EDMs. The analysis is carried out in the framework of the cell model of the liquid coupled with relativistic atomic-structure calculations. We find that compared to an isolated atom, the EDM of an atom of liquid Xe is suppressed by about 40%.

2004-01-01

284

E-commerce usage and business performance in the Malaysian tourism sector: empirical analysis  

British Library Electronic Table of Contents (United Kingdom)

Purpose - Based upon the E-VALUE model developed, this paper aims to investigate the impact of e-commerce usage on business performance in the tourism sector. Design/methodology/approach - A cross-sectional survey is carried out on 165 Malaysian firms involved in the tourism sector (hotels, resorts, and hospitals engaged in health tourism) through the use of a structured questionnaire. Findings - The structural equation modeling results indicate that technology competency, firm size, firm scope, web-technology investment, pressure intensity, and back-end usage have significant influence on e-commerce usage. Among these variables, back-end integration is found to function as a mediator. E-commerce experience (in years) is found to moderate the relationship between e-commerce usage and busin...

2009-01-01

285

Conceptual design of main coolant pump for integral reactor SMART  

Energy Technology Data Exchange (ETDEWEB)

The conceptual design for MCP to be installed in the integral reactor SMART was carried out. Canned motor pump was adopted in the conceptual design of MCP. Three-dimensional modeling was performed to visualize the conceptual design of the MCP and to check interferences between the parts. The theoretical design procedure for the impeller was developed. The procedures for the flow field and structural analysis of impeller was also developed to assess the design validity and to verify its structural integrity. A computer program to analyze the dynamic characteristics of the rotor shaft of MCP was developed. The rotational speed sensor was designed and its performance test was conducted to verify the possibility of operation. A prototypes of the canned motor was manufactured and tested to confirm the validity of the design concept. The MCP design concept was also investigated for fabricability by establishing the manufacturing ...

1999-12-01

286

Comment on "Limits on the Time Variation of the Electromagnetic Fine-Structure Constant in the Low Energy Limit from Absorption Lines in the Spectra of Distant Quasars"  

CERN Document Server

In their Letter [Phys. Rev. Lett. 92, 121302 (2004)] (also [Astron. Astrophys. 417, 853 (2004)]), Srianand et al. analysed optical spectra of heavy-element species in 23 absorption systems along background quasar sight-lines, reporting limits on relative variations in the fine-structure constant: da/a=(-0.06+/-0.06) x 10^{-5}. Here we demonstrate basic flaws in their analysis, using the same data and absorption profile fits, which led to spurious values of da/a and significantly underestimated uncertainties. We conclude that these data and fits offer no stringent test of previous evidence for a varying alpha.

2007-01-01

287

Chemical composition and electronic structure of passive films formed on Alloy 600 in acidic solution  

Energy Technology Data Exchange (ETDEWEB)

The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.

2008-03-15

288

Chemical composition and electronic structure of passive films formed on Alloy 600 in acidic solution  

International Nuclear Information System (INIS)

The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.

2008-03-01

289

Auger electron spectroscopy studies of GaAs and Si metal-semiconductor structures  

Science.gov (United States)

The use of Auger electron spectroscopy (AES) combined with in situ sputter etching for revealing the metallurgy of the metal-semiconductor interface is presented. The physical basis, measurement techniques, and data interpretation for Auger analysis of thin-film structures are briefly reviewed. Results of a detailed study of an alloyed multilayered contact (Ni/Au-Ge) on n-type epitaxial GaAs are summarized to illustrate how electrical and metallurgical contact properties can be correlated using AES. In addition, the results of a study of the growth kinetics and chemical phase identification of palladium silicide on single-crystal Si is given, as well as the initial results of a study of aluminum-palladium silicide interaction at elevated temperature. (auth)

1975-01-01

290

Auger electron spectroscopy studies of GaAs and Si metal-semiconductor structures  

International Nuclear Information System (INIS)

The use of Auger electron spectroscopy (AES) combined with in situ sputter etching for revealing the metallurgy of the metal-semiconductor interface is presented. The physical basis, measurement techniques, and data interpretation for Auger analysis of thin-film structures are briefly reviewed. Results of a detailed study of an alloyed multilayered contact (Ni/Au-Ge) on n-type epitaxial GaAs are summarized to illustrate how electrical and metallurgical contact properties can be correlated using AES. In addition, the results of a study of the growth kinetics and chemical phase identification of palladium silicide on single-crystal Si is given, as well as the initial results of a study of aluminum-palladium silicide interaction at elevated temperature.

291

Assembly of a water-insoluble strontium metal-organic framework with luminescent properties  

British Library Electronic Table of Contents (United Kingdom)

A new strontium metal-organic framework, [Sr2(BTEC)(H2O)4] 2H2O (1) (H4BTEC=benzene-1,2,4,5-tetracarboxylic acid), has been successfully synthesized by mixing the starting reagents. The single-crystal structure analysis showed that compound 1 displayed three-dimensional structures containing inorganic motifs with two-dimensional layers pillar-connected through organic linkers and forming water-coordinated neutral framework. Further studies revealed that compound 1 was insoluble in water and that it emitted strong luminescence at approximately 437nm after dehydration.

2011-01-01

292

Application of polycrystalline diffusion barriers  

International Nuclear Information System (INIS)

Degradation of contacts of the electronic equipment at the raised temperatures is connected with active diffusion redistribution of components contact - metalized systems (CMS) and phase production on interphase borders. One of systems diffusion barriers (DB) are polycrystalline silicide a film, in particular silicides of the titan. Reception disilicide the titan (TiSi_2) which on the parameters is demanded for conditions of microelectronics from known silicides of system Ti-Si, is possible as a result of direct reaction of a film of the titan and a substrate of silicon, and at sedimentation of layer Ti-Si demanded stoichiometric structure. Simultaneously there is specific problem polycrystalline diffusion a barrier (PDB): the polycrystalline provides structural balance and metastability film disilicide, but leaves in it borders of grains - easy local ways of diffusion. In clause the analysis diffusion permeability ...

293

Acoustic resonances in two-dimensional radial sonic crystal shells  

Energy Technology Data Exchange (ETDEWEB)

Radial sonic crystals (RSC) are fluidlike structures infinitely periodic along the radial direction that verify the Bloch theorem and are possible only if certain specially designed acoustic metamaterials with mass density anisotropy can be engineered (see Torrent and Sanchez-Dehesa 2009 Phys. Rev. Lett. 103 064301). A comprehensive analysis of two-dimensional (2D) RSC shells is reported here. A given shell is in fact a circular slab with a central cavity. These finite crystal structures contain Fabry-Perot-like resonances and modes strongly localized at the central cavity. Semi-analytical expressions are developed to obtain the quality factors of the different resonances, their symmetry features and their excitation properties. The results reported here are completely general and can be extended to equivalent 3D spherical shells and to their photonic counterparts.

2010-07-15

294

Strong laser fields as a probe for fundamental physics  

CERN Document Server

Upcoming high-intensity laser systems will be able to probe the quantum-induced nonlinear regime of electrodynamics. So far unobserved QED phenomena such as the discovery of a nonlinear response of the quantum vacuum to macroscopic electromagnetic fields can become accessible. In addition, such laser systems provide for a flexible tool for investigating fundamental physics. Primary goals consist in verifying so far unobserved QED phenomena. Moreover, strong-field experiments can search for new light but weakly interacting degrees of freedom and are thus complementary to accelerator-driven experiments. I review recent developments in this field, focusing on photon experiments in strong electromagnetic fields. The interaction of particle-physics candidates with photons and external fields can be parameterized by low-energy effective actions and typically predict characteristic optical signatures. I perform first estimates of the accessible new-physics parameter space ...

2008-01-01

295

Phase diagram and low temperature magnetization of Gdsub(x)Ysub(1-x)Rh_4B_4  

International Nuclear Information System (INIS)

The phase diagram of Gdsub(x)Ysub(1-x)Th_4B_4 between the paramagnetic, superconducting and ferromagnetic state is reported. Low temperature dc-magnetization measurements reveal that macroscopic electro-magnetic effects are of minor importance for the suppression of Hsub(2c), which shows a smooth bell-shaped behavior for x >= 0.15 with no indication of an anomaly near Tsub(c2). At low temperature in samples with x >= 0.20 a transition from type II to type I superconductivity seems to occur. The low temperature normal state susceptibility follows a Curie-Weiss law indicating reentrant behavior for x >= 0.10. (orig.).

1981-09-01

296

On virtual phonons, photons and electrons  

CERN Document Server

A macroscopic realization of the strange virtual particles is presented. The classical Helmholtz and the quantum mechanical Schr\\"odinger equations are analogous differential equations. Their imaginary solutions are called evanescent modes in the case of elastic and electromagnetic fields. In the case of non-relativistic quantum mechanical fields they are called tunneling solutions. The imaginary solutions of this differential equation point to strange consequences: They are non local, they are not observable, and they described as virtual particles. During the last two decades QED calculations of the imaginary solutions have been experimentally confirmed for phonons, photons, and for electrons. The experimental proofs of the predictions of the non-relativistic quantum mechanics and of the Wigner phase time approach for the elastic, the electromagnetic and the Schr\\"odinger fields will be presented in this article. The results are zero tunneling time and an ...

2009-01-01

297

On the neutrino ball model  

Energy Technology Data Exchange (ETDEWEB)

It is suggested that the model of a neutrino ball described in terms of the standard model extended by adding right-handed neutrinos and the Majorana scalar field can be presented in order to explain a body of weak interacting neutrinos. Neutrino interaction with the scalar Majorana field violates the lepton number and produces the mass splitting of neutrino due to the sea-saw mechanism. In this model a neutrino ball is an object which appears as a result of a first order cosmological phase transition. It can be regarded as a ball filled with Dirac neutrinos and can be treated as a remnant of the phase transition with unbroken global lepton symmetry. In this paper we study the macroscopic parameters of such a configuration. In the result the mass-radius curve M(R) for this object is obtained. (orig.).

1995-07-01

298

Load transfer in bovine plexiform bone determined by synchrotron x-ray diffraction.  

Energy Technology Data Exchange (ETDEWEB)

High-energy synchrotron x-ray diffraction (XRD) has been used to quantify load transfer in bovine plexiform bone. By using both wide-angle and small-angle XRD, strains in the mineral as well as the collagen phase of bone were measured as a function of applied compressive stress. We suggest that a greater proportion of the load is borne by the more mineralized woven bone than the lamellar bone as the applied stress increases. With a further increase in stress, load is shed back to the lamellar regions until macroscopic failure occurs. The reported data fit well with reported mechanisms of microdamage accumulation in bovine plexiform bone.

2008-02-01

299

Inelastic proton scattering as a mean for the determination of neutron and proton matrix element ratios  

Energy Technology Data Exchange (ETDEWEB)

The determination of ratio of neutron over proton matrix elements by inelastic proton scattering, for 0{sup +}{yields}2{sup +} transitions, is investigated via the comparison between experimental data and theoretical calculations. Calculations into the context of a macroscopic and a microscopic description are performed for a wide mass range nuclei: {sup 18}O, {sup 30}Si, {sup 32,34}S, {sup 48}Ca, {sup 88}Sr, for which these ratios were determined previously with an independent technique. At that point the choice of the theoretical model may be very critical. It is thus the purpose of this investigation to point out the most suitable model. It is found that in general both theoretical models can be employed for the reliable determination of neutron over proton matrix element ratios.

1999-12-06

300

Inelastic proton scattering as a mean for the determination of neutron and proton matrix element ratios  

International Nuclear Information System (INIS)

The determination of ratio of neutron over proton matrix elements by inelastic proton scattering, for 0"+#->#2"+ transitions, is investigated via the comparison between experimental data and theoretical calculations. Calculations into the context of a macroscopic and a microscopic description are performed for a wide mass range nuclei: "1"8O, "3"0Si, "3"2","3"4S, "4"8Ca, "8"8Sr, for which these ratios were determined previously with an independent technique. At that point the choice of the theoretical model may be very critical. It is thus the purpose of this investigation to point out the most suitable model. It is found that in general both theoretical models can be employed for the reliable determination of neutron over proton matrix element ratios.

1999-12-06

301

Importance of the Adrenal Gland Blood Supply During Laparoscopic Subtotal Adrenalectomy  

British Library Electronic Table of Contents (United Kingdom)

Abstract Introduction: Laparoscopic subtotal adrenalectomy (LSA) has emerged as a treatment option in the management of certain adrenal pathologies. After LSA, a satisfactory blood supply to the adrenal remnant is vital to preserve steroid function. The aim of this study was to review the adrenal blood supply with relevance to LSA. Materials and Methods: The adrenal blood supply was examined in three ways: 1) a review of six previous cadaver studies looking at adrenal blood supply; 2) a review of our 164 consecutive laparoscopic adrenalectomies (LAs) (January 1999?January 2009); the details of the main adrenal veins and variants had been prospectively recorded; and 3) dissection of 4 cadaver specimens (macroscopic and histologic examination was performed). Results: The six cadaver studies ...

2010-01-01

302

Effects of the alfven wave spectrum in heating experiments in TCA  

International Nuclear Information System (INIS)

Reduction of the metallic impurity concentration in the TCA plasma has enabled us to correlate the observed heating with the calculated position where the rf energy is deposited. In modelling the measured antenna loading due to the presence of Alfven resonance surfaces, and hence inferring the energy deposition profile, both ion cyclotron effects and the toroidal geometry must be considered. In particular, toroidicity couples energy to resonance surfaces that would not be excited in cylindrical geometry. The increase in electron density during a rf pulse changes the positions of these surfaces so that spectrum-related effects may be observed. The appearance of a new surface at the centre of the plasma is seen as a sharp discontinuity on many of the macroscopic parameters, accompanied by evidence of changes in the current density profile. These results, and the predictions of numerical codes, have imposed new constraints on the optimisation of our antenna system.

303

Degradation Improves Tissue Formation in (Un)Loaded Chondrocyte-laden Hydrogels  

British Library Electronic Table of Contents (United Kingdom)

Background Photopolymerizable poly(ethylene glycol) (PEG) hydrogels offer a platform to deliver cells in vivo and support three-dimensional cell culture but should be designed to degrade in sync with neotissue development and endure the physiologic environment. Questions/purposes We asked whether (1) incorporation of degradation into PEG hydrogels facilitates tissue development comprised of essential cartilage macromolecules; (2) with early loading before pericellular matrix formation, the duration of load affects matrix production; and (3) dynamic loading in general influences macroscopic tissue development. Methods Primary bovine chondrocytes were encapsulated in hydrogels (n?=?3 for each condition). The independent variables were hydrogel degradation (nondegrading PEG and degrading olig...

2011-01-01

304

Benign lymphoepithelial lesion of the parotid gland in AIDS patients: CT characteristics  

International Nuclear Information System (INIS)

Contrast agent-enhanced CT scans in nine male patients with histologically proved benign lymphoepithelial lesions of the perotid gland were reviewed. All scans showed cystic-appearing masses with peripheral rim enhancement corresponding to the macroscopic appearance of the lesion. Five patients were seropositive for human immunodeficiency virus (HIV) infection or had infections seen in acquired immunodeficiency syndrome. Three patients were members of high-risk groups. Only one patient had symptoms of the SICCA syndrome. Once a rare cause of parotid gland enlargement, benign lymphoepithelial lesions have recently been seen with increasing frequency in patients with HIV infection. Although the CT appearance is not pathognomic, correlation results of aspiration cytology and with clinical history can lead to a preoperative diagnosis of a benign lymphoepithelial lesion.

305

Atomic scale simulations of arsenic ion implantation and annealing in silicon  

International Nuclear Information System (INIS)

We present results of multiple-time-scale simulations of 5, 10 and 15 keV low temperature ion implantation of arsenic on silicon (100), followed by high temperature anneals. The simulations start with a molecular dynamics (MD) calculation of the primary state of damage after 10ps. The results are then coupled to a kinetic Monte Carlo (MC) simulation of bulk defect diffusion and clustering. Dose accumulation is achieved considering that at low temperatures the damage produced in the lattice is stable. After the desired dose is accumulated, the system is annealed at 800 degrees C for several seconds. The results provide information on the evolution for the damage microstructure over macroscopic length and time scales and affords direct comparison to experimental results. We discuss the database of inputs to the MC model and how it affects the diffusion process.

2004-12-15

306

A phenomenological model for the macroscopic characteristics of irradiated silicon  

International Nuclear Information System (INIS)

The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.

307

A Subchronic Intravenous Toxicity Study of Magnesium Fructose-1,6-Diphosphate in Beagle Dogs  

British Library Electronic Table of Contents (United Kingdom)

Magnesium fructose-1,6-diphosphate is a novel agent of antimyocardial ischaemia. In the present study, the subchronic toxicity of magnesium fructose-1,6-diphosphate was investigated after 13-week repeated intravenous administration in beagle dogs. The animals received doses of 0, 75, 150 and 300 mg/kg/day (three males and three females for each dose). During the study period, clinical signs, mortality, body weights, food consumption, electrocardiogram, urinalysis, haematology, clinical biochemistry, macroscopic findings, organ weights and histopathology were examined. The administration of magnesium fructose-1,6-diphosphate resulted in increased incidence of clinical signs, including salivation and emesis. These effects were transient and were noted in almost all dogs given 300 mg/kg/day a...

2009-01-01

308

A Scheme of 3-D Breakdown-whip Analysis Methodology for High Energy Piping  

Energy Technology Data Exchange (ETDEWEB)

High energy piping systems are operated with either or both conditions of maximum operating temperature exceeding 200 .deg. F(93.3 .deg. C) or maximum operating pressure exceeding 275 psig(19.3kg/cm{sup 2}) during normal operating conditions in nuclear power plants. A high energy pipe failure is postulated in branches or piping that runs larger than one inch nominal diameter. The resultant consequences of these postulated pipe breaks must be analyzed for the effect on maintenance of plant safe shutdown capability, containment integrity. And the analyzed results must be applied to the system design so that a pipe failure can not damage essential systems to an extent of impairing design function nor affect necessary component operability. The considerable effects of pipe break are as follows; dynamic effects such as pipe whip, jet impingement and environmental impact by release of system contents. Two types of forces are occurred by the pipe whip. The one is pipe whip impact force that ...

2007-10-15

309

An analysis of selected atmospheric icing events on test cables  

Energy Technology Data Exchange (ETDEWEB)

In cold countries, the design of transmission lines and communication networks requires the knowledge of ice loads on conductors. Atmospheric icing is a stochastic phenomenon and therefore probabilistic design is used more and more for structure icing analysis. For strength and reliability assessments, a data base on atmospheric icing is needed to characterize the distributions of ice load and corresponding meteorological parameters. A test site where icing is frequent is used to obtain field data on atmospheric icing. This test site is located on the Mt. Valin, near Chicoutimi, Quebec, Canada. The experimental installation is mainly composed of various instrumented but non-energized test cables, meteorological instruments, a data acquisition system, and a video recorder. Several types of icing events can produce large ice accretions dangerous for land-based structures. They are rime due to in-cloud icing, glaze caused by ...

1996-12-01

310

Ventilation as a means of air-conditioning power saving in reinforced concrete telephone-exchange buildings analysis and directions for design  

Energy Technology Data Exchange (ETDEWEB)

The paper presents a computer-aided analysis of the combined use of ventilation and structural heat capacity and insulation as a means of saving air-conditioning power in digital telephone exchanges. It is shown that such savings can be effected by increasing air change with outdoor cool air at night, and when feasible, also in daytime, through the air change unit, in a conventional airconditioning cycle. The total thermal time constant (TTTC) method of calculation used enables the evaluation of daily or seasonal heat-flow balance for a given indoor temperature, considering the tendency of the heat capacity of the building and of envelope components to flatten the fluctuations of this temperature.

1984-12-01

311

The explosion reason analysis of urea reactor of Pingyin  

British Library Electronic Table of Contents (United Kingdom)

In allusion to the explosion of a urea reactor took place in a fertilizer plant at Pingyin, Shandong, China, a series of evidence collection and inspection jobs which includes collecting operation condition and parameters, sampling the explosion fracture, reactor body apart from explosion fracture, and leak detection medium and its hangover, etc., had been carried out firstly. Based on these jobs, farther analysis and computation work has been done to the structural and materials characteristics and the operation condition of the urea reactor, including compositions, metallographic phases, tensile properties, impact energy, strain ageing characteristics, and fracture toughness of the urea reactor steels, the compositions of leak detection medium and its hangover in the urea reactor, and ex...

2009-01-01

312

The assessment of defects in thin shells subject to secondary stress  

International Nuclear Information System (INIS)

This paper is concerned with the fracture analysis of thin cylindrical shells subject to secondary bending stresses with some degree of elastic follow-up. A P.Y.F.M. failure assessment route is utilised for an initial investigation. Results are presented graphically and indicate the differences obtained by considering the stresses as primary or secondary in nature. The Jsup(*) contour integral is computed from the results of a non-linear finite element analysis of a thermally loaded cracked cylinder. Comparison is made between Jsup(*) and the P.Y.F.M. failure criteria demonstrating the degree of conservatism in the latter. It is observed that LEFM may be appropriate for moderate load levels but that the elastic follow-up of the structure causes enhancement of Jsup(*) for higher loads, at which stage LEFM becomes non-conservative. (orig.).

1981-08-21

313

The Morphology, Ontogeny, and Small Subunit rRNA Gene Sequence Analysis of Diophrys parappendiculata n. sp. (Protozoa, Ciliophora, Euplotida), a New Marine Ciliate from Coastal Waters of Southern China  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT. The morphology, morphogenesis, and phylogeny of Diophrys parappendiculata n. sp., a large marine ciliate isolated from the coastal waters of Daya Bay, southern China, were investigated. This new species is characterized by a combination of its large size, appendiculata-pattern of ciliature, and bipartite adoral zone of membranelles. The main stages of morphogenesis during binary fission were also recorded and described. Comparisons of morphological characteristics with similar congeners support the validity of the new species. The small subunit rRNA gene sequence of D. parappendiculata is 96.3-99.94% similar to those of four other congeners; it differs in four nucleotides from that of Diophrys appendiculata (i.e. structural similarity was 99.94%). Phylogenetic analysis indicates ...

2011-01-01

314

Quantization of coupled 1D vector modes in integrated photonic waveguides  

International Nuclear Information System (INIS)

A quantum mechanical analysis of the guided light in integrated photonics waveguides is presented. The analysis is made starting from one-dimensional (1D) guided vector modes by taking into account the modal orthonormalization property on a cross section of an optical waveguide, the vector structure of the guided optical modes and the reversal-time symmetry in order to quantize the 1D vector modes and to derive the quantum momentum operator and the Heisenberg equations. The results provide a quantum-consistent formulation of the linear and nonlinear quantum light propagations as a function of forward and backward creation and annihilation operators in integrated photonics. As an illustration, an application to an integrated nonlinear directional coupler is given, that is, both the nonlinear momentum and the Heisenberg equations of the nonlinear coupler are derived.

2008-06-01

315

Naturally fractured tight gas reservoir detection optimization  

Energy Technology Data Exchange (ETDEWEB)

The three tasks were completed during this reporting period. During this quarter, work focused on a local structural analysis of the Table Rock field, greater Green River basin (GGRB) in southwestern Wyoming. The ultimate objective of the local analysis is to apply the techniques developed and demonstrated during earlier phases of the project in the Rulison Field area of the Piceance basin for sweet-spot delineation. The primary goal of this work is to focus in on the Table Rock field area in the northern Washakie basin of the Greater Green River basin in support of Union Pacific Resources and DOE planned horizontal drilling efforts. The work plan for the quarter of April 1, 1998--June 30, 1998 consisted of three tasks: (1) Acquire necessary seismic data and depth-convert, (2) Map major fault geometry and analyze displacement vectors, (3) Develop and initiate a natural fracture prediction study.

1998-11-15

316

Morphology evolution of Ir-Nb-X (X = Hf, Ta, or Ti) ternary alloys  

Energy Technology Data Exchange (ETDEWEB)

The microstructure evolution of nine samples from three Ir-base ternary systems, Ir-Nb-Hf, Ir-Nb-Ta, and Ir-Nb-Ti, was investigated by microstructure observation using scanning electron microscopy (SEM), composition map-analysis using electron probe microscopy analysis (EPMA), and phase determination using X-ray diffraction (XRD) patterns. The fcc/L1{sub 2} two-phase structure was detected in all the samples. Lattice misfits between fcc and L1{sub 2} phases were calculated. Ir-Nb-Ta and Ir-Nb-Ti alloys exhibited a microstructure quite similar to that of Ni-base superalloys, and the cuboidal L1{sub 2} precipitates in Ir-Nb-Ta and Ir-Nb-Ti alloys could maintain up to 1900 {sup o}C.

2007-01-31

317

Mode shape and natural frequency identification for seismic analysis from background vibration  

International Nuclear Information System (INIS)

Background vibration in a CANDU plant can be used to determine the dynamic characteristics of major items of equipment, such as calandria, the fuelling machines and the primary heat transport pumps. These dynamic characteristics can then be used to verify the seismic response of the equipment which, at present, is based on theoretical models only. The feasibility and basic theory of this new approach (which uses accelerations measured at several points on a structure and does not require knowledge of the source of excitation) was established in Phase I of the study. This report is based on Phase II in which the methods of analysis developed in Phase I were improved and verified experimentally. A Fast Fourier Transform (FFT) algorithm was incorporated and an interactive curve fitting technique was developed to obtain the dynamic characteristics in the form of natural frequencies, mode shapes and damping ratios. The method is now available for ...

1984-02-06

318

KALIMER preliminary conceptual design report  

Energy Technology Data Exchange (ETDEWEB)

This report, which summarizes the result of preliminary conceptual design activities during Phase 1, follows the format of safety analysis report. The purpose of publishing this report is to gather all of the design information developed so far in a systematic way so that KALIMER designers have a common source of the consistent design information necessary for their future design activities. This report will be revised and updated as design changes occur and more detailed design specification is developed during Phase 2. Chapter 1 describes the KALIMER Project. Chapter 2 includes the top level design requirements of KALIMER and general plant description. Chapter 3 summarizes the design of structures, components, equipment and systems. Specific systems and safety analysis results are described in the remaining chapters. Appendix on the HCDA evaluation is attached at the end of this report.

2000-08-01

319

Investigation of light elements in nitrided steel using elastic backscattering analysis  

International Nuclear Information System (INIS)

This work describes the ability of ion beam analysis techniques IBA to simultaneously determine the concentration and the possible depth profile of some light elements, such as carbon, oxygen and nitrogen, in matrices of high atomic number Z, such as stainless steel materials. In fact, the nitriding process of some materials has the potential to improve their tribological and mechanical properties and to offer various advantages as compared with other methods used in the modification of surfaces. Gas and Plasma nitriding were applied to certain types of steel, such as AISI-304 and H-13 which are commonly used in the industry, in order to improve their hardness and their surface corrosion resistance. The improvement was correlated with the depth profile of N and the consequent structure variations. More specifically, non-Rutherford elastic backscattering (alpha, alpha) at 5 MeV was performed on different samples, before and after nitriding, in ...

2006-08-01

320

Investigation into some tribological properties of plasma nitrided hot-worked tool steel AISI H11  

Energy Technology Data Exchange (ETDEWEB)

Interest in the tribological properties of plasma nitriding has increased substantially over the past years because plasma nitriding provides a high nitride depth and improved hard facing. The present study examines the tribological properties of AISI H11 plasma nitrided, hot-worked steel. Different nitriding temperatures and durations were considered. Characterization of the composite structures was investigated with wear tests, x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and microhardness tests. The depth profile of the nitrided zone was measured using the nuclear reaction analysis (NRA) technique. Plasma nitriding affected the microhardness, wear properties, and morphology considerably. Increase in process temperature increased the nitride zone depth.

1996-04-01

321

Housing, consumption and monetary policy: How different are the US and the euro area?  

British Library Electronic Table of Contents (United Kingdom)

This paper provides a systematic empirical analysis of the role of the housing market in the macroeconomy in the US and the euro area. First, it establishes some stylised facts concerning key variables in the housing market on the two sides of the Atlantic, such as real house prices, residential investment and mortgage debt. It then presents evidence from Structural Vector Autoregressions (SVAR) by focusing on the effects of monetary policy, credit supply and housing demand shocks on the housing market and the broader economy. The analysis shows that similarities outweigh differences as far as the housing market is concerned. The empirical evidence suggests a stronger role for housing in the transmission of monetary policy shocks in the US. The evidence is less clear-cut for housing demand...

2011-01-01

322

Generation of synthetic seasonal hydrographs for a large river basin  

British Library Electronic Table of Contents (United Kingdom)

Summary This paper describes a methodology for the generation of synthetic seasonal stage hydrographs with a number of flood waves for a large braided river basin based on statistical analysis of the historical stage records. The synthetic seasonal hydrographs in a river is required for different purposes such as assessing the hydraulic performances of various river training structures, morphological predictions, environmental impact analysis. The typical stage hydrograph of such a river has two components: flood waves and seasonal (monsoonal) response. Using historical stage records, flood waves in a seasonal stage record were identified and their characteristics were approximated using Maxwell distribution. The extracted characteristics of flood waves such as time of occurrence and succe...

2010-01-01

323

First principles investigations of formation of ordered omega phases in Zr-Al alloys  

International Nuclear Information System (INIS)

First-principles density functional theory (DFT) based calculations were performed to study the electronic and cohesive properties of all the intermediate ordered phases appearing in the transformation from bcc-based #beta# to hexagonal ordered #omega# phase in Zr_3Al alloy. Full-potential linear augmented plane wave (FPLAPW) method under the GGA was employed to establish the stability hierarchy and structure-property correlations. Further, effective pair potentials upto the fourth nearest neighbours were extracted, which, subsequently, were used for the thermodynamics analysis of the thermally-induced #beta##->##omega# transformation. The lattice collapse mechanism involving the concept of the onset of a displacement wave where the extent of collapse is viewed as an amplification of the displacement wave was employed for further analysis. (author)

2005-12-05

324

FFTF criteria for run-to-cladding-breach experiments  

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) is a liquid-metal-cooled fast reactor, which is designed to test a variety of different structural and fuel materials. A safety analysis is performed for each experiment that is irradiated in FFTF. The FFTF final safety analysis report (FSAR) assumed that all driver fuel assemblies would maintain cladding integrity during normal operations and all design transients. Maintenance of cladding integrity retains three barriers to any fission gas release to the public and also prevents any potential contact between the fuel and coolant. Experiments are, in general, expected to meet the same criterion. Selected experiments can, however, be classified as run-to-cladding-breach experiments (RTCB). The purpose of this paper is to describe alternative acceptance criteria for RTCB experiments that they feel provide protection equivalent to the maintenance of cladding integrity.

1986-06-15

325

Estimating hip fracture risk from digital x-ray image data  

International Nuclear Information System (INIS)

The authors propose a method for determining the risk of femoral neck fracture in osteoporotic patients that is not based on densitometric techniques. The method is based on a structural analysis performed by a computer on data taken from a single digital anteroposterior projection of the hip. From the image, the effective cross-sectional area and cross-sectional moment of inertia are computed from attenuation principles. Together with other geometric measurements, these data are used in an engineering analysis to compute the yield strength of the proximal femur, under stress applied through the acetabulum in a one-legged stance. An index of fracture risk based on the ratio of estimated yield strength to body weight is proposed. Ultimately it is expected that this work will allow the clinician to estimate hip fracture risk in osteoporotic patient using widely available existing technology, a goal which has eluded bone ...

326

Design and microstructural analysis of magnesium alloys for dynamical applications  

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

327

Computational Complexity of Cyclotomic Fast Fourier Transforms over Characteristic-2 Fields  

CERN Document Server

Cyclotomic fast Fourier transforms (CFFTs) are efficient implementations of discrete Fourier transforms over finite fields, which have widespread applications in cryptography and error control codes. They are of great interest because of their low multiplicative and overall complexities. However, their advantages are shown by inspection in the literature, and there is no asymptotic computational complexity analysis for CFFTs. Their high additive complexity also incurs difficulties in hardware implementations. In this paper, we derive the bounds for the multiplicative and additive complexities of CFFTs, respectively. Our results confirm that CFFTs have the smallest multiplicative complexities among all known algorithms while their additive complexities render them asymptotically suboptimal. However, CFFTs remain valuable as they have the smallest overall complexities for most practical lengths. Our additive complexity analysis also leads to a ...

2011-01-01

328

Combined migration velocity model-building and its application in tunnel seismic prediction  

Science.gov (United States)

We propose a combined migration velocity analysis and imaging method based on Kirchhoff integral migration and reverse time migration, using the residual curvature analysis and layer stripping strategy to build the velocity model. This method improves the image resolution of Kirchhoff integral migration and reduces the computations of the reverse time migration. It combines the advantages of efficiency and accuracy of the two migration methods. Its application in tunnel seismic prediction shows good results. Numerical experiments show that the imaging results of reverse time migration are better than the imaging results of Kirchhoff integral migration in many aspects of tunnel prediction. Field data show that this method has efficient computations and can establish a reasonable velocity model and a high quality imaging section. Combination with geological information can make an accurate prediction of the front of the tunnel geological ...

2010-09-01

329

Characterisation and use of biomass fly ash in cement-based materials  

British Library Electronic Table of Contents (United Kingdom)

This paper presents results about the characterisation of the biomass fly ashes sourced from a thermal power plant and from a co-generation power plant located in Portugal, and the study of new cement formulations incorporated with the biomass fly ashes. The study includes a comparative analysis of the phase formation, setting and mechanical behaviour of the new cement-fly ash formulations based on these biomass fly ashes. Techniques such as X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), thermal gravimetric and differential thermal analysis (TG/DTA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and environmental scanning electron spectroscopy (ESEM) were used to determine the structure and composition of the formulations. Fly ash F1 from the t...

2009-01-01

330

Buckling and ultimate capability of plates and stiffened panels in axial compression  

British Library Electronic Table of Contents (United Kingdom)

This paper presents extensive non-linear finite element (FE) analysis and formulation development work carried out on the ultimate compressive strength of plates and stiffened panels of ship structures. A review of contemporary designs for large ships was carried out. The existing formulae for plate ultimate compressive strength were reviewed and compared with non-linear FE analysis results. A semi-analytical formula for ultimate compressive strength assessments of stiffened panels was proposed and is described. The developed formula was verified against results using ABAQUS non-linear FE software for a series of 61 stiffened panels and a good agreement between the proposed formula and FE results were achieved. The method was verified against a large number of published FE results and was ...

2009-01-01

331

Biological and morphological characterization of human neonatal fibroblast cell culture B-HNF-1  

British Library Electronic Table of Contents (United Kingdom)

In the present study, human neonatal fibroblasts were isolated from a two-month-old human male. The purpose of the present investigation was the analysis of the morphology (light and transmission electron microscopy), karyotype and growth characteristics of the human neonatal fibroblast cell culture B-HNF-1. Moreover, STR typing and mitochondrial DNA amplification and sequencing was also performed. Analysis of chromosomes count showed that B-HNF-1 cell culture is diploid and has normal male karyotype 46, XY, which was stable during cultivation. The transmission electron microscopy demonstrated the ultra-structure of the B-HNF-1 cells; they have typical morphological features of proteosynthesis-active cells. Large number of fibroblasts bearing different shapes and surface characteristics ad...

2010-01-01

332

Spin-resolved magnetic studies of focused ion beam etched nano-sized magnetic structures  

International Nuclear Information System (INIS)

Scanning ion microscopy with polarization analysis (SIMPA) is used to study the spin-resolved surface magnetic structure of nano-sized magnetic systems. SIMPA is utilized for in situ topographic and spin-resolved magnetic domain imaging as well as for focused ion beam (FIB) etching of desired structures in magnetic or non-magnetic systems. Ultra-thin Co films are deposited on surfaces of Si(1 0 0) substrates, and ultra-thin, tri-layered, bct Fe(1 0 0)/Mn/bct Fe(1 0 0) wedged magnetic structures are deposited on fcc Pd(1 0 0) substrates. SIMPA experiments clearly show that ion-induced electrons emitted from magnetic surfaces exhibit non-zero electron spin polarization (ESP), whereas electrons emitted from non-magnetic surfaces such as Si and Pd exhibit zero ESP, which can be used to calibrate sputtering rates in situ. We report on new, spin-resolved magnetic microstructures, such as magnetic 'C' states ...

2005-04-01

333

New materials synthesis: characterization of some metal-doped antimony oxides  

Energy Technology Data Exchange (ETDEWEB)

In order to understand the chemistry of altermetal dopants in antimony oxide, the detailed structural characterization of two ..beta..-Sb/sub 2/O/sub 4/ compounds is reported, Mo-doped ..beta..-Sb/sub 2/O/sub 4/ (1.5 metal%) and V-doped ..beta..-Sb/sub 2/O/sub 4/ (5 metal%). The methods used to characterize these materials are X-ray and neutron diffraction, scanning electron microscopy, Mo K-edge extended X-ray absorption fine structure spectroscopy, and elemental analysis. The atomic position of each of these dopants in Sb/sub 2/O/sub 4/ is radically different as is the overall effect on the host structure. Molybdenum does not substitute for Sb atoms, rather the Mo atoms are found in channels of electron density formed by Sb/sup 3 +/ lone pairs. The two nearest Sb/sup 3 +/ are absent and the oxygen stoichiometry is preserved. The formula is Sb/sub 1.97/Mo/sub 0.015/O/sub 4/. Vanadium incorporates ...

1986-10-01

334

Estimation of underground structure using phase velocities of Love-and Rayleigh-waves from three-component microtremor array observation at Morioka city; Moriokashi ni okeru sanseibun are bido kansoku ni yoru reiri-ha rabu-ha no ryoiso sokudo wo mochiita chika kozo suitei  

Energy Technology Data Exchange (ETDEWEB)

In conventional microtremor prospecting methods, underground structure is estimated using the phase velocity of Rayleigh-wave only. However, it is considered that the underground structure can be estimated at a higher accuracy by using two phase velocities of Rayleigh-wave and Love-wave that directly reflects S-wave velocity structure. Therefore, three-component microtremor array observation of a circle (equilateral triangle) with the maximum radius of 40 to 250 m was carried out at the center of Morioka city. Analysis was carried out by means of extended space with autocorrelation to obtain phase velocities of Love- and Rayleigh-waves. The frequency zone of the obtained Rayleigh-wave phase velocity is 1.5 Hz to 8.6 Hz, and the phase velocity is 2670 m/s to 733 m/s. The frequency zone of the obtained Love-wave phase velocity is 3 Hz to 8.6 Hz, and the phase velocity is 2100 m/s to 412 m/s. The ...

1999-02-01

335

Comparative studies on titanium and tantalum oxides thin film structures for laser mirrors, deposited by ion assisted gun  

International Nuclear Information System (INIS)

For obtaining radiation less damagable laser mirrors, a preliminary optimization of film fabrication suitable for the analysis of laser damage mechanism has been done as the first step. Here, the optimization requires not only the stable fabrication process but also the ideal film structure i.e., the amorphous and smooth film structure simultaneously, eliminating latently unwanted secondary effects such as light scattering during laser damage test. For this purpose, we adopted the ion assisted deposition (IAD) method and modified the deposition conditions for titanium and tantalum oxide films, both of which compose typical high index layers, and where SiO_2 layers are also chosen as low index layers because of their amorphous and smooth nature, in alternative multilayer laser mirrors. Surface and cross sectional film structures and film crystallinity are compared and characterized, using a high ...

1996-10-07

336

The use of industrial energy in seven OECD (Organization for Economic Cooperation and Development) countries  

Energy Technology Data Exchange (ETDEWEB)

The objective of this study was to analyze the industrial demand for energy in seven Organization for Economic Cooperation and Development (OECD) countries with particular emphasis on fuel substitution between oil, natural gas, coal, and electricity. Changing fuel demand also results from economic growth, changes in industrial structure, and changes in the energy intensity of industrial output. A historical analysis of these factors and fuel substitution is undertaken for industry as an aggregate, and for 12 specific industries. The major results of the historical analysis are: (1) fuel use changes are a result of fuel switching, changing energy intensity, changing industrial structure, and economic growth; (2) fuel substitutability depends upon fuel use. The three fossil fuels are substitutes in the industrial heat market, but there are numerous special industrial processes where a particular fuel is ...

1987-01-01

337

Synthesis, spectral and X-ray structural studies of a NO donor Schiff base ligand and its Ni(II) complexes  

British Library Electronic Table of Contents (United Kingdom)

The Schiff base ligand, 4-isopropylbenzaldehyde[N-(3-oxo-3,4-dihydro-2-quinoxalinyl)hydrazone] (Ipbh), the 1:1 condensation product of 4-isopropylbenzaldehyde and 2-hydroxy-3-hydrazinoquinoxiline, has been synthesized and characterized by X-ray crystallography. A series of complexes of Ipbh with Nickel(II), viz., [Ni(Ipbh)2]Cl2 (1), [Ni(Ipbh)2]Br2 (2), [Ni(Ipbh)2]I2 (3), [Ni(Ipbh)2(CH3OH)2](NO3)2(CH3OH)2 (4) and [Ni(Ipbh)2ClO4]ClO4 (5) have been synthesized. All the complexes were characterized by elemental analysis, molar conductivity, CHN analysis, spectroscopic studies, magnetic susceptibility measurements and TG/DTA methods. The solid-state structure of the complex 4 was established by single crystal X-ray crystallography. In all the complexes, Ipbh acts as a bidentate NO chelating age...

2011-01-01

338

Relation between frequency of seismic wave and resolution of tomography; Danseiha tomography kaiseki ni okeru shuhasu to bunkaino no kankei  

Energy Technology Data Exchange (ETDEWEB)

With regard to the elastic wave exploration, discussions have been given on the relationship between frequency and resolution in P-wave velocity tomography using the initial travel time. The discussions were carried out by using a new analysis method which incorporates the concept of Fresnel volume into tomography analysis. The following two arrangements were used in the calculation: a cross hole arrangement, in which seismic source and vibration receiving points were arranged so as to surround the three directions of a region extending 250 m in the horizontal direction and 500 m in the vertical direction, and observation is performed between two wells, and a permeation VSP arrangement in which the seismic source is installed on the ground surface and receiving points installed in wells. Restructuring was performed on the velocity structure by using a total of 819 observation travel times. This method has derived results of ...

1997-05-27

339

Numerical analysis of reaction-diffusion effects on species mixing rates in turbulent premixed methane-air combustion  

Energy Technology Data Exchange (ETDEWEB)

The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high Damkoehler numbers. This suggests a modeling approach to estimate ...

2010-03-15

340

Mine stability evaluation of panel 1 during waste emplacement operations at WIPP  

Energy Technology Data Exchange (ETDEWEB)

The specific objectives of the work were defined by the Environmental Evaluation Group (EEG) as follows: (1) assess the stability of panel 1 during the proposed operation of waste emplacement; (2) estimate the amount of time before room closure would be expected to transfer rock loads to the waste packages. The work consisted of (1) an analysis of geotechnical data and a review of the Department of Energy`s (DOE) plans for waste emplacement in panel 1, (2) an evaluation of ground conditions based on data analysis and observations of changes in ground conditions since the first evaluation in 1993 (USBM 1993), and (3) preparation of a report and presentation of the results to EEG staff. Excluded from this study are radiological safety issues and policies. The study is based on data provided by DOE and Westinghouse Electric Corporation (operator of the site) and conversations with DOE and Westinghouse personnel. MTI cannot independently verify the ...

1998-07-01

341

Microbeam analysis of heavy element phases in polished sections of particulate material -- An improved insight into origin and bioavailability  

Energy Technology Data Exchange (ETDEWEB)

The contamination of environmental materials (soil and dust) by heavy elements is of concern in assessing environmental pollution. Characterization of samples is performed in order to provide information that can be used to assess the potential hazard of the material, to assess remediation strategies, and to determine the source of the heavy element-bearing material. Microbeam analysis using a scanning electron microscope (SEM) or electron microprobe on polished particle mounts allows the size, internal morphology and chemical composition to be determined on a particle-by-particle basis. Computer controlled SEM allows all factors except internal structure to be acquired in an automated fashion. The authors present examples of two studies using microbeam techniques. In the first example, they illustrate how cadmium associated with sphalerite in soils can be quantified at levels down to a few parts per million (ppm) using computer controlled SEM ...

1996-12-31

342

MARS CODE MANUAL VOLUME V: Models and Correlations  

International Nuclear Information System (INIS)

Korea Advanced Energy Research Institute (KAERI) conceived and started the development of MARS code with the main objective of producing a state-of-the-art realistic thermal hydraulic systems analysis code with multi-dimensional analysis capability. MARS achieves this objective by very tightly integrating the one dimensional RELAP5/MOD3 with the multi-dimensional COBRA-TF codes. The method of integration of the two codes is based on the dynamic link library techniques, and the system pressure equation matrices of both codes are implicitly integrated and solved simultaneously. In addition, the Equation-Of-State (EOS) for the light water was unified by replacing the EOS of COBRA-TF by that of the RELAP5. This models and correlations manual provides a complete list of detailed information of the thermal-hydraulic models used in MARS, so that this report would be very useful for the code users. The overall structure of the ...

2002-09-01

343

High resolution alpha-particle spectroscopy using CR-39 plastic track detector  

Energy Technology Data Exchange (ETDEWEB)

A technique has been developed for high resolution alpha particle spectroscopy from track length determination in CR-39 plastic. On individual tracks an energy resolution deltaE close to the range straggling limit is obtainable. For 6 MeV alpha-particle deltaE is proportional 35 keV on individual particles and for groups of particles deltaE proportional 20 keV can be achieved using certain data selection criteria. At 100 keV on individual particles deltaE is proportional 20 keV. The analysis requires 1) a knowledge of the track-etch rate (Vsub(T))-range relationship and 2) a theoretical understanding of alpha-particle track structure in CR-39 as a function of particle energy, dip angle and degree of etching. The structure of alpha-particle etched tracks in CR-39 is described and two methods of analysis discussed. Examples are given of the resolution attainable on tracks of alpha-particles as natural ...

1984-06-15

344

CFD Analysis of a Dry Storage System for MACSTOR/KN-400  

International Nuclear Information System (INIS)

There are four nuclear power plants in operation at Wolsong and, annually, more than 5,000 assemblies of spent nuclear fuels are released from each plant. Thus the concrete silo type dry storage system was constructed from '90. However, after 2006, another dry storage facility is required to accept the all amount of spent nuclear fuels from the plants. Instead of the concrete silo type, MACSTOR/KN-400 was developed to store the CANDU spent nuclear fuel more densely. In this study, computational fluid dynamics (CFD) analysis of the MACSTOR/KN-400 model was performed to confirm the thermal integrity of the facility, especially for the concrete structure, using the commercial CFD code, FLUENT. The MACSTOR/KN-400 which has Thermal Insulation Panel (TIP) and IAEA Re-verification Pipe (RVP) was modeled and analyzed in the view point of the thermal integrity of the concrete structure.

2007-10-01

345

Analysis of the quantitative structure activity relationship of technetium-99m-labeled diaminedithiol (DADT) and propyleneamineoxime (PAO) brain blood flow analogues  

Energy Technology Data Exchange (ETDEWEB)

In the search for new brain imaging agents for use with single photon emission computed tomography (SPECT), quantitative structure activity relationship (QSAR) analysis of the correlations between initial brain uptake and physicochemical parameters like lipophilicity, log P, molecular weight, log MW and log U/D (undissociated/dissociated), of the {sup 99m}Tc-DADT (diaminedithiol) complexes and {sup 99m}Tc-PAO (propyleneaminoxime) complexes have been analyzed. High correlations are found for both the {sup 99m}Tc-DADT complexes (r = 0.94) and for the {sup 99m}Tc-PAO complexes (r = 0.83) which are significant at 99.9 and 99.5 percentile level, respectively. These results will help the further design of better ligands for {sup 99m}Tc in brain imaging. (author).

1991-01-01

346

A study of corrosion resistance behavior for W + C dual implanted H13 steel  

International Nuclear Information System (INIS)

The surface layer optimized in resistance of corrosion and wear has been obtained by W + C dual implantation on H13 steel. The electrochemical polarization measurements show that the peak current density I_D is increased and then saturated with increasing of voltage scanning loops. The I_D is 100 times smaller than that of H13 steel, and 2-3 times smaller than that of tungsten. Then influence of dual implantation order on corrosion resistance is also studied. The I_D for W_5C_8 implanted first with W is half of that for C_5W_5 implanted first with C. The corrosion resistance structure of the samples after corrosion is observed by SEM. The X-ray analysis indicates that the structure consists of disperse phases of WC, W_2C, FeW, Fe_2W, FeW_2C and iron carbides. It is shown from Auger analysis that the optimum complex layer for corrosion resistance consists of thin carbon film on surface, disperse phases ...

347

Numerical analysis and visualization experiment on behavior of borated water during MSLB with RCP running mode in an advanced reactor  

Energy Technology Data Exchange (ETDEWEB)

The core bypass phenomenon of borated water injected through direct vessel injection (DVI) nozzles in APR1400 (Advanced Power Reactor 1400MWe) during main steam line break (MSLB) accidents with a reactor coolant pump (RCP) running mode has been simulated using a two-channel and one-dimensional system analysis model code (MARS), and a three-dimensional computational fluid dynamics (CFD) code (FLUENT). A visualization experiment has also been performed using a scaled-down model of the APR1400. The MARS analysis has predicted a serious core bypass phenomenon of borated water, while the CFD analysis has shown results opposite to the MARS results. The CFD analysis has shown that the flow pattern in the downcomer is fully three-dimensional and that vortex flow structures are formed near the cold legs so that the borated water might pass without difficulty into the high flow region of the ...

2007-04-15

348

Integrated design environment for human performance and human reliability analysis  

Energy Technology Data Exchange (ETDEWEB)

Work over the last few years at the Idaho National Engineering and Environmental Laboratory (INEEL) has included a major focus on applying human performance and human reliability knowledge and methods as an integral element of system design and development. This work has been pursued in programs in a wide variety of technical domains, beginning with nuclear power plant operations. Since the mid-1980`s the laboratory has transferred the methods and tools developed in the nuclear domain to military weapons systems and aircraft, offshore oil and shipping operations, and commercial aviation operations and aircraft design. Through these diverse applications the laboratory has developed an integrated approach and framework for application of human performance analysis, human reliability analysis (HRA), operational data analysis, and simulation studies of human performance to the design and development of complex systems. This ...

1997-05-01

349

Vibration experiment for a three-loop PWR reactor building  

Energy Technology Data Exchange (ETDEWEB)

Forced vibration experiment has been conducted for the reactor building of Sendai Unit 1 nuclear power plant. The beam vibrational behaviors of the outer shielding building and the internal concrete structure have been observed by using a 50 tf vibration for low frequency region, and a 10 tf vibration for high frequency region, respectively. The outline of the experimental methods, the data handling system and the major results of experiment are described. The experimental results were simulated by an analytical model. The proper vibrational frequency and the vibration modes obtained by the analysis were compared with those obtained by the experiment. By these comparisons, the adequacy of the analytical method employed for the design was confirmed.

1983-12-01

350

Thulium-doped vanadate crystals: Growth, spectroscopy and laser performance  

British Library Electronic Table of Contents (United Kingdom)

This work is concentrated on growth, spectroscopy and laser performance of thulium-doped vanadate crystals. At the beginning the growth techniques are analyzed and then the matrix of vanadates crystal, its structure and physicochemical properties are explained together with the rare earth activators influence. Detailed spectroscopy of the thulium-doped vanadate crystals then follows. On the background of this theoretical analysis and state of the art of the subject the description of thulium vanadate lasers (especially Tm:YVO"4, Tm:GdVO"4, and Tm:LuVO"4) together with their generated output radiation characteristics are presented.

2011-01-01

351

The teaching of high energy physics in British universities  

Energy Technology Data Exchange (ETDEWEB)

An analysis is given of a survey of the teaching of high energy physics in British universities. The subject changes quickly, and there is a continual conflict between new and old material. Different courses may deal with this in different ways. To find out what is actually being taught to students, details were obtained from all 50 university physics departments in the United Kingdom (UK) by means of a questionnaire. This covered the course structure - whether it was optional or compulsory or contained both elements - the number of lectures given, and the topics covered in the syllabus. The replies give a comprehensive picture of the state of undergraduate teaching of high energy physics in the UK. (Author).

1992-05-01

352

The chemical link Brazil/Portugal. Abstracts of the 23. annual meeting of the Brazilian Chemical Society. v. 2; A ligacao quimica Brasil/Portugal. Resumos da 23. reuniao anual da Sociedade Brasileira de Quimica. v. 2  

Energy Technology Data Exchange (ETDEWEB)

Several works about annual meeting of the Brazilian Chemical Society are present.The search for medicinal chemistry, natural products, biological chemistry, and organic chemistry are shown. Conventional methods and some techniques are discussed and developments of new methods of determining are studied. The use of new chemical compounds, materials, structures and chemical analysis are shown.

2000-07-01

353

Study on high-resolution sequence stratigraphy framework of uranium-hosting rock series in Qianjiadian sag  

International Nuclear Information System (INIS)

The ore-hosting Yaojia Formation is composed of a set of braided stream medium-fine grained sediments. Guided by the basic theory of high-resolution sequence stratigraphy, and based on the core observation, the analysis of chemical composition of rocks, and data of natural potential logging and apparent resistivity logging, the authors have set up the high-resolution sequence stratigraphy framework of the ore-hosting Yaojia Formation, and discussed the relation of the stratigraphic structure of the middle cycle, as well as the paleotopography, the micro-facies to the formation of uranium deposit. (authors)

2005-07-01

354

Structural analysis of a binary metallic glass model. II. A study of Pdsub(1-x)Sisub(x) alloys  

Energy Technology Data Exchange (ETDEWEB)

We analyse several amorphous Pdsub(1-x)Sisub(x) alloys obtained by simulation. The metalloid atoms environments can be studied in the same way as that described in the first paper of this series. The main part of this paper is devoted to the evolution of the density as a function of the concentration. In order to interpret the values obtained by the simulation, we develop two models: the first one assumes a complete disorder: the second one, which is shown to be better, assumes a tendency to a local ordering: Si atoms are assumed to have only Pd neighbours.

1985-02-01

355

Solid state and materials research  

International Nuclear Information System (INIS)

Within about 10 years, microelectronic devices will be made with more than a billion (10"9) electronic components per chip. To implement such a sophisticated technology it will be essential to have a fundamental understanding of the solid state interaction between the different materials in thin film semiconductor structures. This is the main purpose of this research program. Characterization and analysis is carried out mainly by Rutherford backscattering spectrometry and channelling using accelerated nuclear particles from the Van de Graaff accelerator, while radioactive isotopes provide information about interaction mechanisms. 6 figs., 1 ref.

356

Simulation of non-linear and switching elements for transient analysis based on wave digital filters  

Science.gov (United States)

A previous paper introduced the use of wave digital filters as a basic building block for power system simulation, particularly suitable for real-time applications. This paper stresses the simulation of non-linear and switching elements, emphasizing the advantages of the wave filters implementation. The digital structure is maintained even when non-linear components change their characteristics or power electronic devices switch their states. As a very important by-product, the suppression of numerical oscillations related to the trapezoidal rule is achieved in a rather simple way, with no effects on simulation results.

1996-10-01

357

Secondary stresses on transmission tower structures  

Energy Technology Data Exchange (ETDEWEB)

The power industry is moving toward the use of high-voltage transmission lines on tall, flexible towers. These towers are designed for heavier loadings than were previous towers, but the secondary effects of tower displacement tend to be ignored in the present day tower analysis. This paper examines the secondary effects from the large displacement of flexible towers, reviews the secondary stresses arising from joint rigidity and member continuity, and examines the reliability of tower strength predicted by the ASCE design guidelines. More realistic tower test acceptance criteria and a more reliable tower design methodology are suggested.

1984-06-01

358

Phenomenological implication of KamLAND on lepton mass matrices  

CERN Document Server

By using a model independent Monte Carlo approach, we study the possible structure of charged and neutral lepton mass matrices, under the assumption of an U(2) horizontal symmetry (additional to the usual Standard Model ones) involving the light fermion generations. We assume the most general Majorana mass matrix for neutrinos. We update the results of our previous similar study, by inserting in the analysis the recent KamLAND data, that contributed to find a final solution to the Solar neutrino problem. The introduction of the new experimental data reduce the allowed regions in the nine dimensional space parameters, and show that our procedure gives stable solutions.

2003-01-01

359

Optimal energy conservation policy in Central and Eastern European countries  

International Nuclear Information System (INIS)

The paper presents a comprehensive analysis of the energy conservation policy conducted in the Central and Eastern European countries - its development from the start of reforms and up to the present. The problems of rational energy consumption are shown to be closely connected with the concrete conditions of the transition from the economy based on the command principles to the market economy. The author indicates the main areas of application for energy conservation activities. He also describes the models for determination of energy intensity in different branches of energy economy, and organisational structure of the measures to be taken foe energy conservation. (author)

360

On the mechanism of the nonmonotonic relaxation processes in the metallic melts  

International Nuclear Information System (INIS)

The numerical analysis of the experimental data on viscosity change by time in the period after fast heating and crystal-liquid phase transition for the copper nonequilibrium melts and the Fe_7_0Cr_1_0P_1_3C_7 glass-forming melt near their melting temperatures is accomplished through the method of correlation functions and the Rytov-Dimentberg criterion. The observed dependences have nonmonotonic oscillating character but they do not relate to auto-oscillations. The proposed theoretical model of the properties oscillations origination by relaxation in the nonequilibrium liquids explains them as manifestation of noise-induced transitions in the metastable area near the critical temperatures (melting, structural transitions)

2000-01-01

361

NRC safety research priorities for reactor vessel embrittlement, annealing, and surveillance dosimetry  

Energy Technology Data Exchange (ETDEWEB)

The recent definition of a postulated thermal shock accident followed promptly by system repressurization, termed an overcooling or pressurized thermal shock accident, has set a large analysis and research effort into motion. The essential elements are concerned with defining the accident transients, evaluating the instrumentation and controls that cause the postulated accidents, and evaluating the metallurgical and structural mechanics aspects of the reactor vessel with respect to its failure potential. This paper poses the question faced by the Nuclear Regulatory Commission (NRC) for the vessel steel embrittlement, annealing, and surveillance dosimetry facets of this postulated accident and provides information on our plans for study of this problem as well as current status.

1981-10-01

362

Locked nucleic acid (LNA): High affinity targeting of RNA for diagnostics and therapeutics  

DEFF Research Database (Denmark)

Locked nucleic acid (LNA) is a nucleic acid analogue containing one or more LNA nucleotide monomers with a bicyclic furanose unit locked in an RNA mimicking sugar conformation. This conformational restriction results in unprecedented hybridization affinity towards complementary single stranded RNA and thus, makes LNA uniquely suited for mimicking RNA structures and sequence specific targeting of RNA in vitro or in vivo. The focus of this paper is on LNAantisense, LNA-modified siRNA (siLNA), and detection and analysis of microRNAs by LNA-modified oligonucleotide probes.

2005-01-01

363

Ion beam crystallography of metal-silicon interfaces: Pd-Si(111)  

Energy Technology Data Exchange (ETDEWEB)

The application of medium energy ion scattering in combination with channelling and blocking to the study of the initial stages of palladium silicide formation is discussed. After a brief description of the experimental arrangement and method, the effects on the Rutherford backscattering spectra of depositing small quantities of palladium on clean Si(111) are reported. The uniformity and thermal stability of thin palladium silicide films grown at room temperature were measured. Finally, channelling and blocking results were used to carry out a structural analysis of thin epitaxial Pd/sub 2/Si layers.

1982-07-09

364

Ion beam crystallography of metal-silicon interfaces: Pd-Si(111)  

International Nuclear Information System (INIS)

The application of medium energy ion scattering in combination with channelling and blocking to the study of the initial stages of palladium silicide formation is discussed. After a brief description of the experimental arrangement and method, the effects on the Rutherford backscattering spectra of depositing small quantities of palladium on clean Si(111) are reported. The uniformity and thermal stability of thin palladium silicide films grown at room temperature were measured. Finally, channelling and blocking results were used to carry out a structural analysis of thin epitaxial Pd_2Si layers. (Auth.).

365

Interpretation of EXAFS data from laser shock compressed plasmas  

Energy Technology Data Exchange (ETDEWEB)

Measurements on laser shock compressed aluminium using the EXAFS (Extended X-ray Absorption Fine Structure) technique on the Al K-edge are described. Two methods of analysis of this data were used for the determination of density: the standard EXAFS technique using Fourier transforms and curve fitting, and a method based on a bandstructure calculation of the absorption spectra as a function of compression. These two techniques give results which are in fairly good agreement with each other and also with a hydrodynamic simulation of the experiment. The ion correlation parameter is estimated and shows that two-sided laser irradiation of aluminium foils produces a dense plasma which is strongly coupled. (author).

1989-01-01

366

Glow Discharge Plasma Nitriding of AISI 304 Stainless Steel  

International Nuclear Information System (INIS)

Glow discharge plasma nitriding of AISI 304 austenitic stainless steel has been carried out for different processing time under optimum discharge conditions established by spectroscopic analysis. The treated samples were analysed by X-ray diffraction (XRD) to explore the changes induced in the crystallographic structure. The XRD pattern confirmed the formation of an expanded austenite phase (#gamma#_N) owing to incorporation of nitrogen as an interstitial solid solution in the iron lattice. A Vickers microhardness tester was used to evaluate the surface hardness as a function of indentation depth (#mu#m). The results showed clear evidence of surface changes with substantial increase in surface hardness.

2007-08-01

367

Energetical analysis of sensitivity of hydrogen embrittlement of ordered alloys  

Science.gov (United States)

Intermetallic compounds are regarded as highly promising for applications as high temperature structural materials. However, recent studies have demonstrated that a number of ordered alloys exhibit environmental embrittlement when tested in various environments at ambient temperature. When exposed to hydrogen gas or electrolytically charged with hydrogen, a significant ductility loss has been reported. The reaction of water vapor with reactive elements in the crack tip results in the generation of atomic hydrogen which diffuses from the surface to the interior and causes embrittlement. In this paper, the authors try to analyze the sensitivity of hydrogen embrittlement of ordered alloys based upon energetical considerations.

1993-10-01

368

Effects of FIB milling and pre-straining on the microstructure of directionally solidified Mo pillars: a Laue diffraction analysis  

Energy Technology Data Exchange (ETDEWEB)

White beam Laue micro-diffraction was performed on directionally solidified, single-crystal Mo pillars in the as-grown state, after focused ion beam (FIB) milling and after pre-straining. The Laue diffraction peaks from the as-grown pillars are very sharp and show no broadening, similar to those from single-crystal Si wafers. Significant broadening and streaking of the peaks occurred after FIB milling and pre-straining, indicative of the damage these treatments induce in the nearly perfect crystal structure of the directionally solidified Mo pillars.

2010-05-01

369

Education with ICT in South Korea and Chile  

British Library Electronic Table of Contents (United Kingdom)

This article presents a linear-analytical case study on the development of ICT within the educational systems of Chile and South Korea. Through a comprehensive meta-data analysis and bibliographic review, we collected information on both educational systems and their ICT adoption policies. Key differences necessary to understand how both countries have developed their educational systems by integrating ICT were analyzed, including the educational system structure, the organization of state entities responsible for educational ICT, cultural characteristics, the creation of policies regarding ICT in education, and the effectiveness of such policies for the expansion of infrastructure and the ICT curriculum integration. We analyze these key differences in order to understand two cases of ICT ...

2011-01-01

370

EPR power pattern analysis for cubic sites of Fe"3"+ in MgO  

International Nuclear Information System (INIS)

A complete electron paramagnetic resonance power pattern characterization of Fe"3"+ in cubic sites in presented. A one-to-one correspondence among the peaks appearing in the powder pattern and the outer fine-structure transitions (Mnot = 1/2 ) observed in the single crystal along the , , and directions is shown. It is shown that the process of mechanically grinding the single crystal to a powder (particle size approx.1--10 #mu#) does not remove the cubic symmetry sites. No axial or lower symmetry sites which may be induced by lattice distortion of the crystallites due to strain have been observed.

1984-01-01

371

Diurnal variation of phytoplankton community in a high frequency area of HABs: Daya Bay, China  

British Library Electronic Table of Contents (United Kingdom)

Phytoplankton community was investigated in the cage culture area of Daya Bay during a diurnal cycle. Two rainfalls occurred during the course of the experiment and decreased the surface seawater salinity in the aquaculture area. A total of 38 species were identified, of which the dominant species included Pseudo-nitzschia spp. and Skeletonema costatum. Water stratification obstructed the vertical migration of dinoflagellates. Statistical analysis indicated that Synechococcus showed negative relationship with silicate and ammonia, which indicated that Synechococcus adapted to grow at oligotrophic environment. Phytoplankton community structure implied the risk of Pseudo-nitzschia spp. blooms in the aquaculture area of Daya Bay.

2011-01-01

372

Corrosion and reliability of PWR power plants  

International Nuclear Information System (INIS)

Corrosion is increasingly becoming an important factor reducing the reliability of many nuclear power plant components. The significance is evaluated of corrosion phenomena with respect to the reliability of primary circuit components of LWR's, viz., the reactor pressure vessel, primary piping, steam generator, and fuel elements. The mechanism of corrosion phenomena is explained and methods of minimizing their effects are presented. An analysis is made of the needs to solve the corrosion problems of nuclear power plants from the point of view of Czechoslovak producers and research and development activities. International cooperation is reviewed and main problems are formulated on which the solution of corrosion problems of structural materials used in WWER type nuclear power plants should be focussed. (author).

373

Ancient cosmological tachyons in the present-day world  

Energy Technology Data Exchange (ETDEWEB)

The geodesic equation for space-like objects moving along a circular trajectory in the expanding universe is considered. Our analysis leads to the conclusion that ancient cosmological tachyons may exist in the present-day world and may play an important role in (i) the internal structure of hadrons conceived as nonlocal objects called strings, (ii) the T-symmetry violation observed in the weak K-decays, (iii) the multidimensional unified field theories of Kaluza-Klein type, and in (iv) the classical models of charged particles which combine ordinary electromagnetism with a self-interacting version of Newtonian gravity. 18 refs.

1993-06-01

374

Ancient cosmological tachyons in the present-day world  

International Nuclear Information System (INIS)

The geodesic equation for space-like objects moving along a circular trajectory in the expanding universe is considered. Our analysis leads to the conclusion that ancient cosmological tachyons may exist in the present-day world and may play an important role in (i) the internal structure of hadrons conceived as nonlocal objects called strings, (ii) the T-symmetry violation observed in the weak K-decays, (iii) the multidimensional unified field theories of Kaluza-Klein type, and in (iv) the classical models of charged particles which combine ordinary electromagnetism with a self-interacting version of Newtonian gravity. 18 refs.

375

An object oriented software bus  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a new approach to development of software for highly integrated software-hardware systems such as used for data acquisition and control. This approach, called the Object Oriented Software Bus (OSB), is a way to develop software according to a common specification similar to the way interface hardware has been developed since the advent of bus structures for minicomputers and microcomputers. Key concept of the OSB is extension of the common use of objects to support user interface and data analysis functions to the development of software objects that directly correspond to real- world hardware interfaces and modules.

1995-12-31

376

An experimental and molecular-statistical study of the adsorption of the iodobenzene, 2-iodothiophene, and isomeric iodoadamantane molecules on the graphite basal face surface  

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption of iodobenzene, 2-iodothiophene, and 1- and 2-iodoadamantanes on the surface of graphitized thermal carbon black were determined experimentally. The influence of the special features of the molecular structure of the adsorbates on the thermodynamic characteristics of adsorption was studied. The atom-atom approximation of the semiempirical molecular-statistical theory of adsorption was used to calculate the thermodynamic characteristics of adsorption of the adsorbates using the newly determined potential function parameters of pair intermolecular interaction (?(r)) of I with C atoms of the basal graphite face. For the example of isostructural monohalogenated benzenes, thiophenes, and adamantanes, a comparative analysis of the contributions of ...

2011-01-01

377

An estimation method for basemat uplift behavior of nuclear power plant buildings  

Energy Technology Data Exchange (ETDEWEB)

It is important to accurately estimate the effects of strong earthquake motions on the basemat uplift behavior and structural responses for the seismic design of nuclear power plant buildings. In this paper, an analysis model which describes the soil part using the 3 dimensional FEM was proposed to be used when the ground contact ratio is low, and the validity of this model was confirmed. Furthermore, investigations using the model were carried out where the attaching force under the basemat was taken into account, in order to more realistically estimate the basemat uplift behavior. The effects in the case of the building being embedded were also investigated.

2007-07-15

378

An estimation method for basemat uplift behavior of nuclear power plant buildings  

International Nuclear Information System (INIS)

It is important to accurately estimate the effects of strong earthquake motions on the basemat uplift behavior and structural responses for the seismic design of nuclear power plant buildings. In this paper, an analysis model which describes the soil part using the 3 dimensional FEM was proposed to be used when the ground contact ratio is low, and the validity of this model was confirmed. Furthermore, investigations using the model were carried out where the attaching force under the basemat was taken into account, in order to more realistically estimate the basemat uplift behavior. The effects in the case of the building being embedded were also investigated.

2007-07-01

379

A study on the design method of multi tunnels in geological disposal facility  

International Nuclear Information System (INIS)

In the geological disposal facility of the high-level radioactive waste, a group of galleries is designed in parallel at the depth of more than 300 m below surface. This is an unprecedented structure in the field of conventional engineering, and it is necessary to take this characteristic into consideration in the design of the galleries. In the geological disposal facility, as well as ensuring the dynamic stability of the gallery during construction and operational periods, it is necessary to evaluate the EDZ adequately for long-term stability after the closure. In this study, analysis of the 'multi tunnels model' which represents the whole gallery group was performed and the results about the outbreak behavior of EDZ were summarized. (author)

2008-01-01

380

X-ray absorption spectroscopy, EELS, and full-potential augmented plane wave study of the electronic structure of Ti_2AlC, Ti_2AlN, Nb_2AlC, and (Ti_0_._5Nb_0_._5)_2AlC  

International Nuclear Information System (INIS)

The structural parameters of various Haegg phases (H or M_n_+_1AX_n phases) are studied experimentally by x-ray and electron spectroscopies, x-ray diffraction, and ab initio full potential as well as full mutiple scattering theoretical calculations. Experimentally it was found that the structure of all ternary compounds analyzed herein are relaxed. The values of the lattice parameters and relaxations obtained from ab initio calculations are in excellent agreement with those deduced from the analysis of the experimental data. The bonding scheme has been analyzed and the charge transfer between constituting atoms determined. It is demonstrated that the strength and electrical transport properties in these materials are principally governed by the metallic planes. For the solid solution (Ti_0_._5Nb_0_._5)_2AlC, the most salient result is that the basal planes are corrugated, which could explain the solid solution scattering ...

2005-01-01

381

Thermally stimulated currents in ZnS sandwich structure deposited by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Polycrystalline ZnS semiconducting films have been prepared in sandwich configuration by spray pyrolysis technique using ZnO-coated glass substrates and mixed aqueous solutions of ZnCl{sub 2} and thiourea. The sandwich structures have been produced successfully by means of ZnO-coated glass substrates. The produced ZnS films have been crystallized in a wurtzite structure and had a direct band gap energy of 3.62 eV. The electrical properties of the sample have been studied by an analysis based on the thermally stimulated current spectra in the temperature range of 40-300 K with various heating rates. A set of curves of I (T) for varying initial density of filled traps at a heating rate of {beta} {sub 2}=0.06 K s{sup -1} indicate that the observed peaks in the TSC curve of polycrystalline ZnS films have first-order features. In order to evaluate the trap parameters of ZnS films, we have used curve-fitting method. The values of ...

2007-05-31

382

Synthesis, crystal structure and spectroscopic studies of copper(II) complex of C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane  

British Library Electronic Table of Contents (United Kingdom)

Copper(II) complex coordinated with cyclam-type macrocyclic tetramine, C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane (2Cdmc) has been synthesized and characterized by single crystal X-ray crystallographic analysis and UV?Vis absorption spectra. Solved molecular structure of [Cu(2Cdmc)(H2O)]Cl2?2H2O (1) revealed that macrocyclic ligand 2Cdmc was in the most stable trans-III structure, but the C-methyl groups of 2Cdmc adopted energetically unfavorable axial configuration (C-axial). This complex 1 is the second example of complex of cyclam-type tetramine with only axially oriented C-methyl groups. This complex adopted five-coordinated square-pyramidal geometry with one water molecule occupying one of the two apical sites. Network of hydrogen bonds involving counter anions (Cl?...

2011-01-01

383

Study of ethanol-lysozyme interactions using neutron diffraction  

International Nuclear Information System (INIS)

Single-crystal neutron diffraction has been used to observe the interactions between deuterated ethanol (CD3CD2OH) and lysozyme in triclinic crystals of hen egg white lysozyme soaked in 25% (v/v) ethanol solutions. A total of 6047 observed reflections to a resolution of 2 A were used, and 13 possible ethanol sites were identified. The three highest occupied sites are close to locations for bromoethanol found in an earlier study by Yonath et al. [Yonath, A., Podjarny, A., Honig, B., Traub, W., Sielecki, A., Herzberg, O., and Moult, J. (1978) Biophys. Struct. Mech. 4, 27-36]. Structure refinements including a model for the flat solvent lead to a final crystallographic agreement factor of 0.097. Comparison with earlier neutron studies on triclinic lysozyme showed that neither the molecular structure nor the thermal motions were affected significantly by the ethanol. A detailed analysis of the ethanol-lysozyme contacts showed ...

384

Studies on reactivity of coal surfaces at low temperature; Teion ni okeru sekitan hyomen no hannosei no kento  

Energy Technology Data Exchange (ETDEWEB)

With an objective to learn reactivity of coal at its surface, surfaces of oxidized coal samples were investigated. Miike coal was oxidized by using {sup 18}O2 in a closed loop system. As the reaction progresses, proportion of CO2 including isotopes increased rapidly as a result of oxidation of CO sites existing in the coal and the newly generated C{sup 18}O sites. The oxidizing reaction progressed via oxygen adsorbing sites generated near the surface, and oxygen containing groups. An FT-IR analysis estimated the depth of the oxidized layer to be 10{mu}m or less from particle surface. The oxidized coal was pulverized to see its surface condition. Functional groups introduced by the oxidation enter into the vicinity of the surface in a form to desorb as CO. CO2 is trapped in inner pores. The coal surface was observed by using an atomic force microscope. No observable openings in the pore structure were discerned on the surface before the ...

1996-10-28

385

Structural transition metal chemistry  

CERN Document Server

This thesis is divided up into five chapters as outlined below. Chapter 1 gives the background to the techniques used in this thesis including X-ray structure determination and ab initio methods. An overview of some recent studies using ab initio methods to study transition metal complexes is also given. Chapter 2 investigates structural trans influence in a number of transition metal and p-block complexes. The database and ab initio studies showed that the classical trans influence model based on Pt(II) chemistry does not always hold. For some systems (eg. d sup 1 sup 0 s sup 0 for Sb sup V and Sn sup I sup V) the cis influence is of similar magnitude to the trans influence. For other systems (d sup 0), the trans influence is not as powerful as usually assumed. Chapter 3 is an investigation into the bridging chloride unit. A database study was performed on three systems (M-CI-M', M-CI...H and M-CI...Li/Na/K). Reaction pathway ...

2002-01-01

386

Structural and vibrational studies of LiNi{sub 1-y}Co{sub y}VO{sub 4} (0{<=}y{<=}1) cathodes materials for Li-ion batteries  

Energy Technology Data Exchange (ETDEWEB)

The structure and vibrational properties of high voltage cathode materials, namely LiNi{sub 1-y}CO{sub y}VO{sub 4} solid solution with (0{<=}y{<=}1), have been studied using X-ray diffraction, Raman scattering and FTIR measurements. Rietveld refinements show that LiNi{sub 1-y}Co{sub y}VO{sub 4} vanadates belong to the inverse spinel structure with Fd3m(O{sup 7}{sub h}) space group. Analysis of Raman spectra has been carried out in the molecular approximation using a local environment model including VO{sub 4} tetrahedra, (Ni, Co)O{sub 6} and LiO{sub 6} octahedra as vibrational local units. (orig.)

2000-05-15

387

STEM nanodiffraction technique for structural analysis of CoPt nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

Studying the structure of nanoparticles as a function of their size requires a correlation between the image and the diffraction pattern of single nanoparticles. Nanobeam diffraction technique is generally used but requires long and tedious TEM investigations, particularly when nanoparticles are randomly oriented on an amorphous substrate. We bring a new development to this structural study by controlling the nanoprobe of the Bright and Dark Field STEM (BF/DF STEM) modes of the TEM. The particularity of our experiment is to make the STEM nanoprobe parallel (probe size 1 nm and convergence angle <1 mrad) using a fine tuning of the focal lengths of the microscope illumination lenses. The accurate control of the beam position offered by this technique allowed us to obtain diffraction patterns of many single nanoparticles selected in the digital STEM image. By means of this technique, we demonstrate size effects on the order-disorder ...

2008-06-15

388

STEM nanodiffraction technique for structural analysis of CoPt nanoparticles  

International Nuclear Information System (INIS)

Studying the structure of nanoparticles as a function of their size requires a correlation between the image and the diffraction pattern of single nanoparticles. Nanobeam diffraction technique is generally used but requires long and tedious TEM investigations, particularly when nanoparticles are randomly oriented on an amorphous substrate. We bring a new development to this structural study by controlling the nanoprobe of the Bright and Dark Field STEM (BF/DF STEM) modes of the TEM. The particularity of our experiment is to make the STEM nanoprobe parallel (probe size 1 nm and convergence angle <1 mrad) using a fine tuning of the focal lengths of the microscope illumination lenses. The accurate control of the beam position offered by this technique allowed us to obtain diffraction patterns of many single nanoparticles selected in the digital STEM image. By means of this technique, we demonstrate size effects on the order-disorder transition ...

2008-06-01

389

Research and development project in fiscal 1989 for fundamental technologies for next generation industries. Achievement report on research and development on photoreactive materials (Research on function separating type photochromic materials); 1989 nendo hikari hanno zairyo no kenkyu kaihatsu seika hokokusho. Kino bunrigata photochromic zairyo ni kansuru kenkyu  

Energy Technology Data Exchange (ETDEWEB)

Research and development has been performed on photochromic materials expected to be used in ultra-high density recording, high resolution indication and photoswitches. With regard to molecular orientation in the ternary system mixed LB film, the result of structural analysis by XPM spectrum revealed that the acceptor constituent in the LB film is so structured that it is separated and laminated with two other constituents, and that the sensitizer constituent and the donor constituent are not recognized of being separated definitely. Regarding the electron movement reaction in the solid phase system, a photo-current measuring experiment was carried out on the laminated film which is vacuum-deposited with the ternary system comprising of the donor, sensitizer, and acceptor. It was concluded that the observed photo-current reflects the electron movement reaction in the solid phase as it is. For the photo-current in the LB ...

1990-03-01

390

Radiation damage and hardening of molybdenum in 29 MeV alpha particle straggling zone  

International Nuclear Information System (INIS)

Technique, allowing to investigate straggling zone (full braking) from high-energy charged particles in detail, is described. Experimental results on investigation of efective structure, created in polycrystalline molybdenum (99.97%) within 29 MeV alpha-particles straggling zone for fluences from 3.8x10"1"9 up to 3.7x10"2"1 #alpha#/m"2 by methods of microhardness (H_#mu#, X-ray structural analysis (#DELTA#a/a) and transparent electron microscopy (TEM), are presented. It is determined, that for doses from 3.8x10"2"0 #alpha#/m"2 and higher, at #approx#6 MeV energy, molybdenum ''softening'' is observed, H_#mu# curve within straggling zone is well described by alloyage calculated profile. #DELTA#a/a measurements within straggling zone are well described by damage profile. TEM-investigations have shown the developed defective structure even within molybdenum ''softening'' range.

391

Large-scale structure of a nation-wide production network  

CERN Document Server

Production in economy is a set of firms' activities as suppliers and customers; a firm buys goods from other firms, puts added-values and sells products to others in a giant network of production. Empirical study has been lacking despite of the fact that the structure of production network is important to understand and make models for many aspects of dynamics in economy. We study a nation-wide production network comprising a million of firms and millions of supplier-customer links by using recent statistical methods developed in physics. We show in the empirical analysis scale-free degree distribution, disassortativity, correlation of degree to firm-size, and community structure having sectoral and regional modules. Since suppliers usually provide credit to their customers, who supply to theirs in turn, each link is actually a creditor-debtor relation. We also study chains of failures or bankruptcies that take place along ...

2008-01-01

392

Increasing security of supply: the search for stable models of new nuclear build in the European Union  

International Nuclear Information System (INIS)

Full text. This research assesses models for new nuclear build in European Union (EU) member states to find the most stable form. The countries examined in this study are the United Kingdom and Romania. The results attest that due to various historical, political, competition, and electricity market structural conditions Romania and the United Kingdom have emerged with different models for new build nuclear projects. This paper begins with an assessment of the effects on the nuclear sector from energy, environmental and competition legislation in the EU. Then the political and economic climate of the aforementioned EU member states is completed. Following this an overview of the market structure of the electricity sector in those respective countries is conducted. Then the key research on the models and the phases of new nuclear build are explored. The research concludes each model has transcended from different political and economic forces, ...

2009-10-12

393

Imaging of salt structure; Gan`enso kozo no imaging  

Energy Technology Data Exchange (ETDEWEB)

Due to the improvement of algorithm and the advancement of calculation performance, the imaging by depth migration before stacking is being put into practice from the viewpoint of both calculation cost and accuracy. A lot of imaging examples have been already reported from the survey areas with complicated velocity structures, such as the North Sea and the Gulf of Mexico. Effectiveness of the method has been confirmed. For imaging techniques in Japan National Oil Corporation and Japan Petroleum Exploration Co., Ltd., high-speed depth migration before stacking and high efficiency velocity structure estimation technique have been investigated. This paper describes necessary care to be taken when using depth focusing analysis (DFA) for correcting a velocity model, as an interim stage of case study. The results of depth migration before stacking using dip moveout (DMO) velocity were further inferior to the section obtained by ...

1996-10-01

394

Effects of post-irradiation annealing in alpha-particle bombarded molybdenum  

International Nuclear Information System (INIS)

Structural variations in 39-MeV alpha-particle irradiated (Tsub(irr) = 60 deg C) polycrystalline molybdenum during post-irradiation annealing were studied by X-ray and TEM methods. Despite the high density of irradiation induced defects in the structure of the specimen X-ray measurements showed zero relative lattice parameter change after an irradiation dose of 1.1 x 10"-_2 dpa. However, during the annealing #delta#a/a was changed in the positive range, exhibiting two peaks - at 100 and 300 deg C - whereas the damage structure detected by TEM indicated no changes. Analysis of the results leads to the conclusion that in the range 100 to 250 deg C migration of isolated vacancies and their annihilation at interstitial clusters as well as possible formation of new vacancy clusters occur. The second peak on the #delta#a/a temperature dependence curve is related to the transformation (probably, thermal ...

395

Effect of plasma nitriding on the properties of (Ti, Al)N coatings deposited onto hot work steel substrates  

Energy Technology Data Exchange (ETDEWEB)

The properties of polycrystalline (Ti, Al)N coatings deposited on non-nitrided, classically plasma-nitrided and low pressure plasma-nitrided AISI H11 steel samples were investigated. The plasma deposition and low pressure plasma nitriding were performed in a Z700-LH magnetron sputter ion plating unit, while a separate unit was used for plasma nitriding of specimens at a pressure of several millibars. The (Ti, Al)N coating was deposited onto all the samples using the same equipment as for the plasma deposition and low pressure plasma nitriding. For the characterization of the composite structures, the following methods were used: scratch test, X-ray diffraction analysis, scanning electron microscopy, scanning tunnelling microscopy and microhardness testing. It was found that plasma nitriding prior to coating deposition strongly affects the growth and properties of hard coatings, such as the microhardness, adhesion, preferred orientation, ...

1993-05-15

396

Effect of Ho^3^+ substitutions on the structural and magnetic properties of BaFe12O19 hexaferrites  

British Library Electronic Table of Contents (United Kingdom)

Holmium doped barium based hexaferrites BaFe12-2xHo2xO19 with (x=0.0-1.0) were synthesized by solid state reaction method. Structural and magnetic characterization of these ferrites provide significant information about their reactive physical properties. X-ray analysis reveals that in all samples M-type structure exist with few secondary phases. Scanning electron microscope revealed the grain size of the specimen. The results show that grain size decreases with the substitution degree of Holmium. Thus rare earth element Holmium Ho^3^+ acts as a grain growth inhibitor. The magnetic hysteresis loops show the variation in the values of magnetic parameters like saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) were observed by changing Ho^3^+ content in BaFe12-2xH...

2010-01-01

397

Effect of Ho"3"+ substitutions on the structural and magnetic properties of BaFe_1_2O_1_9 hexaferrites  

International Nuclear Information System (INIS)

Holmium doped barium based hexaferrites BaFe_1_2_-_2_xHo_2_xO_1_9 with (x = 0.0-1.0) were synthesized by solid state reaction method. Structural and magnetic characterization of these ferrites provide significant information about their reactive physical properties. X-ray analysis reveals that in all samples M-type structure exist with few secondary phases. Scanning electron microscope revealed the grain size of the specimen. The results show that grain size decreases with the substitution degree of Holmium. Thus rare earth element Holmium Ho"3"+ acts as a grain growth inhibitor. The magnetic hysteresis loops show the variation in the values of magnetic parameters like saturation magnetization (M_s), remanent magnetization (M_r) and coercivity (H_c) were observed by changing Ho"3"+ content in BaFe_1_2_-_2_xHo_2_xO_1_9 ferrites. Coercivity showed a maximum value of 2230 Oe for (x = 0.4) and then decreasing trend were ...

2010-04-09

398

Cavity detection based on EM migration of TEM data; TEM ho data no denji migration ni yoru kudo kenshutsu no kokoromi  

Energy Technology Data Exchange (ETDEWEB)

With an objective to discuss applicability of resistivity imaging using electromagnetic migration to detection of underground cavity, an applicability test was carried out on calculation of a numerical model and measurement data. By using the numerical model, a calculation was performed on a hypothetical case that a cubic cavity with sides each at 40 m exists in a homogenous medium of 200 ohm-m, with the cavity top located 20 m below the ground surface. As a result, it was possible to structure in a very short calculation time an image of the cavity which cannot be identified by one-dimensional inverse analysis. In the case of this cavity, a center of the image was structured on its lower face. It was shown that a location to indicate the image must be changed according to difference in the measurement locations. In a test on data measured in an underground cavity in the city of Utsunomiya, Tochigi Prefecture, it was found ...

1997-05-27

399

Behaviour of nonlinear supports on a PWR coolant system during a postulated LOCA. Pt. 1; Effect of modelling methods  

Energy Technology Data Exchange (ETDEWEB)

A 4-loop Pressurised Water Reactor (PWR) primary coolant system has been analysed for the postulated Loss of Coolant Accident (LOCA) event in order to derive peak dynamic loads for qualifying the design of equipment supports and pipe whip restraints. Pipe whip restraints as well as pipe and equipment supports are nonlinear by nature because of the presence of gaps and the different directional stiffnesses arising from snubber, steelwork and geometric and material interaction at the concrete to steel embedment. The different structural idealisations for the supports and restraints have an influence on the dynamic response of the structure. In the first of the two part paper a range of idealisation models for the Steam Generator and Reactor Coolant Pump vertical columns ranging from elastic stiffnesses to bilinear stiffnesses with or without preload were examined. Due to both structural and loading complexity, the behaviour ...

1993-07-01

400

Micro area analysis and measurement of electronic device material (challenge to utmost limits). Characterization of interface elect`ron structure by photon-and electron-spectroscopies; Denshi debaisu yo zairyo no bisho ryoiki bunseki-keisoku (kyokugen eno chosen). Koshi-denshi bunkoho ni yoru kaimen denshi jotai hyoka  

Energy Technology Data Exchange (ETDEWEB)

A method for detecting electrons emitted as secondary particles by photon incidence to a specimen, as well as a method of using the photons emitted by electron incidence as detecting particles are explained. Pd-Si(100)2{times}1 system is adopted for a case study of using photo-electron spectroscopy where synchrotron emitted light in soft X-ray region is used as the incident light. Pd atoms are deposited little by little on clean Si surface to investigate the electron structure of the surface, and the interface electron structure after bonded formation of Pd(thin film)-Si(substrate) is estimated. Radiation soft X-ray spectroscopy is employed to observe the real state of the bonded interface of Pd(thin film)-Si(substrate) prepared by depositing Pd film in a short period of time. In the case of radiation soft X-ray spectroscopy with electron beam excitation, bonded system of thin film and substrate can be investigated by nondestructive ...

1995-07-20

401

Eddy current signal analysis techniques for assessing degradation of support plate structures in nuclear steam generators  

Energy Technology Data Exchange (ETDEWEB)

The steam generator (SG) is one of the most critical components of the heat transfer system in nuclear generation stations. Testing the structural integrity of SG tubing and SG internals is a key element of the fitness-for-service assessments to assure the safe and continuous operation of nuclear power plants. Recent eddy current (ET) inspections of two nuclear power plants revealed degradation of some of the tube support plate (TSP) structures, which was also confirmed by visual inspection. The phenomena was described as metal loss, caused by flow-accelerated corrosion of the carbon steel trefoil support plate and varying from minor to complete loss of the ligaments. This loss of TSP ligaments results in lack of support for the adjacent tubes making them more susceptible to fretting-wear damage and fatigue cracking. A signal analysis method, based on the responses at low frequency of two types of eddy current probes, has ...

2006-07-01

402

Characterization of the surface film growth during the electrochemical process: Part 2 (90 % copper-10 % nickel system)  

Energy Technology Data Exchange (ETDEWEB)

In order to understand the resistance of passive films formed during corrosion processes, an analytical technique using x-ray diffraction was developed to examine the structure of metal in closest proximity to the metal/liquid interface. The in-situ structure at the metal liquid interface was examined for 90 % copper and 10 % nickel (90-10 Cu-Ni) in KOH solution at room temperature and at four different potentistatically controlled potentials ({minus}0.5 V, {minus}0.1 V, +0.5 V and +0.10 V versus Ni/NiO). The chemical changes at the metal interface were studied over a period of 48 hours. It was found that the integrity of the 90-10 Cu-Ni foil in KOH was lost after a continued application of the potential over 48 hours. The x-ray diffraction results indicated that the structure of both the inner and the outer passive layers, at {minus}0.5V and {minus}0.1 V (versus Ni/NiO), is comprised of Ni(OH){sub 2}, Cu(OH){sub 2}, NiOOH ...

1998-06-01

403

How does sorbent particle structure influence sulfur capture under PFBC conditions?  

Energy Technology Data Exchange (ETDEWEB)

The physical structure of a limestone or dolomite to be used in in-bed sulfur capture in fluidized bed boilers has great impact on the efficiency of sulfur capture and sorbent use. Therefore in process optimization and model calculations parameters describing the pore structure of these sorbents must be included. In this study an unreacted shrinking core model with variable effective diffusivity is applied to sulfation test data from a pressurized thermogravimetric apparatus (P-TGA) for various limestone and dolomite samples. The particle size was 250--300 {micro}m for all sorbents. The tests were done under typical conditions for a pressurized fluidized bed combustor, i.e. 850 C or 950 C, 15 bar, and were reported earlier at the 12th International Conference on Fluidized Bed Combustion. At these conditions the limestone remains uncalcined, while the dolomite is half-calcined. The sorbents were characterized by chemical composition ...

1995-12-31

404

Ultra-fast charge transfer in organic electronic materials and at hybrid interfaces studied using the core-hole clock technique  

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} The use of resonant photoemission in its 'core-hole clock' expression for the study of the dynamical charge transfer across hybrid organic-inorganic interfaces and for the intermolecular charge transfer in the bulk of organic thin films is reviewed. {yields} The electronic coupling to the substrate and the efficiency of charge transport across hybrid interfaces is different for individual electronic subsystems of the molecular adsorbate. {yields} The intermolecular charge transfer in the bulk of discotic liquid crystals occurs on the order of a few femtoseconds and is faster than expected from the macroscopic charge transport characteristics of the material. -- Abstract: The focus of this brief review is the use of resonant photoemission in its 'core-hole clock' expression for the study of two important problems relevant for the field of organic electronics: the dynamical charge transfer across ...

2011-01-15

405

Tumour control probability (TCP) for non-uniform activity distribution in radionuclide therapy  

Energy Technology Data Exchange (ETDEWEB)

Non-uniform radionuclide distribution in tumours will lead to a non-uniform absorbed dose. The aim of this study was to investigate how tumour control probability (TCP) depends on the radionuclide distribution in the tumour, both macroscopically and at the subcellular level. The absorbed dose in the cell nuclei of tumours was calculated for {sup 90}Y, {sup 177}Lu, {sup 103m}Rh and {sup 211}At. The radionuclides were uniformly distributed within the subcellular compartment and they were uniformly, normally or log-normally distributed among the cells in the tumour. When all cells contain the same amount of activity, the cumulated activities required for TCP = 0.99 (A-tilde{sub TCP=0.99}) were 1.5-2 and 2-3 times higher when the activity was distributed on the cell membrane compared to in the cell nucleus for {sup 103m}Rh and {sup 211}At, respectively. TCP for {sup 90}Y was not affected by different radionuclide distributions, whereas for {sup 177}Lu, it was slightly ...

2008-08-21

406

Numerical investigation of boiling regime transition mechanism by a Lattice-Boltzmann model  

Energy Technology Data Exchange (ETDEWEB)

A numerical study has been performed to investigate the hydrodynamic aspects of the pool boiling on horizontal-, vertical- and downward-facing surfaces. The FlowLab code, which is based on a Lattice-Boltzmann (LB) model of two-phase flows, is employed. Macroscopic properties, such as surface tension ({sigma}) and contact angle ({beta}), are implemented through the fluid-fluid (G{sub {sigma}}) and fluid-solid (G{sub t}) interaction potentials. The model is found to express a linear relation between the macroscopic properties ({sigma}, {beta}) and microscopic parameters (G{sub {sigma}}, G{sub t}). The simulation results on bubble departure diameter appear to have the same parametric dependence as the empirical correlation. Hydrodynamic aspects of two-phase flow regime transition mechanism are investigated for different surface-coolant configurations. Results of the LB simulation clearly demonstrate that not only the bubble nucleation site density ...

2001-02-01

407

Linking ab initio energetics to experiment: kinetic Monte Carlo simulation of transient enhanced diffusion of B in Si  

Energy Technology Data Exchange (ETDEWEB)

We have developed a kinetic Monte Carlo (kMC) simulator that links atomic migration and binding energies determined primarily from first principles calculations to macroscopic phenomena and laboratory time scales. Input for the kMC simulation is obtained from a combination of ab initio planewave pseudopotential calculations, molecular dynamics simulations, and experimental data. The simulator is validated against an extensive series of experimental studies of the diffusion of B spikes in self-implanted Si. The implant energy, dose, and dose rate, as well as the detailed thermal history of the sample, are included. Good agreement is obtained with the experimental data for temperatures between 750 and 950 C and times from 15 to 255 s. At 1050o C we predict too little diffusion after 105 s compared to experiment: apparently, some mechanism which is not adequately represented by our model becomes important at this temperature. Below 1050o C, the kMC simulation produces ...

1998-12-16

408

Seismic stratigraphy based chronostratigraphy (SSBC) of the Serbian Banat region of the Pannonian Basin  

Science.gov (United States)

Seismic stratigraphy based chronostratigraphic (SSBC) analysis of the Serbian Banat region allows the delineation of the spatial and stratigraphic relationships of the generally regressive and shallowing upward Neogene depositional fill of a tectonically unstable central portion of the Pannonian Basin. When geometrically restored in time and space, the sediment dispersal directions, sediment source directions, types of sedimentation breaks and the tectonic events influencing basin evolution can be delineated. For such an analysis the time-transgressive lithostratigraphic units used in the neighbouring Hungarian part of the Pannonian Basin are conveniently introduced based upon their characteristic seismic facies and constrained borehole log records as mappable seismic stratigraphic sequence units, termed "seismic operational sequences". The respective Neogene stage and operational sequence equivalents (Hungarian lithostratigraphic units or ...

2010-12-01

409

Vibration test report on the instrumented capsule for fuel irradiation test  

Energy Technology Data Exchange (ETDEWEB)

The fluid-induced vibration level of instrumented capsule, which was manufactured for fuel irradiation test at the reactor core of HANARO, was investigated. For this purpose, the instrumented capsule was loaded at the OR site of the HANARO design verification test facility that could simulate identical flow condition as the HANARO core. Then, vibration signals of the instrumented capsule subjected to various flow conditions were measured by using vibration sensors. In time domain analysis, maximum amplitudes and RMS values of the measured acceleration and displacement signals were obtained. By using frequency domain analysis, frequency components of the fluid-induced vibration were analyzed. In addition, natural frequencies of the instrumented capsule were obtained by performing modal test. The frequency analysis results showed that the natural frequency components near 7.5Hz and 17.5Hz were dominant in the fluid-induced ...

2003-01-01

410

Verification of maximum impact force for interim storage cask for the Fast Flux Testing Facility  

Energy Technology Data Exchange (ETDEWEB)

The objective of this paper is to perform an impact analysis of the Interim Storage Cask (ISC) of the Fast Flux Test Facility (FFTF) for a 4-ft end drop. The ISC is a concrete cask used to store spent nuclear fuels. The analysis is to justify the impact force calculated by General Atomics (General Atomics, 1994) using the ILMOD computer code. ILMOD determines the maximum force developed by the concrete crushing which occurs when the drop energy has been absorbed. The maximum force, multiplied by the dynamic load factor (DLF), was used to determine the maximum g-level on the cask during a 4-ft end drop accident onto the heavily reinforced FFTF Reactor Service Building`s concrete surface. For the analysis, this surface was assumed to be unyielding and the cask absorbed all the drop energy. This conservative assumption simplified the modeling used to qualify the cask`s structural integrity for this ...

1996-06-01

411

Systems Analysis of Safeguards Effectiveness in a Uranium Conversion Facility  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) is interested in developing tools and methods for potential U.S. use in designing and evaluating safeguards systems. For this goal several DOE National Laboratories are defining the characteristics of typical facilities of several size scales, and the safeguards measures and instrumentation that could be applied. Lawrence Livermore National Laboratory is providing systems modeling and analysis of facility and safeguards operations, diversion path generation, and safeguards system effectiveness. The constituent elements of diversion scenarios are structured using directed graphs (digraphs) and fault trees. Safeguards indicator probabilities are based on sampling statistics and/or measurement accuracies. Scenarios are ranked based on value and quantity of material removed and the estimated probability of non-detection. Significant scenarios, especially those involving timeliness or randomly varying order of ...

2004-06-16

412

Psychological factors affecting public acceptance of nuclear energy. Comparative analysis focusing on regional characteristics and degree of knowledge  

International Nuclear Information System (INIS)

The purpose of this research is to clarify how psychological factors' impact on public acceptance of nuclear energy varies with where they live and their degree of knowledge. For this purpose, we carried out questionnaire survey about nuclear energy at three urban areas and two nuclear power plant siting areas. After collecting data, we applied factor analysis to the data, and found four factors which construct cognitive structure of nuclear energy. Using multiple regression analysis, we evaluated the impact of the four factors on two issues: the decision for or against nuclear policy and the reaction to nuclear power plant siting, and compared changes of the impact by where respondents live and their degree of knowledge. Consequently, we found that the impact of all four factors on the two issues varies with where respondents live. We also found that the impact of respondents' degree of knowledge to four factors varies ...

2003-12-01

413

Optimization of sorghum-methane production systems  

Energy Technology Data Exchange (ETDEWEB)

This dissertation concerns a study of the utilization of sorghum biomass as the fuel for a methane production system. The objective of this research is to determine an optimal sorghum-methane production system based on anaerobic batch digestion technology. The system is described as the interaction of three components: estimation of available biomass, storage of biomass, and the gas production. Levelized costs are obtained for each component. The biomass supply is assumed to decay exponentially in quality with storage time. The gas production process is a batch type of digestion with an exponential production rate. Gas production is formulated for a fixed planning horizon (one year) as a function of the number of batches and the batch residence times. The cost equation is then described as a function of these gas production equations and their levelized costs. The structure of this resulting equation is exploited to obtain the minimum unit gas cost. This ...

1984-01-01

414

GDH pipe break transient analysis of the RBMK - 1500.  

Energy Technology Data Exchange (ETDEWEB)

Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. The cases of GDH impact on an adjacent GDH and its attached piping are investigated in this paper. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material characteristics. The results of the study indicate that a ...

2002-05-15

415

Follow up of the functioning of a lithium-polymer battery using confocal Raman micro-spectroscopy; Suivi du fonctionnement d`un accumulateur lithium-polymere par microspectrometrie Raman confocale  

Energy Technology Data Exchange (ETDEWEB)

The confocal Raman micro-spectroscopy has been used for the study of a Lithium/polymer electrolyte-LiTFSI/V{sub 2}O{sub 5} type battery in which the polymer electrolyte thickness is of about 80 {mu}m. The analysis is performed on the side of the battery thanks to a specially designed cell which preserves all the characteristics of the real system. The analysis is performed on 20 points aligned between the anode and the cathode and with a depth of several tenth of {mu}m. The analysis of data obtained during charging/output cycles allows to evaluate the gradients of salt concentration inside the electrolyte, the pollutions of LiOH, Li{sub 2}CO{sub 3}, Li{sub 2}O and Li{sub 3}N -type at the lithium interface, but also the structural modifications of the cathode material. The in-situ study of concentration gradients inside the electrolyte is of prime importance for the understanding of dendrites growth. ...

1996-12-31

416

Fault analysis in the very shallow seismic reflection method. 2; Gokusenso hanshaho ni okeru danso kaiseki. 2  

Energy Technology Data Exchange (ETDEWEB)

Fault analysis is required in addition to the ordinary process of structural analysis (CDP stacking) for the examination of discontinuity in the reflection horizon in question. The fault shape restoration principle is that the reflection point of a reflection wave observed at a certain receiving point is on an ellipse with the shock point and receiving point at its focal points and that the sum of the distances between the reflection point and the focal points is equal to the reflection wave propagation time. The DMO velocity is worked out by calculation using the positive travel time and inverse travel time from the common reflection surface. When the reflection surface is inclined by {theta}, the average interval velocity/cos{theta} is called the DMO velocity. When the reflection surface inclination and the average interval velocities are determined separately in this way, the position of the reflection point may be ...

1997-05-27

417

Estimation of gross calorific value based on coal analysis using regression and artificial neural networks  

Energy Technology Data Exchange (ETDEWEB)

Relationships of ultimate and proximate analysis of 4540 US coal samples from 25 states with gross calorific value (GCV) have been investigated by regression and artificial neural networks (ANNs) methods. Three set of inputs: (a) volatile matter, ash and moisture (b) C, H, N, O, S and ash (c) C, H{sub exclusive} {sub of} {sub moisture}, N, O{sub exclusive} {sub of} {sub moisture}, S, moisture and ash were used for the prediction of GCV by regression and ANNs. The multivariable regression studies have shown that the model (c) is the most suitable estimator of GCV. Running of the best arranged ANNs structures for the models (a) to (c) and assessment of errors have shown that the ANNs are not better or much different from regression, as a common and understood technique, in the prediction of uncomplicated relationships between proximate and ultimate analysis and coal GCV. (author)

2009-07-01

418

Dielectric properties of fluxed barium titanate ceramics with zirconia additions  

Energy Technology Data Exchange (ETDEWEB)

BaTiO{sub 3} compacts, when fluxed with {lt} 2 vol% of a complex borate glass phase, were sintered to near theoretical density at temperatures {lt} 1175{degrees}C in 2 h. Microstructural analysis showed a uniform grain size {lt} 1.0 {mu}m with 0.75 wt% ZrO{sub 2} added to the flux phase as a grain growth inhibitor. TEM analysis revealed a microcrystalline grain-boundary phase with the ZrO{sub 2} resident along the grain boundaries. These samples displayed an essentially flat dielectric profile, low dissipation factors ({lt} 2%) over the range 25{degrees} to 125{degrees}C, a near linear dependence ({approx} {+-} 15%) between 25{degrees} and {minus} 55{degrees}C, and significantly increased voltage stability. X-ray diffraction analysis of these small-grained materials indicates a suppression of the tetragonal structure toward a more cubic modification.

1990-03-01

419

Dielectric properties of fluxed barium titanate ceramics with zirconia additions  

International Nuclear Information System (INIS)

BaTiO_3 compacts, when fluxed with < 2 vol% of a complex borate glass phase, were sintered to near theoretical density at temperatures < 1175 degrees C in 2 h. Microstructural analysis showed a uniform grain size < 1.0 #mu#m with 0.75 wt% ZrO_2 added to the flux phase as a grain growth inhibitor. TEM analysis revealed a microcrystalline grain-boundary phase with the ZrO_2 resident along the grain boundaries. These samples displayed an essentially flat dielectric profile, low dissipation factors (< 2%) over the range 25 degrees to 125 degrees C, a near linear dependence (#approx# #+-# 15%) between 25 degrees and - 55 degrees C, and significantly increased voltage stability. X-ray diffraction analysis of these small-grained materials indicates a suppression of the tetragonal structure toward a more cubic modification.

420

Crystal growth, structural and optical characterization of a semi-organic single crystal for frequency conversion applications  

International Nuclear Information System (INIS)

Single crystals of semi-organic L-histidine hydrobromide have been grown by slow evaporation technique from a mixture of L-histidine and hydrobromic acid in aqueous solution at ambient temperature. From high-resolution X-ray diffraction analysis, the crystalline perfection of the grown crystal has been studied. Single crystal X-ray diffraction analyses, Nuclear Magnetic Resonance spectral analysis, Thermo-Gravimetry (TG), Differential Thermal Analysis (DTA) and hardness test have been employed to characterize the as-grown crystals. The UV cutoff wavelength of the grown crystal is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics have been studied using Q switched Nd:YAG laser (#lambda#=1064 nm). The second harmonic generation conversion efficiency of the grown crystals confirms their suitability for frequency ...

2010-12-15

421

Computed radiography in X-ray examination of stomach. Evaluation by phantom experiments and clinical studies  

Energy Technology Data Exchange (ETDEWEB)

The usefulness and clinical applicability of computed radiography(FCR) in X-ray examination of the stomach were evaluated in comparison with film-screen (FS) radiography by both phantom experiments and clinical studies. Receiver operating characteristic (ROC) curve analysis consisting of 25 normal and 25 artificially created simulated lesions on an orginally created Styrofoam phantom showed no difference in lesion detectability between FCR and FS radiography. Both were also equal in evaluation of the internal structure and margin of the 25 lesions by visual ranking. ROC curve analysis of clinical cases was performed in 30 cases, 20 normal and 10 abnormal, while evaluation by visual ranking was performed on 18 lesions. There was no significant difference between FCR and FS radiography either with ROC curve analysis or visual ranking, although the variations were somewhat greater in the clinical cases ...

1995-08-01

422

Computed radiography in X-ray examination of stomach. Evaluation by phantom experiments and clinical studies  

International Nuclear Information System (INIS)

The usefulness and clinical applicability of computed radiography(FCR) in X-ray examination of the stomach were evaluated in comparison with film-screen (FS) radiography by both phantom experiments and clinical studies. Receiver operating characteristic (ROC) curve analysis consisting of 25 normal and 25 artificially created simulated lesions on an orginally created Styrofoam phantom showed no difference in lesion detectability between FCR and FS radiography. Both were also equal in evaluation of the internal structure and margin of the 25 lesions by visual ranking. ROC curve analysis of clinical cases was performed in 30 cases, 20 normal and 10 abnormal, while evaluation by visual ranking was performed on 18 lesions. There was no significant difference between FCR and FS radiography either with ROC curve analysis or visual ranking, although the variations were somewhat greater in the clinical cases ...

1995-01-01

423

Composition determination of sputter-deposited HgS films by electron microprobe analysis  

Energy Technology Data Exchange (ETDEWEB)

The composition of sputter-deposited HgS films was determined by electron microprobe analysis. From the relative x-ray intensity as a function of film thickness, the depth of the ionizations that produce SK sub(..cap alpha..) and HgM sub(..cap alpha..) was found to be approximately 0.65 ..mu..m at an accelerating voltage of 15 kV. This value agreed well with a value calculated from Castaings' empirical law after absorption correction. The determination of film composition was limited to sufficiently thicker films than this critical value, usually 1 - 2 ..mu..m thick. The relation between the conposition of bulk standard determined by chemical analysis and the x-ray intensity ratio was used for the correction of film composition. The results showed that the crystal structure of HgS films was independent of the composition, i.e., the growth of metastable ..beta..-HgS films was not caused by the nonstoichiometry, and ...

1982-01-01

424

Composition determination of sputter-deposited HgS films by electron microprobe analysis  

International Nuclear Information System (INIS)

The composition of sputter-deposited HgS films was determined by electron microprobe analysis. From the relative x-ray intensity as a function of film thickness, the depth of the ionizations that produce SK sub(#alpha#) and HgM sub(#alpha#) was found to be approximately 0.65 #mu#m at an accelerating voltage of 15 kV. This value agreed well with a value calculated from Castaings' empirical law after absorption correction. The determination of film composition was limited to sufficiently thicker films than this critical value, usually 1 - 2 #mu#m thick. The relation between the conposition of bulk standard determined by chemical analysis and the x-ray intensity ratio was used for the correction of film composition. The results showed that the crystal structure of HgS films was independent of the composition, i.e., the growth of metastable #betta#-HgS films was not caused by the nonstoichiometry, and that the composition of ...

1982-01-01

425

Valence electronic structure of Ti, Cr, Fe and Co in some alloys from K{beta}-to-K{alpha} X-ray intensity ratio studies  

Energy Technology Data Exchange (ETDEWEB)

K{beta}-to-K{alpha} X-ray intensity ratios of Ti, Cr, Fe and Co in pure metals and in Cr{sub 0.26}Fe{sub 0.74}, Cr{sub 0.80}Co{sub 0.20} and Ti{sub 0.80}Cr{sub 0.20} alloys have been measured following excitation by 59.54 keV {gamma}-rays from a 7400 MBq (200 mCi) {sup 241}Am point-source. The valence electronic structure of Ti, Cr, Fe and Co in the samples have been evaluated by the comparison of the measured K{beta}-to-K{alpha} intensity ratios with the results of multiconfiguration Dirac-Fock calculations performed for various electronic configurations of these metals. The 3d-electron populations obtained for pure metallic Ti, Cr, Fe and Co agree well with the results of band structure calculations of Papaconstantopoulos (Handbook of band structure of elemental solids, Plenum Press, New York, 1986). Our analysis indicates significant increase of 3d-electron population of Ti, Cr and Fe in the alloys ...

2002-10-01

426

Valence electronic structure of Ti, Cr, Fe and Co in some alloys from K#beta#-to-K#alpha# X-ray intensity ratio studies  

International Nuclear Information System (INIS)

K#beta#-to-K#alpha# X-ray intensity ratios of Ti, Cr, Fe and Co in pure metals and in Cr_0_._2_6Fe_0_._7_4, Cr_0_._8_0Co_0_._2_0 and Ti_0_._8_0Cr_0_._2_0 alloys have been measured following excitation by 59.54 keV #gamma#-rays from a 7400 MBq (200 mCi) "2"4"1Am point-source. The valence electronic structure of Ti, Cr, Fe and Co in the samples have been evaluated by the comparison of the measured K#beta#-to-K#alpha# intensity ratios with the results of multiconfiguration Dirac-Fock calculations performed for various electronic configurations of these metals. The 3d-electron populations obtained for pure metallic Ti, Cr, Fe and Co agree well with the results of band structure calculations of Papaconstantopoulos (Handbook of band structure of elemental solids, Plenum Press, New York, 1986). Our analysis indicates significant increase of 3d-electron population of Ti, Cr and Fe in the alloys with respect to ...

2002-10-01

427

Redesigning standard retail tariffs for competition: New tools and strategies  

Energy Technology Data Exchange (ETDEWEB)

Utilities looking to thrive in increasingly competitive markets are reexamining their approach to pricing. To compete effectively, utilities will need to both control costs and offer customers pricing options that are competitive and reflect the diversity in their customer base. These price structures must reflect two key factors -- marginal costs, which will increasingly reflect market prices, and consumers` responsiveness to those price structures. To accomplish this requires the capability to forecast customers` response to price structures that often provide complex signals to customers about how changes in their energy consumption and maximum power demand affect their bill, and to calculate corresponding changes in utility profits and customer net benefits. Much discussion of competitive pricing focuses on innovative new rate structures. However, significant opportunities are present to improve ...

1996-03-01

428

A statistical pattern recognition paradigm for structural health monitoring  

Energy Technology Data Exchange (ETDEWEB)

The process of implementing a damage detection strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring (SHM). Here damage is defined as changes to the material and/or geometric properties of these systems, including changes to the boundary conditions and system connectivity, which adversely affect the system's current or future performance. Our approach is to address the SHM problem in the context of a statistical pattern recognition paradigm (Farrar, Nix and Doebling, 2001). In this paradigm, the process can be broken down into four parts: (1) Operational Evaluation, (2) Data Acquisition, (3) Feature Extraction, and (4) Statistical Model Development for Feature Discrimination. When one attempts to apply this paradigm to data from 'real-world' structures, it quickly becomes apparent that data cleansing, normalization, fusion and compression, which can be ...

2004-01-01

429

Statistical Analysis of Designed Experiments  

CERN Document Server

Statistical Analysis of Designed Experiments

2010-01-01

430

Investigation of new materials for SOFC applications; Untersuchungen zum Einsatz neuer Werkstoffe fuer SOFC-Anwendungen  

Energy Technology Data Exchange (ETDEWEB)

Fuel cells based on solid oxides ('SOFC') are excellent alternative devices for power generation, when they are operated at high temperature, e.g. above 600 C. Having only fixed parts for the power generating part of the device is only one advantage of the fuel cell. Due to their unique design, these devices offer a maximum of efficiency for energy conversion compared to conventional power generating systems, which are mainly based on turbines. One aim of this thesis is the examination of alternative electrolyte and cathode materials for the SOFC applications at reduced temperatures, which means in the temperature range between 600 C and 750 C. For the first main task, several materials from the oxygen ion conducting electrolytes were selected. Different strontium and magnesium doped lanthanum gallate (LSGM) materials with additional transition metal doping were selected and prepared via two different preparation methods. The optimum calcining conditions were ...

2007-05-04

431

In vitro MRI of brain development  

International Nuclear Information System (INIS)

In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ...

2006-02-01

432

Deep subsurface structure modeling based on microtremor and earthquake observation. Applicability of microtremor array measurements at the Kashiwazaki-Kariwa Nuclear Power Station  

International Nuclear Information System (INIS)

During the 2007 Niigataken Chuetsu-oki earthquake, strong ground motion with the peak acceleration of 680 cm/s/s which was larger than that of the empirical prediction was recorded at the base mat of the No.1 reactor building of Kashiwazaki-Kariwa Nuclear Power Station (NPS). Furthermore, in the Kashiwazaki-Kariwa NPS, over twice difference of 680 vs. 322 cm/s/s of peak acceleration between the No.1 and the No.6 reactor buildings was observed on the base mat. From the results of recent research, it is suggested that the deep sedimentary layers can be one of the important factors to elucidate these phenomena. In this study, at first, the applicability of microtremor array measurements for estimation of deep S-wave velocity structure (#approx#Vs=3 km/s layer) are discussed. Vertical microtremors were observed in three arrays at the Kashiwazaki-Kariwa NPS with the maximum station spacings of 3.04 km, 1.49 km and 0.75 km, respectively. The Rayleigh wave phase velocity ...

2010-05-01

435

Creative Australia  

Wastenet

The structure of the creative industries is changing 15

436

Study of ytterbium doping effects on structural, mechanical and opto-thermal properties of sprayed ZnO thin films using the Boubaker Polynomials Expansion Scheme (BPES)  

Energy Technology Data Exchange (ETDEWEB)

In this work, ZnO thin films have been grown on glass substrates by using a solution of propanol (C{sub 3}H{sub 8}O), water (H{sub 2}O) and zinc acetate (Z{sub n}(CH{sub 3}CO{sub 2}){sub 2}) in acidified medium (pH 5). The obtained films were n doped with ytterbium (Yb) at the rates of 100, 200 and 300 ppm. The structural features of the doped films were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. XRD analysis shows a strong (0 0 2) X-ray diffraction line for increasing Yb-doping amounts. This c-axis preferential orientation of ZnO crystallites is naturally required to use this oxide as transparent conductor in optoelectronic applications. Atomic force microscopy (AFM) analysis shows an enhancement in the surface roughness of the doped ZnO:Yb thin films. Optical measurements were performed in 300-1800 nm domain via transmittance T(lambda) and reflectance R(lambda) spectra. ...

2009-10-19

437

Study of ytterbium doping effects on structural, mechanical and opto-thermal properties of sprayed ZnO thin films using the Boubaker Polynomials Expansion Scheme (BPES)  

International Nuclear Information System (INIS)

In this work, ZnO thin films have been grown on glass substrates by using a solution of propanol (C3H8O), water (H2O) and zinc acetate (Zn(CH3CO2)2) in acidified medium (pH 5). The obtained films were n doped with ytterbium (Yb) at the rates of 100, 200 and 300 ppm. The structural features of the doped films were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. XRD analysis shows a strong (0 0 2) X-ray diffraction line for increasing Yb-doping amounts. This c-axis preferential orientation of ZnO crystallites is naturally required to use this oxide as transparent conductor in optoelectronic applications. Atomic force microscopy (AFM) analysis shows an enhancement in the surface roughness of the doped ZnO:Yb thin films. Optical measurements were performed in 300-1800 nm domain via transmittance T(?) and reflectance R(?) spectra. Conjoint optical and thermal properties were deduced ...

2009-10-19

438

Predicting the response of high damping rubber bearings using simplified models and finite element analysis  

International Nuclear Information System (INIS)

The International Atomic Energy Agency has initiated a co-ordinated research programme on implementation of base-isolation for nuclear structures. This paper discusses two areas relevant to modelling elastomeric base-isolators. These are the use of simplified models to predict the response of isolated structures to earthquake inputs and finite element analysis for calculating the stress distributions within the isolators. In the former, a curvilinear hysteretic model of the high damping natural rubber able to accommodate the stiffening of the rubber at large shear deflections is presented. Its predictions of structural accelerations and bearing displacement produced by design earthquakes and those above the design level are compared with those using a linear spring and dashpot model. A comparison has been made between two finite element analyses using MARC and ABAQUS of the force-deformation behaviour ...

1996-05-27

439

Ionizing radiation target groups of band 3 inserted into egg lecithin liposomes as determined by Raman spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

The purified integral membrane protein, band 3, from human erythrocytes was inserted into egg lecithin liposomes. The insertion of band 3 was determined from thermal transition data from the analysis of the C-H stretching region bands recorded at temperatures from 25 to -22[sup o]C. Raman spectra show that band 3 considerably broadens and lowers the thermal transition of egg lecithin liposomes, suggesting the insertion of band 3. The band 3-inserted liposomes were irradiated with gamma-rays (40 Gy) and the radiation target groups were determined by the analysis of the structural sensitive Raman bands in the 1600-1700 cm[sup -1] (amide I), 1200-1300 cm[sup -1] (amide III) and 550-1030 cm[sup -1] (side chain amino groups) regions. The radiation-sensitive groups as identified from Raman spectra in the region 550-1030 cm[sup -1] are tyrosines and cysteines. The radiation-induced changes in the secondary ...

1993-03-01

440

Ionizing radiation target groups of band 3 inserted into egg lecithin liposomes as determined by Raman spectroscopy  

International Nuclear Information System (INIS)

The purified integral membrane protein, band 3, from human erythrocytes was inserted into egg lecithin liposomes. The insertion of band 3 was determined from thermal transition data from the analysis of the C-H stretching region bands recorded at temperatures from 25 to -22"oC. Raman spectra show that band 3 considerably broadens and lowers the thermal transition of egg lecithin liposomes, suggesting the insertion of band 3. The band 3-inserted liposomes were irradiated with gamma-rays (40 Gy) and the radiation target groups were determined by the analysis of the structural sensitive Raman bands in the 1600-1700 cm"-"1 (amide I), 1200-1300 cm"-"1 (amide III) and 550-1030 cm"-"1 (side chain amino groups) regions. The radiation-sensitive groups as identified from Raman spectra in the region 550-1030 cm"-"1 are tyrosines and cysteines. The radiation-induced changes in the secondary structure were ...

441

Influence of anchor behaviour on the earthquake response of liquid storage tanks  

International Nuclear Information System (INIS)

The dynamic response of thin liquid storage tanks to earthquakes is a very complicated phenomenon, because it can be highly non linear. Among others, one can meet material and geometric non linearities of the tank shell leading eventually to static or dynamic buckling non linear behavior of anchor bolts, contact non-linearities due to the uplift of the tank base and to the unilateral character of the fluid pressure on the shell and high amplitude fluid oscillations. Moreover, linear or non linear soil structure interaction affects considerably the response of the fluid structure system under consideration. In this paper we focus attention on problems related only to the base uplift and anchors plastification. We study a tank similar to the Hualien project tank, but we neglect the soil structure interaction. The studied tank is representative of medium height to radius ratio ratio tanks with relatively thick bottom plate. ...

442

Jet flow analysis of liquid poison injection in a CANDU reactor using source term  

Energy Technology Data Exchange (ETDEWEB)

For the performance analysis of Canadian deuterium uranium (CANDU) reactor shutdown system number 2 (SDS2), a computational fluid dynamics model of poison jet flow has been developed to estimate the flow field and poison concentration formed inside the CANDU reactor calandria. As the ratio of calandria shell radius over injection nozzle hole diameter is so large (1055), it is impractical to develop a full-size model encompassing the whole calandria shell. In order to reduce the model to a manageable size, a quarter of one-pitch length segment of the shell was modeled using symmetric nature of the jet; and the injected jet was treated as a source term to avoid the modeling difficulty caused by the big difference of the hole sizes. For the analysis of an actual CANDU-6 SDS2 poison injection, the grid structure was determined based on the results of two-dimensional real- and source-jet simulations. The maximum injection ...

2001-01-01

443

Analysis of impurities in beryllium, affecting evaluation of the tritium breeding ratio  

International Nuclear Information System (INIS)

In most conceptual fusion power reactor designs, it is proposed to use beryllium as a neutron multiplier in the blanket. Detailed chemical composition of beryllium is necessary for evaluation of the tritium breeding ratio, and estimating the activation and transmutation of beryllium in the fusion reactor. In the present report, special attention was paid to a detailed analysis of impurities in beryllium, relevant to the tritium breeding ratio evaluation. Two different methods were used for the study of impurities: an analysis of the local sample by the ICP-MS method, and an integral analysis of the beryllium assembly, using the pulsed neutron method. The latter method was proposed as the most effective way of analyzing the integral effect to impurities in beryllium on production of the tritium on the lithium-6. The evaluation of the integral effect was based on time behaviour observations of the thermal neutron flux, ...

444

The interaction of /sup 125/I-insulin with cultured 3T3-L1 adipocytes: quantitative analysis by the hypothetical grain method  

Energy Technology Data Exchange (ETDEWEB)

The murine 3T3-L1 fibroblast under appropriate incubation conditions differentiates into an adipocyte phenotype. This 3T3-L1 adipocyte exhibits many of the morphologic, biochemical, and insulin-responsive features of the normal rodent adipocyte. Using quantitative electron microscopic (EM) autoradiography we find that, when /sup 125/I-insulin is incubated with 3T3-L1 adipocytes, the ligand at early times of incubation localizes to the plasma membrane of the cell preferentially to microvilli and coated pits. When the incubation is continued at 37 degrees C, /sup 125/I-insulin is internalized by the cells and preferential binding to the villous surface is lost. With the internalization of the ligand, two intracellular structures become labeled, as determined by the method of hypothetical grain analysis. These include large clear, presumably endocytotic, vesicles and multivesicular bodies. Over the first hour of incubation the labeling of these ...

1983-07-01

445

Structural Equation Modeling for High School Principals' Data-Driven Decision Making: An Analysis of Information Use Environments  

Science.gov (United States)

Background: Accountability demands are increasingly pushing school leaders to explore more data and do more sophisticated analyses. Data-driven decision making (DDDM) has become an emerging field of practice for school leadership and a central focus of education policy and practice. Purpose: This study examined principals' DDDM practices and identified the factors influencing DDDM using the theoretical frame of information use environments. Participants: Participants were 183 public high school principals in a Midwestern state. Research Design: The research design was cross-sectional survey research. Data Collection and Analysis: Survey instruments were developed and administered to principals. Structural equation modeling was conducted to determine what factors significantly affect principals' DDDM practices in different leadership dimensions. Findings: Principals used data more frequently in instructional and organization operational ...

2007-12-01

446

Corrosion behaviors of Zn/Al-Mn alloy composite coatings deposited on magnesium alloy AZ31B (Mg-Al-Zn)  

International Nuclear Information System (INIS)

After being pre-plated a zinc layer, an amorphous Al-Mn alloy coating was applied onto the surface of AZ31B magnesium alloy with a bath of molten salts. Then the corrosion performance of the coated magnesium alloy was examined in 3.5% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the single Zn layer was active in the test solution with a high corrosion rate while the Al-Mn alloy coating could effectively protect AZ31B magnesium alloy from corrosion in the solution. The high corrosion resistance of Al-Mn alloy coating was ascribed to an intact and stable passive film formed on the coating. The performances of the passive film on Al-Mn alloy were further investigated by Mott-Schottky curve and X-ray photoelectron spectroscopy (XPS) analysis. It was confirmed that the passive film exhibited n-type semiconducting behavior in 3.5% NaCl solution with a carrier density two orders of magnitude less ...

2009-12-30

447

Perovskite-type SrTi1-xNbx(O,N)3 compounds: Synthesis, crystal structure and optical properties  

International Nuclear Information System (INIS)

The synthesis, crystal structure, thermal stability and absorbance spectra of perovskite-type oxynitrides with the general formula SrTi1-xNbx(O,N)3 (x=0.05, 0.10, 0.20, 0.50, 0.80, 0.90, 0.95) have been investigated. Oxide samples were prepared by a polymerized complex synthesis route and post-treated under ammonia at 850 oC for 24 h to substitute nitrogen for oxygen. Synchrotron X-ray powder diffraction (XRD) evidenced that the mixed oxide phases were all transformed into oxynitrides with perovskite-type structure during a thermal ammonolysis. SrTi1-xNbx(O,N)3 with compositions x?0.80 crystallized in a cubic and samples with x?0.90 in a tetragonal structure. The Rietveld refinement indicated a continuous enlargement of the lattice parameters towards higher niobium content of the samples. Thermogravimetric analysis (TGA) and hotgas extraction revealed the dependence of the nitrogen incorporation upon ...

2011-04-01

448

The importance of accurate crystal structure determination of uranium minerals. Pt. 1  

International Nuclear Information System (INIS)

On the basis of accurate crystal structure determination, the mineral phosphuranylite corresponds to the chemical formula KCa(H_3O)_3(UO_2)_7(PO_4)_4O_4.8H_2O. Cmcm, a=15.778 (3)-15.899(2), b=13.702(2)-13.790(5), c=17.253(3)-17.330(3)A, Z=4, D_x=4.575-4.631g cm"-"3, #mu#=287.6-291.1cm"-"1. The presence of potassium (about 1.80wt%K_2O), overlooked until now, has been confirmed by microprobe analysis on samples from four different localities. The best data for structure determination have been obtained by single-crystal X-ray diffraction on specimens from Capoterra, Sardinia, and Bois Noirs, France; here 1453 and 1254 independent reflections, respectively, were used in the refinement, and the corresponding final R index is 0.036 and 0.048. The structure consists of layers of phosphate groups connected with hexagonal, pentagonal and tetragonal dipyramids centered on the U atoms. The Ca and K atoms are ...

449

Synthesis and crystal structure of a new open-framework iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4]: Novel linear trimer of corner-sharing Fe(III) octahedra  

International Nuclear Information System (INIS)

A new iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2 mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P21/n (No. 14), a=6.2614(13) A, b=9.844(2) A, c=14.271(3) A, ?=92.11(1)o, V=879.0(3) A3). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO4) groups to form ten-membered-ring channels along [1 0 0]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO4)3(OH)2F2], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic ...

2010-12-01

450

Structure-activity relationships of anthraquinones on the suppression of DNA-binding activity of the aryl hydrocarbon receptor induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin.  

Science.gov (United States)

Anthraquinones are widely present in plant kingdom, and clinically used as laxatives. Environmental contaminants, dioxins, develop various adverse effects through transformation of a cytosolic aryl hydrocarbon receptor (AhR). We investigated the effects of 18 anthraquinones and 7 of their structurally related compounds on transformation of the AhR estimated by its DNA-binding activity in the cell-free system. 1,4-Dihydroxyanthraquinone (quinizarin), 1,5-dihydroxyanthraquinone (anthrarufin), 1,8-dihydroxyanthraquinone (danthron), and 5-hydroxy-1,4-naphthoquinone (juglone) strongly suppressed DNA-binding activity of the AhR induced by 0.1 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with their IC(50) values around 1 muM. On the other hand, anthraquinone, 2,6-dihydroxyanthraquinone (anthraflavic acid), and 2-hydroxy-1,4-naphthalendione (lawsone) showed moderate effects. Quantitative structure-activity relationships analysis ...

2009-03-01

451

Magnetic and transport properties of Ba_2Co_9O_1_4 and Ba_1_._9A_0_._1Co_9O_1_4 (A=La or Na)  

International Nuclear Information System (INIS)

The valence and spin-state distributions of Co ions and the complex structure of antiferromagnetic Ba_2Co_9O_1_4 have led to the suggestion that doped Ba_2Co_9O_1_4 compounds may be good thermoelectric materials. We have checked this suggestion by measuring the magnetic properties as well as the transport properties of nominal Ba_1_._9A_0_._1Co_9O_1_4 (A=La or Na). We show that although all compounds are indicated to be single phase by powder X-ray diffraction analysis, they are all p-type polaronic conductors with low mobile-hole concentrations. Magnetic-susceptibility data of the parent and La-doped compounds give evidence of a second magnetic phase with ferromagnetic order setting in below 215 K; but this second phase is not seen in the Na-doped sample. We conclude that the structure is stabilized by oxidation and that cation exolution from the Ba_2Co_9O_1_4 structure creates cation vacancies that ...

2010-11-01

452

Laboratory tests on the effects of partial embedment on soil-structure interaction (embedment effect test on soil-structure interaction)  

International Nuclear Information System (INIS)

A series of Model Tests of Embedment Effect on Reactor Buildings has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and Industry (MITI) of Japan. Reactor buildings in Japan are partially embedded in general. Therefore, it is important to know how partial embedment affects the vibration characteristics of reactor buildings relating to seismic safety. Laboratory tests were conducted using a ground model made of silicone rubber (Young's modulus 2.3x10"6 Pa, Poisson's ratio 0.484, Density 1.24x 10"3 kg/m3 , Damping ratio 0.01) and a foundation model made of aluminum shown to study the effects of embedment on soil-structure interaction with different backfill types. The ground model is a cylinder, 70 cm high and 300 cm in diameter, with pit where the parallelepiped foundation model with square plan of 30 cm x 30 cm and 18 cm high was placed. Four types of backfill of silicone rubber ...

1993-08-15

453

Design and commission of an experimental test rig to apply a full-scale pressure load on composite sandwich panels representative of an aircraft secondary structure  

Science.gov (United States)

This paper describes the design of a test rig, which is used to apply a representative pressure load to a full-scale composite sandwich secondary aircraft structure. A generic panel was designed with features to represent those in the composite sandwich secondary aircraft structure. To provide full-field strain data from the panels, the test rig was designed for use with optical measurement techniques such as thermoelastic stress analysis (TSA) and digital image correlation (DIC). TSA requires a cyclic load to be applied to a structure for the measurement of the strain state; therefore, the test rig has been designed to be mounted on a standard servo-hydraulic test machine. As both TSA and DIC require an uninterrupted view of the surface of the test panel, an important consideration in the design is facilitating the optical access for the two techniques. To aid the test rig design a finite element (FE) ...

2010-01-01

454

Weak Ties: A Subtle Role in the Information Diffusion of Online Social Networks  

CERN Document Server

As a social media, online social networks play a vital role in the social information diffusion. However, due to its unique complexity, the mechanism of the diffusion can be different from the ones in other types of networks and remains unclear to us. Meanwhile, few works have been done to reveal the coupled dynamics of both the structure and the diffusion of online social networks. To this end, in this paper, we propose a model to investigate how the structure is coupled with the diffusion in online social networks from the view of weak ties. Through numerical experiments on large-scale online social networks, we find that in contrast to some previous research results, selecting weak ties preferentially to republish cannot make the information diffuse quickly, while random selection can achieve this goal. However, when we remove the weak ties gradually, the coverage of the information will decrease sharply even in the case of random selection. ...

2010-01-01

455

Turnover of texture in low rate sputter-deposited nanocrystalline molybdenum films  

International Nuclear Information System (INIS)

The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 (angstrom)s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 microm, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from ...

1997-04-04

456

Transient data acquisition techniques under EDS  

Energy Technology Data Exchange (ETDEWEB)

This paper is the first of a series which describes the Enrichment Diagnostic System (EDS) developed for the MARS project at Lawrence Livermore National Laboratory. Although EDS was developed for use on AVLIS, the functional requirements, overall design, and specific techniques are applicable to any experimental data acquisition system involving large quantities of transient data. In particular this paper will discuss the techniques and equipment used to do the data acquisition. Included are what types of hardware are used and how that hardware (CAMAC, digital oscilloscopes) is interfaced to the HP computers. In this discussion the author will address the problems encountered and the solutions used, as well as the performance of the instrument/computer interfaces. The second topic the author will discuss is how the acquired data is associated to graphics and analysis portions of EDS through efficient real time data bases. This discussion will include how the ...

1985-06-01

457

The formation of vertically aligned biaxial tungsten nanorods using a novel shadowing growth technique  

International Nuclear Information System (INIS)

Biaxially textured tungsten nanorods (A15 crystal structure) have been grown by oblique angle DC magnetron sputtering using a novel rotation mode called 'two-step rotation'. In this mode, the substrate is given a fast rotation through 1800 at 90 rpm and this is followed by a rest period of 30 s. These nanorods are vertically aligned and have a [100] texture normal to the substrate along with preferential in-plane texture as shown by x-ray pole figure analysis. In contrast, the tungsten nanorods obtained without substrate rotation are slanted at an angle of ?450 and have a [100] texture tilted 160 with respect to the substrate normal. The flux is incident from two diametrically opposite points on the sample at an oblique angle, averaging out the growth into vertical columns that retain the in-plane texture. Scanning electron microscopy shows that the tungsten nanorods have a mixture of {211} and {421} crystal habits; these planes are both ...

2009-11-18

458

Thai Family Health Routines: scale development and psychometric testing.  

Science.gov (United States)

The aims of the study were to develop and test the psychometric properties of the Thai Family Health Routines (TFHR) scale, a 70-item self-report questionnaire used to measure the health of Thai families through their routine behaviors in daily life. Development of the TFHR was based on the structural domains of Denham's Family Health Model. The TFHR scale was initially composed of 85 items and tested on 1,040 families living in the central region of Thailand. The confirmatory factor analysis, with an acceptable factor structure model, yielded 70 items aligned with six factors: self-care, safety and prevention, mental health behavior, family care, family caregiving, and illness care routines. The preliminary psychometric properties demonstrated that the TFHR scale had satisfactory internal consistency, criterion validity, and construct validity. The test results suggested that the TFHR scale has potential benefits for ...

2009-05-01

459

Synthesis, structural activity-relationships, and biological evaluation of novel amide-based allosteric binding site antagonists in NR1A/NR2B N-methyl-d-aspartate receptors  

British Library Electronic Table of Contents (United Kingdom)

The synthesis and structure-activity relationship analysis of a novel class of amide-based biaryl NR2B-selective NMDA receptor antagonists are presented. Some of the studied compounds are potent, selective, non-competitive, and voltage-independent antagonists of NR2B-containing NMDA receptors. Like the founding member of this class of antagonists (ifenprodil), several interesting compounds of the series bind to the amino terminal domain of the NR2B subunit to inhibit function. Analogue potency is modulated by linker length, flexibility, and hydrogen bonding opportunities. However, unlike previously described classes of NR2B-selective NMDA antagonists that exhibit off-target activity at a variety of monoamine receptors, the compounds described herein show much diminished effects against the...

2009-01-01

460

Study on pyrolysing behavior of NiO-SDC composite particles prepared by spray pyrolysis technique  

Energy Technology Data Exchange (ETDEWEB)

The NiO-samaria doped ceria (SDC) composite powders were prepared by spray pyrolysis technique at temperatures between 400 and 1000 C. The variation of the particle structure was investigated by X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), scanning electron microscope (SEM), and transmission electron microscope (TEM)-energy-dispersive X-ray spectroscopy (EDS). The thermal analysis of raw materials was also carried out. The following facts became clear in this study. Ceria and nickel have been already separated at 400 C. Samaria is amorphous phase below 600 C, and is dissolved in ceria at 600 C or higher. Samaria is distributed uniformly inside the particles before dissolving in ceria. The thermal decomposition temperatures of metal nitrate are: cerium < nickel < samarium. The results of these analyses were explained without contradiction. It was found that it is important to optimize the ...

2007-03-15

461

Study of the influence of alloying additions on the passivity of aluminum. Annual report 1 Dec 89-30 Nov 90  

Energy Technology Data Exchange (ETDEWEB)

Whereas supersaturated aluminum alloys demonstrate enhanced passivity, conventional aluminum alloys spontaneously pit in air-saturated chloride solutions. We have concentrated on three areas: evaluation and characterization of Al-W alloys, which exhibit the best corrosion performance of any alloy system studied to date; characterization of the passive-film structure of Al-Mo alloys; and production and characterization of Al-W and Al-Ta powders, which will be used for compaction into bulk material. Surface analysis of the Al-W passive films formed during polarization show surprising little oxidized solute compared to other alloys. These results indicate that the barrier layer formation and electrostatic repulsion mechanisms used to explain the passivity of other alloys are not involved here. Instead the W may act to stabilize the passive film structure in a way similar to the way molybdenum acts in Al-Mo alloys. That is ...

1991-03-01

462

Structure determination and investigation on cytotoxicity of potassium dichlorido(l-prolinato)platinate(II) versus chlorido(dimethyl sulfoxide)(l-prolinato)platinum(II) complex -In vitro antitumor deactivation by Cl^-/dmso ligand exchange  

British Library Electronic Table of Contents (United Kingdom)

Potassium dichlorido(l-prolinato)platinate(II), K[PtCl"2(l-pro"?"H)] (1), and chlorido(dimethyl sulfoxide)(l-prolinato)platinum(II), [PtCl(l-pro"?"H)(dmso)] (2), were synthesized by ligand substitution reactions. Both complexes were characterized by ^1H, ^1^3C, and ^1^9^5Pt NMR spectroscopy, elemental analysis, and HR-ESI-MS. The molecular structures of 1 and 2 were determined by single crystal X-ray diffraction, proving bidentate coordinated l-prolinato ligand and SP-4-4 configuration of 2a. With the help of DFT calculations stability of possible isomers of 1 and 2 was studied. A considerable difference in the in vitro cytotoxicity of 1 versus 2a (exchange of one chlorido ligand by dmso) against four human cancer cell lines was found.

2011-01-01

463

Structural, optical, electrical and dielectrical properties of electrosynthesized nanocrystalline iron oxide thin films  

International Nuclear Information System (INIS)

Electrodeposition of semiconducting iron oxide (Fe_2O_3) thin film was carried out from an alkaline sulphate bath. A 0.1 M ferrous sulphate (FeSO_4#centre dot#7H_2O) was complexed with 0.1 M citric acid. By addition of 1 N NaOH, pH of the solution was made alkaline (pH=9) and deposition of iron oxide (Fe_2O_3) thin films was carried out potentiostatically at room temperature (300 K). From cyclic voltametry (CV), electrochemical studies were carried out for deposition of iron oxide thin films. The XRD studies reveal that Fe_2O_3 with epsilon (#epsilon#) phase having monoclinic crystal structure is formed. By observing scanning electron microscope (SEM), it is seen that iron oxide films were homogeneous, uniform and well covered to surface of the substrate. Grain size was found to be in nanometers range from XRD analysis. The optical band gap of Fe_2O_3 thin film was estimated to be 1.90 eV. Electrical resistivity was order of 10"4 #OMEGA# cm. ...

2003-09-28

464

Structural, electronic and magnetic properties of splat-quenched FeCsub(x) alloys (x<0.05)  

International Nuclear Information System (INIS)

The results of a combined investigation of splat-quenched Fe-Csub(x) (x<0.05) alloys by resistivity, X-ray diffraction and Moessbauer spectroscopy are presented. The residual resistivity increases linearly with the carbon content (#DELTA#rho=5#mu##OMEGA#cm/at.%) with a slope identical to that observed in the dilute ferritic phase. X-ray diffraction reveals the presence of a martensite structure in addition to a small fraction of residual austenite; the dependence of the a and c lattice parameters on xsub(c) agrees with earlier measurements. A detailed investigation of the relative reflexion intensities shows that the as-quenched martensites consist of a mixing of massive martensite and tetragonal martensite for low carbon content and of tetragonal martensite only for xsub(c) approximately 0.05. The Moessbauer spectra reveal 3 or 4 magnetically non equivalent iron sites. From a detailed analysis of the intensity dependence of the subspectra ...

2006-01-01

465

Structural and magnetic properties of barium-gadolinium hexaferrites  

Energy Technology Data Exchange (ETDEWEB)

A series of Gd-substituted M-type barium hexaferrites has been prepared by the ceramic route, according to the formula (Ba{sub 1-x}Gd{sub x})O.5.25Fe{sub 2}O{sub 3} (x=0-0.30). XRD analysis revealed that all the samples present primarily an M-type structure. Samples x=0 and x=0.05 are single-phase. Hematite (Fe{sub 2}O{sub 3}) and GdFeO{sub 3} were detected in the remaining samples. Coercivity (H{sub c}) shows remarkably high values, {approx}293kA/m for x=0.20 and 0.30 with a maximum of 322kA/m for x=0.25. Specific saturation magnetization ({sigma}{sub sat}) of the samples presents a small increase up to x=0.10. The microstructure examination indicates that Gd may act as a grain growth inhibitor.

2007-03-15

466

Structural and magnetic properties of barium-gadolinium hexaferrites  

International Nuclear Information System (INIS)

A series of Gd-substituted M-type barium hexaferrites has been prepared by the ceramic route, according to the formula (Ba_1_-_xGd_x)O.5.25Fe_2O_3 (x=0-0.30). XRD analysis revealed that all the samples present primarily an M-type structure. Samples x=0 and x=0.05 are single-phase. Hematite (Fe_2O_3) and GdFeO_3 were detected in the remaining samples. Coercivity (H_c) shows remarkably high values, #approx#293kA/m for x=0.20 and 0.30 with a maximum of 322kA/m for x=0.25. Specific saturation magnetization (#sigma#_s_a_t) of the samples presents a small increase up to x=0.10. The microstructure examination indicates that Gd may act as a grain growth inhibitor.

2007-03-01

467

Structural analysis of piping after a large pipe break in a WWER-440 type reactor  

International Nuclear Information System (INIS)

In the WWER-440 reactor the primary piping consists of six horizontal loops going radially from the pressure vessel, each loop having a horizontal steam generator. In this reactor type the relatively long primary piping with many curved sections requires special attention in order to successfully eliminate the consequences of the design basis accident. Emergency supports are located in appropriate places to restrict the movements of the pipe in 1, 2, 3 or 4 directions depending on the geometry of the pipe near the support. Under normal conditions there is a gap of some centimeters between the pipe and a support so that the pipe can be deformed freely under changing loads. In order to analyse the behaviour of the broken piping system with the support structures a computer code called PIPEBREAK has been written. The main objects in the analyses have been to calculate the deformations of the supports and to evaluate the stresses in the pipe. The results indicate that ...

1975-09-01

468

Stoichiometry controlled conversion efficiency in nanostructured heterojunction solar cell of CdS/CuInSXSe2-X grown by chemical ion exchange method at room temperature  

British Library Electronic Table of Contents (United Kingdom)

Here in the present paper, we report on growth of stoichiometric and nonstoichiometric nanostructured heterojunction solar cell of CdS/CuInSXSe2-X varying X from 0 to 2 in the interval of 0.5 using cost effective, simple, chemical ion exchange method at room temperature on ITO glass substrate. The as-grown varying composition solar cells annealed at 200degreeC in air and characterized for structural, compositional, optical and illumination studies. The X-ray diffraction pattern obtained from CdS/CuInSXSe2-X solar cell confirms the formation of CuInSe2, CuInS0.5Se1.5, CuInS1Se1, CuInS1.5Se0.5 and CuInS2 phases having tetragonal structure with varying crystallite size from 19, 19.37, 28, 33 and 20nm respectively. The energy dispersive X-ray analysis (EDAX) confirms the expected elemental com...

2011-01-01

469

Pulsatile viscous flow in a curved pipe: Effects of pulsation on the development of secondary flow  

International Nuclear Information System (INIS)

This work presents an experimental and numerical study of pulsated Dean flow, three-dimensional pulsatile flow in a curved pipe. The numerical study is performed by CFD code (Fluent 6) in which a pulsated velocity field is imposed as an inlet condition. The experimental setup involves principally a 'Scotch-yoke' pulsatile generator and a 90o bend. Laser Doppler Velocimetry (LDV) measurements have shown that the Scotch-yoke generator produces pure sinusoidal instantaneous mean velocities with a mean deviation of 3%. Visualizations by laser-induced fluorescence (LIF) and velocity measurements, coupled with the numerical results, have permitted analysis of the evolution of the swirling secondary flow structures that develop along the bend during the pulsation phase. These measurements were made for a range of stationary Reynolds number (300?Rest?1200), frequency parameter (1??=r0(?/?)1/2max,osc/Ust). We observe satisfactory agreement between the ...

2010-10-01

470

Palladium(II) and platinum(II) saccharinate complexes containing pyridine and 3-acetylpyridine: Synthesis, crystal structures, fluorescence and thermal properties  

British Library Electronic Table of Contents (United Kingdom)

New palladium(II) and platinum(II) complexes of saccharinate (sac), trans-[Pd(py)"2(sac)"2] (1), cis-[Pt(py)"2(sac)"2] (2), trans-[Pd(3-acpy)"2(sac)"2] (3) and cis-[Pt(3-acpy)"2(sac)"2] (4) (py=pyridine and 3-acpy=3-acetylpyridine) have been synthesized. Elemental analysis, UV-Vis, IR, NMR and TG/DTA characterizations have been carried out. The structures of 1-4 were determined by X-ray diffraction. The palladium(II) and platinum(II) ions are coordinated by two N-bonded sac ligands, and two nitrogen atoms of py or 3-acpy, forming a distorted square-planar geometry. The palladium(II) complexes (1 and 3) are trans isomers, while the platinum(II) complexes (2 and 4) are cis isomers. The mononuclear species in the solid state are connected by weak intermolecular C-H...O hydrogen bonds, C-H...@...

2011-01-01

471

PVD-CrN coated magnesium alloy AZ91hp and steel 100Cr6 - investigation on the influence of the substrate material on coating properties; PVD-CrN Beschichtungen auf Magnesium AZ91hp und Stahl 100Cr6 - Untersuchung des Substrateinflusses auf die Schichteigenschaften  

Energy Technology Data Exchange (ETDEWEB)

PVD-chromium-nitride coated samples of substrates of the magnesium alloy AZ91hp and the roller and ball bearing steel 100Cr6 were investigated regarding structure, mechanical characteristics, adhesion and internal stresses. For the coatings the parameters layer thickness and substrate BIAS voltage were varied. Both substrate materials were coated in one lad. Results of the X-ray analysis of the internal stresses show significant differences between the coated magnesium and the coated steel substrates. In the case of the variation of the substrate BIAS voltage, for the coated steel a dependency of the internal stresses to coating parameters could be obtained. For the coated magnesium no dependency was recognizable. The coating structure was examined with scanning electron microscopy. Element depth profiles of the coated samples were performed with SIMS. (orig.)

2001-03-01

472

Observation of two charged bottomonium-like resonances  

CERN Document Server

We report the observation of two narrow structures at 10610MeV/c^2 and 10650MeV/c^2 in the pi^{\\pm}Upsilon(nS) (n=1,2,3) and pi^{\\pm}h_b(mP) (m=1,2) mass spectra that are produced in association with a single charged pion in Upsilon(5S) decays. The measured masses and widths of the two structures averaged over the five final states are M_1=10608.4\\pm2.0MeV/c^2, Gamma_1=15.6\\pm2.5MeV and M_2=10653.2\\pm1.5MeV/c^2, Gamma_2=14.4\\pm3.2MeV. Analysis favors quantum numbers of I^G(J^P)=1^+(1^+) for both states. The results are obtained with a 121.4fb^{-1} data sample collected with the Belle detector near the Upsilon(5S) resonance, at the KEKB asymmetric-energy e+e- collider.

2011-01-01

473

New Insights into the Design of Inhibitors of Human S-Adenosylmethionine Decarboxylase: Studies of Adenine C[superscript 8] Substitution in Structural Analogues of S-Adenosylmethionine  

Energy Technology Data Exchange (ETDEWEB)

S-Adenosylmethionine decarboxylase (AdoMetDC) is a critical enzyme in the polyamine biosynthetic pathway and depends on a pyruvoyl group for the decarboxylation process. The crystal structures of the enzyme with various inhibitors at the active site have shown that the adenine base of the ligands adopts an unusual syn conformation when bound to the enzyme. To determine whether compounds that favor the syn conformation in solution would be more potent AdoMetDC inhibitors, several series of AdoMet substrate analogues with a variety of substituents at the 8-position of adenine were synthesized and analyzed for their ability to inhibit hAdoMetDC. The biochemical analysis indicated that an 8-methyl substituent resulted in more potent inhibitors, yet most other 8-substitutions provided no benefit over the parent compound. To understand these results, we used computational modeling and X-ray crystallography to study C{sup 8}-substituted adenine ...

2009-04-02

474

Neutronic aspects of the safety and environmental performance of silicon carbide as blanket structural material  

Energy Technology Data Exchange (ETDEWEB)

Safety and environmental assessments have been made of conceptual fusion power plant designs employing silicon carbide composites (SiC/SiC) as the first wall and blanket structure material. These have used similar analysis methods to earlier studies of designs based on vanadium alloy or low-activation martensitic steel, allowing direct comparisons. The very low short-term activation of silicon carbide results in an almost insignificant level of decay heat in postulated loss of coolant accidents, and a lower {gamma}-dose rate on the timescale of relevance to handling for maintenance operations. However on the longer time-scale, of interest in possible recycling operations, decommissioning and waste management, SiC/SiC appears to perform no better than vanadium alloy or low-activation martensitic steel, due in part to the activation of impurities in a realistic composition. Furthermore, its increased neutron transparency may result in higher ...

2001-04-01

475

Morphological classification and structural parameters for early-type galaxies in the Coma cluster  

CERN Document Server

We present the results of an isophotal shape analysis of three samples of galaxies in the Coma cluster. Quantitative morphology, together with structural and photometric parameters, is given for each galaxy. Special emphasis has been placed on the detailed classification of early-type galaxies. The three samples are: i) a sample of 97 early-type galaxies brighter than m_B = 17.00 falling within one degree from the center of the Coma cluster; these galaxies were observed with CCD cameras, mostly in good to excellent resolution conditions; ii) a magnitude complete sample of 107 galaxies of all morphological types down to m_B = 17.00 falling in a circular region of 50 arcmin diameter, slightly offcentered to the North-West of the cluster center; the images for this and the next sample come from digitized photographic plates; iii) a complete comparison sample of 26 galaxies of all morphological types down to m_R = 16.05 (or m_B \\simeq 17.5), also ...

1995-01-01

476

Isolation and characterization of humic acids from peat soil  

International Nuclear Information System (INIS)

In this study, two different humic acids extracted from England and China peat soil, as well as three purified products extracted from commercially available humic acids [Fluka (Fluka, Neu-Ulm, Germany, Alfa (Alfa Aesar, Ward Hill, USA) and Aldrich (Aldrich-Chemical Co, Gillingham-Dorset)] were obtained respectively with the modified IHSS (International humic substances society) procedure. The chemical and structural information of these humic acids were characterized by some techniques, such as elemental analysis, ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and electropotential titration. UV-Vis spectra, infrared spectra, values for elemental composition and the contents of carboxyls, phenolic hydroxyls and total acidities of these humic acids were acquired. It is indicated that all these humic acids are different in the aspect of chemical structure, respectively, and these ...

2009-05-01

477

Influence of metallurgical factors on corrosion and electrochemical behavior of structural materials  

Energy Technology Data Exchange (ETDEWEB)

An analysis of the passive films formed on amorphous alloys of the system Fe-10% Cr-5% Mo-P-metalloid and Fe-10% Cr-5% Mo-B-Si revealed that they are more markedly enriched with chromium in silicon-free alloys. In silicon-containing amorphous alloys the passive films were highly enriched with silicon, which occurred in these films in the form of a corrosion product close to SiO/sub 2/. As shown by the investigations of a study of the anodic behavior of Fe/sub 40/Ni/sub 40/P/sub 14/B/sub 6/ and Fe/sub 40/Ni/sub 38/Mo/sub 4/B/sub 18/, phosphorus facilitates the passivation of amorphous alloys by reducing the solution current in the active state and enriching the surface layers of the metal in the form of a black prepassivation film which also contains nickel and iron. The behavior of Fe-Ni amorphous alloys containing only boron as metalloid additive differs little from that of crystalline alloys of similar composition but without the boron. The authors note that in ...

1986-07-01

478

Influence of metallurgical factors on corrosion and electrochemical behavior of structural materials  

International Nuclear Information System (INIS)

An analysis of the passive films formed on amorphous alloys of the system Fe-10% Cr-5% Mo-P-metalloid and Fe-10% Cr-5% Mo-B-Si revealed that they are more markedly enriched with chromium in silicon-free alloys. In silicon-containing amorphous alloys the passive films were highly enriched with silicon, which occurred in these films in the form of a corrosion product close to SiO_2. As shown by the investigations of a study of the anodic behavior of Fe_4_0Ni_4_0P_1_4B_6 and Fe_4_0Ni_3_8Mo_4B_1_8, phosphorus facilitates the passivation of amorphous alloys by reducing the solution current in the active state and enriching the surface layers of the metal in the form of a black prepassivation film which also contains nickel and iron. The behavior of Fe-Ni amorphous alloys containing only boron as metalloid additive differs little from that of crystalline alloys of similar composition but without the boron. The authors note that in this survey they have considered the ...

1986-01-01

479

In-Situ Analysis of Electronic Properties of Passive Film on Fe by Photo-Electrochemical and Impedance Techniques  

Energy Technology Data Exchange (ETDEWEB)

Electronic properties of passive films formed on Fe at various applied potentials in pH 8.5 buffer solution were examined through the photocurrent measurement and impedance spectroscopy. Passive film formed on Fe at relatively low potentials was found to be r-FeOOH layer and internal r-Fe{sub 2}O{sub 3} layer. However, the r-FeOOH layer became unstable and disappeared at potentials below 400mV and hence may be an adsorbed layer. An electronic band structure model for the passive film of Fe was suggested on the basis of the spinel band model with involving two types of electronic excitation processes, i. e., the p-d and the d-d transition together. The effects of applied potential on the photocurrent behaviors of the passive film on Fe were explained appropriately by separating the photocurrent spectra depending on the transition type. The Mott-Schottky behavior for the passive film on Fe and the photocurrent variation with applied potential were also analyzed in ...

1999-04-01

480

Hybridization and Modification of the Ni/C{sub 60} Composites  

Science.gov (United States)

Hybridization and thermal evolution of the Ni+C{sub 60} composites, deposited on Si(001) at room temperature, were studied using Scanning Electron Microscopy, {mu}-Raman spectroscopy and Rutherford Backscattering. As-deposited, the hybrid films exhibited a granular nano-structure with Ni nano-particles encapsulated in C{sub 60} polymerized rinds. The Ni and C (C{sub 60}) distributions in a top layer were found homogeneous with a stable Ni/C (C{sub 60}) ratio; in the larger depth the distributions were inhomogeneous and their ratio dramatically varied. At elevated temperatures, all structural parameters were changed. In the subsurface layer Ni- and C (C{sub 60})-rich zones were formed (due to the induced phase separation), C{sub 60}-molecules decayed and their fragments were transformed into amorphous carbon (a-C). The free volume distribution of the stressed hybrid matter was analyzed by the Hg marker that (in a form of vapors) in-diffused in ...

2009-03-10

481

Human tissue factor pathway inhibitor (TFPI) gene: Complete genomic structure and localization on the genetic map of chromosome 2q  

Energy Technology Data Exchange (ETDEWEB)

Tissue factor pathway inhibitor (TFPI), a protease inhibitor that circulates in association with plasma lipoproteins (VLDL, LDL and HDL), helps to regulate the extrinsic blood coagulation cascade. The authors have cloned a 125-kb genomic region containing the entire human TFPI gene on six overlapping cosmids and prepared a restriction map of this contig to clarify gene structure. More than half (45 kb) of the 85-kb gene is occupied with 5[prime] noncoding elements: coding begins at exon 3. A HindIII RFLP identified with one cosmid was genotyped in the CEPH panel of 559 reference families. Linkage analysis using markers on human chromosome 2 located the TFPI gene on 2q, 36 cM proximal to D2S43(pYNZ15) and 13 cM distal to the crystalline [gamma]-polypeptide locus CRYGP1(p5G1). 31 refs., 3 figs., 3 tabs.

1993-08-01

482

Fuel storage basin seismic analysis  

International Nuclear Information System (INIS)

The 105-KE and 105-KW Fuel Storage Basins were constructed more than 35 years ago as repositories for irradiated fuel from the K East and K West Reactors. Currently, the basins contain irradiated fuel from the N Reactor. To continue to use the basins as desired, seismic adequacy in accordance with current US Department of Energy facility requirements must be demonstrated. The 105-KE and 105-KW Basins are reinforced concrete, belowground reservoirs with a 16-ft water depth. The entire water retention boundary, which currently includes a portion of the adjacent reactor buildings, must be qualified for the Hanford Site design basis earthquake. The reactor building interface joints are sealed against leakage with rubber water stops. Demonstration of the seismic adequacy of these interface joints was initially identified as a key issue in the seismic qualification effort. The issue of water leakage through seismicly induced cracks was also investigated. This issue, coupled with the ...

1991-10-15

483

Experimental simulation of heat transfer augmentation by break-jets in passive containment cooling system  

International Nuclear Information System (INIS)

The studies of forced jet augmentation of natural convection heat transfer are introduced. It investigates experimentally mixed convection and heat transfer augmentation by forced jets in a large rectangular enclosure with a vertical cooling surface. The experiment is designed to measure the key parameters governing the heat transfer augmentation by a forced jet, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio, on conditions simulating those of actual passive containment cooling systems and scales approaching those of actual containment buildings or compartments. The tests that cover a variety of injection modes will contribute to reveal the nature of mixing and stratification phenomena under accident conditions to a new generation of inherently safe reactors. With similarity considerations on governing equations, the heat transfer of mixed convection can be ...

2010-02-01

484

Evaluation of pipe whip impacts on neighboring piping and walls of the Ignalina Nuclear Power Plant  

Energy Technology Data Exchange (ETDEWEB)

Stress corrosion cracks have been discovered in Group Distribution Headers (GDH) at the Ignalina and Chernobyl Nuclear Power Plants. This increases the probability that a guillotine pipe break can occur that creates a whipping pipe (GDH) with the potential to damage surrounding structures-i.e. adjacent GDH and its attached piping or adjacent reinforced concrete compartment wall. The GDH is the most important component for reactor safety in case of an accident. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the ECSS into the GDH. Presented in this paper is the transient analysis of a Group Distribution Header following a guillotine break at the blind end of the header. Using a very conservative force loading function, the transient response of a whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is obtained using finite element methodology. The ...

2007-04-15

485

Electronic structure of passive films formed on molybdenum-containing ferritic stainless steels  

Energy Technology Data Exchange (ETDEWEB)

The effect of molybdenum on the electronic structure of the passive films formed on ferritic (Fe-Cr and Fe-Cr-Mo) stainless steels is examined by capacitance and photoelectrochemical measurements. The capacitance study is supported by a mathematical analysis of the Schottky barrier developed at the semiconductor-electrolyte interface in the case of a semiconductor with multiple bulk electronic states in the bandgap. The numerical simulations, based on the more general Mott-Schottky relation proposed, are in good agreement with the experimental results. It can be concluded that the capacitance behavior of the passive films is related to the contributions of a shallow donor level very close to the conduction band and a deep donor level at about 0.4 eV below the conduction band. The addition of molybdenum decreases the donor density of the deep level. Photoeffects observed for subbandgap photon energies reveal that this deep donor level behaves ...

1996-10-01

486

Effect of microalloying and thermomechanical processing on the structure and mechanical properties of constructional steel  

Energy Technology Data Exchange (ETDEWEB)

The effect of microalloying with carbide-forming (V,Ti,Nb) and rare-earth elements and of high-temperature thermomechanical processing (HTMP) on the structure, mechanical properties and low temperature behaviour of 38CrSi steel has been investigated. It has been shown that in the case of dissolution of carbides during heating for quench hardening, the tempering resistance of the steel increases. It has also been found that - as a result of HTMP - the susceptibility of the steel irreversible temper brittleness decreases, irrespective of the steel having been microalloyed or not. The data, originating from tensile testing and impact testing (with the help of laser interferometry) in the temperature range from +20 to -196 degC, has been explained in terms of fractographic analysis. It has been shown that microalloying and HTMP favour the occurrence of ductile microvoids in the fracture. On the other hand, HTMP and rare-earth elements changes the ...

1998-10-01

487

Development of magnetic drive packless valves for commercial purpose  

Energy Technology Data Exchange (ETDEWEB)

A study on development of magnetic drive packless valves for commercial purpose showed the results as follows; 1. Study on the radial rays effecting to the permanent magnets -Measurement of the strength of Nd-magnets according to irradiation of radial rays. 2. Effects of temperature on the magnetic driving device -Temperature dependency of the Nd-casting magnets. -Effects of temperature on the heat releasing fins of high-temperature valve. 3. Optimization of torque -Arranging method of permanent magnets -Measuring method and results of torque. 4. Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Calculation and design for the flat circular plates under pressure of the magnetic power transmitting device -Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Comparison of the characteristics between magnetic drive valve and ...

1995-09-01

488

Comparative study of the reactions of metal oxides with H[sub 2]S and SO[sub 2  

Energy Technology Data Exchange (ETDEWEB)

Primary objective was to investigate the effects of pore structure on capacity of porous metal oxides for removal of SO[sub 2] from power plant fuel gas and H[sub 2]S from hot coal gas. During this period, a comparative study was carried out on the direct reaction with H[sub 2]S and SO[sub 2] of the three limestones used as CaO precursors: Greer limestone, Georgia marble, and Iceland spar calcite. Sulfation was carried out at 750 and 850 C in a thermogravimetric analysis system under simulated high pressure (enough CO[sub 2] to prevent decomposition of CaCO[sub 3]). Results are presented as conversion vs time graphs. Mercury penetration and gas adsorption were used to analyze the structure. Activation energies and effective diffusivities were determined. A variable diffusivity shrinking-core model was used to analyze the data. In the future, this limestone study will be completed, and a study on supported CuO sorbent will ...

1992-01-01

489

B-spline methods for radial Dirac equations  

International Nuclear Information System (INIS)

Although B-spline techniques have been used to solve two-point boundary value problems with Dirac Hamiltonians for more than 20 years, the treatment of boundary conditions is still a matter of controversy. Spurious, non-physical, solutions are endemic when boundary conditions are not handled correctly. These pathological problems are absent when traditional finite difference methods are used as in computer packages such as GRASP. Accurate approximation using both finite differences and B-splines depends on controlling local approximation errors, and this common property suggests no a priori reason to suppose that B-spline algorithms should be more prone to generate spurious solutions. The relativistic Bloch operators of [24], when added to the Dirac differential operator, permit the construction of a self-adjoint differential operator for the two-point boundary value problem on a finite interval. Approximate solution of this problem exploiting the properties of B-splines in variational ...

2009-03-14

490

Acoustic metamaterials for sound focusing and confinement  

Energy Technology Data Exchange (ETDEWEB)

We give a theoretical design for a locally resonant two-dimensional cylindrical structure involving a pair of C-shaped voids in an elastic medium which we term as double 'C' resonators (DCRs) and imbedded thin stiff bars, that displays the negative refraction effect in the low frequency regime. DCRs are responsible for a low frequency band gap which hybridizes with a tiny gap associated with the presence of the thin bars. Using an asymptotic analysis, typical working frequencies are given in closed form: DCRs behave as Helmholtz resonators modeled by masses connected to clamped walls by springs on either side, while thin bars behave as a periodic bi-atomic chain of masses connected by springs. The discrete models give an accurate description of the location and width of the stop band in the case of the DCR and the first two dispersion bands for the periodic thin bars. We then combine our asymptotic formulae for arrays of DCR ...

2007-11-15

491

Acoustic metamaterials for sound focusing and confinement  

International Nuclear Information System (INIS)

We give a theoretical design for a locally resonant two-dimensional cylindrical structure involving a pair of C-shaped voids in an elastic medium which we term as double 'C' resonators (DCRs) and imbedded thin stiff bars, that displays the negative refraction effect in the low frequency regime. DCRs are responsible for a low frequency band gap which hybridizes with a tiny gap associated with the presence of the thin bars. Using an asymptotic analysis, typical working frequencies are given in closed form: DCRs behave as Helmholtz resonators modeled by masses connected to clamped walls by springs on either side, while thin bars behave as a periodic bi-atomic chain of masses connected by springs. The discrete models give an accurate description of the location and width of the stop band in the case of the DCR and the first two dispersion bands for the periodic thin bars. We then combine our asymptotic formulae for arrays of DCR and thin-bars to ...

2007-11-01

492

A risk based approach to assess the incidence of ice loads on small concrete dams  

International Nuclear Information System (INIS)

Some considerations regarding ice load in risk-based dam safety analysis are presented for small concrete dams. The most significant physical mechanisms leading to ice thrust on dams (such as thermal expansion and water level fluctuations) are outlined. Published literature on dam ice loads to examine ice load magnitude-return period relationships, sliding and overstressing failure mechanisms and structural performance criteria to resist ice loads, are also reviewed. Related loading combinations for structural safety evaluations were determined regarding the issue of simultaneity of ice loads with other events such as earthquakes. Parametric analyses were conducted on a small gravity dam section, 3m high, and a taller dam, 17.9 m high, to demonstrate the ultimate ice load carrying capability as a function of dam geometry and shear and tensile strengths of construction joints. Since the failure mechanism of a dam subjected ...

493

A comprehensive Network Security Risk Model for process control networks.  

Science.gov (United States)

The risk of cyber attacks on process control networks (PCN) is receiving significant attention due to the potentially catastrophic extent to which PCN failures can damage the infrastructures and commodity flows that they support. Risk management addresses the coupled problems of (1) reducing the likelihood that cyber attacks would succeed in disrupting PCN operation and (2) reducing the severity of consequences in the event of PCN failure or manipulation. The Network Security Risk Model (NSRM) developed in this article provides a means of evaluating the efficacy of candidate risk management policies by modeling the baseline risk and assessing expectations of risk after the implementation of candidate measures. Where existing risk models fall short of providing adequate insight into the efficacy of candidate risk management policies due to shortcomings in their structure or formulation, the NSRM provides model structure and an associated ...

2008-10-24

494

The importance of turbulence modelling in the design of a novel delivery system for a single-belt steel casting process  

Energy Technology Data Exchange (ETDEWEB)

In this work, a comprehensive model including heat transfer, fluid flow and solidification was used to evaluate the performance of a novel delivery system for a single-belt steel casting process. This near-net-shape casting, although still in development, is one of the most promising routes for casting of low-carbon steel in large scale. This paper focuses on the performance of a low-Re {kappa}-{epsilon} model that was employed to simulate the three-dimensional turbulent flows fully-coupled with heat transfer and macroscopic solidification. Simulations were run for the intended conditions of caster operation, and the results obtained with the {kappa}-{epsilon} were compared with the results obtained with an ad hoc viscosity model, where the molecular viscosity was boosted 100 times, uniformly throughout the computational domain. A semi-analytical solution was employed for validating the models and the results showed that the ad hoc viscosity model overestimated the ...

2000-01-01

495

Magnetic resonance imaging in multiple sclerosis. Imagerie nouvelle par resonance magnetique nucleaire au cours de la sclerose en plaques  

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging (MRI) has rapidly attained a major position among the examinations used in the diagnostic approach of multiple sclerosis because it is highly sensitive in demonstrating lesions. However, these lesional images may have several meanings, and there is the problem of distinguishing between oedema, which is said to reflect recent lesions, and gliosis which is thought to betray old lesions. The intrinsic MRI parameters studied (i.e. relaxation times) are unable to make this distinction, whereas it is provided by paramagnetic contrast media such as gadolinium. There is no correlation between the changes observed at MRI and the severity of the disease. Another problem is the accuracy of lesion localization, since visualization is predominantly macroscopic. This raises several questions about the demonstration of correlations between clinical signs and site of the lesion(s). At the moment, several teams of neuroradiologists are trying to find the ...

1991-09-15

496

Macroscopic consequences of calcium signaling in microdomains: A first passage time approach  

CERN Document Server

Calcium (Ca) plays an important role in regulating various cellular processes. In a variety of cell types, Ca signaling occurs within microdomains where channels deliver localized pulses of Ca which activate a nearby collection of Ca-sensitive receptors. The small number of channels involved ensures that the signaling process is stochastic. The aggregate response of several thousand of these microdomains yields a whole-cell response which dictates the cell behavior. Here, we study analytically the statistical properties of a population of these microdomains in response to a trigger signal. We apply these results to understand the relationship between Ca influx and Ca release in cardiac cells. In this context, we use a first passage time approach to show analytically how Ca release in the whole cell depends on the single channel kinetics of Ca channels and the properties of microdomains. Using these results, we explain the underlying mechanism for the graded relationship between Ca ...

2007-01-01

497

Hardening by point defects in neutron irradiated AlN and SiC  

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 hardening in irradiated ...

498

Evaluation of the mobility of an organic pollutant in triphasic conditions; Evaluation de la mobilite d'un polluant organique en conditions triphasiques  

Energy Technology Data Exchange (ETDEWEB)

Soil contamination by liquid organic pollutants represents a serious threat to phreatic ground water. These organic liquids get into the ground and migrate through the porous medium until they finally reach the aquifer. After a critical study of the literature, we listed various existing multiple displacements under three-phase conditions of a disconnected polluting phase that may or not spread over water. The aim of this thesis is to model (at pore scale level) and integrate in the pore network model the various flows that occur when three phases (gas, pollutant and air) are present in a porous medium. The porous medium is supposed completely water-wet. The polluting phase may be connected or not, and the spreading coefficient of the pollutant over water may either be positive or negative. The goal of our study is to obtain macroscopic parameters such as relative permeabilities and capillary pressure. These parameters can be then incorporated in a larger-scale ...

2006-10-15

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Effective Dynamics, Big Bounces and Scaling Symmetry in Bianchi Type I Loop Quantum Cosmology  

CERN Document Server

The detailed formulation for loop quantum cosmology (LQC) in the Bianchi I model with a scalar massless field has been constructed. In this paper, its effective dynamics is studied in two improved strategies for implementing the LQC discreteness corrections. Both schemes show that the big bang is replaced by the big bounces, which take place up to three times, once in each diagonal direction, when the area or volume scale factor approaches the critical values in the Planck regime measured by the reference of the scalar field momentum. These two strategies give different evolutions: In one scheme, the effective dynamics is independent of the choice of the finite sized cell prescribed to make Hamiltonian finite; in the other, the effective dynamics reacts to the macroscopic scales introduced by the boundary conditions. Both schemes reveal interesting symmetries of scaling, which are reminiscent of the relational interpretation of quantum mechanics and also suggest ...

2007-01-01