In situ texture analysis under applied load
International Nuclear Information System (INIS)
The in-situ measurement of a crystallographic texture is a special type of a non-destructive measurement, which need special equipments. Due to the high photon flux and the excellent brilliance high energetic synchrotron radiations are a fantastic tool particular in fast experimentation. Moreover, a high penetration power allows the investigation of standard tensile sample of the DIN-norm. A loading device with a power up to 20 kN was installed at the hard wiggler beamline BW5 (HASYLAB-DESY) to perform in-situ strain and in-situ texture analysis. Using 100keV X-rays one gets short wavelength so that a 2D image-plate detector offers a wide range of diffraction pattern within the first 10 degree in 2 theta. Thermal neutron is another radiation with a high penetration power, which is the standard method for global texture analysis of bulk samples. As an example rectangular extruded Mg- ...
International Nuclear Information System (INIS)
This paper presents a new methodology to create realistic 3D microstructures of polycrystals. The virtual microstructures are based on statistical data describing the morphological and crystallographic textures of a sample, obtained from an EBSD analysis. In addition, the methodology can reproduce the observed surface on top of the simulated microstructure. This feature allows finite element calculations on these virtual aggregates to be compared to experimental results of mechanical tests. Such a comparison leads to the identification of the mechanical parameters of constitutive laws, such as critical resolved shear stress and strain hardening, using an optimization algorithm. Two materials were simulated in this study: TiAl and grade 702 zirconium. The first one presents twins inside the microstructure and the second one has an anisotropic texture. Based on 2D simulations, the important parameters ...
Texture development and texture influence on the mechanical properties of the Mg-alloy AZ31
Energy Technology Data Exchange (ETDEWEB)
The texture influence on tensile tests of AZ31, one of the common Mg alloys, has been studied. Starting material was a rectangular extruded bar, which has a strong texture. Due to the preparation of three tensile samples with 0 , 45 , 90 to the extrusion direction, the initial bar texture influences differently on the mechanical behaviour under tensile load. This results in a variation of the yield strength (90 MPa and 175 MPa) the ultimate tensile strength (250 MPa - 278 MPa) and the final texture. Experimental texture analysis was completed by texture simulations using the VPSC-model (visco plastic self-consistent). The good agreement between experimental and simulated pole figures allows the determination of the activated deformation modes related to the initial texture. (orig.)
2002-07-01
Texture development of AZ31 magnesium alloy during ECAE processing
Energy Technology Data Exchange (ETDEWEB)
Mg-3%Al-1%Zn (AZ31) alloy was subjected to ECAE processing at 523 and 573 K. Microstructure observation and texture analysis were carried out using optical microscope and SEM-EBSD technique in order to investigate the process of microstructural changes including texture development during ECAE processing. Grain refinement during ECAE processing is enhanced by dynamic continuous recrystallization. The texture of the ECAE-processed AZ31 alloy specimens change with ECAE processing temperature, and the textural changes relate to deformation mechanisms that change with ECAE processing temperature. (orig.)
2003-07-01
Mechanical properties and texture evolution of AZ31 Mg alloy during equal channel angular pressing
Energy Technology Data Exchange (ETDEWEB)
Microstructure and texture evolution in the AZ31 Mg alloy subject to equal channel angular pressing (ECAP) have been investigated and correlated with the mechanical properties. When AZ31 Mg alloy was ECAPed up to 8 passes following the route B{sub c}, grain refinement occurred effectively. Texture was also changed during ECAP. The original fiber texture of the extruded AZ31 Mg alloy changed to a new texture component of (01 anti 11)[5 anti 2 anti 3 anti 1], and the texture of (01 anti 11)[5 anti 2 anti 3 anti 1] orientation was rotated to (13 anti 46)[7 anti 5 anti 20] orientation after 6-pass ECAP process. The variation of the strength with the pass number was explained by the texture and grain size. The strength data of AZ31 Mg alloys followed the standard Hall-Petch relationship when the similar texture was retained during the ECAP ...
2005-07-01
Textured silicon nitride: processing and anisotropic properties
International Nuclear Information System (INIS)
Textured silicon nitride (Si_3N_4) has been intensively studied over the past 15 years because of its use for achieving its superthermal and mechanical properties. In this review we present the fundamental aspects of the processing and anisotropic properties of textured Si_3N_4, with emphasis on the anisotropic and abnormal grain growth of #beta#-Si_3N_4, texture structure and texture analysis, processing methods and anisotropic properties. On the basis of the texturing mechanisms, the processing methods described in this article have been classified into two types: hot-working (HW) and templated grain growth (TGG). The HW method includes the hot-pressing, hot-forging and sinter-forging techniques, and the TGG method includes the cold-pressing, extrusion, tape-casting and strong magnetic field alignment techniques for #beta#-Si_3N_4 seed crystals. Each processing technique is ...
2008-07-01
Texture development of ARB processed Mg/Al multilayers
International Nuclear Information System (INIS)
Our work deals with accumulative roll bonding (ARB) of pure Mg sheet (0.9mm thickness) and of Al5052 sheet (0.5mm). A stacking of Al-Mg-Al was firstly rolled to 50% reduction at 400"0C and secondly ARB has been processed up to 3 cycles. In such multilayers as well as highly mixed composites of two-phased system texture development, phase reactions and strain accumulation are of basic interest, which needs a combination of different experimental methods for characterization. The present paper deals with the global texture evolution measured by thermal neutrons to average always over the whole sample thickness, SEM and optical microscopy indicates the macroscopic development of Mg and Al layers. The initial materials show typical and strong basal plane texture of hexagonal Mg (17.9mrd) and a recrystallization texture of cubic Al (8.5mrd). Co-deformation of Al/Mg/Al leads to strong decrease of both ...
2010-07-01
Study of nuclear materials by neutron scattering.
Following studies on fiber and sheet texture of hexagonal crystal system in 1988, work has been extended to tube texture. Using the zircaloy-4 fuel cladding of Wolsung-type reactor as specimen, six pole figures for different crystallographic planes were m...
1990-01-01
International Nuclear Information System (INIS)
Formation of basis type texture at rolling of Ti + 6.0% Al + 1.5% V + 1.0% Mo system alloy with initial prismatic texture is investigated by means of X-ray techniques. Variations of mechanical features in titanium alloy sheets depending on temperature-deformation conditions of rolling are investigated. Main conditions for formation of the intensive basis textute in the investigated alloy sheets which provides for isotropic properties in sheet plane and for increased ductility are determined.
Hydrogen effect or texture and deformation mechanism in #beta#-titanium alloy cold rolling
International Nuclear Information System (INIS)
The relationships of hydrogen alloyed #beta#-titanium alloy deformation behaviour to its microstructure and texture are investigated. It is shown that plasticity increases and strain induced texture changes at low hydrogen contents (0.1-0.2 mass %). Possible mechanisms responsible for specific features of #beta#-Ti alloy deformation are discussed. The study is made using alloy VT35 doped with hydrogen
1999-09-01
Calculation method of elastic moduli of textured two-phase titanium alloys
International Nuclear Information System (INIS)
On the basis of symmetry way of texture description a calculation method of elastic moduli of two-phase titanium alloys with rolling texture has been suggested. Efficiency of the calculation formulas is checked by comparing the calculation results of Young modulus anisotropy in the sheet plane of (#alpha#+#beta#)-titanium alloy VT23 with the experimental data.
Occurence of active layer optical properties on some Lasing characteristics dye-doped Ch LC
Effect of a planar texture quality and its thickness on lasing spectrums and thresholds in dye-doped cholesteric liquid crystal (CLC) of steroid type is explored. Transition from the qualitative planar texture to the poor texture quality is accompanied by change of characteristic mode structures and by shift of barycentre in the long-wave side and the considerable growth of the lasing threshold. It is found that in the CLC texture created by substrates with perpendicular directions of orientation the stable single-mode lasing takes place. The nature of oscillated modes in such texture is caused by phase jump. The gained results show that in steroid CLC, unlike induced one, lasing spectrums is possible to feature with the coupled wave model. Key words: steroidal cholesteric liquid crystal, distributed feedback lasing, oscillation thresholds, phase defect of periodical structure, ...
2010-01-01
Hydrogen effect on the deformation and annealing textures in the #beta# titanium alloy VT35
International Nuclear Information System (INIS)
A study is made into textures of deformation and primary recrystallization forming in a #beta#-titanium alloy doped with hydrogen in amounts from 0.04 to 0.55 mass. %, on cold rolling with a 70%-reduction and dehydrogenating annealing at 860 deg C. It is shown that a volume fraction of recrystallization texture components is determined by the nature of corresponding deformation texture, in its turn, depending on hydrogen concentration in the alloy. At low hydrogen contents the main texture components are #left brace#111#right brace# and #left brace#001#right brace#. A hydrogen content increase up to 0.09 - 0.18 mass. % results in formation of dominant components of #left brace#111#right brace# and #left brace#112#right brace#
2003-12-01
Investigation of texturization for crystalline silicon solar cells with sodium carbonate solutions
Energy Technology Data Exchange (ETDEWEB)
We investigate a new texturization technique for crystalline silicon solar cells with sodium carbonate (Na{sub 2}CO{sub 3}) solutions. We show the dependence of the hemispherical surface reflectance on solution temperature, the etching time and the Na{sub 2}CO{sub 3} concentration. Furthermore, we investigate what element in Na{sub 2}CO{sub 3} solution influences the texturing for reducing the texturing time. As a result of experiments, we find it possible to get low reflectance in a shorter texturing time by the addition of NaHCO{sub 3}. The size of texture becomes smaller by the addition of NaHCO{sub 3} but the etching rate does not change. We conclude carbonic ion and/or its compound seems to play an important role as the initiator of pyramidal structure. This texturing method is cost effective because there is no need of expensive IPA, and the surface ...
2000-04-01
Radiation dose in computerized tomography
International Nuclear Information System (INIS)
Dosimetric studies in 80 patients examined with the tomographic device 'Somatom' are reported. The gonad doses are compared to those of conventional radiographic techniques.
Clinical application of FCR for the portable chest radiographs in ICU
Energy Technology Data Exchange (ETDEWEB)
The diagnostic value of the portable chest radiography obtained with Fuji computed radiography (FCR) was evaluated in comparison with conventional images in 23 patients who were admitted to ICU in Yokohama City University Hospital. On the whole , FCR produced more exellent images than conventional screen-film radiographs. Especially the evaluation for the demonstration of the catheters, the endotracheal tubes and the tracheal shadows obtained high score. We discuss the clinically utility of FCR for the portable chest radiographs in ICU. (author).
1989-08-01
Clinical application of FCR for the portable chest radiographs in ICU
International Nuclear Information System (INIS)
The diagnostic value of the portable chest radiography obtained with Fuji computed radiography (FCR) was evaluated in comparison with conventional images in 23 patients who were admitted to ICU in Yokohama City University Hospital. On the whole , FCR produced more exellent images than conventional screen-film radiographs. Especially the evaluation for the demonstration of the catheters, the endotracheal tubes and the tracheal shadows obtained high score. We discuss the clinically utility of FCR for the portable chest radiographs in ICU. (author).
1989-01-01
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 ...
1997-04-04
Seismic and Rockphysics Diagnostics fo Multiscale Reservoir Textures
Energy Technology Data Exchange (ETDEWEB)
We have continued to finish up our work on analyzing relationships between elastic properties and rock microstructure. We have worked on theoretical models for the effects of sorting and packing on elastic moduli and seismic velocities. After analyzing the scanning acoustic images of shales to quantify textures at different scales, we are now using theoretical inclusion models to quantify the elastic property variation with texture. In the closing phases of this project most of our efforts are now focused on writing up the results and preparing the final reports.
2005-02-01
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
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.
Microstructure, texture and mechanical properties of the magnesium alloy AZ31 processed by ECAP
Energy Technology Data Exchange (ETDEWEB)
To investigate the influence of equal channel angular pressing on the microstructure and texture of the magnesium alloy AZ31, electron backscattering diffraction and well as neutron diffraction experiments were carried out. Through these experiments it was possible to trace the microstructure and texture evolution with strain accumulated with the increasing number of equal channel angular pressing passes. It was further demonstrated by subsequent compression tests that the microstructural changes produced by equal channel angular pressing have a beneficial effect on both the compressive strength and ductility of AZ31. (orig.)
2008-01-15
Energy Technology Data Exchange (ETDEWEB)
By characterising the microstructure, quantitative image analysis allows to draw conclusions on the mechanical properties of materials. On fine microstructures with low contrast, e.g. of hardened steels, texture analysis has to be applied for quantification. Feeding texture parameters according to Haralick into a trained neural network, a correlation between the microstructure and the hardness of the steels C45 and 100Cr6 can be achieved. (orig.)
2001-08-01
Energy Technology Data Exchange (ETDEWEB)
A full scale experiment was carried out to investigate the texture characteristics of the falling water of free falling and slope failing types. According to the increase of Reynolds number, the texture of falling water was classified into three categories for both types: stability of free surface, transition and whole turbulence. In the first category the stability of the free surface was related to the growth of minute disturbance. Surface tension works as a counter, force to the disturbance in free falling water, and gravity in slope falling water. 14 refs., 15 figs., 3 tabs.
1998-05-21
Radiographic features of Ewing's sarcoma of the bones of the hands and feet
International Nuclear Information System (INIS)
The radiographic features of Ewing's sarcoma of the bones of the hands and feet are reviewed utilizing cases obtained from the Mayo Clinic patient files and the consultation files of Drs. D.C. Dahlin and K.K. Unni. This series consists of a total of 43 cases of pathologically proven Ewing's sarcoma involving the small bones of the hands and feet. The classic radiographic features of Ewing's sarcoma in the long bones, including lytic, permeative destruction, aggressive periosteal reaction, cortical violation, and a soft tissue mass, are also seen in the bones of the hands and feet, with similar frequency. These classic features are most commonly present in lesions affecting the short tubular bones. Lesions affecting the tarsal bones more often demonstrate atypical radiographic features. These atypical radiographic appearances may play a role in the reported delay in diagnosis of Ewing's sarcoma within ...
2001-03-01
Energy Technology Data Exchange (ETDEWEB)
Cold deformation of YBa{sub 2}Cu{sub 3}O{sub 7-x}(phase 123, T{sub c} = 88.5-92 K) powders and strips causes partial decomposition of the 123 phase, a reduction in the degree of orthorhombicity of the structure up to almost complete degradation, and a decrease in T{sub c}. When they are deformed, yttrium high temperature superconductors acquire basal (001) (110) texture with high pole density (13-15 arbitrary units), low scattering angle ({+-} 6deg--7deg from the normal direction), and a weak preference for a, b or a + b in the rolling direction; traces of (139) orientations may also be found. This texture is known to be favourable for increasing j{sub k}. The combined effect of cold deformation and a carbon-containing binder leads, however, to a complete loss of superconductivity at 77 K or above. Depending on the regime of subsequent annealing, the following effects may be observed: degradation of the orthorhombic structure with a decrease in ...
1991-09-20
THE OGIP FORMAT FOR 2-D (IMAGE) POINT SPREAD FUNCTION ... - NASA
tial/angular spreading of incident photons from a point source caused by the instrument (de- .... Filter. CDTP0001= 'DATA. ' / Type of calibration. CCNM0001= '2D_PSF ' ... the final resolution of sigma=0.5 arcmin in all energy bands. ...
UK PubMed Central (United Kingdom)
BackgroundRecessive mutations in guanylate cyclase-1 (Gucy2d) are associated with severe, early onset Leber congenital amaurosis-1(LCA1). Gucy2d...Full Text Available
UK PubMed Central (United Kingdom)
Purpose:To investigate the clinical usage of dose verification of Helical Tomotherapy plans by using 2D-array ion chambers, and to develop an efficient way to validate the dose delivered...Full Text Available
UK PubMed Central (United Kingdom)
BackgroundIn current comparative proteomics studies, the large number of images generated by 2D gels is currently compared using spot matching algorithms. Unfortunately, differences...Full Text Available
Longitudinal changes in extended roles in radiography
Energy Technology Data Exchange (ETDEWEB)
Purpose: The purpose of this research was to identify the extent and scope of changes to radiography practice. Method: Questionnaires were sent to radiology managers at acute National Health Service (NHS) hospitals in 2000 as a follow-up to an initial survey conducted in 1998. Information was sought on region, teaching/non-teaching status, the nature of extended role tasks undertaken and the year in which these tasks were first undertaken. Results: Some 172 questionnaires were returned from a total of 253 dispatched (68%). In 161 hospitals radiographers administered intravenous injections and performed barium enemas in 119 hospitals, while a red-dot system was in operation in 141 hospitals. Reporting by radiographers had increased since 1998. Replies indicated that, at 124 hospitals, radiographers were reporting in ultrasound. Skeletal reporting was the second most-frequently-reported activity, with 63 hospitals indicating ...
2002-11-01
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 ...
2009-11-18
In-plane crystallographic texture of bcc metal films on amorphous substrates
International Nuclear Information System (INIS)
The authors show that dramatically different in-plane crystallographic textures can be produced in body centered cubic (bcc) metal thin films deposited under different conditions. The orientation distribution of polycrystalline bcc thin films on amorphous substrates often has a strong (110) fiber texture, and an in-plane texture may develop when deposition takes place with an off-normal incidence flux of energetic ions or atoms. Three orientations in Nb films have been observed in which the energetic particle flux coincides with crystal channeling directions. In-plane orientations in Mo films have also been obtained in magnetron sputtering systems. The selected orientations are reviewed, and examples are given in which the in-plane orientation of Mo deposited in two similar magnetron system differs by a 90 deg C rotation. The origins of in-plane texture in rectangular magnetron sputtering systems are ...
1997-04-04
Energy Technology Data Exchange (ETDEWEB)
The principle of radiodiagnosis consists in the fact the X-ray beam is attenuated at different degrees by distinct tissues. For this reason, the anatomical structures have distinct radiological opacities, that produce the radiographic image. The progresses in radiology are related to the development if new radiographic image formation systems that enable an amplification in the quality, with low dose and/or risk to the patient. The objective of this work is the sensitometric valuation of a screen-film combination, that is still the most used, for the standardization, of radiographic images. Thinking about this, were constructed homogeneous phantoms of the chest, skull and pelvis, for the calibration of X-ray beams, with the purpose of obtaining radiographic images of good quality, basing in the routine of a radiodiagnosis service and in the scientific knowledge. Questions were approached about the ...
1996-12-31
Opportunistic esophagitis in AIDS: Radiographic diagnosis
International Nuclear Information System (INIS)
Between 1983 and 1986, 35 of 90 patients with acquired immunodeficiency syndrome (AIDS) had double-contrast esophagograms to rule out opportunistic esophagitis. The radiographs were reviewed without knowledge of the clinical or endoscopic findings. Candida esophagitis was diagnosed radiographically in 17 patients who had varying degrees of plaque formation and viral esophagitis in three who had discrete ulcers without plaques. All three patients with viral esophagitis (herpes in 2 and cytomegalo virus in one) and 15 of 17 with Candida esophagitis had endoscopic and/or clinical corroboration of the radiographic diagnosis. Thus, the authors' experience suggests that fungal and viral esophagitis can often be differentiated on double-contrast esophagography, so that appropriate antifungal or antiviral therapy can be instituted without need for endoscopic intervention.
Evaluation of digital radiography (Fuji computed radiography) for portable chest radiographs in ICU
Energy Technology Data Exchange (ETDEWEB)
To evaluate the usefulness of portable chest radiographs by Fuji computed radiography (FCR) in ICU, FCR radiographs of 56 patients who were admitted to General Intensive Care Unit of Keio University Hospital were compared with the conventional portable images. Because FCR could show two differently processed images in one film and allowed a wide range of image reproduction, visualization of the trachea, bone soft tissues and catheters by FCR was easier than that by the conventional radiography. Repeated radiographs by FCR had similar optical densities and limited exposure errors. Furthermore, radiation was reduced than that of the conventional radiography. In conclusion, FCR is thought to be a useful technique for portable chest radiography in ICU patients. (author).
1992-12-01
Evaluation of digital radiography (Fuji computed radiography) for portable chest radiographs in ICU
International Nuclear Information System (INIS)
To evaluate the usefulness of portable chest radiographs by Fuji computed radiography (FCR) in ICU, FCR radiographs of 56 patients who were admitted to General Intensive Care Unit of Keio University Hospital were compared with the conventional portable images. Because FCR could show two differently processed images in one film and allowed a wide range of image reproduction, visualization of the trachea, bone soft tissues and catheters by FCR was easier than that by the conventional radiography. Repeated radiographs by FCR had similar optical densities and limited exposure errors. Furthermore, radiation was reduced than that of the conventional radiography. In conclusion, FCR is thought to be a useful technique for portable chest radiography in ICU patients. (author).
1992-01-01
Cost Sensitivity Analysis for Radiology Department Planning
UK PubMed Central (United Kingdom)
Two complementary computer programs have been developed for forecasting the demands and evaluating the costs of proposed radiographic facilities. The models are employed here in analyses of the sensitivity...Full Text Available
1971-01-01
Clinical evaluations of intra-arterial subtraction angiography using Fuji computed radiography
International Nuclear Information System (INIS)
Intra-arterial subtraction angiography(IADSA) using Fuji computed radiography(FCR) was performed on 130 patients with cervical, pelvic, peripheral and abdominal diseases. It was compared with conventional angiography(radiographs produced by combining photographic film with an intensifying screen) performed on same patients. Radiographs produced by FCR were better than conventional radiographs in cervical, pelvic and peripheral angiography. In the abdominal angiography using FCR, there was misregistration artifact in some cases, but in hepatic angiography, the new radiographs under the injection of small amount of contrast medium(about 10ml) and the short exposure duration(about 10 seconds) were excellent. It was as valuable as conventional angiography (infusion hepatic angiography) for diagnosing hepatic neoplasms. (author).
1985-01-01
Energy Technology Data Exchange (ETDEWEB)
Evaluation and interpretation of CT colonography is based on both 2D and 3D techniques. The 2D techniques are popular mainly because the time needed for evaluation is short. The 3D techniques allow better definition than the 2D techniques, especially of polyps close to folds or at the base of a fold. The evaluation strategies generally accepted so far (primarily 2D, with 3D for problem cases, or vice versa) demand knowledge of both 2D and 3D techniques. Newer 3D visualization techniques help make it possible to acquire more complete and faster recording particularly of areas that are not easily accessible to endoscopic examination. These user-friendly developments are thus well suited to improving the detection and the security of detection of polyps. It must be remembered that ...
2008-02-15
The deformation texture in an AZ31B magnesium alloy
Energy Technology Data Exchange (ETDEWEB)
Extruded and hot-rolled 200 C {proportional_to} 500 C AZ31B plates were studied their texture using ODFs analysis. The as-extruded specimen has the strongest intensity of (0001)-ND fiber and 300 C and 400 C hot-rolled ones have the next, but the 200 C hot-rolled one has the lowest intensity. Compared with the corresponding tensile properties, this feature evidents that a pronounced (0001) basal texture will reduce ductility of AZ31B alloy. The ODFs results also indicate that (05 anti 52)- and (01 anti 10)-ND fibers are related to the ductility of AZ31B alloy. (orig.)
2003-07-01
Strain and Texture in Al-Interconnect Wires Measured by X-Ray Microbeam Diffraction
Energy Technology Data Exchange (ETDEWEB)
The local strain and texture in Al interconnect wires have been investigated using white and monochromatic x-ray microbeams on the MHATTCAT undulator beam line at the Advanced Photon Source. Intergrain and intragrain orientations were obtained with ~0.01 degree sensitivity using white beam measurements on wide Al pads (~100 Mu-m) and thin (2 Mu-m) Al wires. Orientation changes of up to 1 degree were found within individual grains of the (111) textured Al interconnects. Deviatoric strain measurements indicate small intragranular strain variations, but intergranular strain variations were found to be quite large.
1999-04-05
Microstructure and mechanical properties of magnesium alloy AZ31B laser beam welds
International Nuclear Information System (INIS)
Microstructure and properties of a Mg AZ31B laser beam weld without filler are studied using electron microscopy, X-ray diffraction and mechanical tests. The microstructure of the weld is characterized by a narrow heat affected zone, columnar grains and precipitate coarsening in the fusion zone. Texture in the fusion zone is significantly different from the texture of the base material. The residual stress distribution observed is similar at the top and the bottom of the weld, maximum tensile residual stress values are observed in the fusion zone. Tensile tests reveal differences in the mechanical behavior of the fusion zone and the parent material, which can be related to the differences of texture and the resulting deformation mechanisms.
2008-06-25
Improving the sheared edge in the blanking of commercial AZ31 sheet through texture modification
British Library Electronic Table of Contents (United Kingdom)
Commercial rolled magnesium sheets of alloys AZ31 (Mg-3 mass%Al-1 mass%Zn) and ZE10 (Mg-1 mass% Zn-<1 mass% Rare Earths) in O-temper condition were used for blanking experiments near room temperature. A serrated fracture surface can be observed in case of AZ31 but not in case of ZE10. During the shearing process of the AZ31 sheet, many micro cracks parallel to the sheet plane are generated in the shearing zone. These micro cracks lead to the formation of loose particles during the shearing operation, which interfere with further processing of the part and incur additional costs by increasing the scrap rate. It is found that the strong basal texture of this alloy is an important reason for the generation of such serrated cracks. In this paper a new method of selective texture modification i...
2011-01-01
Hydrogen effect on cold rolling texture of stable #beta#-titanium alloy
International Nuclear Information System (INIS)
A study was made into microstructure and texture of cold rolled titanium alloy VT-35 with various hydrogen content aimed to reveal hydrogen influence on the mechanism of cold plastic deformation by rolling. Experiments were carried out using sheets 1.2 mm thick hydrogenated up to hydrogen concentrations from 0.06 to 0.554 mass. %. All specimens constituted a single-phase FCC #beta#-solid solution. It is shown that small hydrogen additions have a plasticizing effect on #beta#-titanium alloys in their cold rolling. The character of texture is dependent on hydrogen concentration and determined by deformation mechanism. 6 refs.; 5 figs.
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 ...
1996-10-01
Two-phase fluid flow measurements in small diameter channels using real-time neutron radiography
International Nuclear Information System (INIS)
A series of real-time, neutron radiography, experiments are ongoing at the Texas A and M Nuclear Science Center Reactor (NSCR). These tests determine the resolving capabilities for radiographic imaging of two phase water and air flow regimes through small diameter flow channels. Though both film and video radiographic imaging is available, the real-time video imaging was selected to capture the dynamic flow patterns with results that continue to improve. (author)
1994-04-05
Quasilinear theory of the 2D Euler equation
Motivated by the numerical investigations of Laval, Dubrulle & Nazarenko (1999), we develop a quasilinear theory of the 2D Euler equation and derive an integro-differential equation for the evolution of the coarse-grained vorticity. This equation respects all the invariance properties of the Euler equation and conserves angular momentum in a circular domain and linear impulse in a channel (as well as in an infinite domain). The explicit energy is not rigorously conserved as it is partly transfered into fine-grained fluctuations but the total energy is conserved. We prove a H-theorem for the Fermi-Dirac entropy and make the connection with statistical theories of 2D turbulence.
2000-01-01
The influence of a seed crystal on the texture of a bulk YBaCuO specimen
International Nuclear Information System (INIS)
To investigate the dependence of the local texture of parts of an YBaCuO specimen on the distance of the seed crystal from the position of the part of the specimen, a very good textured YBaCuO specimen was cut into 9 rectangular pieces and into 12 boundary pieces of the cylindric original specimen. From the individual parts of the YBaCuO specimen the texture was measured by neutron diffraction at the Geesthacht reactor with an equal area raster. The grid width was 1 up to 10 deviation from the cylinder axis of the original YBaCuO cylinder and 2 from 10 deviation until 20 deviation. From the sum of the counted neutrons on small circles on the pole sphere the individual values of the distributions of the angular deviations of the c-axes of the crystalline domains from the cylinder axis have been calculated. The mean deviation of the c-axes from the axis of the original cylinder increases from the inner part with the seed ...
UK PubMed Central (United Kingdom)
The noninvasive assessment of cardiac function is of first importance for the diagnosis of cardiovascular diseases. Among all medical scanners only a few enables radiologists to evaluate the local cardiac...Full Text Available
2009-01-01
Influence of the porous texture of coals on their hydrogenation processes catalyzed by Fe
Energy Technology Data Exchange (ETDEWEB)
Nine coals from Spanish, British, German and American mining basins were hydrogenated using Fe catalyst precursors (red mud and FeSO{sub 4}), without solvent at 300, 350, and 400 {degree}C and 10 MPa of H{sub 2}. Overall conversion and product distribution are related to the textural characteristics of the original coals and are studies throughout the distinct hydrogenation processes. Results reveal that with FeSO{sub 4} as a catalyst precursor, conversions increase with coal surface area. However, when red mud (RM) is used, conversions are independent of coal textural characteristics. Higher conversions are obtained with FeSO{sub 4} than with RM at 300 and 350 {degree}C whereas at 400 {degree}C higher conversions are obtained with RM. This different catalytic activity is also reflected in the changes of the textural characteristics observed in each case. Up to 350 {degree}C, the residues from FeSO{sub 4}-catalyzed ...
1995-03-01
Effects of local texture and grain structure on the sputtering performance of tantalum
Energy Technology Data Exchange (ETDEWEB)
Tantalum and tantalum-based thin films have gained precedence as the diffusion barrier for copper interconnects used in the latest generation of integrated circuits (ICs). The paper presents insight and observations on the covariance of texture and grain size of wrought tantalum sputtering targets and their influence on sputtering performance. Previous studies involving deposition trials of tantalum targets of varying metallurgical character had demonstrated that both grain size and textural homogeneity is critical for assuring reliable sputtering performance of tantalum. Subsequently, a model had been proposed to prescribe how localized texture bands and orientation clusters in tantalum are effectively resistant to sputter erosion. In this paper, results of atomic force microscopy (AFM) and orientation imaging microscopy (OIM{sup TM}) analyses on the eroded surface of a tantalum sputtering target are presented. Initial ...
2002-07-01
Aluminum nitride precipitation and texture development in batch-annealed bake-hardening steel
Energy Technology Data Exchange (ETDEWEB)
A model is presented that describes the development of texture during the production process of bake-hardening steel recrystallized in a batch-annealing furnace. Proper conditions are analyzed to generate a pronounced {gamma}-fiber texture and a pancake microstructure that shows superior deep drawability. The {gamma}-fiber texture is assumed to be caused by the interaction between tertiary precipitating aluminum nitride particles and the recrystallization process during heating in the furnace. Deep drawability is presented in terms of the logarithmic {gamma}- and {alpha}-fiber X-ray intensity ratio. The computer simulation of the coupled aluminum nitride precipitation and recrystallization kinetics is based on an iterative procedure. A comparison between simulation results and available experimental data proves the ability of the model to predict the final deep drawability, taking into account the initial aluminum and ...
1999-06-01
notes4.htm - NASA's History Office
Subcommittee of the Joint Committee on Atomic Energy of the United States, Outer Space Propulsion by Nuclear Energy, hearings, 85th Cong., 2d sess., 22, ...
Sandia National Labs: PCNSC: Departments: Semiconductor Material...
For coupled quantum wires and dots, tunneling effects and coherent transport for quantum computing are being studied. In 2D systems, electron-hole bilayers for exciton...
2011-07-05
Planet Forming Protostellar Disks - NASA Technical Report Server ...
terms of 11) numerical models, 2D SPH simulations, and analytic models. The 1D model was useful for determining the evolution over very long timescales. ...
UK PubMed Central (United Kingdom)
The processes of neuronal outgrowth and guidance have typically been studied in classic 2D cell culture systems that do not recapitulate topographical cues present in the in vivo extracellular matrix...Full Text Available
2011-07-01
Appendix A 1994 Fish and Wildlife Service and National Marine Fisheries Service
... is not a "significant portion of its range." Asarco, Inc. v. EPA, 616 F.2d 1153, 1159 ( ... ...
British Library Electronic Table of Contents (United Kingdom)
A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparabl...
2009-01-01
Texture of YBa_2Cu_3O_7_-_x superconductor thick films
International Nuclear Information System (INIS)
YBa_2Cu_3O_7_-_x thick films have been deposited on silver sheets and MgO single crystals by spray pyrolysis. Film texture is related to film thickness and sintering temperature. The X-ray intensity ratio of the 005 peak to the 110 peak is higher for thin films deposited at the higher temperatures. However, elevated temperatures promote copper diffusion and second-phase formation in films deposited on silver. Films deposited on MgO can have larger grain sizes and are more oriented than those deposited on silver.
1991-05-02
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
Recrystallization during and following hot working of magnesium alloy AZ31
Energy Technology Data Exchange (ETDEWEB)
The microstructures of magnesium AZ31 are examined following hot compression testing and annealing. The grain size, fraction dynamically recrystallized and, in a couple of cases, the crystallographic texture are reported. It was found that the progress of dynamic recrystallization is strongly sensitive to processing conditions but that the dynamically recrystallized grain size was less sensitive to stress than in other metals. It was also found that, for structures containing between 80 and 95% dynamic recrystallization, abnormal grain growth occurs during annealing. The crystallographic texture produced is also sensitive to the deformation conditions. (orig.)
2003-07-01
Bidimensional instability in antiferroelectric liquid crystals
Scientific Electronic Library Online (English)
Abstract in english In the last decade it has been experimentally found a periodic domain pattern arising in smectic C* liquid crystals in surface stabilized bookshelf geometry. Such a periodic texture appears after switching-off an external electric field, even in strong anchoring conditions. It has a static character and can be bidimensional, being dependent on both directions normal to the smectic planes and normal to the cell plates. In the present work an explanation to this phenomenon (more) is proposed. According to our model in the antiferroelectric phase the biperiodic texture is a threshold phenomenon, appearing for values of the spontaneous polarization greater than a critical value, whereas in the ferroelectric phase this type of bidimensional instability is hindered.
2002-06-01
British Library Electronic Table of Contents (United Kingdom)
A novel class of pyrrolidinyl-acetyleneic thieno[3,2-d]pyrimidines has been identified which potently inhibit the EGFR and ErbB-2 receptor tyrosine kinases. Synthetic modifications of the pyrrolidine carbamate moiety result in a range of effects on enzyme and cellular potency. In addition, the impact of the absolute stereochemical configuration on cellular potency and oral mouse pharmacokinetics is described.
2009-01-01
UK PubMed Central (United Kingdom)
The halogenated benzimidazoles BDCRB (2-bromo-5,6-dichloro-1-;2;-d-riborfuranosyl benzimidazole riboside) and TCRB (2,5,6-trichloro-1-;2;-d-riborfuranosyl benzimidazole...Full Text Available
2004-02-01
Accurate positioning for head and neck cancer patients using 2D and 3D image guidance
UK PubMed Central (United Kingdom)
Our goal is to determine an optimized image-guided setup by comparing setup errors determined by two-dimensional (2D) and three-dimensional (3D) image guidance for head and neck cancer (HNC)...Full Text Available
2DIR spectroscopic studies on cholic acid
Based on our cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, the two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds. Fine spectral structures were revealed by asynchronous 2D FT-IR spectra. The co-relationship among various bands was discussed according to the synchronous 2D FT-IR spectra. .
2000-03-01
International Nuclear Information System (INIS)
Larsen syndrome is an autosomal-dominant disorder characterized by multiple joint dislocations, vertebral anomalies and dysmorphic facies. Both autosomal-dominant and autosomal-recessive forms of the disorder have been proposed. Individuals with autosomal-dominant Larsen syndrome have characteristic ''cylindrical-shape'' thumbs caused by broad, shortened phalanges. Autosomal-dominant Larsen syndrome results from heterozygosity for mutations in filamin B, a cytoskeletal protein involved in multicellular processes. We report here a patient with a duplicated or accessory distal thumb phalanx and multiple large joint dislocations who was shown to be heterozygous for a filamin B mutation predicting the amino acid substitution G1691S. This adds a new radiographic finding, duplicated or accessory distal phalanx, to the radiographic abnormalities seen in this rare dominant disorder. (orig.)
2006-09-01
Plain radiographic predictors of survival in treated Ewing's sarcoma
International Nuclear Information System (INIS)
We analyzed 16 radiographic features of primary Ewing's sarcoma in 342 patients from the IESS 7299 (Intergroup Ewing's Sarcoma Study) for prognostic significance. Of these, 3 features demonstrated a statistically significant relationship to survival: maximal tumor dimension, tumor location, and an appearance of honeycombing within the lesion. Those individuals with primary lesions centered in the pelvis, femur, or humerus had a worse survival rate than those with lesions centered elsewhere. Similarly, we observed an inverse relationship between the greatest dimension of the osseous portion of the lesion and survival. The radiographic finding of honeycombing also showed a statistical association with improved survival. However, this feature was observed infrequently, and its significance should be assessed further. Otherwise, no other feature that we analyzed showed any relationship to patient prognosis. (orig.).
British Library Electronic Table of Contents (United Kingdom)
Abstract Objective: To compare the vertical dimensional changes with regard to graft height in a long-term follow-up in patients treated with two different grafting materials used in maxillary sinus floor elevation procedures. Material and methods: Twenty consecutive patients were included. One group was grafted with autogenous bone from the mandible (chin area), and the other group was augmented with a 100%b-tricalcium phosphate (b-TCP). During a 4- to 5-year period, in each patient, at least five panoramic radiographs were made. These panoramic radiographs were used for morphometric measurements, at three different locations. The three locations were the first bone to implant contact at the distal side of the second most posterior implant (L1), halfway between this implant and the most p...
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
The radiographs and initial clinical findings of 73 patients who had sustained trauma to the cervical spine without bony injury in vehicle collisions were reviewed. The patients were also re-examined clinically two years after the injury. Forty eight (65.8%) had abnormal radiographs at presentation - prevertebral soft tissue swelling in 15 (20.6%), degenerative changes in 15 (20.6%), and an angular deformity between two adjacent vertebral bodies in 27 (37.0%). The exact mode of inury is not associated with any specific radiographic appearance except that ''roll overs'' and side collisions are more likely to cause angulation in the cervical spine. (orig./GDG).
1988-10-01
Computed tomography of the acetabular fractures
Energy Technology Data Exchange (ETDEWEB)
In a retrospective study of 21 patients, in whom the acetabular fractures were suspected on initial radiographs, we compared and analysed the computed tomographic findings and plain radiographic findings. The results were as follow: 1. In patients with multiple trauma, no further change in position was required during CT examinations. 2. CT showed intraarticular loose bodies, which were invisible on plain radiographs. 3. CT was useful in detecting the fractures of acetabular rims, medial wall of acetabulum, and femoral head. 4. CT permitted better evaluation of shape, extent, and degree of separation of fracture fragments. 5. CT was helpful in detecting the associated fractures and soft tissue injuries. 6. CT also demonstrated the adequacy of reduction, the position of metallic fixation devices, and the presence or absence of remaining intraarticular osseous fragments after surgery.
1986-04-15
Spinous process palpation using the scapular tip as a landmark vs a radiographic criterion standard
UK PubMed Central (United Kingdom)
AbstractObjectiveThis study aimed at determining the standing spinal landmark that corresponds to the inferior tip of the scapula and determining the accuracy of experienced...Full Text Available
2007-01-01
UK PubMed Central (United Kingdom)
BackgroundAn abdominal aortic aneurysm (AAA) that is identified when the abdomen is imaged for some other reason is known as an incidental AAA. No population-based studies have...Full Text Available
Radiographic experience with power transmission equipment
Energy Technology Data Exchange (ETDEWEB)
This paper describes radiography as one of the most efficient and cost effective methods for inspecting electric cabls. Details of one project in particular, i.e., the inspection of high-pressure, oil-filled, pipe-type cables (HPOF) are given. 2 refs.
1980-01-01
Energy Technology Data Exchange (ETDEWEB)
Purpose: calculation of conversion coefficients for the reconstruction of organ doses from entrance doses for abdomen radiographs of 0, 1, 5, 10, 15, and 30-year-old patients in conventional pediatric radiology for the radiographic settings recommended by the German and European guidelines for quality management in diagnostic radiology. Materials und method: using the commercially available personal computer program PCXMC developed by the Finnish Center for Radiation and Nuclear Safety (Saeteilyturvakeskus STUK), conversion coefficients for conventional abdomen radiographs were calculated performing Monte Carlo simulations in mathematical hermaphrodite phantom models describing patients of different ages. The possible clinical variation of beam collimation was taken into consideration by defining optimal and suboptimal radiation fields on the phantoms' surfaces. Results: conversion coefficients for the ...
2009-10-15
UK PubMed Central (United Kingdom)
Idiopathic frozen shoulder is a common medical diagnosis for patients seeking physical therapy. Radiographic and surgical evidence exists that describes the coracohumeral ligament (CHL) as a major contributor...Full Text Available
2009-01-01
Late metastasis from neuroblastoma mimicking Ewing's sarcoma
International Nuclear Information System (INIS)
The case of an unusual late metastasis of neuroblastoma to the calcaneum, appearing as a sole recurrence 9 years after surgery, is reported. The radiographic features of the osseous lesion were very suggestive of primary bone malignancy, Ewing's sarcoma as the first option, with extraosseous spread to the soft tissues. (orig.).
International Nuclear Information System (INIS)
Iodixanol is a new nonionic dimer, isotonic with blood at all clinically relevant concentrations. Iodixanol (270 mg I/ml) was compared in a double-blind, randomized, parallel-group, phase-III study to the monomeric nonionic iohexol (300 mg I/ml) for evaluation of safety, tolerability and radiographic efficacy during cerebral CT. One hundred adult patients scheduled to undergo contrast-enhanced cerebral CT were randomly allocated to receive either iodixanol or iohexol. All completed the trial. Safety was evaluated by recording discomfort and other adverse events, tolerance by assessing intensity and incidence of discomfort. Radiographic efficacy was assessed from the diagnostic information and the radiographic density. No serious adverse events occurred. One patient (2 %) in the iodixanol group and one patient (2 %) in the iohexol group experienced a transient reddening at the neck and lower neck-line, respectively. Both ...
1999-09-01
Ewing's sarcoma presenting as a solitary cyst
International Nuclear Information System (INIS)
This case describes a 10-year-old girl who developed a Ewing's sarcoma in her proximal fibula. The radiologic features mimicked those of a unicameral bone cyst. The presence of pain and the atypical location led to a prompt biopsy and the correct diagnosis. The mechanism of this unusual radiographic presentation is discussed. (orig.)
2006-07-01
Energy Technology Data Exchange (ETDEWEB)
To evaluate the diagnostic accuracy of Fuji computed radiography (FCR) in the detection of interstitial pulmonary infiltrates, FCR life-size images at a pixel size of 0.1 mm were compared with conventional radiographs taken on the same day. Seventeen radiologists assessed the radiographs and FCR images of 56 cases, including 39 cases of various interstitial lung diseases such as interstitial pneumonia, pulmonary abnormalities associated with collagen disease, sarcoidosis, multiple pulmonary metastases, diffuse panbronchiolitis and pulmonary emphysema, and 17 normal controls. All of the pulmonary abnormalities were confirmed by high resolution CT. Observer performance tests were carried out using receiver operating characteristic analysis. In 21 cases of increased pulmonary density revealed by high resolution CT, FCR was significantly superior to conventional radiographs in the detection of reticular or linear shadows. In 11 ...
1991-11-01
International Nuclear Information System (INIS)
To evaluate the diagnostic accuracy of Fuji computed radiography (FCR) in the detection of interstitial pulmonary infiltrates, FCR life-size images at a pixel size of 0.1 mm were compared with conventional radiographs taken on the same day. Seventeen radiologists assessed the radiographs and FCR images of 56 cases, including 39 cases of various interstitial lung diseases such as interstitial pneumonia, pulmonary abnormalities associated with collagen disease, sarcoidosis, multiple pulmonary metastases, diffuse panbronchiolitis and pulmonary emphysema, and 17 normal controls. All of the pulmonary abnormalities were confirmed by high resolution CT. Observer performance tests were carried out using receiver operating characteristic analysis. In 21 cases of increased pulmonary density revealed by high resolution CT, FCR was significantly superior to conventional radiographs in the detection of reticular or linear shadows. In 11 ...
1991-01-01
Changes in inflammatory mediators in experimental periodontitis in the rhesus monkey.
UK PubMed Central (United Kingdom)
Ligature-induced periodontitis was monitored for 6 months in eight Macaca mulatta monkeys to examine clinical status, radiographic bone level, and crevicular fluid (CF) levels of prostaglandin E2 (PGE2),...Full Text Available
1993-04-01
UK PubMed Central (United Kingdom)
PurposeThe aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmented sinus using Osteon, a bone graft material, and to assess the height...Full Text Available
2011-04-01
UK PubMed Central (United Kingdom)
This cross-sectional study evaluated the association between radiographic evidence of alveolar bone loss and the concentration of host-derived bone resorptive factors (interleukin-1 beta, tumor...Full Text Available
2007-03-01
UK PubMed Central (United Kingdom)
AbstractA 6-month-old female alpaca was presented for stranguria. Based on the history, physical examination findings, and radiographic studies, the alpaca was diagnosed with bladder...Full Text Available
2005-03-01
UK PubMed Central (United Kingdom)
BackgroundThis in vitro study was conducted to compare the accuracy of two digital image receptors in identifying the location of tip of a fine endodontic file and radiographic apex...Full Text Available
2010-11-01
Energy Technology Data Exchange (ETDEWEB)
Out of the R and D of mesoscopic metal group composite materials, the paper described the fiscal 1997 results. In the in-situ method as a composite material making method, elucidated to some degree were chemical composition of Fe-C-Cr-V-Nb-Mo-W-Ni base multi-dimensional alloys, and wear resistance and oxidation resistance of MC type carbide dispersion multi-phase texture crystallizing as primary crystal and eutectic. In the composite material making with ceramic fiber and alloy by the pressure infiltration method, the paper clarified the texture formation mechanism in solidification/heat treatment by a combination of Al alloys and alumina long fiber, and the relation between fiber configuration and wear resistance. By MA and MG methods as the powder metallurgy composite material making method, a composed body of {alpha}-stainless steel of Fe-12%Cr composition and M23C6 of 40-90vol% are designed for alloy composition, and powder of amorphous or ...
1998-03-01
Intermediate form of osteopetrosis with recessive inheritance
International Nuclear Information System (INIS)
The clinical and radiographic features of the intermediate form of osteopetrosis in two sibs are presented in which the disorder appears to have been inherited as a recessive trait. Although this form of osteopetrosis has been poorly delineated, its recognition is practically important in order to give an accurate prognosis. This paper also presents an unusual complication of bilateral avascular necrosis of the femoral head in the younger sib. Radiographic changes of the femoral heads suggest those of Legg-Calve-Perthes disease, though the possibility of avascular necrosis following unrecognized femoral neck fracture is not completely excluded. (orig.).
Dextranomer/hyaluronic acid copolymer (Deflux) implants mimicking distal ureteral calculi on CT
Energy Technology Data Exchange (ETDEWEB)
Periureteral or subtrigonal injection of dextranomer/hyaluronic acid (Dx/HA) copolymer (Deflux, Q-Med, Uppsala, Sweden) is an increasingly common endoscopic treatment for vesicoureteral reflux. We report a confusing radiographic finding of bilateral calcified Dx/HA injections initially thought to represent bilateral distal ureteral stones in a boy who presented with intermittent periumbilical pain. Urologists, radiologists, and emergency room physicians should be aware of the potential for calcification of ureteral implants of Dx/HA, and of the potentially confusing radiographic images that may result. (orig.)
2008-01-15
A somatic dose index for diagnostic radiology
International Nuclear Information System (INIS)
Irradiation of the human body in diagnostic X-ray procedures results in different absorbed doses in the various body organs. A somatic dose index in formulated by applying the relative sensitivity of the human to each of the most important somatic effects and utilizing the absorbed dose in the affected organs. This quantity is used to convey a cumulative somatic impact and is computed for common radiographic views in diagnostic radiology as a function of beam quality for a nominal IR entrance exposure. Using typical X-ray beam qualities and exposures, the frequency of the various radiographic views that make up an examination and the frequencies of the various examinations in the national population, illustrative examples of the application of the somatic dose index are presented. (author).
1978-01-01
Visual search behaviour in skeletal radiographs: a cross-speciality study
Energy Technology Data Exchange (ETDEWEB)
Aim: To determine whether experience improves the consistency of visual search behaviour in fracture identification in plain radiographs, and the effect of specialization. Material and methods: Twenty-five observers consisting of consultant radiologists, consultant orthopaedic surgeons, orthopaedic specialist registrars, orthopaedic senior house officers, and accident and emergency senior house officers examined 33 skeletal radiographs (shoulder, hand, and knee). Eye movement data were collected using a Tobii 1750 eye tracker with levels of diagnostic confidence collected simultaneously. Kullback-Leibler (KL) divergence and Gaussian mixture model fitting of fixation distance-to-fracture were used to calculate the consistency and the relationship between discovery and reflective visual search phases among different observer groups. Results: Total time spent studying the radiograph was not significantly different between the ...
2007-11-15
The formation mechanism of textured YBa sub 2 Cu sub 3 O sub 7-. delta
Energy Technology Data Exchange (ETDEWEB)
The formation of textured YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (123) from a liquid phase according to the peritectic reaction Y{sub 2}BaCuO{sub 5} (211) + liquid {yields} 123 was analyzed using real-time analysis techniques of high-temperature X-ray diffraction, high-temperature optical microscopy, and environmental scanning electron microscopy (ESEM). Results were coupled with conventional ''post-mortem'' SEM analysis of processed samples at various stages of microstructural development. Observations of 123 formation and growth from the peritectic melt permit the conclusion that the presence of crystalline 211 primarily acts as a source of yttrium. The slow dissolution of 211 into the yttrium deficient liquid phase is the rate controlled step in the formation and growth of the textured 123, rather that its acting as a nucleation site for 123 grains as has been widely assumed. (orig.).
1992-05-20
Energy Technology Data Exchange (ETDEWEB)
The possibility of improving the cold formability of wrought magnesium alloys is considered in light of their good hot forming characteristics. Magnesium alloy AZ31B sheet is selected as a model system. Parameters affecting formability, such as strain hardening rate, strain rate sensitivity, and the degree of anisotropy are examined systematically by conducting tensile tests over a range of temperatures (room temperature to 250 C) and strain rates (1 x 10{sup -5} to 0.1 s{sup -1}). The plastic anisotropy and deformation texture evolution are examined in samples aligned with the sheet rolling and transverse directions. Polycrystal plasticity simulations using a viscoplastic self-consistent (VPSC) formulation are used to model the observed anisotropy and texture evolution. The adjustable parameters in the model are the relative critical resolved shear stresses of the dislocation mechanisms known to operate within magnesium. The experimental ...
2003-07-01
'Mu-Tau' symmetry, tribimaximal mixing and four zero neutrino Yukawa textures
Within the type-I seesaw framework with three heavy right chiral neutrinos and in the basis where the latter and the charged leptons are mass diagonal, a near `mu-tau' symmetry in the neutrino sector is strongly suggested by the neutrino oscillation data. There is further evidence for a close to the tribimaximal mixing pattern which subsumes `mu-tau' symmetry. On the other hand, the assumption of a (maximally allowed) four zero texture in the Yukawa coupling matrix Y_nu in the same basis leads to a highly constrained and predictive theoretical scheme. We show that the requirement of an exact `mu-tau' symmetry, coupled with observational constraints, reduces the `seventy two' allowed textures in such a `Y_nu' to 'only four' corresponding to just two different forms of the light neutrino mass matrix `m_nu'. The effect of each of these on measurable quantities can be described, apart from an overall factor of the neutrino mass scale, in terms of ...
2009-01-01
Locally resonant acoustic metamaterials with 2D anisotropic effective mass density
British Library Electronic Table of Contents (United Kingdom)
A two-dimensional (2D) lattice model with anisotropic resonant microstructures is found to provide an anisotropic band gap structure. A 2D continuum with anisotropic effective mass density is introduced to represent this lattice system. Two methods are proposed to derive the equivalent continuum. In the first method, the effective mass density of the equivalent continuum is obtained by matching the dispersion relations for harmonic waves propagating in the principal directions. The second approach employs an approximate estimation of the effective mass density by volume-averaging an effective mass that represents the resonant microstructure. For both equivalent continuum models, the effective mass density is frequency-dependent and may become negative in certain frequency ranges. Subsequen...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Academic, government, and industrial field researchers have generated a significant database of field studies of the volatility of soil applied fumigants. However, limited work exists in validating physical models against field volatility data sets and fully exploring the volatility parametric response surface. Field studies quantifying atmospheric flux for soil fumigants 1,3-dichloropropene and chloropicrin are validated against the United States Department of Agriculture (USDA Salinity Laboratory) soil physics model CHAIN_2D that was modified specifically for agronomic uses of soil fumigants. Comparison between model predictions and field observations for six unique field trials in five different states indicate that CHAIN_2D effectively captures the magnitude and duration of fumigant em...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Background: Obstructive sleep apnea (OSA), a highly prevalent condition, is independently associated with increased risks of developing type 2 diabetes mellitus (T2D) and metabolic syndrome. It is unclear, however, if the severity of OSA has any impact on glycemic control among patients with T2D. We therefore aimed to determine the independent association between OSA severity and glycosylated hemoglobin (HbA1c) in patients with T2D. Methods: This was an observational cross-sectional study of 52 consecutive patients attending the diabetes obesity clinic between January 2008 to February 2010 with risk factors for sleep apnea and who underwent polysomnography study. Clinical, demographic, and lifestyle data were recorded using a questionnaire. Results: Prevalence of OSA in this clini...
2011-01-01
2D SPH simulations of planet-disc interactions.
Current theories on planetary formation establish that massive objects accrete gaseous envelopes, becoming gaseous planets if the accretion process proceeds before the accretion disc dissolution. One of the unsolved problems is that the planet formation is contextual to their quick migration towards the central star, due to the protoplanets-disc interaction, on a timescale lower by an order of magnitude than that of gas accretion onto the protoplanet. These arguments have been recently broached using N-body and/or Eulerian fluid-dynamics codes, mainly in 2D, or a mixing of them. In this work, 2D simulations with a SPH code are performed, to study the migration of one protoplanet. The goal is to scrutinise the protoplanet dragging as a function of planet's mass.
2009-01-01
The sensory quality of irradiated breaded poultry products
International Nuclear Information System (INIS)
The colour, odour, flavour and texture of a breaded turkey escalope irradiated at doses of 2 and 4 kGy was assessed using a trained sensory panel. Irradiation did not affect raw appearance but during storage the irradiated breaded products became paler than the control samples. The off odour of the raw irradiated products was stronger than that of the unirradiated samples. Irradiation also affected the odour, flavour and texture of the cooked products. Although the trained panelists were able to detect significant differences between irradiated and unirradiated breaded turkey escalopes, the numerical differences between treatments were often quite small. It is possible that an untrained consumer group would be unable to detect these differences. Further research is needed with consumer groups to establish if irradiated breaded products are acceptable. (author). 10 refs, 3 tabs.
1994-07-01
International Nuclear Information System (INIS)
In this study the results of mathematical simulation and experimental research of texture transition in stress assisted shear phase transformations are discussed. The orientation distribution function (ODF) calculation model to the any type crystalline lattice symmetry materials has been suggested. By crystalline lattice symmetry analysis this computer program determines necessary amount of the initial experimental data. The experimental verification supports this model well. The ODF calculation model after shear phase transformation with equal use of all possible variants of orientation relationship or with various degrees of variant selection worked out. In this study the experimental and calculating data of the direct and reversal shear transformations #alpha# <=> #gamma# in Fe-alloys and B2 <=> B19' in Ti-Ni alloys are discussed. The stress assisted shear phase transformation model and computer program to calculate ODF after transformation have been ...
International Nuclear Information System (INIS)
The purpose of this experimental study is to investigate the micromechanical fatigue behavior, in terms of slip nature and preferential cracking sites, of a commercial #alpha#/#beta#-forged Ti-6Al-4V alloy. Electron backscattering diffraction is extensively used to identify the deformation (prismatic, basal, pyramidal slip) and crack formation modes activated by fatigue at the surface of several hundred primary #alpha# nodules. Some fatal crack formation sites are also characterized. Cracking in basal planes is identified as the most critical damage mode leading to fracture. An explanation is proposed which involves the resolved shear stress, taking into account the Schmid factor and the normal stress in relation to the elastic anisotropy of the #alpha#-phase. Finally, the spatial distribution of the secondary cracks is analyzed according to the crystallographic textures (macrozones) present on a mesoscopic scale in the Ti-6Al-4V alloy.
2008-09-01
British Library Electronic Table of Contents (United Kingdom)
Intrusive degassing and recycling of degassed and dense magma at depth have been proposed for a long time at Stromboli. The brief explosive event that occurred at the summit craters on 9 January 2005 threw out bombs and lapilli that could be good candidates to illustrate recycling of shallow degassed magma at depth. We present an extensive data set on both the textures and the mineral, bulk rock and glassy matrix chemistry of the ?9 Jan? products. The latter have the common shoshonitic?basaltic bulk composition of lavas and scoriae issued from typical strombolian activity. In contrast they differ by the heterogeneous chemistry of their matrix glasses and their crystal textures that testify to crystal dissolution event(s) just prior magma crystallization upon ascent and eruption. Comparison...
2008-01-01
British Library Electronic Table of Contents (United Kingdom)
Crustal xenoliths (pyroxenites and plagioclase + quartz + pyroxene lithologies) from the Quaternary Big Pine volcanic field on the eastern flank of the Sierra Nevada Batholith in California (USA) represent the products of metasomatic reaction between the margins of a Cretaceous granodioritic pluton and Paleozoic marbles, possibly at mid-crustal depths based on the equilibration temperatures recorded by Ti-in-quartz geothermometry. This interpretation is based on the presence of plagioclase showing relict plutonic textures, pyroxenite characterized by nearly pure diopside clinopyroxene, recrystallized plagioclase with anomalously high anorthite content, textures indicating replacement of plagioclase by clinopyroxene (and vice versa), `ghost' plagioclase rare earth element signatures in some...
2011-01-01
Microstructural evolution during hot rolling of an AZ31 Mg alloy
Energy Technology Data Exchange (ETDEWEB)
The microstructural evolution of a AZ31 Mg alloy during hot rolling has been investigated using optical microscopy and texture (macro and micro) analysis as the main characterization tools. In particular, the differences between the microstructure obtained by unidirectional rolling (UR) and cross rolling (CR) are studied. Significant twinning activity is observed in both cases. Additionally, after cross rolling, a rather heterogeneous microstructure develops, with scattered regions populated by very fine grains. The strong basal fiber texture of the as-received material remains present after both hot rolling schemes. The impossibility to obtain accurate EBSD measurements within the twinned regions suggests that significant localized deformation takes place in those areas. Thus, these regions become preferential sites for the onset of recrystallization due to the increase in the local strain energy. (orig.)
2003-07-01
British Library Electronic Table of Contents (United Kingdom)
A procedure based on electrophoretic deposition (EPD) was developed to coat metal plates with powder catalysts. The method was tested on stainless-steel plates with three Ni-based catalysts for the steam reforming of ethanol. The catalysts (Ni/La2O3/g-Al2O3) contained 15% Ni and 8% La, and were prepared using three types of g-alumina with different textural properties. The powder catalysts were suspended in isopropanol, and EPD deposition was performed with a voltage of 100V and a distance between electrodes of 2cm. Deposition time was varied between 3 and 7min, which gave a thickness of the catalyst layer from around 30 to 100mm. The morphology of the catalyst layer was dependent on the textural characteristics of the g-Al2O3 used to prepare the catalyst. The activity of the catalyst plat...
2010-01-01
Bounds on R-parity Violating Couplings at the Weak Scale and at the GUT Scale
We present an update of the most stringent experimental bounds on the trilinear R-parity violating couplings. We then analyse bounds on the R-parity violating couplings at the unification scale by renormalising the weak scale bounds. We derive unification scale upper bounds upon the couplings which are broadly independent of the fermion mass texture assumed. The R-parity violating couplings are factors of two to five more severely bounded at the unification scale than at the electroweak scale. In the presence of quark mixing, a few of the bounds are orders of magnitude stronger than their weak scale counterparts due to new R-parity violating operators being induced in the renormalisation between high and low scales. These induced bounds are fermion mass texture dependent. New bounds upon the weak scale couplings are obtained by the requirement of perturbativity between the weak and unification scales. A comprehensive set of the latest limits is ...
1999-01-01
Anisotropic properties of magnesium sheet AZ31
Energy Technology Data Exchange (ETDEWEB)
Car weight corresponds directly to fuel consumption and driving performance. So in order to improve the fuel efficiency and performance of a car the weight has to be reduced. Magnesium as a light metal offers a wide range of weight saving opportunities, especially Magnesium wrought alloys with their improved mechanical properties have a high potential for structural applications. Mechanical properties in terms of their quality and anisotropy are dependent on the microstructure of the material and can be characterized by their degree of inhomogeneity, their grain size distribution and their crystallographic texture. Therefore the orientation distribution of grains, the grain size, its size distribution, the chemical composition (precipitates) itself influence the mechanical parameters and their anisotropy. In this presentation first results of mechanical anisotropy are given: differences in yield stress, r-values and their relation to the ...
2003-07-01
Simple fractal method of assessment of histological images for application in medical diagnostics
UK PubMed Central (United Kingdom)
We propose new method of assessment of histological images for medical diagnostics. 2-D image is preprocessed to form 1-D landscapes or 1-D signature of the image contour and then their complexity is...Full Text Available
Energy Technology Data Exchange (ETDEWEB)
The diffusion of ion beam injected self-interstitials (I) and their interaction with impurities in crystalline Si has been investigated and modeled. In particular, the I-substitutional carbon (C) interactions have been studied, using a molecular-beam-epitaxy grown Si{sub 1-y}C{sub y} layer interposed between the shallow I-source and a deeper B-spike (marker for I-concentration). Substitutional C atoms are shown to trap I's, to be removed from their substitutional sites, and to form stable precipitates into the C-rich region. The I-trapping mechanism was quantitatively studied by a simulation code. The reactions causing trapping and deactivation are described. In addition, the boron markers approach was extended to the two dimensional (2D) diffusion. High resolution scanning capacitance microscopy was used for quantitative measurements of the 2D boron transient enhanced diffusion induced on a ...
2003-05-01
International Nuclear Information System (INIS)
The diffusion of ion beam injected self-interstitials (I) and their interaction with impurities in crystalline Si has been investigated and modeled. In particular, the I-substitutional carbon (C) interactions have been studied, using a molecular-beam-epitaxy grown Si_1_-_yC_y layer interposed between the shallow I-source and a deeper B-spike (marker for I-concentration). Substitutional C atoms are shown to trap I's, to be removed from their substitutional sites, and to form stable precipitates into the C-rich region. The I-trapping mechanism was quantitatively studied by a simulation code. The reactions causing trapping and deactivation are described. In addition, the boron markers approach was extended to the two dimensional (2D) diffusion. High resolution scanning capacitance microscopy was used for quantitative measurements of the 2D boron transient enhanced diffusion induced on a boron delta array ...
2003-05-01
MudPIT Analysis: Application to Human Heart Tissue
UK PubMed Central (United Kingdom)
Although two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) has been used as the standard proteomic approach for separating proteins in a complex mixture, this technique has many drawbacks....Full Text Available
2009-01-01
Mapping Proprioception across a 2D Horizontal Workspace
UK PubMed Central (United Kingdom)
Relatively few studies have been reported that document how proprioception varies across the workspace of the human arm. Here we examined proprioceptive function across a horizontal planar workspace,...Full Text Available
Large-scale association analysis of TNF/LTA gene region polymorphisms in type 2 diabetes
UK PubMed Central (United Kingdom)
BackgroundThe TNF/LTA locus has been a long-standing T2D candidate gene. Several studies have examined association of TNF/LTA...Full Text Available
UK PubMed Central (United Kingdom)
Insulin resistance in skeletal muscle is a key phenotype associated with type 2 diabetes (T2D) for which the molecular mediators remain unclear. We therefore conducted an expression analysis of human...Full Text Available
2011-03-01
... ions. MATERIALS AND METHODS Cell Culture Culture of NT2/D1 cells was carried out as described previously (18, 19). NT2 cells were plated at a density of 2. ... ...
Ct3d: tracking microglia motility in 3D using a novel cosegmentation approach
UK PubMed Central (United Kingdom)
Motivation: Cell tracking is an important method to quantitatively analyze time-lapse microscopy data. While numerous methods and tools exist for tracking cells in 2D time-lapse images,...Full Text Available
2011-02-15
Energy Technology Data Exchange (ETDEWEB)
The major problem of measurement of a power spectral density (PSD) distribution of the surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF tends to distort the PSD at higher spatial frequencies. It has been suggested [Proc. SPIE 7077-7, (2007), Opt. Eng. 47 (7), 073602-1-5 (2008)] that the instrumental MTF of a surface profiler can be precisely measured using standard test surfaces based on binary pseudo-random (BPR) patterns. In the cited work, a one dimensional (1D) realization of the suggested method based on use of BPR gratings has been demonstrated. Here, we present recent achievements made in fabricating and using two-dimensional (2D) BPR arrays that allow for a direct 2D calibration of the instrumental MTF. The 2D BPRAs were used as standard test surfaces for ...
2009-07-07
Energy Technology Data Exchange (ETDEWEB)
In the present work, we describe application of binary pseudo-random gratings (BPRG) and arrays (BPRA) as effective 1D and 2D test surfaces suitable for calibration of different surface profilometers, including a number of interferometric microscopes and scatterometers.
2009-06-17
Beyond AICA Riboside: In Search of New Specific AMP-activated Protein Kinase Activators
UK PubMed Central (United Kingdom)
Summary5-Aminoimidazole-4-carboxamide-1-;2;-d-ribofuranoside (AICA riboside) has been extensively used in vitro and in vivo to...Full Text Available
2009-01-01
Azimuth Quadrupole Systematics in Au-Au Collisions
We have measured $p_t$-dependent two-particle number correlations on azimuth and pseudorapidity for eleven centralities of $\\sqrt{s_{NN}} = 62$ and 200~GeV Au-Au collisions at STAR. 2D fits to these angular correlations isolate the azimuth quadrupole amplitude, denoted $2 v_2^2 \\{ 2D \\} ( p_t )$, from localized same-side correlations. Event-plane $v_2 ( p_t )$ measurements within the STAR TPC acceptance can be expressed as a sum of the azimuth quadrupole and the quadrupole component of the same-side peak. $v_2 \\{ 2D \\} ( p_t )$ can be transformed to reveal quadrupole $p_t$ spectra which are approximately described by a fixed transverse boost and universal L\\'evy form nearly independent of centrality. A parametrization of $v_2 \\{ 2D \\} ( p_t )$ can be factored into centrality and $p_t$-dependent pieces with a ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparable only at higher angle of ...
2009-10-15
UK PubMed Central (United Kingdom)
In many radiotherapy clinics, geometric uncertainties in the delivery of 3D conformal radiation therapy and intensity modulated radiation therapy of the prostate are reduced by aligning the...Full Text Available
2007-07-01
... and mean rainfall rates, Rm, in the liquid hydrometeor layers using the .... large latitudinal movement of cirrus cloud cover with the changing seasons. ... We study the statistical distribution of PSCs by particle composition using .... the high resolution Cloud Particle Imager (CPI) and standard PMS 2D-C and ...
CT in the study of thoracic-pulmonary complications after liver transplantation
International Nuclear Information System (INIS)
In this article is reviewed the role of Computed Tomography (CT) in thoracic complications following ortho topic liver transplantation (OLT). In a post-OLT population of 567 patients transplanted in the Italian institutions, 100 patients (17.6%) were examined with chest CT. It was reviewed data relative to the total number of examinations, clinical and/or radiographic indications, the CT technique-i.e., conventional (with (out) intravenous, i.v., contrast material) or high-resolution (HRCT). It also reviewed the radiologic patterns and their correlation with the other clinical, bronchoscopic and/or laboratory results. Of 152 chest CT examinations, 45 (29.6%) were performed because of clinical indications, 31 (20.4%) because of a radiographic abnormality, 64 (42.1%) because of clinical and radiographic abnormality, 64 (42.1%) because of clinical and radiographic indications, while in 12 cases (7.9%) the ...
2000-12-01
Energy Technology Data Exchange (ETDEWEB)
We investigate the formation of nanostructures in 2D strained alloys on face centered cubic (111) surfaces by means of equilibrium Monte Carlo simulations. In the framework of an off-lattice model, we consider one monolayer of two bulk-immiscible adsorbates A and B with negative and positive misfit relative to the substrate, respectively. Simulations show that the adsorbates partly self-organize into island or stripe-like patterns. We show how these structures depend on the relative misfits, interaction, and concentration of components. The morphology is quite different for phase separation and intermixing regimes.
2008-07-02
Self-magnetically insulated, high-voltage transmission lines are used in inertial confinement fusion particle accelerators in order to transmit power from the vacuum insulator to the diode. This paper describes a time-dependent 2-D code (MITL) for calculating (for planar or triplate geometries) the motion of test electrons through the tapered input or output convolutes of such lines. MITL results show that the electron canonical momentum in the direction of the flow changes as the electron passes through the convoluted geometry; it is suggested that these electrons lead to losses observed in long self-magnetically insulated lines.
1979-01-01
A comprehensive, numerical model of electro-thermal propulsion
A computer model of an electrothermal accelerator has been developed which applies to the plasma generator as well as the gun barrel, and it for the first time allows study of the interdependent physical processes in both components simultaneously. The code comprises a 2D transient description of the plasma arc, a 2D, two-phase interior ballistics module, and a preprocessor delivering the required plasma physical data. Some results on the flow field, pressure and temperature in a typical accelerator are presented, and probable limitations on the performance of such a system are discussed. The code is to be applied to different concepts of electrothermal chemical guns.
1993-01-01
2D Electrostatic Simulation of the Modulated Electron Beam Interaction with Inhomogeneous Plasma
International Nuclear Information System (INIS)
Electrostatic plasma simulation code for 2D rectangular geometry is presented. Main distinguishing feature of the code is its orientation on the beam-plasma interaction. The code and its graphical interface were developed using MATLAB programming language. Simulation results of inhomogeneous plasma interaction with modulated electron beams of different width are compared. In case of wide beam the front of Langmuir waves generated in point of local plasma resonance is planar and in case of thin beam (or ribbon beam) the front has approximately half-circular form.
2006-01-01
Neutron-computer tomography using real-time neutron radiography
Energy Technology Data Exchange (ETDEWEB)
A real-time neutron radiography facility was constructed including the capability of neutron tomography. The neutron beam was measured for total neutron flux ((1.0 +/- 0.2) x 10/sup 11/ m/(m/sup 2/-sec)), gold cadmium ratio (52 +/- 3) and effective neutron temperature (83/sup 0/C +/- 8/sup 0/C). The angular divergence or nonparallelism of the neutron beam was measured to be 2.3/sup 0/ +/- 0.1/sup 0/ thereby providing a means of quantifying the collimator effectiveness. The resolution capabilities of both static film and real-time neutron radiographs were quantified using a Fourier transform algorithm to calculate the modulation transfer function of both types of radiographs. The contrast sensitivity of both types of radiographs. The contrast sensitivity of both types of radiographs was measured as 3.1% for film and 4.0% for real-time radiographs. Two tomography algorithms, the ...
1986-01-01
Neutron-computer tomography using real-time neutron radiography
International Nuclear Information System (INIS)
A real-time neutron radiography facility was constructed including the capability of neutron tomography. The neutron beam was measured for total neutron flux ((1.0 +/- 0.2) x 10"1"1 m/(m"2-sec)), gold cadmium ratio (52 +/- 3) and effective neutron temperature (83"0C +/- 8"0C). The angular divergence or nonparallelism of the neutron beam was measured to be 2.3"0 +/- 0.1"0 thereby providing a means of quantifying the collimator effectiveness. The resolution capabilities of both static film and real-time neutron radiographs were quantified using a Fourier transform algorithm to calculate the modulation transfer function of both types of radiographs. The contrast sensitivity of both types of radiographs. The contrast sensitivity of both types of radiographs was measured as 3.1% for film and 4.0% for real-time radiographs. Two tomography algorithms, the simultaneous iterative ...
1986-01-01
Energy Technology Data Exchange (ETDEWEB)
One requirement of a thermophotovoltaic (TPV) radiator is to efficiently emit photons at high temperatures to TPV cells for conversion to electric power. Because many candidate radiator materials with adequate structural properties display low emissivity, coatings or other surface modifications are required for enhancement of emissivity. Six plasma sprayed coatings and one textured surface demonstrated adequate thermal stability and emittance values of 0.8 or greater. Promising attributes of modified surfaces are identified.
1999-03-01
Physical Properties of Liquid Crystals
This handbook is a unique compendium of knowledge on all aspects of the physics of liquid crystals. In over 500 pages it provides detailed information on the physical properties of liquid crystals as well as the recent theories and results on phase transitions, defects and textures of different types of liquid crystals. An in-depth understanding of the physical fundamentals is a prerequisite for everyone working in the field of liquid crystal research. With this book the experts as well as graduate students entering the field get all the information they need.
1999-01-01
Magnetic resonance appearance of fibromatosis
International Nuclear Information System (INIS)
We reviewed retrospectively the magnetic resonance (MR) images of 14 soft-tissue lesions of fibromatosis (desmoid tumors) encountered in 11 patients. The lesions were typically inhomogeneous in texture and round to oval in configuration. Margins were well-defined in 78% of the lesions at presentation and were infiltrating in all recurrences. (orig./DG).
Energy Technology Data Exchange (ETDEWEB)
Two aspects of the deformation behavior of magnesium sheets are the subject of this paper. First it will give a mechanical characterization of a commercial magnesium with a focus on the anisotropy and the possible microstructural causes of this behavior. The rolling process will be part of the second aspect. The aim is to show the influence of the parameters on the microstructure and texture and how this could affect the anisotropy in the rolled sheets. (Abstract Copyright [2003], Wiley Periodicals, Inc.)
2003-12-01
Flavor Mixing of Quarks and Neutrinos
The "texture zero mass matrices" for the quarks and leptons describe very well the flavor mixing of the quarks and leptons. We can calculate the angles of the unitarity triangle. We expect the angle alpha of the unitarity triangle to be 90 degrees. The masses of the neutrinos can be calculated - they are very small, the largest neutrino mass is 0.05 eV. We calculated the matrix element of the mixing matrix, relevant for the reactor mixing angle. It can be measured in the near future in the DAYA BAY experiment.
2011-01-01
Tetracycline treatment of periodontal disease in the beagle dog
Energy Technology Data Exchange (ETDEWEB)
Bone-seeking radiopharmaceutical uptake (BSRU) was used to examine alveolar bone metabolism in a longitudinal study of tetracycline efficacy in beagle dogs. BSRU was measured in untreated control dogs and in beagles receiving either 250 mg or 500 mg oral tetracycline-HCl daily for 16 months. The rate of bone loss was determined for radiographs taken semiannually for a 6-month pretreatment period and for a 24-month treatment period. Measurements of BSRU obtained at month 16 of treatment were correlated with rates of bone loss determined radiographically in an attempt to determine whether BSRU was indicative of the subsequent rate of bone loss. A reduced rate of alveolar bone loss was found in the 500 mg tetracycline group at month 16 of the study relative to the untreated controls which was consistent with the decreased bone-seeking radiopharmaceutical uptake observed in this group. A significantly increased BSRU (p<.0001) was found in the ...
1982-01-01
International Nuclear Information System (INIS)
Somatostatin receptor expression has been demonstrated on a number of plasma cell lines. Therefore, we questioned whether somatostatin receptor scintigraphy (SRS) can be used to demonstrate in vivo multiple myeloma (MM) activity. SRS was performed in newly diagnosed (n = 9) or relapsing (n = 18) MM patients or in patients with localized plasmacytoma (n = 2). The results were compared with radiographic findings. A positive SRS was demonstrated in 44% of the newly diagnosed patients, in 83% of the relapsed patients and in both patients with plasmacytoma. The SRS findings corresponded with radiographic abnormalities in 40% of the patients. However, in relapsed patients 60% demonstrated increased SRS uptake in areas without new radiographic abnormalities. The positive SRS corresponded with histologically proven disease activity and responded upon treatment. Moreover, immunohistochemical staining of MM material demonstrated ...
2010-01-01
Radionuclide scintimetry for diagnosis of complications following femoral neck fracture
Energy Technology Data Exchange (ETDEWEB)
A scintimetric study using Tc-99m MDP was made of 54 patients with delayed union, nonunion, or late segmental collapse of the femoral head, 4-92 months after femoral neck fracture. In radiographically verified collapse, the radionuclide uptake ratio between the femoral head on the fractured and on the intact side (HHR) was significantly higher than in fractures resulting in delayed union or nonunion. On the basis of scintimetric and radiographic findings, the patients with healing disturbances could be divided into three groups, characterized by the following features: (1) Satisfactory post-reduction position of the fracture without subsequent redisplacement and a high HHR, which as a rule turned out to be delayed union; (2) The same radiographic pattern but with a lower HHR, which in most cases resulted in nonunion; (3) Inadequate reduction or early redisplacement of the fracture with a high HHR, which resulted in ...
1984-01-01
Femoral neck buttressing: a radiographic and histologic analysis
International Nuclear Information System (INIS)
Objective. To examine the incidence, radiographic and histologic findings of medial femoral neck buttressing in a consecutive group of patients undergoing total hip arthroplasty.Design. Biomechanical parameters were evaluated on standard anteroposterior pelvic radiographs of 113 patients prior to hip replacement surgery. Demographic information on all patients was reviewed and histologic evaluation was performed on specimens obtained at the time of surgery.Results. The incidence of medial femoral neck buttressing was found to be 50% in a consecutive series of patients undergoing total hip arthroplasty. The incidence was slightly higher in women (56% vs 41%). Patients with buttressing had increased neck-shaft angles and smaller femoral neck diameters than were seen in patients without buttressing. Histologic evaluation demonstrated that the buttress resulted from deposition bone by the periosteum on the femoral neck in the absence of any ...
2000-10-01
International Nuclear Information System (INIS)
Many mechanical parts are subjected to stresses and strains that may eventually lead to their failure. In order to prevent the costly delays associated with equipment down-time, many parts have to be tested for weaknesses and defects when machinery is constructed or dismantled for maintenance. These procedures are known as Non-Destructive Testing (NDT) methods. Five types of non-destructive testing methods routinely used are radiographic testing, ultrasonic testing, magnetic particle inspection, liquid penetrant testing and eddy current testing. Out of these five techniques industrial radiography plays an important role in non-destructive testing to reveal interior defects in materials. In radiography almost two-thirds of the radiation reaching the film is scattered radiation which does not form the image of defects. Scattered radiation generated inside and outside a material has a very large effect on sensitivity of flaw detection since it reduces image contrast. ...
1998-02-01
An asymptomatic pink discoloration of a maxillary right fourth premolar tooth was discovered during a routine oral examination on a 9 year-old Belgian Malinois dog. A radiolucent lesion was seen in the pulpal chamber on radiographic examination. The lesion had perforated the mesiobuccal root of the tooth. The primary differential diagnosis was idiopathic internal resorption. The tooth was treated by partial resection (removal of the mesiobuccal root and associated crown). A vital pulpotomy and amalgam restoration was performed on the remaining tooth structure. A follow-up 1 year later demonstrated a successful treatment outcome. The animal was asymptomatic and able to perform military duties. Clinical and radiographic signs of healing were evident and the tooth was functional. PMID:10518874
1998-12-01
Energy Technology Data Exchange (ETDEWEB)
Forty-five patients with recent cervical hip fractures were included in a prospective, clinical, radiographic and sequential scintimetric study. Striking changes in radionuclide uptake over the entire hip region on the fracture side were found during the first 5 postoperative months. Fractures that healed without complications showed the highest relative femoral head uptake at 1 week and a peak value at 6 weeks, followed by a gradual decline at the subsequent examinations. Fractures with complications (redisplacement, nonunion, or late segmental collapse) showed a lower initial uptake and a more gradual increase and only a slight tendency towards increased uptake after 3 months. The accuracy in predicting nonunion with scintimetric examination alone is high both at 1 and at 6 weeks, and the accuracy is almost equally high with combined scintimetric, radiographic, and clinical assessment 3-5 months postoperatively.
1987-01-01
Radiation-induced large intracranial vessel occlusive vasculopathy.
Two patients who developed large intracranial vessel occlusion after standard radiation therapy for brain tumor are described. This form of vascular occlusion is usually seen in patients who have previously been treated by radiotherapy for intracranial tumor who then develop a relatively acute change in neurologic status. Histology of the lesion mimics accelerated focal arteriosclerosis. The clinical and radiographic manifestations of one case were highly atypical. The vasculopathy became evident shortly after termination of radiation therapy for a fourth ventricular ependymoma, and the angiographic picture stimulated a diffuse arteritis. The second patient was more typical, with clinical symptoms developing 12 years after radiation therapy for an oligodendroglioma. Occlusion of a proximal vessel that had been included in the radiation port was demonstrated radiographically and confirmed by pathologic examination. The clinical, angiographic, ...
1980-01-01
Radiation-induced large intracranial vessel occlusive vasculopathy
Energy Technology Data Exchange (ETDEWEB)
Two patients who developed large intracranial vessel occlusion after standard radiation therapy for brain tumor are described. This form of vascular occlusion is usually seen in patients who have previously been treated by radiotherapy for intracranial tumor who then develop a relatively acute change in neurologic status. Histology of the lesion mimics accelerated focal arteriosclerosis. The clinical and radiographic manifestations of one case were highly atypical. The vasculopathy became evident shortly after termination of radiation therapy for a fourth ventricular ependymoma, and the angiographic picture stimulated a diffuse arteritis. The second patient was more typical, with clinical symptoms developing 12 years after radiation therapy for an oligodendroglioma. Occlusion of a proximal vessel that had been included in the radiation port was demonstrated radiographically and confirmed by pathologic examination. The clinical, angiographic, ...
1980-01-01
Destructive spondyloarthropathy in hemodialysis patients. Report of four cases and prospective study
Energy Technology Data Exchange (ETDEWEB)
A destructive spondyloarthropathy is reported in four patients undergoing maintenance hemodialysis for chronic renal disease. In a separate investigation a controlled, prospective radiographic study of the cervical spine revealed this spondyloarthropathy in 4 (15%) of 26 long-term dialysis patients. A single disk level was involved in three patients, and two disc levels were involved in one patient. This spondyloarthropathy correlated with the duration of dialysis but not with the radiographic evidence of renal osteodystrophy or severity of laboratory abnormalities associated with hyperparathyroidism. Three of these four patients also had discovertebral erosions or destruction involving the lumbar spine. Cervical spine flexion views revealed evidence of ligamentous laxity or instability in three (12%) dialysis patients, all with vertebral resorption and disc space narrowing. It is postulated that this instability may contribute to the ...
1988-04-01
A method of stereotaxic localization adopted for conventional and digital radiography
International Nuclear Information System (INIS)
A method for the determination of stereotaxic coordinates in radiography, e.g. angiography, pneumoencephalography or digital vascular radiography, is described. A special localization frame containing radiopaque structures and scales defines a diagnostic coordinate system. This frame is fixed to the X-ray-table prior to the radiographic procedure and two projections are obtained at arbitrary angles to each other. The focus-film distances do not have to be fixed. The target coordinates are then determined either by a simple graphical procedure or with the use of a digitizing x-y-table, by a computer. With the computer method the films are placed on the digitizing table and the target and a few reference points are marked using a cursor. From the relative positions the computer calculates the coordinates. With the special head fixation system, coordinates of structures visualized in radiographic examinations can be transferred to various ...
1986-01-01
Digitonin abolishes free 2-deoxy-D-glucose accumulation in isolated rat adipocytes
Energy Technology Data Exchange (ETDEWEB)
The hypothesis that accumulation against sizable chemical gradients of free (non-phosphorylated) 2-deoxy-D-glucose (2dGlc) in isolated rat adipocytes results from an intracellular compartmentation of free hexose was investigated. Cells exposed to 20 ..mu..g/ml digitonin for 10' demonstrated an increased plasma membrane permeability indexed by increased L-glucose entry rates and cellular (presumably cytosolic) protein and K/sup +/ loss. Functional integrity of intracellular organelles was indicated by the ability of the cells to support ATP-driven /sup 45/Ca/sup 2 +/-uptake. Equilibrium 3-O-methylglucose (3-O-MG, a non-accumulated hexose) levels were unaffected. These data suggest a specific permeabilizing action of digitonin at the plasma membrane having no effect on intracellular organelles or passively distributed solutes. Upon addition of digitonin, free 2dGlc fell from 66.5 +/- 8.9 to 7.4 ...
1986-03-05
Energy Technology Data Exchange (ETDEWEB)
A procedure and software have been developed to transform the area distribution of the residual surface heights available from the measurement with the Micromap interferometric microscope into a two-dimensional (2D) power spectral density (PSD) distribution of the surface height. The procedure incorporates correction of one of the spectral distortions of the PSD measurement. The distortion appears as a shape difference between the tangential and sagittal PSD spectra deduced from the 2D PSD distribution for an isotropic surface. A detailed investigation of the origin of the anisotropy was performed, and a mathematical model was developed and used to correct the distortion. The correction employs a modulation transfer function (MTF) of the detector deduced analytically based on an experimentally confirmed assumption about the origin of the anisotropy due to the asymmetry of the read-out process of the ...
2005-05-12
International Nuclear Information System (INIS)
Using the linearized augmented-plane-wave (LAPW) -calculated electron and positron charge densities for YBa_2Cu_3O_7, the Brillouin-zone-reduced electron-positron momentum density is computed and the zone-reduced two-dimensional angular correlation of annihilation radiation (2D ACAR) spectrum is produced. The calculations show that the relative weights of the Fermi-surface discontinuities are substantially altered due to the positron preferentially sampling the Cu-O chain region. In addition, the reduced 2D ACAR spectrum contains large k-dependent wave-function effects. The theoretical zone-reduced 2D ACAR spectrum is compared to the several existing experimental spectra. It is concluded that, at present, positron-annihilation experiments do not provide consistent and clear evidence for the existence and shapes of Fermi surfaces in YBa_2Cu_3O_7.
Some authors have concluded that spiral structures and shocks do not develop if an adiabatic index gamma > 1.16 is adopted in accretion disc modelling, whilst others have claimed that they obtained well defined spirals and shocks adopting a gamma = 1.2 and a M_2/M_1 = 1 stellar mass ratio. In our opinion, it should be possible to develop spiral structures for low compressibility gas accretion discs if the primary component is a black hole. We considered a primary black hole of 8 solar mass and a small secondary component of 0.5 solar mass to favour spiral structures formations and possible spiral shocks via gas compression due to a strong gravitational attraction. We performed two 3D SPH simulations and two 2D SPH simulations and characterized a low compressibility model and a high compressibility model for each couple of simulations. 2D models reveal spiral structures existence. Moreover, spiral ...
2001-12-01
% In this work we investigated, in the Smooth Particle Hydrodynamics (SPH) framework, the development of spiral structures and shock fronts in the radial flow of accretion discs in close binary systems. These shock waves take place when the initially supersonic radial flow penetrating the disc bulk, reduces substantially its speed becoming suddenly subsonic. To this purpose, keeping constant the mass of the compact primary (M1 = 1 MO ), the separation between the two components and the injection speed at the inner Lagrangian point L1 (close to the local sound speed), we carried out 2D SPH simulations for four values of the stellar mass ratio M2/M1. We worked out 2D models because the damping effect of the artificial viscosity is too strong in 3D. Furthermore, the 2D environment seems the most suitable in order to evidence shock fronts in highly compressible ...
2000-06-01
Energy Technology Data Exchange (ETDEWEB)
Examination of a chloroform extract of Dracaena loureiri Gagnep (Agavaceae), a Thia medicinal plant possessing antibacterial activity, has led to the isolation of fifteen flavenoids. The biogenic relationships among these flavenoids isolated were briefly discussed. Definition of the skeleton and the unambiguous assignment of all of the protons of the isolates was achieved through extensive 2D-homonuclear chemical shift correlation, nuclear Overhauser effect (NOE) difference spectroscopy and 2D-NOE experiments. The {sup 1}H and {sup 13}C NMR spectra of staurosporine, a potent biologically active agent from Streptomyces staurosporeus, were unambiguously assigned by using 2D homonuclear chemical shift correlation, NOE, {sup 1}H-detected heteronuclear multiple-quantum coherence via direct coupling and via multiple-bond coupling for resonance assignments of ...
1988-01-01
Inhibitory effect of minocycline on osteoclastogenesis in mouse bone marrow cells
British Library Electronic Table of Contents (United Kingdom)
Objective: To study the effects of minocycline hydrochloride (MINO) on the formation of tartrate-resistant acid phosphatase (TRAP) staining-positive multinucleated osteoclast-like cells in mouse bone marrow cells (BMCs) treated with 1@a,25(OH)"2D"3 or soluble receptor activator of nuclear factor-@kB ligand (s-RANKL). Materials and methods: Mouse BMCs were cultured in alpha-modified minimum essential medium containing foetal calf serum (10%) and tetracyclines (2.5, 5 and 10@mM), such as MINO, tetracycline hydrochloride (TC), oxytetracycline hydrochloride (OXT) or doxycycline (DOXY) in the presence of 1@a,25(OH)"2D"3 (10nM) or s-RANKL (20ng/ml) for 7 days, and the number of TRAP staining-positive osteoclast-like cells was counted. In RNA isolated from BMCs treated with 1@a,25(OH)"2D"3 or s-R...
2011-01-01
Exploring the 2D to 3D dimensionality crossover in thin iron films
Energy Technology Data Exchange (ETDEWEB)
The temperature dependence of the spontaneous magnetization of epitaxial iron films with a thickness ranging from d=20 to 200nm has been measured. The films are grown on GaAs (100) substrates which are covered by a 150nm thick silver (100) buffer layer. For three-dimensional BCC iron it was observed already in 1929 that saturation of the spontaneous magnetization for T->0 is perfectly described by a T{sup 2} power law. On the other hand, for thin two-dimensional (2D) iron films a T{sup 3/2} law has been established in many recent experimental investigations. In our iron films grown on diamagnetic silver, this dimensionality change occurs at a thickness between d=100 and 200nm. Comparison of the here-observed T{sup 3/2} coefficients with those on iron films grown on paramagnetic tungsten (110) shows that the 2D interactions are {approx}20 times larger in the films on tungsten. Recent results on Fe ...
2006-05-15
Energy Technology Data Exchange (ETDEWEB)
The consistency of different instruments and methods for measuring two-dimensional (2D) power spectral density (PSD) distributions are investigated. The instruments are an interferometric microscope, an atomic force microscope (AFM) and the X-ray Reflectivity and Scattering experimental facility, all available at Lawrence Berkeley National Laboratory. The measurements were performed with a gold-coated mirror with a highly polished stainless steel substrate. It was shown that these three techniques provide essentially consistent results. For the stainless steel mirror, an envelope over all measured PSD distributions can be described with an inverse power-law PSD function. It is also shown that the measurements can be corrected for the specific spatial frequency dependent systematic errors of the instruments. The AFM and the X-ray scattering measurements were used to determine the modulation transfer function of the interferometric microscope. ...
2005-07-12
Energy Technology Data Exchange (ETDEWEB)
The consistency of different instruments and methods for measuring two-dimensional (2D) power spectral density (PSD) distributions are investigated. The instruments are an interferometric microscope, an atomic force microscope (AFM) and the X-ray Reflectivity and Scattering experimental facility, all available at Lawrence Berkeley National Laboratory. The measurements were performed with a gold-coated mirror with a highly polished stainless steel substrate. It was shown that these three techniques provide essentially consistent results. For the stainless steel mirror, an envelope over all measured PSD distributions can be described with an inverse power-law PSD function. It is also shown that the measurements can be corrected for the specific spatial frequency dependent systematic errors of the instruments. The AFM and the X-ray scattering measurements were used to determine the modulation transfer function of the interferometric microscope. ...
2005-04-17
Core reactor calculation using the adaptive remeshing with a current error estimator
International Nuclear Information System (INIS)
With the objective to improve the reactor physics calculation on a 2D and 3D nuclear reactor via the Diffusion Equation, an adaptive automatic finite element remeshing method, based on the elementary area (2D) or volume (3D) constraints, has been developed. The adaptive remeshing technique, guided by a posteriori error estimator, makes use of two external mesh generator programs: Triangle and TetGen. The use of these free external finite element mesh generators and an adaptive remeshing technique based on the current field continuity show that they are powerful tools to improve the neutron flux distribution calculation and by consequence the power solution of the reactor core even though they have a minor influence on the critical coefficient of the calculated reactor core examples. Two numerical examples are presented: the 2D IAEA reactor core numerical ...
Computational models of stellar collapse and core-collapse supernovae
International Nuclear Information System (INIS)
Core-collapse supernovae are among Nature's most energetic events. They mark the end of massive star evolution and pollute the interstellar medium with the life-enabling ashes of thermonuclear burning. Despite their importance for the evolution of galaxies and life in the universe, the details of the core-collapse supernova explosion mechanism remain in the dark and pose a daunting computational challenge. We outline the multi-dimensional, multi-scale, and multi-physics nature of the core-collapse supernova problem and discuss computational strategies and requirements for its solution. Specifically, we highlight the axisymmetric (2D) radiation-MHD code VULCAN/2D and present results obtained from the first full-2D angle-dependent neutrino radiation-hydrodynamics simulations of the post-core-bounce supernova evolution. We then go on to discuss the new code Zelmani ...
2009-07-01
Visualization of liquid metal two-phase flow by a real time neutron radiography system
Energy Technology Data Exchange (ETDEWEB)
In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).
1995-11-01
Visualization of liquid metal two-phase flow by a real time neutron radiography system
International Nuclear Information System (INIS)
In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).
1995-01-01
Screen-film-combinations for radiography - present and future spectrum of application
Energy Technology Data Exchange (ETDEWEB)
From the numbers of radiographs of the different examinations and the total amount of radiological diagnostics in the GDR their possible modification by new imaging techniques is discussed under the aspects of costs and radiation burden. Film-screen-systems are of special importance, because they also will be most frequently used image recording system in future. The importance of their various properties and parameters, methods of determining these parameters as well as future developments are analyzed from the standpoint of practical requirements.
1985-01-01
Screen-film-combinations for radiography - present and future spectrum of application
International Nuclear Information System (INIS)
From the numbers of radiographs of the different examinations and the total amount of radiological diagnostics in the GDR their possible modification by new imaging techniques is discussed under the aspects of costs and radiation burden. Film-screen-systems are of special importance, because they also will be most frequently used image recording system in future. The importance of their various properties and parameters, methods of determining these parameters as well as future developments are analyzed from the standpoint of practical requirements. (author).
Radiation exposure of the population of the GDR by X-ray diagnostics
International Nuclear Information System (INIS)
The radiation burden of the people of the GDR in relation to biomedical radiography altogether as well as organ doses, gonad doses and genetically significant doses in detail are outlined. The concepts of radiation protection and standards of radiographic examination are demonstrated. Possibilities of influencing radiation exposure by scientifically based indication of X-ray examination, application of new and improvement of usual examination techniques are discussed with regard to quality assurance and control. Proposals concerning the reduction of radiation exposure of the GDR population are presented.
1986-01-01
Principium research of real-time neutron radiography in No. 300 reactor
International Nuclear Information System (INIS)
The characteristics of real-time neutron radiography are described briefly in this paper, and the acquirement of neutron flux, the selection of convertor and the structure of the twilight imaging system and the image-sampling and image-processing system in SPRR-300 reactor are also analyzed detailedly. The experimental result of real-time neutron radiograph is too analyzed in this paper
2002-12-01
Energy Technology Data Exchange (ETDEWEB)
Iodixanol is a new nonionic dimer, isotonic with blood at all clinically relevant concentrations. Iodixanol (270 mg I/ml) was compared in a double-blind, randomized, parallel-group, phase-III study to the monomeric nonionic iohexol (300 mg I/ml) for evaluation of safety, tolerability and radiographic efficacy during cerebral CT. One hundred adult patients scheduled to undergo contrast-enhanced cerebral CT were randomly allocated to receive either iodixanol or iohexol. All completed the trial. Safety was evaluated by recording discomfort and other adverse events, tolerance by assessing intensity and incidence of discomfort. Radiographic efficacy was assessed from the diagnostic information and the radiographic density. No serious adverse events occurred. One patient (2 %) in the iodixanol group and one patient (2 %) in the iohexol group experienced a transient reddening at the neck and lower neck-line, respectively. Both ...
1999-09-01
UK PubMed Central (United Kingdom)
An 8-year-old child presented with severe chest pain and respiratory distress after he accidentally bit an automobile tyre tube which burst into his mouth. The chest radiograph revealed left-sided pneumothorax....Full Text Available
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Image representations have gained wide acceptance in displaying data collected during optical, ultrasonic, radiographic, and thermographic inspections. Applying imaging techniques to eddy current testing is explored in this article. The authors show that flaw interpretation and characterization are made considerably simpler when images are used to visualize the impedance changes in eddy current probes.
1993-04-01
Demonstration of realtime radiography on pipeline girth welds: Final report
Energy Technology Data Exchange (ETDEWEB)
Conventional radiography has been the accepted nondestructive testing (NDT) method used for many years to either ''accent'' or ''reject'' a field weld in the pipeline industry. However, conventional radiography requires the expense of film, developing chemicals, and manpower for film development. It also normally has a delay of 2 hours or more between when the weld was radiographed and when the radiographic film of the weld is available for interpretation. Over the last few years, a newer approach to performing radiographic testing, called ''realtime'' radiography, has been used in several different types of field inspection operations. The realtime radiography system forms the image with optical imaging in lieu of photographic film. Objectives of this project were: (Task 1) Integration of realtime x-ray system ...
1988-09-01
Study on warm caliber rolling of magnesium alloy
Energy Technology Data Exchange (ETDEWEB)
The warm caliber rolling was experimented using the AZ31 magnesium alloy round bar of 20 mm in diameter machined from cast ingot materials. In warm caliber rolling in final size of 10 mm in diameter at 623 K via 8passes, each width-spreading, the change of each microstructure, X-ray analysis of final texture and final mechanical properties were investigated. Microstructure, texture and mechanical properties of warm caliber rolled round bar at 473 K via latter 4passes were compared with those at 623 K consistently. Obtained results are as follows: (1) The width-spreading in caliber rolling of round bar is relatively large, compared with that in flat rolling of the flat bar. The largeness of width-spreading of round bar makes the shape control of cross section difficult, and causes the cracks around the free surface. (2) Finer microstructure and inclined c axis of hexagonal lattice of 10 degrees to vertical direction of the rolled surface are ...
2003-07-01
Energy Technology Data Exchange (ETDEWEB)
Coal bed natural gas (CBNG) development in the Powder River (PR) Basin produces modestly saline, highly sodic wastewater. This study assessed impacts of wetting four textural groups (0-11%, 12-22%, 23 -33%, and > 33% clay (g clay/100 g soil) x 100%))with simulated PR or CBNG water on water retention. Soils received the following treatments with each water quality: a single wetting event, five wetting and drying events, or five wetting and drying events followed by leaching with salt-free water. Treated samples were then resaturated with the final treatment water and equilibrated to -10, -33, -100, -500, or -1,500 kPa. At all potentials, soil water retention increased significantly with increasing clay content. Drought-prone soils lost water-holding capacity between saturation and field capacity with repeated wetting and drying, whereas finer textured soils withstood this treatment better and had increased water-retention capacity at ...
2007-07-01
International Nuclear Information System (INIS)
Highly conductive biaxially textured RuO_2 thin films were deposited on technically important SiO_2/Si substrates by pulsed laser deposition, where yttria-stabilized zirconia (YSZ) produced by ion-beam-assisted-deposition (IBAD) was used as a template to enhance the biaxial texture of RuO_2 on SiO_2/Si. The biaxially oriented RuO_2 had a room-temperature resistivity of 37 #mu##OMEGA#-cm and residual resistivity ratio above 2. We then deposited Ba_0_._5Sr_0_._5TiO_3 thin films on RuO_2/IBAD-YSZ/SiO_2/Si. The Ba_0_._5Sr_0_._5TiO_3 had a pure (111) orientation normal to the substrate surface and a dielectric constant above 360 at 100 kHz. copyright 1998 Materials Research Society.
1998-09-01
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 subsurface pole figures revealed broadened poles and ...
1998-07-01
On methods for improving the fatigue performance of the wrought magnesium alloys AZ31 and AZ80
Energy Technology Data Exchange (ETDEWEB)
The tensile and compressive properties as well as LCF and HCF performance of the extruded magnesium alloys AZ31 and AZ80 were determined in extrusion (L) and long-transverse (T) directions. Owing to marked crystallographic textures, both alloys showed pronounced directional mechanical properties in monotonic as well as cyclic loading with strength values in L-direction being significantly superior to those in T-direction. Thermomechanical treatments such as pressing, swaging and rolling were found to increase yield stresses and HCF strengths and to alter the directionality in properties due to textural modifications. To further improve HCF strengths, mechanical surface treatments such as shot peening, roller-burnishing and deep rolling were utilized. The results indicate marked improvements provided that suitable process parameters are used. The improvement of the HCF strengths is explained by the process-induced changes in near-surface ...
2003-07-01
Mineralogical study of borehole MW-206 Asarco smelter site, Tacoma, Washington
Energy Technology Data Exchange (ETDEWEB)
The mobility of metals in ground water is an important consideration for evaluating remedial options at the Asarco smelter site. Tacoma, Washington. One factor in assessing metal mobility is the degree of secondary mineralization in a slag-fill aquifer extending into the intertidal zone along the Puget Sound shoreline. Samples of aquifer material were collected for mineralogical analysis from borehole MW-206 at five-foot intervals within the slag fill from 5 to 25 feet below the ground surface, and in the underlying marine sand and gravel at 27 feet. Grab samples of slag fragments with visually apparent secondary minerals were also collected at five intermediate depths between 12 and 19 feet. Samples were analyzed by a variety of techniques including hydride generation/atomic absorption for arsenic concentration, scanning electron microscopy/electron microprobe for mineralogical texture and microanalysis, powder x-ray diffraction for mineral identification, and ...
1998-10-01
Studies of human mutation rates
Energy Technology Data Exchange (ETDEWEB)
November 1989, marked the beginning of a new three-year cycle of DOE grant support, in connection with which the program underwent a major reorganization. This document presents the progress on the three objectives of the present program which are: to isolate by the technique of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), proteins of special interest because of the relative mutability of the corresponding gene, establish the identity of the protein, and, for selected proteins, move to a characterization of the corresponding gene; to develop a more efficient approach, based on 2-D PAGE, for the detection of variants in DNA, with special reference to the identification of mutations in the parents of the individual whose DNA is being examined; and, to continue an effective interface with the genetic studies on the children of atomic bomb survivors in Japan, with reference to both the ...
1990-01-01
Strings through the Microscope
Over the last few years, string theory has changed profoundly. Most importantly, novel duality relations have emerged which involve gauge theories of brane excitations on one side and various closed string backgrounds on the other. In this lecture, we introduce the fundamental ingredients of modern string theory and explain how they are modeled through 2D (boundary) conformal field theory. This so-called `microscopic description' of strings and branes is an active research area with new results ranging from the classification and construction of boundary conditions to studies of 2D renormalization group flows. We shall provide an overview of such developments before concluding the lecture with an extensive outlook on some research that is motivated by current problems in string theory. This includes investigations of non-rational and non-unitary conformal field theories.
2004-01-01
We assess the accuracy and relevance of the numerical algorithms based on the principles of Geometrical Optics (GO) and Physical Optics (PO) in the analysis of reduced-size homogeneous dielectric lenses prone to behave as open resonators. As a benchmark solution, we use the Muller boundary integral equations discretized with trigonometric Galerkin scheme that has guaranteed and fast convergence as well as controllable accuracy. The lens cross-section is chosen typical for practical applications, namely an extended hemiellipse whose eccentricity satisfies the GO focusing condition. The analysis concerns homogeneous lenses made of rexolite, fused quartz, and silicon with the size varying between 3 and 20 wavelengths in free space. We consider the 2-D case with both E- and H-polarized plane waves under normal and oblique incidence, and compare characteristics of the near fields.
2010-01-01
On the evolution of supernova remnants: Pt. 2
International Nuclear Information System (INIS)
Supernova explosions within wind-driven bubbles are studied with 2D hydrodynamical calculations. Two different density distributions for the ejecta are considered: (i) a smooth, unfragmented power-law stratification, and (ii) a fragmented distribution. As in 1D models, the presence of the shell of interstellar swept-up matter causes the rapid evolution of the remnant to the radiative phase. The main 2D effects, for both fragmented and unfragmented ejecta, include: (i) substantial chaotic deviations from a purely radial flow in the remnant interior, (ii) efficient turbulent mixing between the ejecta and the shocked wind, resulting in homogenization of the former wind cavity, and (iii) severe distortion of the wind-driven shell by cooling and Rayleigh-Taylor instabilities. (author).
We present here a study based on the migration of protoplanets in an accretion disc of a forming star, as the mainly proposed scenario for the formation of planetary systems. Attention is here focused on the mutual interactions between two protoplanets, both embedded in the accretion disc, as a function of the protoplanets masses, their relative positions, the dynamic properties of the accretion disc particles. The study is performed through a 2D SPH code and preliminary results show an oscillation of the distance between the two protoplanets, together with a slow migration of the two planets towards the central star when two Jupiter-like planets are considered. Less correlated behaviour is observed when at least one of the two protoplanets has an Earth-like mass. The role played by the disc particles initial angular momentum is discussed.
2010-01-01
Mass-loss in 2D zero-age main-sequence stellar models
British Library Electronic Table of Contents (United Kingdom)
Abstract A large number of massive stars are known to rotate rapidly, resulting in a significant distortion and variation in surface temperature from the pole to the equator. Radiatively driven mass-loss is temperature-dependent, so rapid rotation produces a variation in the mass-loss and angular momentum loss rates across the surface of the star, which is expected to affect the evolution of rapidly rotating massive stars. In this work, we use zero-age main-sequence (ZAMS) stellar models to investigate the two-dimensional effects of rotation on stellar mass-loss, using two common prescriptions for radiatively driven mass-loss. The associated loss of angular momentum from these models is also considered. Using 2D stellar models, which give the variation in surface parameters as a function o...
2011-01-01
First trimester measurements of nasal bone length using three-dimensional ultrasound
British Library Electronic Table of Contents (United Kingdom)
Objectives To investigate the feasibility and reproducibility of measurements of nasal bone length using a three-dimensional (3D) ultrasound in the first trimester. Methods In a prospective study, 118 consecutive pregnant women attending for Down syndrome screening at 11-13 + 6 weeks were recruited. They had successful fetal nasal bone measurement by two-dimensional (2D) ultrasound by four operators. Three-dimensional volumes were recorded in the mid-sagittal plane of fetal profile by the fifth operator and examined using multiplanar techniques. Another independent investigator randomly compared his measurements with one of the four operators. Results In the subsequent 3D examination, the nasal bone length could be examined in 94 cases (79.7%). The mean difference between the 2D and 3D mea...
2009-01-01
Exploring the potential energy surface for proton transfer in acetylacetone
Energy Technology Data Exchange (ETDEWEB)
The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecular proton transfer reaction is studied using ab initio and DFT methods. The best estimate of the barrier governing proton transfer was found to be 3.4 kcal mol{sup -1} at the MP4(FC)/6-311 + G(2d,2p)//MP2(FC)/6-311 + G(2d,2p) level of theory. Six stationary points on the PES were characterized as well as the reaction paths connecting these points. Special attention paid to the pathway of intramolecular proton transfer reveals that the internal rotation of the methyl group adjacent to the carbonyl group and the proton transfer reaction are consecutive processes.
2004-11-15
Discretization of complex 3-D flow domains with adaptive hybrid grids
Energy Technology Data Exchange (ETDEWEB)
There is an ever increasing demand to perform flow simulations that incorporate the complete details of geometry as well as sophisticated flow physics. This has led to the development of numerical algorithms that can simulate the actual flow phenomena with greater fidelity. However, the success of these algorithms hinges on the grid that models the geometry. Grid generation methods for 2-D models have long existed and the general lack of complexity of the simpler 2-D models has not quite challenged the efforts in this area. However, demands for generating better 3-D geometric models for flow simulations involving complex geometries have completely changed the perspective of grid generation strategies. As a consequence, grid generation efforts have earned equal significance as that of numerical solver efforts.
1996-12-31
A Detector for 2-D Neutron Imaging for the Spallation Neutron Source
Energy Technology Data Exchange (ETDEWEB)
Abstract - We have designed, built, and tested a 2-D pixellated thermal neutron detector. The detector is modeled after the MicroMegas-type structure previously published for collider-type experiments. The detector consists of a 4X4 square array of 1 cm 2 pixels each of which is connected to an individual preamplifier-shaper-data acquisition system. The neutron converter is a 10B film on an aluminum substrate. We describe the construction of the detector and the test results utilizing 252Cf sources in Lucite to thermalize the neutrons.Drift electrode (Aluminum) Converter (10B) 3 mm Conversion gap neutron (-900 V)
2006-07-01
2D SPH simulations of a single planet migration in a protoplanetary disc
Migration of protoplanets inside an accretion disc of a forming star is the most probable scenario for planetary system formation according to current models. Unsolved problems exist, concerning migration times and mechanisms. We report here the results of a 2D hydrodynamic study within an SPH scheme, analysing migration of an Earth-like or a Jupiter-like planet inside an inviscid sub-Keplerian accretion disc, as a function of the initial specific angular momentum of the infalling accretion disc matter. Particle capture by the protoplanet causes a rapid migration, within a few orbits, for the Earth like planet, and about 104 orbits for the Jupiter like planets. The effect of a planet pseudo-atmosphere is also discussed.
2010-01-01
Topological Defects in the Moduli Sector of String Theory
We point out that the moduli sector of the $(2,2)$ string compactification with its nonperturbatively preserved non-compact symmetries is a fertile framework to study global topological defects, thus providing a natural source for the large scale structure formation. Based on the target space modular invariance of the nonperturbative superpotential of the four-dimensional N=1 supersymmetric string vacua, topologically stable stringy domain walls are found. They are supersymmetric solutions, thus saturating the Bogomolnyi bound. It is also shown that there are moduli sectors that allow for the global monopole-type and texture-type configurations whose radial stability is ensured by higher derivative terms.
1991-01-01
The requirements for a sustainable restoration project
Energy Technology Data Exchange (ETDEWEB)
The purpose is to describe problems associated with the establishment of vegetation on mined lands and practical rehabilitation and restoration methods for establishing a rehabilitation plan. Land disturbed by mining should be restored to its original state, when the mine is decommissioned, but before that can be attained, site problems such as toxicity, moisture supply, and texture must be rectified. The land may need to pass through several conditioning stages, and links need to be formed to maintain a functioning ecosystem. A key aspect to rehabilitation is the need to increase the organic matter content of the substrate. This improves soil structure, increases the moisture holding ability, and provides a pool for nutrient cycling. 11 refs., 2 tabs.
1991-06-01
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.
Energy Technology Data Exchange (ETDEWEB)
This review of methods and designs of transducers for nondestructive determination of the magnitude and nature of the anisotropy of magnetic properties (permeability, induction, coercive force, energy loss due to magnetization reversal) in local portions of ferromagnetic sheet and, in some cases, in individual parts of products. The need to measure the anisotropy is considered for two angles: for the case when the anisotropy is due to the crystallographic texture and determines the main operating characteristics of widely used sheet such as electrical steel and automobile body sheet, and for crystallographically isotropic materials, in which the anisotropy of magnetic properties as a result of mechanical stresses is a measure for determining the internal stresses.
1995-04-01
Inhomogeneity of mechanical and fatigue properties of Al-Li alloys extrusions
Energy Technology Data Exchange (ETDEWEB)
Aluminium-lithium extrusions possess high inhomogeneity of properties across the cross section. Mechanical properties such as R{sub p0,2}, R{sub m} and hardness, but also fatigue properties, change their value in dependence with the cross section position where test specimens were taken. Positions, where extreme values of properties are measured, are characteristic for a given extrusion shape. The positions with different properties have different structure and texture. Properties and structure inhomogeneity is affected mainly by extrusion shape and heat treatment parameters. (orig.)
1996-12-01
Energy Technology Data Exchange (ETDEWEB)
The study examines the isothermal fatigue properties of novel ODS iron-base or nickel-base superalloys at temperatures of 850 C and 1050 C. The materials are different in grain structure and texture, so that particularly the effects of grain structures and textures can be studied. In order to also perform examinations of creep-fatigue interactions, various load cycles are applied. It is shown that the LCF-affected life of the grain structures of both alloy types is determined by the elastic modulus. The cyclic lifetimes determined by the conventional Manson-Coffin method for both alloy types exhibit differences of up to two orders of magnitude. Using the product of the total strain range and the elastic modulus, however, will yield precise life predictions. Under conditions of LCF stress only, the grain structure has no effect on the materials` service life, other than in the case of creep-fatigue, but the grain structure has a decisive ...
1995-12-31
Anisotropy of H/sub c2/ and its implications to grain-boundary flux pinning in V$sub 3$Si
The anisotropy of H/sub c2/ was measured in a V$sub 3$Si monocrystal and was found to be much larger than in other materials. The max elementary pinning force f/sub p/ is estimated to be approximately 0.01 dyn/cm at the reduced field H/H/sub c/ = 0.25 and 4.2$sup 0$K. Control of texture as well as of grain size is important for improving J/sub c/ in A-15 compounds. (DLC)
1975-10-01
Vertex operator representation of OS/sub rho/(M/N)/sup (1)/
Energy Technology Data Exchange (ETDEWEB)
Using the boson-fermion equivalence in 2-d conformal field theory and the boson-boson equivalence of the superconformal bosonic ghost fields of the string theory, the authors construct a level {Kappa} = +1 representation of the affine superalgebra OSp(M*N)/sup 1/ in terms of vertex operators.
1988-01-01
Two dimensional analysis for equilibrium core of CANDU-PHWR
Energy Technology Data Exchange (ETDEWEB)
The WBURN (2-D, 2-group, coarse mesh) code is developed to analyze the equilibrium core characteristics of CANDU-PHWR. The equilibrium characteristics of Wolsung reactor computed by using WBURN are compared with the values given in the Wolsung FSR. The changes of equilibrium core characteristics caused by the variation of design parameters for operating conditions are also investigated. The numerical results indicate that the average discharge irradiation in the Wolsung reactor can be increased up to about 5%.
1983-06-01
Two dimensional analysis for equilibrium core of CANDU-PHWR
International Nuclear Information System (INIS)
The WBURN (2-D, 2-group, coarse mesh) code is developed to analyze the equilibrium core characteristics of CANDU-PHWR. The equilibrium characteristics of Wolsung reactor computed by using WBURN are compared with the values given in the Wolsung FSR. The changes of equilibrium core characteristics caused by the variation of design parameters for operating conditions are also investigated. The numerical results indicate that the average discharge irradiation in the Wolsung reactor can be increased up to about 5%. (Author).
1983-01-01
International Nuclear Information System (INIS)
The rare earth antimonates RE_3Sb_5O_1_2 constitute an isostructural series, where the rare earth site symmetry is S_4. The spectroscopic properties of pure or doped compounds of this family are studied in order to derive their energy level schemes and to simulate them through the crystal field theory, by using the approximated D_2_d potential. The paramagnetic susceptibilities are calculated with the derived wavefunctions and compared to experiment.
1990-09-01
Energy Technology Data Exchange (ETDEWEB)
We demonstrate a two-dimensional device simulator for MOSFET structures that incorporates models for defect distributions and show predicted effects on device switching performance for various spatial distributions of defects in amorphous and polycrystalline silicon.
1994-06-01
Supersonic flutter of composite sandwich panels
A flutter-motion equation is presently derived for a 2D composite sandwich panel considering the total lateral displacement of the plate as the sum of the displacement due to bending of the plate, and that which is due to shear deformation at the core. The effects of core thickness and stacking sequence of the faces on the flutter boundary of the plate are discussed; it is shown that the sandwich panel greatly improves the flutter boundary over that of a composite laminate panel, provided it has sufficient core thickness.
1992-12-01
In our previous paper (Lanzafame et al. 2000, PASJ 52, 515) we showed, through 2D SPH simulations, that the stellar mass ratio, M 2 / M 1, of a close binary system (that determines the position and then the initial specific angular momentum at L 1) plays a fundamental role in the formation and development of spiral structures and shock fronts in the radial flow of accretion discs. In that work only a quasi-sonic value of the injection velocity at L 1 was considered. In the present work we also carried out 2D SPH simulations with the aim to investigate the development of such structures, while keeping constant the mass of the compact primary (M 1 = 1 M odot) and the separation between the two components, and assuming as an initial condition of two different supersonic injection velocities at L 1, characterizing two sets of simulations. For each set we considered four values of the secondary to primary ...
2001-02-01
Simulation aided hardening of N-channel power MOSFETs to prevent single event burnout
International Nuclear Information System (INIS)
2D MEDICI simulator is used to investigate hardening solutions to single-event burnout (SEB). SEB parametric dependencies such as carrier lifetime reduction, base enlargement, and emitter doping decrease have been verified and a p"+ plug modification approach for SEB hardening of power MOSFETs is validated with simulations on actual device structures.
1995-07-17
Isomerization of 1-O-Indol-3-Ylacetyl-?-d-Glucose 1
UK PubMed Central (United Kingdom)
The first compound in the series of reactions leading to the ester conjugates of indole-3-acetic acid (IAA) in kernels of Zea mays sweet corn is the acyl alkyl acetal, 1-O-indol-3-ylacetyl-;2;-d-glucose...Full Text Available
1990-09-01
UK PubMed Central (United Kingdom)
ObjectiveWe wanted to assess the usefulness of four-dimensional (4D) ultrasonography (US), i.e., real-time three-dimensional US, as an adjunct for performing various US-guided interventional...Full Text Available
2006-01-01
UK PubMed Central (United Kingdom)
Objective and designLow grade inflammation is of pathogenic importance in atherosclerosis and in the development of cardiovascular disease (CVD) and type 2 diabetes (T2D). Matrix...Full Text Available
Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system
Energy Technology Data Exchange (ETDEWEB)
The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of /sup 203/Pb and /sup 47/Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol (1,25(OH)/sub 2/D/sub 3/) as their only source of the vitamin, the absorption of both /sup 47/Ca and /sup 203/Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in /sup 47/Ca and /sup 203/Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with 1,25(OH)/sub ...
1984-04-01
Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system
International Nuclear Information System (INIS)
The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of "2"0"3Pb and "4"7Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol [1,25(OH)_2D_3] as their only source of the vitamin, the absorption of both "4"7Ca and "2"0"3Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in "4"7Ca and "2"0"3Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with ...
Enzymic Synthesis of Indole-3-Acetyl-1-O-?-d-Glucose 1
UK PubMed Central (United Kingdom)
The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-;2;-d-glucose...Full Text Available
1988-12-01
UK PubMed Central (United Kingdom)
Background: Diet plays a key role in the development of type 2 diabetes (T2D), but little is known about the contributions of specific nutrients in populations in which dietary patterns...Full Text Available
2009-04-01
Energy Technology Data Exchange (ETDEWEB)
While tritium exposure to the site-workers in Wolsung NPP is up to about 40% of the total personnel exposure, Ministry of Science and Technology has asked tritium removal facility for requirement of post heavy-water reactor construction. For the purpose of essential removal of tritium from the Wolsung heavy-water reactor system, a preliminary study on the cryogenic Ar-N{sub 2} and H{sub 2}-D{sub 2} distillation process for development of liquid-phase catalytic exchange cryogenic hydrogen distillation process technology. The Ar-N{sub 2} distillation column showed good performance with approximately 97% of final Ar concentration, and a computer simulation code was modified using these data. A simulation code developed for cryogenic hydrogen isotopes (H{sub 2}, HD, D{sub 2}, HT, DT, T{sub 2}) distillation column showed good performance after comparison with the result of a JAERI code, and a H{sub 2}-D{sub ...
1995-12-01
Development of 2-D velocity structure model input tool
Energy Technology Data Exchange (ETDEWEB)
The seismic reflection exploration technique which is one of the geophysical methods for oil exploration became effectively to image the subsurface structure with rapid development of computer. As a tool to perform seismic inversion, seismic forward modeling program using ray tracing should be developed. In this study, we have developed the algorithm that is to calculate the travel time of the complex geological structure using ray tracing by subdividing the geologic model into triangular element (finite element) having the constant velocity. We can analytically calculate Jacobian with some information by this current ray tracing. With this Jacobian, we will develop new algorithm which is to obtain geological properties and to image the subsurface. Since the FEM (Finite Element Method) ray tracing we have developed goes well the inverse velocities structure, we can apply the inversion problem to complex geological model. For the convenience of velocity model input data which is needed ...
1996-12-01
International Nuclear Information System (INIS)
Power devices such as MOSFETSs and IGBTs, include parasitic structures that can give rise to destructive failures such as breakdown and latch-up. To determine a suitable strategy for device radiation hardening, simulation software like MEDICI-2D can be used to model the effects of technological modifications and device parameters that are difficult to measure experimentally. (authors).
Besarhanamides A and B from the marine cyanobacterium Lyngbya majuscula
British Library Electronic Table of Contents (United Kingdom)
Besarhanamides A (1) and B (2) are fatty acid amides purified from the marine cyanobacterium, Lyngbya majuscula, collected from Pulau Hantu, Singapore. The structure determination of these secondary metabolites was carried out using extensive 2D NMR spectral data as well as chemical manipulations including the Marfey's method. In addition, besarhanamide A exhibited moderate toxicity with LD50 at 13mM in the brine shrimp toxicity bioassay.
2008-01-01
BACCHUS: A numerical approach to two-phase flow in a rod bundle
Energy Technology Data Exchange (ETDEWEB)
We present in this paper the computer code BACCHUS, to analyze the thermal-hydraulics in a rod bundle in single or two-phase flow regime. The model is 2-D and uses the porous body approach. The two-phase model is an extension of the classical homogeneous model, and includes a differential non-equilibrium equation. Results are shown for the extension of the boiling region in a 19-pin bundle.
1984-10-01
BACCHUS: A numerical approach to two-phase flow in a rod bundle
International Nuclear Information System (INIS)
We present in this paper the computer code BACCHUS, to analyze the thermal-hydraulics in a rod bundle in single or two-phase flow regime. The model is 2-D and uses the porous body approach. The two-phase model is an extension of the classical homogeneous model, and includes a differential non-equilibrium equation. Results are shown for the extension of the boiling region in a 19-pin bundle. (orig.).
1984-01-01
Application of river basin simulation for flood hazard assessment
Energy Technology Data Exchange (ETDEWEB)
2D simulation modeling of a river basin is based on notion of a River Basin as an opened non equilibrium nature system. All components of the system (elevation, water, soil properties and others) are linked to single multi - functional model. The objective of flood simulation is one the model functions. The objectives of the paper are as follows: a mean scale basin floods computing and the model validation; a large scale basin simulation and demands for its validation; results and demands for flood hazard assessment. (orig.)
2000-07-01
Scientific Electronic Library Online (English)
Abstract in english This paper presents an HP-Adaptive Procedure with Hierarchical formulation for the Boundary Element Method in 2-D Elasticity problems. Firstly, H, P and HP formulations are defined. Then, the hierarchical concept, which allows a substantial reduction in the dimension of equation system, is introduced. The error estimator used is based on the residual computation over each node inside an element. Finally, the HP strategy is defined and applied to two examples.
2002-03-01
UK PubMed Central (United Kingdom)
The current investigation attempted to confirm the beneficial actions of a chemically characterized Radix Astragali decoction (AM-W) against type 2 diabetic (T2D) Sprague-Dawley (SD) rats. Using a case/control...Full Text Available
2011-01-01
2D cavity grid quantum computing
Energy Technology Data Exchange (ETDEWEB)
We propose a novel scheme for scalable solid state quantum computing, where superconducting microwave transmission line resonators (cavities) are arranged in a two-dimensional grid on the surface of a chip, coupling to superconducting qubits (charge or flux) at the intersections. We analyze how tasks of quantum information processing can be implemented in such a topology, including efficient two-qubit gates between any two qubits on the grid and elements of fault-tolerant computation.
2008-07-01
The role of Computerized Tomography in osteoid-osteoma diagnosis
International Nuclear Information System (INIS)
Alcaptonuria is a rare autosomal recessive metabolic disease, due to the lack of homogentisic acid oxidase. The following accumulation of homogentisic acid brings about a black discoloration of both the urine alcaptonuria) and connective tissue (ochronosis). The ochronotic alterations into joint cartilages cause degenerative arthropathy and osteopenia. The radiological features of three unrelated cases of alcaptonuria are reported. Radiographic abnormalities of ochconotic arthropathy are found in both the spine and the extraspinal joints. In the spine, the progressive calcification and ''vacuum'' phenomenon of disc spaces are the most characteristic findings. Disc space narrowing is associated with calcification and marginal sclerosis of vertebral bodies and is accentuated by osteopenia. Osteophytes are usually absent or of small size; neverthless progressive formation of marginal intervertebral bridges and obliteration of disc spaces at multiple levels ...
1988-01-01
Energy Technology Data Exchange (ETDEWEB)
35 patients with ankle sprain were examined by MRI and stress radiographs. 13 were operated afterwards, 22 patients underwent a functional conservative therapy and were examined by MRI and stress radiographs and second time after three months. MRI reports were correct in 12 of 13 operated cases. After conservative therapy we did not find any disrupted ankle ligament. MRI showed intact ligaments thickened by scar. (orig./MG) [Deutsch] 35 Patienten mit klinischem Verdacht auf Aussenbandruptur wurden mit der MRT untersucht. 13 Patienten wurden operiert, 22 konzervativ therapiert. Letztere wurden nach drei Monaten erneut mit MRT und gehaltenen Aufnahmen untersucht. Die MRT-Befunde stimmten in 12 von 13 Faellen mit den operativ erhobenen Befunden ueberein. Nach dreimonatiger konzervativer Therapie waren alle 22 Sprunggelenke stabil. Die rupturierten Baender stellten sich verdickt und durchgaengig dar. (orig./MG)
1995-09-01
Fuji computed radiography (FCR) for the diagnosis of spinal disorders
International Nuclear Information System (INIS)
Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the cervicothoracic region, where it is usually difficult to obtain clear cervicothoracic films in conventional radiography. We can obtain much precise ...
1987-01-01
International Nuclear Information System (INIS)
The radiographic appearance of Ewing's sarcoma was studied retrospectively in 22 patients who survived 5 years or longer after diagnosis and treatment. Expected changes from treatment, including regression of the extraosseous soft tissue mass, periostitis, and reconstitution of the cortex, occurred in all patients. Local recurrence occurred in one patient 10 years after complete remission whereas secondary osteosarcoma occurred more than 5 years after complete remission in two other cases. Both recurrent and secondary tumors presented as new lytic foci at the site of the original primary lesion. Lytic changes from radiation (radiation osteitis) may develop more than 2 years after treatment and in this sample; such findings were widely distributed in the radiation port. The authors conclude that bone remodeling and postradiation changes occur slowly over 2 years after treatment, and that any localized lysis at the primary site is suspicious for recurrence or ...
Evaluation of selective alveolo-bronchography with Fuji computed radiography and x-ray CT
International Nuclear Information System (INIS)
Selective alveolo-bronchography (SAB) has been routinely used to evaluate anatomical changes in the bronchiole and its distal air spaces. A narrowing of the bronchiole and abnormal pooling of contrast medium in the destroyed air space are the prime findings. Since the object of radiography is extremely thin, direct magnification radiography is mandatory to obtain radiologic details. However, the problem with this technique is that radiographic quality varies depending upon the size of the patient and the concentration of contrast medium to be introduced in the lung. This study had two goals. One was to improve the image quality of SAB by Fuji Computed Radiography (FCR). FCR provides radiographs with a good contrast and stable density throughout a wide range of exposure factors which occur in the use of SAB. The other goal was to separately evaluate morphological abnormalities in the outer and inner zones of the lung using X-ray CT. This idea ...
1986-01-01
Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures
Energy Technology Data Exchange (ETDEWEB)
AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium ...
2002-04-01
Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures
International Nuclear Information System (INIS)
AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium ...
2002-04-01
International Nuclear Information System (INIS)
Introduction: There are many problems in the radiological diagnosis of aseptic loosening in total hip arthroplasty. Computed tomography (CT) and magnetic resonance tomography (MRT) are not usable for metallic implants (stainless steel, cobalt alloy, titanium alloy). Material and Methods: From April 1993 to December 1993 15 CFRP non-cemented hip prostheses have been implanted. In a prospective clinical study plane radiographs, CT and MRT have been analysed. Results: Three stems were revised (1 femoral fracture, 1 severe thigh pain, 1 aseptic loosening). CFRP are not visible in plane radiographs. There was a complete (two-third of the cases) or nearly complete (one-third of the cases) small sclerotic interface between the prosthesis and the bone, these were apparent in CT and MRT in stable implant cases and did not have any clinical correlations. Discussion: The small sclerotic interface is quite different in comparison to so called 'Reactive ...
Computed tomography of the chest in the postoperative recurrences of bronchogenic carcinoma
International Nuclear Information System (INIS)
The authors describe the different types of postoperative carcinoma recurrences, as seen on CT examinations of the chest, in 38 patients who underwent different surgical procedures for bronchogenic carcinoma (12 pneumonectomies, 22 lobectomies, 2 segmentectomies, and 2 atypical resections). The recurrences were classified as follows: 1) recurrence in the bronchial stump; 2) limph node enlargement; 3) recurrence in the thoracic wall; 4) recurrence in the residual lobe; 5) pleural effusion; 6) nodule in the contralateral lung. The CT findings, Correlated with those from plain chest radiographs and clinical simptoms, indicate a higher incidence of recurrences in the hilar region, either in the bronchial stump or as node after total and subtotal resection are separately analyzed. While after pneumonectomy plain chest radiographs fail to demonstrate the recurrence in most cases, so that CT is nearly always mandatory, after subtotal resection the ...
1990-01-01
Energy Technology Data Exchange (ETDEWEB)
The atrial myocardium has been barely visible with thallium-201 myocardial scintigraphy. This is probably related to the difference in size, distance from anterior chest wall, and small coronary blood flow of the atrium, compared with the ventricle. We have encountered eight cases of visualization of the right atrial appendix (RAA). The RAA was identified from multiple projections in all cases and sometimes confirmed by radionuclide angiocardiography. Evidence derived from ECG, chest radiographs, and cardiac catheterization, indicated that the most important factor in the visualization might be the displacement of the RAA to a more anterior position.
1980-10-01
Energy Technology Data Exchange (ETDEWEB)
The authors present a guide to the imaging of facial fractures. It is illustrated with conventional radiographs and computed tomograms; the magnetic resonance images primarily suggest the potential applications of this technique. This book provides a source of imaging information on facial trauma. A section on pertinent anatomy is followed by a systematic discussion of the common isolated and complex facial fractures. Perspectives are offered on some commonly seen but infrequently described relationships, such as the tripod-LeFort II association. Consideration is also given to related soft-tissue injuries. The book includes a brief chapter on the type and utility of supplementary imaging studies in the evaluation of those intracranial injuries that may occur concurrently.
1988-01-01
International Nuclear Information System (INIS)
The textbook is primarily intended for radiologic staff and radiologic safety officers and gives information on the current regulatory provisions of the German X-ray Ordinance, applications of X-rays, quality assurance, organisational aspects of film processing and quality requirements of X-rays. An annex lists the guidelines of the Bundesaerztekammer (German National Chamber of Physicians) relating to quality assurance aspects, and further useful information on commercially available film-screen systems, the various associations of physicians in Germany, and requirements and performance of radiation surveys. (vhe).
Radiodiagnosis of Ewing's sarcoma of the rib in children
International Nuclear Information System (INIS)
The results of the examination of 23 children with Ewing's sarcoma of the rib were analyzed: panoramic chest X-rays in 4 projections, spot radiographs of the robs, superexposed pictures, laterograms, urography, angiography, computerized tomography, and scanning of the skeleton. Causes of diagnostic errors made at the first consultation by a physician, were identified. Peculiarities of X-ray signs of tumors of this site in children were studied. Diagnostic difficulties in tumors complicated by pleurisy and in tumors of small sizes with extrapleural growth were shown. Inclusions in the extraoseous tumor component were noted in 8.7% of the cases.
Radiation-protection survey guide: fixed radiographic unit. Final report, June 1980-April 1985
Energy Technology Data Exchange (ETDEWEB)
Prior to routine use, all newly installed x-ray machines must have a radiation-protection survey by a qualified expert. The survey is an evaluation of existing or potential radiation hazards associated with the use of diagnostic x-ray equipment under specific conditions. Such evaluation includes the measurement of exposure levels in the environment as well as environmental levels arising from operation of the equipment. The survey also includes an evaluation of the safety characteristics of the x-ray unit.
1985-05-01
Energy Technology Data Exchange (ETDEWEB)
Thirty-two patients with AIDS related complex (ARC) or acquired immunodeficiency syndrome (AIDS) underwent /sup 67/Ga scans as part of their evaluation. Three patterns of /sup 67/Ga biodistribution were found: lymph node uptake alone; diffuse pulmonary uptake; normal scan. Gallium-67 scans were useful in identifying clinically occult Pneumocystis carinii pneumonia in seven of 15 patients with ARC who were asymptomatic and had normal chest radiographs. Gallium scans are a useful ancillary procedure in the evaluation of patients with ARC or AIDS.
1987-07-01
Organ doses to atomic bomb survivors during photofluorography, fluoroscopy and computer tomography
Energy Technology Data Exchange (ETDEWEB)
Doses to the salivary glands, thyroid gland, breast, lung, stomach and colon during mass radiological gastric screening, mass radiographic chest screening, upper gastrointestinal series and computed tomography were determined by exposing a female human phantom to simulated radiological X-ray examinations as performed in community hospitals. The doses were measured using thermoluminescent dosemeters, and the results will be used to document organ doses received by participants in the Atomic Bomb Casualty Commission/Radiation Effects Research Foundation Adult Health Study. (Author).
1991-08-01
Organ doses to atomic bomb survivors during photofluorography, fluoroscopy and computer tomography
International Nuclear Information System (INIS)
Doses to the salivary glands, thyroid gland, breast, lung, stomach and colon during mass radiological gastric screening, mass radiographic chest screening, upper gastrointestinal series and computed tomography were determined by exposing a female human phantom to simulated radiological X-ray examinations as performed in community hospitals. The doses were measured using thermoluminescent dosemeters, and the results will be used to document organ doses received by participants in the Atomic Bomb Casualty Commission/Radiation Effects Research Foundation Adult Health Study. (Author).
1991-01-01
Neutron radiography with the cyclotron, 5
International Nuclear Information System (INIS)
Reliable facility of cyclotron-based real time neutron radiography system has been developed and applied to some industrial components. The equipment for neutron fluoroscopy is based on a sub-compact cyclotron and a LiF/ZnS (Ag) fluorescent screen viewed by a silicon intensifier target TV camera. The real time image is monitored on a CRT, recorded with a standard video recorder and processed by a digital image processor. The effectiveness of our real time neutron radiograph has been demonstrated to be applicable to not only the dynamic observation but also the magnifying and stereoscopic observation of fluoroscopic images. (author).
1987-01-01
Lung cancer screening program using annual chest radiographs with computed radiography (FCR)
Energy Technology Data Exchange (ETDEWEB)
In the Wajima lung cancer screening program conducted under the auspices of Kanazawa University Hospital, Fuji Computed Radiography (FCR) was utilized in a new chest radiography trial. The results of the screening program are that the necessity of repeat examinations due to poor image quality are less common and the method enables detection of small pulmonary nodular shadows which are possibly candidates for surgery. Oblique chest X-ray with FCR is remarkably effective for the detection and the identification of small lesions. However, the disadvantage of slow processing and high cost must be fully satisfied if FCR is to become a new imaging modality for mass screening.
1987-08-01
Lung cancer screening program using annual chest radiographs with computed radiography (FCR)
International Nuclear Information System (INIS)
In the Wajima lung cancer screening program conducted under the auspices of Kanazawa University Hospital, Fuji Computed Radiography (FCR) was utilized in a new chest radiography trial. The results of the screening program are that the necessity of repeat examinations due to poor image quality are less common and the method enables detection of small pulmonary nodular shadows which are possibly candidates for surgery. Oblique chest X-ray with FCR is remarkably effective for the detection and the identification of small lesions. However, the disadvantage of slow processing and high cost must be fully satisfied if FCR is to become a new imaging modality for mass screening. (author).
1987-01-01
International trends in radiation protection
International Nuclear Information System (INIS)
The great uranium debate throughout the industrialised world has intensified awareness of the biological hazards from ionizing radiation. It is therefore appropriate to use this awareness to draw attention to medical X-Radiation which today represents the most significant risk to future generations. There is ample legislation to control proliferation of nuclear development but in diagnostic radiology proliferation is unlimited; most international surveys indicate an unchecked annual growth rate of 15%. The article looks at risk hypotheses, dose measurements and the responsibilities of practising radiographers, and also reviews the international situation as reported at the 1977 world congress of radiation protection.
Energy Technology Data Exchange (ETDEWEB)
Marginal fractures of the tibial plateau are associated with a high incidence of soft tissue injuries to the stabilising structures of the knee joint. Injuries to the anterior cruciate ligament are associated with the Segond fracture and impingement fractures of the posteromedial tibial plateau. Recognition of these fractures aids diagnosis of these injuries. Marginal fractures of the tibial plateau associated with posterior cruciate ligament injuries are less common, though recently a ''reverse'' Segond fracture has been recognised. We describe a fracture of the anteromedial tibial plateau associated with complete disruption of the posterior cruciate ligament and posterolateral complex. (orig.)
2001-02-01
Imaging Automation and Volume Tomographic Visualization at Texas Neutron Imaging Facility
Energy Technology Data Exchange (ETDEWEB)
A thermal neutron imaging facility for real-time neutron radiography and computed tomography has been developed at the University of Texas reactor. The facility produced good-quality radiographs and two-dimensional tomograms. Further developments have been recently accomplished. A computer software has been developed to automate and expedite the data acquisition and reconstruction processes. Volume tomographic visualization using Interactive Data Language (IDL) software has been demonstrated and will be further developed. Volume tomography provides the additional flexibility of producing slices of the object using software and thus avoids redoing the measurements.
1999-11-14
Hard X-ray phase imaging and tomography using a grating interferometer
International Nuclear Information System (INIS)
An interferometric technique for hard X-rays is presented. It is based on two transmission gratings and a phase-stepping technique, and it provides separate radiographs of the phase and absorption profiles of bulk samples. Tomographic reconstruction yields quantitative three-dimensional maps of the X-ray refractive index and of the attenuation coefficient, with a spatial resolution down to a few microns. The method is mechanically robust, it requires little monochromaticity, and can be scaled up to large fields of view. These are important prerequisites for use with laboratory X-ray sources. Numerous applications ranging from wave front sensing to medical radiography are presently under investigation.
2007-07-01
FCR (Fuji Computed Radiography) in neurosurgery
Energy Technology Data Exchange (ETDEWEB)
As part of the evolution of computer technology, Fuji Computed Radiography (FCR) has been developed as a new system for radiographical diagnosis. In this system, the X-ray energy is stored on the imaging plate and then converted into digital signals utilizing scanning laser-stimulated luminence. After proper image processing, it offers much more improved information for diagnosis than the conventional film system does. Since April, 1986, we have principally used FCR (System 101) for neurosurgical practice. In this article, we present our recent experience and evaluate its usefulness.
1988-08-01
FCR (Fuji Computed Radiography) in neurosurgery
International Nuclear Information System (INIS)
As part of the evolution of computer technology, Fuji Computed Radiography (FCR) has been developed as a new system for radiographical diagnosis. In this system, the X-ray energy is stored on the imaging plate and then converted into digital signals utilizing scanning laser-stimulated luminence. After proper image processing, it offers much more improved information for diagnosis than the conventional film system does. Since April, 1986, we have principally used FCR (System 101) for neurosurgical practice. In this article, we present our recent experience and evaluate its usefulness. (author).
1988-01-01
Estimation of armature condition in concrete with gamma-absorption method
International Nuclear Information System (INIS)
Bases of the algorithm for assessing the reinforcement status in reinforced concrete products by gamma-absorption method are presented. Analytical equations are obtained for estimation of error of the parameter characterizing the degree of reinforcement destruction. It is recommended to use high-energy Bremsstrahlung sources-betatrons of 4-10 MeV maximum energy for testing products of 500-600 mm thick. Linear radiation attenuation factor (LAF) of concrete in estimated equation is replaced by effective LAF of concrete, and LAF of reinforcement and corrosion materials - by differential LAF. Corresponding LAF of nonevident form in the algorithm is assessed by the results of processing of direct-shadow radiographs of defectometers
Computer-aided diagnosis of bone tumours and tumour-like skeletal abnormalities in childhood
Energy Technology Data Exchange (ETDEWEB)
The method, use and results of computer-aided diagnosis of bone tumours and tumour-like skeletal abnormalities in childhood are described. One hundred and twentyone histologically verified cases were analysed and subjected to computer-aided diagnosis. Statistical methods were used, resulting in an accuracy of 96.7% and 91.7% respectively. In order to obtain additional confirmation of the diagnosis, a so-called growth rate was calculated by the computer. This proved to be a reliable criterion for evaluating the biological behaviour of tumours, irrespective of the histological diagnosis. The reasons for misdiagnosis were discussed. Attention is drawn to the importance of an accurate analysis of the radiographs and its input into the computer.
1982-06-01
Computed tomography in spinal osteoblastoma
International Nuclear Information System (INIS)
In order to stress the role of computed tomography (CT) in the evaluation of benign spinal osteoblastoma, the authors examined by CT 10 patients with surgically and histologically proved osteoblastomas of the spine. Basing on surgical and histopathological findings CT proved to be a very important method for attesting the presence of the tumors (usually showed by radiographic examination), and specially for their staging and follow-up. CT in fact showed the real extent of the tumor into the spinal canal and towards the paraspinal soft tissues, and allowed the aerly detection of post surgical relapses. The authors conclude that CT is a primary diagnostic modality for preoperative planning and follow-up of benign osteoblastoma.
1986-01-01
British Library Electronic Table of Contents (United Kingdom)
Prostate cancer can be successfully treated using dynamic adaptive external beam radiation techniques along with interstitial brachytherapy to deliver curative therapies with low urinary, rectal and erectile function morbidity. Through the use of sophisticated, state-of-the art radiographic imaging for staging and treatment planning, a precise, individual design for treatment is accomplished. Symptom management and patient education are of paramount importance and are integrated throughout the treatment process.
2009-01-01
The goal of this research program has been to add to our understanding of the breakup of molten fuel jets penetrating reactor coolant. Easily handled working fluids are used to simulate fuel jet breakup, so that detailed observations may be obtained from a relatively large number of experiments. The tools used for observing this behavior are high speed notion picture photography, Flash X-radiography, and X-ray cine. Jet breakup lengths are determined from motion pictures; the mechanisms by which the jets are fragmented may be inferred from radiographs.
1992-01-01
CT findings of foreign bodies in the chest: a pictorial essay
Energy Technology Data Exchange (ETDEWEB)
The most common causes of tracheobronchial foreign bodies are peanuts in children, and meat and dentures in adults. The most common causes of esophageal foreign bodies are coins in children and meat in adults. It is passable to diagnose a foreign body by visualization on a chest radiograph, if the foreign bodies are radio opaque. However, if the foreign bodies are radiolucent and the patients do not remember the history of aspiration, it is important to evaluate CT findings for foreign bodies and their complications. We describe the CT findings of various thoracic foreign bodies in children and adults.
2008-05-15
Avascular necrosis associated with nailing of femoral neck fracture
Energy Technology Data Exchange (ETDEWEB)
Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. Sr/sup 85/-scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures.
1983-01-01
Avascular necrosis associated with nailing of femoral neck fracture
International Nuclear Information System (INIS)
Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. SR"8"5-scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures. (author).
Application of the tracer technique to study on casting solidification
International Nuclear Information System (INIS)
The results and techniques of radiographic study on solidification of iron and steel mould castings are described. The study was made to determine the causes of the mold castings defects. The liquid metal is either labelled in the ladle, or relabelled inside the mould in present time intervals. In the former case, the radioactive phosphorus is segregated in the last-solidifying casting locations, and in the latter, the radioactive phosphorous is distributed along the solid-liquid interface at the time of the next addition in turn. The solidification process parameters may be arrived at by the autoradiograms taken in the pipe-sensitive casting sections. Using these data it is possible to proceed to the proper modifications in the steel casting process.
The effect of patient shield position on gonad dose during lumbar spine radiography
Energy Technology Data Exchange (ETDEWEB)
Background: In an effort to standardise radiological practices in the Republic of Ireland, current legislation states that 'written protocols for every type of standard radiological practice shall be established'. In order to fulfil this requirement the Irish Medical Council recommends the protocols issued by the Commission of European Communitees (CEC) for adoption in the country. Whilst this document does provide good guidance with regard to various radiographic factors, patient shielding instructions are notably ambiguous. The aim of this study was to remove some of this ambiguity by defining the optimal method of positioning patient shielding in antero-posterior (AP) and lateral lumbar spine radiographic examinations. These projections were chosen on the basis of their area of coverage being in close to and in some cases including the reproductive organs. They also represent the highest source of collective population dose ...
2010-05-15
The effect of patient shield position on gonad dose during lumbar spine radiography
International Nuclear Information System (INIS)
Background: In an effort to standardise radiological practices in the Republic of Ireland, current legislation states that 'written protocols for every type of standard radiological practice shall be established'. In order to fulfil this requirement the Irish Medical Council recommends the protocols issued by the Commission of European Communitees (CEC) for adoption in the country. Whilst this document does provide good guidance with regard to various radiographic factors, patient shielding instructions are notably ambiguous. The aim of this study was to remove some of this ambiguity by defining the optimal method of positioning patient shielding in antero-posterior (AP) and lateral lumbar spine radiographic examinations. These projections were chosen on the basis of their area of coverage being in close to and in some cases including the reproductive organs. They also represent the highest source of collective population dose of any ...
2010-05-01
Stochastic risk estimation from medical x-ray diagnostic examinations, 2
International Nuclear Information System (INIS)
The risks of genetic, leukemia and malignant diseases from medical X-ray diagnostic examinations were estimated using the frequency of radiographic and fluoroscopic exposures per diagnostic examination, child expectancy, leukemia and malignancy significant factors, and using a weighting factor determined on the basis of data concerning the cancer mortality among atomic bomb survivors in Nagasaki and of a recommendation of International Commission of Radiological Protection. The organ or tissue doses with respect to the stochastic risks were determined with ionization chambers and thermoluminescent dosimeters placed at the positions of the organs or tissues in a RANDO woman phantom which was exposed to diagnostic X-rays according to technical factors of typical radiographic and fluoroscopic examinations obtained from a nationwide survey. The resultant risks by age-group and type of radiographic and fluoroscopic examination ...
1981-01-01
Energy Technology Data Exchange (ETDEWEB)
Purpose: Reconstruction of organ doses of selected organs and tissues from radiographic settings and exposure data collected during chest X-ray examinations of children of various age groups performed in Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007. Materials and Method: The dosimetric data of all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 119 150 chest radiographs of all age groups. Reconstruction of organ doses in 40 organs and tissues in X-ray examinations of the chest was performed based on the conversion factor concept. Results: The radiation exposure of organs in projection radiography is determined by the exact site of the organs relative to the edges of ...
2009-05-15
Energy Technology Data Exchange (ETDEWEB)
Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and displayed four images as a subsidiary diagnosis. The upper two images were displayed ...
1989-08-01
Pulmonary nodule detection of chest phantom with CRT images
International Nuclear Information System (INIS)
Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and displayed four images as a subsidiary diagnosis. The upper two images were displayed ...
1989-01-01
Utilization of fractional Brownian motion in constrained least-squares restoration of medical images
International Nuclear Information System (INIS)
Constrained least-squares techniques have been used to produce a well known class of image restoration algorithms. These techniques typically involve minimizing a linear operator on a vector representation of an image, subject to a constraint. For cases where an equality constraint is appropriate the method of Lagrange multipliers can be used to produce a restored image. In this work a fractal textural model, fractional Brownian motion, is used to represent images of interest. Using a variance fractal dimension estimator a non-linear operator, that represents the squared difference between the fractal dimension of the restored image and on a priori value is minimized, subject to the constraint that the norm of the residual between the restored image and available measurement equal the norm of the additive noise.
Thin film GaAs solar cells on glass substrates by epitaxial liftoff
Energy Technology Data Exchange (ETDEWEB)
In this work, we describe the fabrication and operating characteristics of GaAs/AlGaAs thin film solar cells processed by the epitaxial liftoff (ELO) technique. This technique allows the transfer of these cells onto glass substrates. The performance of the lifted-off solar cell is demonstrated by means of electrical measurements under both dark and illuminated conditions. We have also optimized the light trapping conditions in this direct-gap material. The results show that good solar absorption is possible in active layers as thin as 0.32 {mu}m. In such a thin solar cell, the open circuit voltage would be enhanced. We believe that the combination of an epitaxial liftoff thin GaAs film, and nano-texturing can lead to record breaking performance. {copyright} {ital 1997 American Institute of Physics.}
1997-02-01
Energy Technology Data Exchange (ETDEWEB)
Studies the quality of metallurgical coke produced from a mixture of USA (80%) and Soviet (20%) coking coals. Properties of coal were analyzed according to ICCP and ISO international standards, including mechanical and petrographic tests. Content of the coal mixture included 8.2% moisture, 7.6% ash, 0.98% sulfur, 27.7% volatiles. The swelling index was 6 and dilation index 15%. Properties of coke produced from this coal mixture in the Croatian Bakar coking plant are presented for lump sizes of 25-80 mm, 10-25 mm and 0-10 mm. The produced coke was of favorable quality, having a strength index of 4.70, an ASTM stability factor of 61, and an M40 strength of 73.3%. 9 refs.
1990-01-01
Stress measurements in welds: Problem areas
Energy Technology Data Exchange (ETDEWEB)
There have been many stress measurements on welds by neutron diffraction over the past 20 years but there are still a number of serious experimental issues that are often not addressed. The primary fact is that the microstructure generally changes across the weld and accompanying this may be a change in the concentration of strengthening elements in solution. This will lead to a shift in lattice spacing which may be incorrectly interpreted as a strain. Secondly, a gradient of plastic deformation near the weld may be expected. Since plastic deformation by application of a stress always generates intergranular (type-2) strains this may lead to a range of intergranular effects superposed on the conventional weld-related strains. The effects are illustrated by neutron diffraction studies of Zr-4, ferritic and austenitic welds where chemistry, intergranular effects and crystallographic texture can all play a role.
2006-11-10
Significance of microstructure for a MOCVD-grown YSZ thin film gas sensor
Energy Technology Data Exchange (ETDEWEB)
The authors report the fabrication and characterization of a low temperature (200--400 C) thin film gas sensor constructed from a MOCVD-grown yttria-stabilized zirconia (YSZ) layer sandwiched between two platinum thin film electrodes. A reproducible gas-sensing response is produced by applying a cyclic voltage which generates voltammograms with gas-specific current peaks and shapes. Growth conditions are optimized for preparing YSZ films having dense microstructures, low leakage currents, and maximum ion conductivities. In particular, the effect of growth temperature on film morphology and texture is discussed and related to the electrical and gas-sensing properties of the thin film sensor device.
1996-11-01
Ru/SiO2 AND CuRu/SiO2 PREPARED BY SOL-GEL: EFFECT OF pH AND WATER AMOUNT
Scientific Electronic Library Online (English)
Abstract in english Ru(1%)/SiO2 and Cu(1%)Ru(1%)/SiO2 catalysts were prepared by cogelation. The effect of pH and the amount of water on the physical-chemical properties and the catalytic properties of them were analyzed. The acid medium increased the formation of microporosity and the formation of small size of metallic ruthenium particle. The variation of the water quantity used in the gelation not modify considerably the texture neither the dispersion of the noble metal. The reduction lev (more) el of all prepared catalyst was similar, showing displacement in some of reduction peaks. The toluene hydrogenation indicated that the conversion and the quantity of hydrogenate product varied with the pH and the quantity of water used in the gelation. The addition of copper to Ru/SiO2 catalysts diminished the reactive conversion and their hydrogenant activity
2003-06-01
We study the renormalization group running of the tri-bimaximal mixing predicted by the two typical $S_4$ flavor models at leading order. Although the textures of the mass matrices are completely different, the evolution of neutrino mass and mixing parameters is found to display approximately the same pattern. For both normal hierarchy and inverted hierarchy spectrum, the quantum corrections to both atmospheric and reactor neutrino mixing angles are so small that can be neglected. The evolution of solar mixing angle $\\theta_{12}$ depends on $\\tan\\beta$ and mass spectrum, the deviation from its tri-bimaximal value could be large. Taking into account the renormalization group running effect, the neutrino spectrum is constrained by experimental data on $\\theta_{12}$ and the inverted hierarchy spectrum is disfavored for large $\\tan\\beta$. The evolution of light neutrino masses is approximately described by a common scaling factor.
2010-01-01
Removal of short range order minerals prior to grain size analysis of volcanic ash soils
British Library Electronic Table of Contents (United Kingdom)
Abstract Incomplete dispersion of aggregates is a well known difficulty when analyzing soil texture of Andosols, particularly if no fresh soil material is available. To facilitate such investigations, several dispersion procedures were carried out on air dried samples rich in short range order minerals, originating from selected Andosol profiles (S Mexico). As a result, we propose an improved method based on a sequential chemical treatment with K oxalate, NH4 oxalate, and oxalic acid that reliably removes cementing agents and allows for a stable dispersion of soil particles after addition of Na pyrophosphate. This method was proved to be well reproducible and highly reliable for routine grain size determinations. The potential error caused by the inherent risk of dissolving primary mineral...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
DVR project concerns the creation of a virtual reality OpenGL system for desktop applications in archaeology. The main goal is the creation of a 3D information system using the real time interaction of OpenGL environments. The first case study implemented is the Vettii House, one of the most important and outstanding monuments in Pompei. The virtual reconstruction of these architectural models is based on very detailed photogrammetric surveys and it is connected with information layers and archaeometric data-bases regarding the state of conservation of walls, structures and any type of materials of the monument. A full 3D interface characterizes the system, comprising a high resolution texturing with detailed volumetric and geometric data. Finally, for the future, the project plans to fit the system for scientific and end users through the installation of stations on site.
2001-07-01
Energy Technology Data Exchange (ETDEWEB)
As thin films become increasingly popular (for solar cells, LEDs, microelectronics, batteries), quantitative morphological information is needed to predict and optimize the film's electronic, optical and mechanical properties. This quantification can be obtained quickly and easily with X-ray diffraction using an area detector and synchrotron radiation in two simple geometries. In this paper, we describe a methodology for constructing complete pole figures for thin films with fiber texture (isotropic in-plane orientation). We demonstrate this technique on semicrystalline polymer films, self-assembled nanoparticle semiconductor films, and randomly-packed metallic nanoparticle films. This method can be immediately implemented to help understand the relationship between film processing and microstructure, enabling the development of better and less expensive electronic and optoelectronic devices.
2010-02-19
Predicting soil erodibility in northern Iraq using natural runoff plot data
British Library Electronic Table of Contents (United Kingdom)
Data from natural runoff plots at two experimental sites in northern Iraq were used to predict soil erodibility in this semiarid region. The first site has a mean seasonal rainfall of about 400mm with the plots situated on 40% uniform slope; the soil at the site has a loam texture and belongs to the Xerorthent suborder; it has 46% of gravel by weight in its surface layer. The second site has a mean seasonal rainfall of more than 900mm with the plot situated on 17% uniform slope; the soil at the site is silty clay and belongs to the Calcixeroll suborder. At both sites, soil loss and runoff measurements were collected for two rainfall seasons. Results from both experimental sites showed that storm-to-storm variation in soil erodibility is high reflecting the importance of long term measureme...
2007-01-01
Piccolo logic for a picture database computer and its implementation
Energy Technology Data Exchange (ETDEWEB)
The logic named Piccolo for a picture database computer and its implementation is presented. The logic is shown to have three major advantages. One advantage is that the computer design based on this logic can handle a universal variety of pictorial data structures. Another advantage is that a set of data generated by rules such as texture distribution rules is stored in the picture computer efficiently. The third advantage is that this logic can serve as the basis of a logic for parallel processing machines. For implementation of the logic, a new methodology named architecture engineering is introduced as an architecture/design oriented methodology. Implementation case studies show the usefulness of the methodolgy. Two implementations on an abstract machine that are also on a parallel LISP machine are reported. 19 references.
1982-10-01
Nanoporous YSZ film in electrolyte membrane of Micro-Solid Oxide Fuel Cell
International Nuclear Information System (INIS)
Yttria stabilized zirconia (YSZ) with 8 mol% Y was deposited by reactive magnetron sputtering onto oxidized (100) silicon substrates. It was possible to switch film texture from (111) to (200) by applying a strong RF substrate bias. Transmission electron microscopy showed that the film deposited under bias is porous and exhibits nanoscaled grains, whereas the film deposited without bias is dense and columnar. The ionic conductivity as a function of temperature revealed an activation energy of 1.04 eV. The mechanical stress could be tuned to low values by thermal post-annealing. Using the dense (111) film as electrolyte layer, and the porous (200) film as an interlayer to a porous Pt anode, an open circuit voltage of 0.85 V was obtained in a micro machined fuel cell structure.
2010-06-01
Microstructure and tool electrode erosion in EDMed of TiN/Si_3N_4 composites
International Nuclear Information System (INIS)
Conductive TiN/Si_3N_4 ceramic composites were processed by electrical discharge machining (EDM) and their microstructure and conductivity were investigated. The whole process of tool electrode wear is evaluated by sinker-EDM. The machined surfaces of TiN/Si_3N_4 ceramic composites were examined by scanning electron microscopy (SEM) and profilometry to determine the surface finish. The electrode wear rate of brass is higher than copper electrode for all EDMed tests. The surface texture was found to have greater dependence on pulse energy. It was observed that the sinker-EDM at higher pulse energy caused severe microdamage in the surface. The surface roughness (Ra) values also increase with increasing pulse energy.
2003-12-20
Internal strain and texture evolution during deformation twinning in magnesium
Energy Technology Data Exchange (ETDEWEB)
The development of a twinned microstructure in hexagonal close-packed rolled magnesium compressed in the in-plane direction has been monitored in situ with neutron diffraction. The continuous conversion of the parent to daughter microstructure is tracked through the variation of diffraction peak intensities corresponding to each. Approximately 80% of the parent microstructure twins by 8% compression. Elastic lattice strain measurements indicate that the stress in the newly formed twins (daughters) is relaxed relative to the stress field in the surrounding matrix. However, since the daughters are in a plastically 'hard' deformation orientation, they quickly accumulate elastic strain as surrounding grains deform plastically. Polycrystal modeling of the deformation process provides insight about the crystallographic deformation mechanism involved.
2005-06-15
Influence of annealing on the microstructure of commercial Mg alloy AZ31 after mechanical forming
International Nuclear Information System (INIS)
The microstructure of commercial rolled magnesium alloy AZ31B (nominal composition Mg-3Al-0.9Zn-0.15Mn in wt.%) was investigated with the help of light microscopy, electron backscatter diffraction (EBSD) and X-ray diffraction technique after annealing in the temperature range from room temperature (RT) to 400 deg. C. Tensile tests at RT were performed to show the influence of the microstructure on mechanical properties. Static recrystallization (SRX) was observed during annealing of as-received alloy at and above 150 deg. C. Twins play an important role during SRX and serve as nucleation sites and preferred paths for growth of grains. The strong basal texture caused by rolling was weakened by SRX. Significant differences in the stress strain curves were observed for as-received and annealed specimens.
2006-09-25
Hydrotalcites with different Al/Al+Mg ratios, and prepared at different pH and different aging temperatures of the gel were used as precursors of Mg-Al mixed oxides, and their textural and physicochemical properties were determined. A complete reaction network for the isopropanol decomposition on these catalysts has been established, and it is shown that the concentration of acetone in the products cannot always be used for a direct estimation of the rate of dehydrogenation. The Al/Al+Mg ratio for which the maximum in activity is obtained depends on the base strength needed for each particular reaction. For dehydrogenation of isopropanol, this is found at Al/Al+Mg [approx] 0.25. 36 refs., 10 figs., 2 tabs.
1994-07-01
International Nuclear Information System (INIS)
The grain size dependence of the tensile properties and the deformation mechanisms responsible for those properties are examined for Mg alloy, AZ31B, sheet. Specifically, the Hall-Petch effect and strain anisotropy (r-value) are characterized experimentally, and interpreted using polycrystal plasticity modeling. {1 0 . 2} extension twins, {1 0 . 1} contraction twins, and so-called 'double-twins' are observed via microscopy and diffraction-based techniques, and the amount of twinning is found to increase with increasing grain size. For the sheet texture and tensile loading condition examined, {1 0 . 2} extension twinning is not expected, yet the polycrystal plasticity model predicts the observed behavior, including this 'anomalous' tensile twinning. The analysis shows that the Hall-Petch strength dependence, of the polycrystal as a whole, is primarily determined by the grain size dependence of the strength of the prismatic slip systems.
2008-07-15
Flavor Mixing, Quark Masses, Neutrino Masses and Neutrino Oscillations
We discuss first the flavor mixing of the quarks, using the texture zero mass matrices. Then we study a similar model for the mass matrices of the leptons. We are able to relate the mass eigenvalues of the charged leptons and of the neutrinos to the mixing angles and can predict the masses of the neutrinos. We find a normal hierarchy - the masses are 0.004 eV, 0.01 eV and 0.05 eV. The atmospheric mixing angle is given by the mass ratios of the charged leptons and the neutrinos. we find about 40 degrees, consistent with the experiments. The mixing element, connecting the first neutrino wit the electron, is predicted to be 0.05. This prediction can soon be checked by the Daya Bay experiment.
2009-01-01
Evolution of lattice strain in Ti-6Al-4V during tensile loading at room temperature
International Nuclear Information System (INIS)
The evolution of intergranular lattice strains in a textured, forged bar (Bar) sample of the #alpha# - #beta# titanium alloy Ti-6Al-4V has been characterised using in situ X-ray diffraction. A two-phase elastic-plastic self-consistent (EPSC) model has been developed to rationalise the results. Of the orientations analysed, it is found that the #left brace#2 0 0#right brace# #beta# orientation is the most compliant and that load partitions to this orientation during plasticity. The results from the bar material have then been used to predict the response of unidirectionally rolled plate (UD) Ti-6Al-4V. It is predicted that the residual lattice strains in the #left brace#101-bar0#right brace# and #left brace#112-bar0#right brace# orientations will be significantly higher in the UD material.
2008-12-01
Development of technology on the material surveillance of CANDU pressure tubes
International Nuclear Information System (INIS)
Material degradation of pressure tubes, which are the most important components in CANDU fuel channel, can only be evaluated by removing and examining them(material surveillance). This study aimed at establishment of overall evaluation technology including the evaluation of the material degradation for the integrity of pressure tubes of Wolsung units. Material tests for pressure tubes were performed as follows; (1) Evaluation on life limiting factors of pressure tubes (2) Review on leak-before-break and integrity maintenance technology of pressure tubes (3) Survey on selection criteria for tubes to be inspected and on related regulations for material surveillance (4) Analysis of material surveillance test procedure (5) Basic examinations of Wolsung unit 1 pressure tube material(TEM, texture, chemical component etc) (6) Manufacture of test equipments and test (DHCV, hydriding, grip and tensile specimen etc). 23 figs, 6 tabs, 59 refs. (Author).
1997-05-21
British Library Electronic Table of Contents (United Kingdom)
An innovative hybrid powder prepared using computer simulation allowed development of a new foundation having a fine, smooth texture that has never been achieved before. The optical structure/design of the powder was based on the results of measurements and analyses conducted on the optical characteristics of a baby's delicate skin, which is the envy of many women. To obtain the optimal optical characteristics, the finite differential time domain (FDTD) method for solving Maxwell's differential equation by difference and time domain was applied to the computer simulation method. For synthesis of the hybrid powder based on the optical model, a proprietary shape regulation coating technology was used in which flaky substrates were coated with microspherical forms of barium sulfate crystals. ...
2008-01-01
British Library Electronic Table of Contents (United Kingdom)
Functional properties of commercial and membrane processed pea protein isolates (PPI) prepared from yellow peas were investigated. Four protein isolates were prepared from yellow pea flour using water and KCl extractions at 25^oC followed by ultrafiltration and diafiltration (UF and DF) at pHs of 7.5 and 7.5 or 6 respectively. Following assessment of compositional attributes; solubility, foaming, flow and dynamic rheology, emulsification ability and heat-induced textural and rheological properties of prepared PPIs and a commercially available PPI were tested and compared. Membrane purification of proteins resulted in 28% to 68% reduction in phytic acid and enhanced, comparatively, the tested functional properties. Solubility of membrane processed PPIs, at all tested pHs, was superior and t...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
SBA-15 supported nano-scaled copper oxide was synthesized by impregnation method via ultrasonic-assisted route. The removal test from gas mixture containing 0.1?vol.% hydrogen sulfide was carried out over this material at atmospheric conditions. The effects of the chemical nature of copper oxide and the textural properties of the material on removal capacity were studied. The materials before and after the removal test were analyzed by nitrogen adsorption, X-ray diffraction, Transmission Electron Microscope, X-ray photoelectron Spectroscopy, Fourier Transform Infrared Spectrometer and Inductive Coupled Plasma. The results showed that copper species are located predominantly in mesopore channels, existing as copper oxide nanoparticles. Mesopores are active sites for removal reaction. The ou...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
A residue in the production of alumina by the Bayer process is red mud. It contains oxides of Fe and Ti, active as hydrogenation catalyst in sulfided form, and whose catalytic activity can be improved by the activation method proposed by Pratt and Christoverson. The paper describes how the development of its activity and selectivity with reaction time was studied for the hydrogenation of a light fraction of an anthracene oil, and compared with untreated sulfided red mud. Catalyst samples were collected at different reaction times, and their texture, morphology and composition characterized by nitrogen adsorption, SEM and SEM-EDX. The loss of catalytic activity of activated sulfided red mud is slower than for untreated sulfided red mud. The main cause of this decrease in catalytic activity is the loss of surface area and superficial Fe.
1998-06-01
Characterising and reducing seizure wear of inconel and incoloy superalloys in a sliding contact
British Library Electronic Table of Contents (United Kingdom)
Superalloys, such as Inconels and Incoloys, are extensively used where high strength is a requirement. However, where these materials are required to slide against one another, particularly with poor or no lubrication, high friction levels and seizure are commonly seen to occur, which can cause component failure. In this work seizure characteristics of three superalloys (Inconel 718 and Incoloys 945 and 945X) were investigated, uncoated, coated with Armoloy (a hard, thin, dense chrome coating with a micro-nodular surface texture) and plasma nitrided in dry sliding conditions. A rig purpose built for initiating seizure was used. It involves sliding a ball against a disc at constant speed while the load is increased. Tests are designed to last less than one rotation so that the wear scar can...
2011-01-01
Change from polycrystalline to amorphous growth in sputtered CoZr/Cu multilayers
International Nuclear Information System (INIS)
The authors present an investigation of structural changes occurring in bilayer stacks with crystalline columnar growth when one of the layers is substituted by layers known to grow amorphous. In Co/Cu multilayers the Co layers were substituted by CoZr layers of varying Zr content and layer thickness. Structural characterization was performed by transmission electron microscopy (TEM). They show that the amorphization of the CoZr layers leading to a destruction of the columnar growth depends both on the Zr content and on the thickness of the CoZr layers. Additionally a change to textured growth with a normal to the substrate occurs with increasing Zr content. They explain their observations by a simple picture based on the hard sphere model.
1997-04-04
Assessing soil quality under intensive cultivation and tree orchards in Southern Italy
British Library Electronic Table of Contents (United Kingdom)
Concerns about groundwater contamination as well as pesticide residues in food and soil have fuelled vigorous debates about the sustainability of chemical-intensive agriculture. Search has been prompted for agronomic strategies with lower environmental hazards. In this multidisciplinary study we compared the characteristics of soils from 20 agricultural farms selected in five geographical areas of Southern Italy with different soil types. In each farm, fields with management regime classified as high-input (HIMR, intensive cultivation under plastic tunnels) or low-input (LIMR, tree orchards) were selected. Soil samples were analyzed for 31 parameters including physical and chemical properties (bulk density, water holding capacity, texture, pH, limestone, electrical conductivity, organic C ...
2011-01-01
International Nuclear Information System (INIS)
The gliding modes of a duplex Ti-6Al-4V titanium alloy were investigated through in situ (scanning electron microscopy) tensile tests. A method based on electron back-scattering diffraction (EBSD) measurements was used to identify activated slip systems. The approach applied to a large number of grains allowed a statistical analysis of the nature (basal, prismatic, pyramidal) and distribution of the slip systems according to the crystallographic texture. A discussion concerning the pertinence of Schmid's law to explain the occurrence and succession of slip events is then proposed. The domain in favor of each type of slip system is finally presented by using inverse pole figures mapped with Schmid's factor iso-curves.
2005-02-01
Energy Technology Data Exchange (ETDEWEB)
The growth of the Pd{sub 2}Si thin fllms on Si(111) substrates has been monitored by an {ital in} {ital situ} x-ray diffraction technique in vacuum and in helium atmosphere from 160 to 250 {degree}C. A familiar parabolic growth rate was found, confirming the diffusion-controlled film growth process. The activation energies were found to be 1.34 and 1.37 eV for the measurements performed in vacuum and helium environment, respectively. Stress relaxation in the growing Pd{sub 2}Si fllm was observed when the reaction temperature exceeds 200 {degree}C. The relaxed films showed a higher degree of texture as evidenced by the rocking curve measurements.
1990-04-15
The growth of the Pd{sub 2}Si thin fllms on Si(111) substrates has been monitored by an {ital in} {ital situ} x-ray diffraction technique in vacuum and in helium atmosphere from 160 to 250 {degree}C. A familiar parabolic growth rate was found, confirming the diffusion-controlled film growth process. The activation energies were found to be 1.34 and 1.37 eV for the measurements performed in vacuum and helium environment, respectively. Stress relaxation in the growing Pd{sub 2}Si fllm was observed when the reaction temperature exceeds 200 {degree}C. The relaxed films showed a higher degree of texture as evidenced by the rocking curve measurements.
1990-04-15
Alignment of nematic liquid crystals on mixed Langmuir-Blodgett mono-layers
Mono-layers of stearic and behenic acids and mixtures of them in different proportions, deposited with the Langmuir-Blodgett technique, were used to study the alignment and the alignment dynamics in nematic liquid crystal cells. A relaxation process from a splay-bend flow induced metastable orientation to the homeotropic one occurs. The lifetime of the metastable state was found to depend on the mono-layer composition. The transition between the homeotropic and the conical anchoring was found to be irreversible in the case of the mixed aligning mono-layers: on cooling from the isotropic phase a quasi-planar nematic state (schlieren texture) appears. It is stable in a range of a few degrees below the clearing point and, on decreasing the temperature, relaxes to the homeotropic state in form of expanding domains.
1998-01-01
Adhesion studies of Au films on GaAs using ion-assisted deposition techniques
International Nuclear Information System (INIS)
This paper reports on a series of experiments performed to examine the ability of ion beam assisted thermal deposition to produce good adhesion of Au metallization on GaAs left-angle 100 right-angle substrates. A study of the influence of Ar ion-assisted thermal deposition of the Au films as well as in situ pre-sputtering of the GaAs surface with low-energy Ar ions prior to thermal deposition, shows that strong adhesion can be achieved without resorting to chemical cleaning. The substrate temperature and the relative flux of Ar ions to incident Au atoms were varied in order to correlate these parameters with film adhesion. The interfaces of films processed under these various conditions were examined by XTEM, RBS and XPS. Orientation texture was studied by x-ray diffraction (XRD).
(Ti,Cr,Nb)CN coatings deposited on nitrided high-speed steel by cathodic arc method
British Library Electronic Table of Contents (United Kingdom)
The combined processes of plasma nitriding and cathodic arc deposition of (Ti,Cr,Nb)CN coatings were applied to HSS substrates. The nitrided layers, obtained in a mixture of H2 (70%) and N2 (30%) at two different temperatures (480^oC and 510^oC), were examined for the microhardness depth profiles. Characterization of the duplex coatings was performed by investigating elemental and phase composition, texture, hardness, friction and wear. XRD and XPS analyses revealed the formation of a mixture of a carbonitride fcc solid solution, in a dominant proportion, and metallic chromium. The film hardness was measured to be ~34GPa. The duplex (Ti,Cr,Nb)CN coatings exhibited superior tribological behavior as compared to both nitrided layers and non-duplex coatings.
2011-01-01
In the present study, applications of the SPH method to industrial related issues are considered by starting from an existing open source 2D SPH code, namely the SPHYSICS code, which offers an effective ground for numerical developments, which are performed in order to bring an answer to industrial problems, such as simulations of solid/fluid coupling in a free surface flow context. The purpose of the present paper is therefore to expose the numerical developments which yield an enhanced version (referred to as "SPHYSIC2") of the initial code. Firstly, the different features added to obtain the operational code needed for engineering applications are described, and so are the problems raised on this way, offering a kind of review of SPH methods for engineers. Secondly, the validation of the proposed code is partially presented with two well known but difficult test cases, namely the classical "dam break" and "wedge entry" problems. Thirdly, ...
2010-01-01
We develop a 3-D model to simulate the synthetic aperture radar (SAR) image formation process of an undulated vegetation canopy such as corn grown in fields with large periodic drainage reliefs. We explain how the simulated SAR image of undulated vegetation medium is obtained by the convolution of a 2-D slice of the 3-D simulated SAR system point spread function [(PSF), emulating the SAR beam modeled by a cosine modulated Gaussian], with the 2-D projection of the observed undulated vegetation canopy (modeled with scatterers randomly distributed in 3-D undulated space) followed by the extraction of each look envelope, the summation of looks, and sampling in azimuthal and range directions. Our model is useful to study the parameters involved in the formation and the analysis of SAR images of undulated vegetation medium. Validation of simulations made with actual SAR images shows that undulated corn crop ...
2001-10-01
Energy Technology Data Exchange (ETDEWEB)
In the development of the man-made island siting technology of nuclear power plants, assessing the stability of the seawall against large ocean waves and earthquakes is indispensable. Concerning with the seismic stability of the seawall, prediction of the deformation like sliding and settlement of the seawall during earthquake including the armour units in front of the caisson becomes important factor. For this purpose, the authors have developed the two-dimensional DEM-FEM coupled analysis method (SEAWALL-2D) to predict the deformation of the seawall covered with the armour units during earthquake. In this method, movements of the armour units are calculated in DEM analysis part and deformation of the caisson, rubble moundsand seabed and back fill are calculated in FEM analysis part taking the nonlinearity of the soil materials based on the effective stress into account. Numerical simulations of dynamic centrifuge model tests of the seawall ...
1999-02-01
Spectrally condensed fluid turbulence and L-H transitions in plasma
International Nuclear Information System (INIS)
Recent experimental and theoretical studies of two-dimensional (2D) turbulence reveal that spectrally condensed turbulence which is a system of coupled large-scale coherent flow and broadband turbulence, is similar to plasma turbulence near the L-H transition threshold. Large condensate vortices fed via the turbulent inverse energy cascade, can control both the level of the broadband turbulence by shear decorrelation, and the energy injected into turbulence at the forcing scale via sweeping of the forcing-scale vortices. The interaction between these ingredients of spectrally condensed fluid turbulence is in many aspects similar to the interactions in the zonal flow-GAMs-turbulence system in plasma. In this paper we overview recent results on condensed 2D turbulence and present evidence of interaction between its three components: condensate structures, turbulence and forcing-scale vortices. This is ...
2009-06-01
Ovariectomy-induced changes in aged beagles : histomorphometry of rib cortical bone.
Energy Technology Data Exchange (ETDEWEB)
Bone loss associated with estrogen depletion is well documented in cancellous bone but less well characterized in cortical bone. The effects of ovariectomy on the aged beagle skeleton were studied by histomorphometric analysis of the cortical bone in sequential rib biopsies. Biopsies were taken from each ovariectomized or sham-operated dog at the time of surgery and at 1, 4, and 8.5 months after surgery. Just prior to each postoperative biopsy, tetracycline, calcein, and xylenol orange, respectively, were administered by a fluorochrome labeling procedure (2d-10d-2d) to provide markers of bone formation. Analysis of sequential rib biopsies provided a means to follow the ovariectomy response over time and to compare each animal against its own baseline. Though ovariectomy did not influence histomorphometric indices at 1 month after surgery, a transient increase in cortical bone formation occurred ...
1998-03-01
OPTICAL FIBRE ARRAY MANUFACTURE (OFAM)
Environmental Research Database
Objectives1. The study of the automatic alignment of electrically charged optical fibres.~%~~%~2. The design and construction of a prototype system for assembly of the fibres.~%~~%~3. The fabrication of a proof-of-principle 4-by-4 fibre array.~%~~%~4. The test and characterisation of the prototype fibre bundle in terms of translational and angular positioning accuracy.~%~~%~5. A paper design of a full-scale automated system.~%~~%~6. Enable commercial exploitation.~%~DescriptionThis multidisciplinary programme aims to investigate and develop an 'adventurous' process for manufacturing 2-D optical fibre arrays, with at least an order of magnitude improvement in the positional and angular tolerances of the mono-mode fibres compared to conventional techniques. Manufacturable, dense 2-D optical fibre arrays are essential ...
2002-01-31
British Library Electronic Table of Contents (United Kingdom)
Aim: The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise. Methods: Ten adults with T2D (age: 55.8+/-7.7 years; weight: 79.4+/-14.0kg; fasting glucose: 133.0+/-36.7mg.dL^-^1) underwent: (1) AER: 20min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO2, respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interve...
2011-01-01
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 the wide area ...
1996-10-01
British Library Electronic Table of Contents (United Kingdom)
This study examined the oxygen permeation behavior of Ce0.9Gd0.1O2-d (Gadolinium-Doped Ceria, GDC)/Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF) composite membranes fabricated using a conventional sintering technique. GDC/BSCF composite membranes with a relative density >95% could be obtained when a green compact of BSCF and GDC was sintered at 1150^oC for 5h. It appears that GDC serves as a grain growth inhibitor because the average grain size of the composite decreased with increasing GDC content. The oxygen permeability of the BSCF and GDC/BSCF composite membranes strongly depends on the grain size and membrane thickness. The addition of GDC to BSCF resulted in a small grain size, low thermal expansion coefficient and high hardness. However, it is believed that oxygen permeation was blocked by GDC, a...
2010-01-01
Current theories on planetary formation establish that giant planet formation should be contextual to their quick migration towards the central star due to the protoplanets-disc interactions on a timescale of the order of $10^5$ years, for objects of nearly 10 terrestrial masses. Such a timescale should be smaller by an order of magnitude than that of gas accretion onto the protoplanet during the hierarchical growing-up of protoplanets by collisions with other minor objects. These arguments have recently been analysed using N-body and/or fluid-dynamics codes or a mixing of them. In this work, inviscid 2D simulations are performed, using the SPH method, to study the migration of one protoplanet, to evaluate the effectiveness of the accretion disc in the protoplanet dragging towards the central star, as a function of the mass of the planet itself, of disc tangential kinematics and of the presence of a planet ``pseudo-atmosphere''. To this ...
2009-01-01
Histamine Molecule and Dianion Oxalate are Efficient Blocks for Building 2D Supramolecular Networks
British Library Electronic Table of Contents (United Kingdom)
One salt and two Cu(II) complexes (H2hsm)(ox), 1, [Cu(hsm)(ox)], 2, and [Cu(hsm)(ox)H2O], 3, have been synthesized and X-ray characterized (hsm is histamine and ox2? is the oxalate dianion). Starting from the prochiral tetracoordinated complex 2, pentacoordinated complex 3 crystallizes as a racemic mixture of the enantiomeric ? and ? isomers, in space group P21/c. In all cases, the side chain of the hsm group is gauche, allowing the formation of strong hydrogen bonds in the salt 1, and to chelate the metal center in complexes 2 and 3. The combination hsm/ox seems to favor the formation of 2D supramolecular structures (planes or wavy planes), through efficient networks of N?H???O hydrogen bonds. Cell parameters: 1, P21/c, a?=?6.260 (2) ?, b?=?11.500 (4) ?, c?=?12.525 (4) ?, ??=?104.047 (17)...
2011-01-01
Gas and stellar dynamics in NGC 1068. Probing the galactic gravitational potential
We present Sauron 2D spectrography of the central 1.5 kpc of the nearby Sey2 galaxy NGC1068, encompassing the well-known NIR inner bar. We have successively disentangled the respective contributions of the ionized gas and stars, thus deriving their 2D distribution and kinematics. The [OIII] and Hbeta emission lines exhibit very different spatial distribution and kinematics, the latter following inner spiral arms with clumps associated with star formation. Strong inwards streaming motions are observed in both the Hbeta and [OIII] kinematics. The stellar kinematics also exhibit clear signatures of a non-axisymmetric tumbling potential, with a twist in both the velocity and h3 fields. We re-examined the long-slit data of Shapiro et al (2003) using pPXF: a strong decoupling of h3 is revealed, and the central decrease in h4 hinted in the Sauron data is confirmed. These data also suggest that NGC1068 is a ...
2006-01-01
Functional MRI of the pharynx in obstructive sleep apnea (OSA) with rapid 2-D flash sequences
International Nuclear Information System (INIS)
Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager ('Vision', Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of ...
Energy Technology Data Exchange (ETDEWEB)
Our studies have shown that endotoxin intratracheally instilled into the rat lung induces proliferation of alveolar type II cells. In that study, the alveolar type II cells. In that study, the alveolar type II cell hyperplasia occurred 2 d after instillation of endotoxin and persisted for a further 2 d. After hyperplasia, the lung remodeled and returned to a normal state within 24-48 h. Understanding the mechanisms involved in the remodeling process of this transient hyperplasia may be useful to identify molecular changes that are altered in neoplasia. The purpose of the present study was to corroborate induction of epithelial cell hyperplasia by endotoxin and to delineate mechanisms involved in tissue remodeling after endotoxin-induced alveolar type II cell hyperplasia. In conclusion, immonostaining with cyclin D1 and cytokeratin shows that endotoxin induced epithelial cell proliferation and resulted ...
1995-12-01
International Nuclear Information System (INIS)
The excitation cross sections by electron impact from the Cd II ground state to the laser upper state 5s_2 _2D/sub 5/2/ (Beutler state) and the laser lower state 5p _2P/sub 3/2/ (resonance state) have been measured by using a crossed-beam method of electrons and Cd"+ ions and a photon-counting method. The electron-energy region investigated was from the threshold energy (5.8 eV) for the excitation of the 5p _2P/sub 3/2/ state to 20 eV. It has been shown that the excitation cross section for the ionic Beutler state 5s_2 _2D/sub 5/2/ is of the order of 10"-_1_5 cm_2 and has a sharp peak near the threshold energy for the excitation. The excitation cross section for the resonance state 5p _2P/sub 3/2/ has also been of the order of 10"-_1_5 cm_2 and has a relatively broad maximum.
Enhanced defect detection and sizing accuracy using matrix phased array ultrasonic tools
Energy Technology Data Exchange (ETDEWEB)
Although ultrasonic testing inspection technology and tools have improved significantly, there is still a need for more reliable detection, monitoring, and accurate sizing of crack-like and planar defects, complex corrosion damage, and detection of secondary features within deformed pipe. Ultrasonic two dimensional (2D) matrix phased array technology offers some unique advantages that make the technology promising for improving detection and sizing of pipeline flaws resulting from welding or from in-service damage. Ultrasonic modeling and simulation has been conducted to evaluate the detection and sizing capabilities of 2D matrix arrays for various pipeline inspection concepts. Simulations have been performed using both flexible and rigid array probes. Inspection concepts using rigid probes were evaluated for inspections from both the outside and inside pipe surfaces, while flexible probes were ...
2009-07-01
Energy Technology Data Exchange (ETDEWEB)
The behaviour of bare aluminium is studied in atmospheric exposure at 11 natural testing stations with salinity levels ranging between 2.1 and 684 mg Cl''- m''-2 d''-1. In atmospheres of low or moderate aggressivity aluminium behaves as a passive material, though the insignificant corrosion that is produced is sufficient to spoil its appearance. In contrast, at salinity levels of 50 mg Cl''- m''-2 ''-1 or above, aluminium is susceptible to pitting corrosion even in the first year of atmospheric exposure, or in the second year at salinities of {<=} 10 mg Cl''- m''-2 d''-1. For comparative purposes, results are included for aluminium protected with an anodic film of 28 {mu}m thickness exposed at the same testing stations. A 28 {mu}m anodic ...
2004-07-01
Cross sections for electron scattering by atomic potassium
International Nuclear Information System (INIS)
Electron elastic and collisional excitation cross sections from the ground state of potassium are calculated using the noniterative integral-equation method of Henry, Rountree, and Smith [Comput. Phys. Commun. 23, 233 (1981)] in the electron energy range 4#<=#E#<=#200 eV. Configuration-interaction target wave functions that take account of correlation and polarization effects are used to represent the ground state and the six lowest excited states 4p "2P degree, 5s "2S, 3d "2D, 5p "2P degree, 4d "2D, and 6s "2S. Elastic and discrete excitation cross sections are obtained in a seven-state close-coupling (7CC) approximation. The 7CC elastic and excitation cross sections are compared and contrasted. Near threshold the elastic cross section dominates the resonance, 4s "2S#->#4p "2P degree, and the sum of the other remaining excitation cross sections. Comparison of our total cross sections with some ...
British Library Electronic Table of Contents (United Kingdom)
A mixture of long-chain hydrocarbons constituted by nonacosane (29C, 7.5%), hentriacontane (31C, 48.3%), and tritriacontane (33C, 30.1%), the ester 1?-acetyloxymethylpentacosa-20?-enyl 10-hydroxydecanoate (2), ?-amyrin (3), friedelin (4), and lupeol (5), and 3?-hydroxy-D:B-friedo-olean-5-ene (6) were identified as constituents of fruits of Maytenus salicifolia Reissek (Celastraceae). The structural formula and the stereochemistry of compound 6 were established by the data obtained through 1H and 13C NMR spectroscopy, including DEPT-135 and 2D (HMQC, HMBC, and NOESY) experiments. By analysis of the spectral data, it was possible to correct seven chemical shift assignments of compound 6, which were erroneous attributed and published in the scientific literature.
2010-01-01
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 distribution between SG cassettes was reduced upto about 0.1% and the pressure loss from ...
2003-12-01
Blending of nanoscale and microscale in uniform large-area sculptured thin-film architectures
The combination of large thickness ($>3$ $\\mu$m), large--area uniformity (75 mm diameter), high growth rate (up to 0.4 $\\mu$m/min) in assemblies of complex--shaped nanowires on lithographically defined patterns has been achieved for the first time. The nanoscale and the microscale have thus been blended together in sculptured thin films with transverse architectures. SiO$_x$ ($x\\approx 2$) nanowires were grown by electron--beam evaporation onto silicon substrates both with and without photoresist lines (1--D arrays) and checkerboard (2--D arrays) patterns. Atomic self--shadowing due to oblique--angle deposition enables the nanowires to grow continuously, to change direction abruptly, and to maintain constant cross--sectional diameter. The selective growth of nanowire assemblies on the top surfaces of both 1--D and 2--D arrays can be understood and predicted using simple geometrical shadowing ...
2003-01-01
Energy Technology Data Exchange (ETDEWEB)
The rate coefficients for the reactions of OH radical with CH3Br and CH2Br2 were measured as functions of temperature using the laser photolysis - laser induced fluorescence method. This data was incorporated into a semiempirical model (Solomon et al., 1992) and a 2D model to calculate the steady-state ozone depletion potentials (ODP) and atmospheri lifetimes, tau, with greatly improved accuracy as compared to earlier studies. The calculated ODPs and tau are 0.65 and 1.7 years and 0.17 and 0.41 years for CH3Br and CH2Br2, respectively, using the semiempirical model. These lifetimes agree well with those calculated using a 2D model. This study better quantifies the ODPs and tau of these species which are needed inputs for discussion of possible regulation of human emissions currently under international considerations. 29 refs.
1992-10-01
[Experimental and kinetic modeling of acid/base and redox reactions over oxide catalysts
Energy Technology Data Exchange (ETDEWEB)
The research has involved the characterization of catalyst acidity, [sup 2]D NMR studies of Bronsted acid sites, and kinetic, calorimetric, and spectroscopic studies of methylamine synthesis and related reactions over acid catalysts. Approach of this work was to explore quantitative correlations between factors that control the generation, type, strength, and catalytic properties of acid sites on zeolite catalysts. Microcalorimetry, thermogravimetric analysis, IR spectroscopy, and NMR spectroscopy have provided information about the nature and strength of acid sites in zeolites. This was vital in understanding the catalytic cycles involved in methylamine synthesis and related reactions over zeolite catalysts.
1993-01-01
Energy Technology Data Exchange (ETDEWEB)
The rare earth antimonates RE{sub 3}Sb{sub 5}O{sub 12} constitute an isostructural series, where the rare earth site symmetry is S{sub 4}. The spectroscopic properties of pure or doped compounds of this family are studied in order to derive their energy level schemes and to simulate them through the crystal field theory, by using the approximated D{sub 2d} potential. The paramagnetic susceptibilities are calculated with the derived wavefunctions and compared to experiment.
1991-01-01
Energy Technology Data Exchange (ETDEWEB)
Surface doping of conjugated polymers is realized by depositing a thin layer of graphene oxide (GO) on top of the polymers. The high proton density and the unique 2D structure of GO facilitate the protonic surface doping of conjugated polymers to achieve high conductivities. This finding represents a new strategy for improving charge transport across the metal/conjugated polymer interface to achieve much improved performance in organic solar cells. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
2011-04-26
Energy Technology Data Exchange (ETDEWEB)
A comprehensive Scanning Tunneling Microscopy (STM) study of submonolayer nucleation and growth of 2D islands in Ag/Ag(100) homoepitaxy for temperature between 295K and 370K is presented. The initial stages of multilayer kinetic roughening is also studied. Analysis of an appropriate model for metal (100) homoepitaxy, produces estimates of 350 meV for the terrace diffusion barrier, 400 meV for the adatom bond energy, and 25 meV for the additional Ehrlich-Schwoebel step-edge barrier.
1996-08-01
Spiral Structure in IP Peg Confronting Theory and Observations
Steeghs et al. (1997) have found the first convincing evidence for spiral structure in the accretion disc in IP Pegasi. We perform two kinds of 2D hydrodynamic simulations, a SFS finite volume scheme and a SPH scheme, in the case of mass ratio of 0.5. Both results agree well each other. We construct the Doppler maps and line flux-binary phase relation based on the density distributions. Both of our results agree well with those obtained by the observation.
1998-01-01
Energy Technology Data Exchange (ETDEWEB)
Twenty-seven patients with symptoms or clinical findings suggesting joint or bone disorders of the anterior chest wall (ACW) were evaluated by spiral CT with 3-dimensional (3-D) and multiplanar reconstructions. Preceding conventional ACW tomography was performed in 10 patients. ACW joint and bone changes were visualized more adequately by coronal 2-D reconstructions based on spiral CT than by conventional tomography. In addition, nonossified costal cartilages and soft tissue lesions were demonstrated. 3-D reconstructions sometimes added information, especially in patients with fracture and dislocation. (orig.).
1994-09-01
Simulation of concrete perforation based on a continuum damage model
Energy Technology Data Exchange (ETDEWEB)
Numerical simulation of dynamic fracture of concrete slabs, impacted by steel projectiles, was carried out in this study. The concrete response was described by a continuum damage model. This continuum damage model was originally developed to study rock fragmentation and was modified in the present study with an emphasis on the post-limit structural response. The model was implemented into a transient dynamic explicit finite element code LS-DYNA2D and the code was then used for the numerical simulations. The specific impact configuration of this study follows the experiment series conducted by Hanchak et al. Comparisons between calculated results and measured data were made. Good agreements were found.
1994-10-01
Reverse time migration in tilted transversely isotropic media
Energy Technology Data Exchange (ETDEWEB)
This paper presents a reverse time migration (RTM) method for the migration of shot records in tilted transversely isotropic (TTI) media. It is based on the tilted TI acoustic wave equation that was derived from the dispersion relation. The RTM is a full depth migration allowing for velocity to vary laterally as well as vertically and has no dip limitations. The wave equation is solved by a tenth-order finite difference scheme. Using 2D numerical models, we demonstrate that ignoring the tilt angle will introduce both lateral and vertical shifts in imaging. The shifts can be larger than 0.5 wavelength in the vertical direction and 1.5 wavelength in the lateral direction.
2004-07-01
Perturbing the ground ring of 2D string theory
Energy Technology Data Exchange (ETDEWEB)
In this paper, the authors use free field techniques in D = 2 string theory t calculate the perturbation of the special state algebras when the cosmological constant is turned on. In particular, the authors find that the 'ground cone' preserved by the ring structure is promoted to a three-dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1,1) current algebra of moduli deformations is computed completely, and no simple geometrical interpretation is found. The authors also quote some facts concerning the Liouville matrix a model dictionary in this class of theories.
1992-12-10
Particle-hole excitations in N=50 nuclei
Energy Technology Data Exchange (ETDEWEB)
Energy levels in N=50 nuclei are calculated allowing single-particle excitations from the p{sub 1/2} and g{sub 9/2} shells into the d{sub 5/2}, s{sub 1/2}, d{sub 3/2}, and g{sub 7/2} shells. Important parts of the interaction are determined by least-squares fits to known levels. Agreement with experiment is very good. The high-spin particle-hole states appear to be mainly yrast levels in mass 93 and higher, but are not in {sup 90}Zr. {copyright} {ital 1997} {ital The American Physical Society}
1997-03-01
On the 2D Cahn-Hilliard equation with inertial term
P. Galenko et al. proposed a modified Cahn-Hilliard equation to model rapid spinodal decomposition in non-equilibrium phase separation processes. This equation contains an inertial term which causes the loss of any regularizing effect on the solutions. Here we consider an initial and boundary value problem for this equation in a two-dimensional bounded domain. We prove a number of results related to well-posedness and large time behavior of solutions. In particular, we analyze the existence of bounded absorbing sets in two different phase spaces and, correspondingly, we establish the existence of the global attractor. We also demonstrate the existence of an exponential attractor.
2008-01-01
Mechanisms of high-T/sub c/ superconductivity in low-dimensional materials
Energy Technology Data Exchange (ETDEWEB)
High-T/sub c/ superconductivity is due to the action of two mechanisms: (1) plasmon mechanism, i.e., exchange of two-dimensional (2-D) plasmons and (2) strong electron--phonon coupling. The low dimensionality and the small value of the carrier concentration make the plasmon mechanism favorable. The small value of the coherence length leads to a unique opportunity to observe a multigap structure. The proximity effect can be used in order to increase T/sub c/ of A-15 compounds.
1987-11-01
Energy Technology Data Exchange (ETDEWEB)
A 2D matrix allows a fairly rapid verification of irradiation parameters transferred on computer processing equipment without expanding the dosimetry means to implement. Associated to 'Multicheck and Verisoft' software it will handle some of the regulatory recommendations of the A.F.S.S.A.P.S. for quality control of accelerators and ensure the traceability of testing carried out. (N.C.)
2007-11-15
International Nuclear Information System (INIS)
Hitherto in this laboratory, ionization coefficients alpha and attachment coefficients #eta# have been determined from Townsend's discharge experiments by a curve-fitting method. However, the method proved to be laborious, Formulae have been derived in this paper to give value of alpha and #eta# as a function of Isubo, Isub1 and Isub2 where Isubo is the photoelectric current at a gap setting d and Isub2 the current at another gap setting 2 d. The values of alpha and #eta# obtained give currents in agreement to within 3% in the best cases with the observed currents.
Efficient Cartesian-grid-based modeling of rotationally symmetric bodies
DEFF Research Database (Denmark)
Axially symmetric waveguides, resonators, and scatterers of arbitrary cross section and anisotropy in the cross section can be modeled rigorously with use of 2-D Cartesian-grid based codes by means of mere redefinition of material permittivity and permeability profiles. The method is illustrated by the frequencydomain simulations of resonant modes in a circular-cylinder cavity with perfectly conducting walls, a shielded uniaxial anisotropic dielectric cylinder, and an open dielectric sphere for which, after proper implementation of the perfectly matched layer boundary conditions, the radiation quality factor is also determined.
2007-01-01
Chemical constituents of Galianthe brasiliensis (Spreng.) E.L.Cabral and Bacigalupo (Rubiaceae)
International Nuclear Information System (INIS)
This paper describes the chemical constituents isolated from aerial parts of the plant Galianthe brasiliensis. From a methanol extract, the iridoid glycosides asperuloside, deacetylasperuloside, mixture of Z- and E-6-O-p-coumaroylscandoside methyl ester, the triterpene ursolic acid and the steroids stigmasterol, campesterol, b-sitosterol and 3-O-b-glucopyranosyl sitosterol were isolated. The structures of the natural products were identified on the basis of spectral data, including 2D NMR experiments. The antiproliferative properties of the crude methanolic extract were investigated against a series of nine human cancer cell lines. (author)
Advances in imaging THGEM-based detectors
International Nuclear Information System (INIS)
We report on recent measurements with Thick GEM-like (THGEM)-based imaging detectors. The THGEM is a robust gaseous electron multiplier similar to GEM but with larger dimensions. It has high electron multiplication, of 105 and 107 in single- and double-THGEM structure, respectively, fast signals and ?10MHz/mm2 counting rate capability. It can be produced in any shape and over large area. In view of many possible applications of THGEM-based imaging detectors, in particle physics and beyond, we have recently studied the localization properties of a 2D 10x10cm2 detector. The results of these studies are presented.
2007-03-01
A combinatorial spanning tree model for knot Floer homology
We iterate Manolescu's unoriented skein exact triangle in knot Floer homology with coefficients in the fraction field of the group ring (Z/2Z)[Z]. The result is a spectral sequence which converges to a stabilized version of delta-graded knot Floer homology. The (E_2,d_2) page of this spectral sequence is an algorithmically computable chain complex expressed in terms of spanning trees, and we show that there are no higher differentials. This gives the first combinatorial spanning tree model for knot Floer homology.
2011-01-01
&C:sIC> uC%m$C C(k6C* 1CFM 2dC% !C3U J*C0! CV$,Co\\ lC$\\JC ...
C C*R C" dC*9 4hC2 CX2VCTF CK/XCL` CCNA C?Q C.:FC C?v As1)Ax^IA} AyU$ =FA%WNA AfgJA Aw;ZAzg AyA!A A=!nA> CA!n/A* ? ...
Synopsis of some preliminary computational studies related to unsaturated zone transport at Area G
Energy Technology Data Exchange (ETDEWEB)
Computational transport models are described with applications in three problem areas related to unsaturated zone moisture movement beneath Area G. These studies may be used to support the ongoing maintenance of the site Performance Assessment. The three areas include: a 1-D transient analysis with average tuff hydraulic properties in the near surface region with computed results compared to field data; the influence on near surface transient moisture percolation due to realistic distributions in hydraulic properties derived statistically from the observed variance in the field data; and the west to east moisture flow in a 2-D steady geometry approximation of the Pajarito Plateau. Results indicate that a simple transient model for transport of moisture volume fraction fits field data well compared to a moisture pulse observed in the active disposal unit, pit 37. Using realistic infiltration boundary conditions for summer showers and for spring ...
1998-03-01
Depth migration in transversely isotropic media with explicit operators
Energy Technology Data Exchange (ETDEWEB)
The author presents and analyzes three approaches to calculating explicit two-dimensional (2D) depth-extrapolation filters for all propagation modes (P, SV, and SH) in transversely isotropic media with vertical and tilted axis of symmetry. These extrapolation filters are used to do 2D poststack depth migration, and also, just as for isotropic media, these 2D filters are used in the McClellan transformation to do poststack 3D depth migration. Furthermore, the same explicit filters can also be used to do depth-extrapolation of prestack data. The explicit filters are derived by generalizations of three different approaches: the modified Taylor series, least-squares, and minimax methods initially developed for isotropic media. The examples here show that the least-squares and minimax methods produce filters with accurate extrapolation (measured in the ability to ...
1994-12-01
Energy Technology Data Exchange (ETDEWEB)
We present an efficient parallel algorithm and its implementation for computing the diagonal of $H^-1$ where $H$ is a 2D Kohn-Sham Hamiltonian discretized on a rectangular domain using a standard second order finite difference scheme. This type of calculation can be used to obtain an accurate approximation to the diagonal of a Fermi-Dirac function of $H$ through a recently developed pole-expansion technique \\cite{LinLuYingE2009}. The diagonal elements are needed in electronic structure calculations for quantum mechanical systems \\citeHohenbergKohn1964, KohnSham 1965,DreizlerGross1990. We show how elimination tree is used to organize the parallel computation and how synchronization overhead is reduced by passing data level by level along this tree using the technique of local buffers and relative indices. We analyze the performance of our implementation by examining its load balance and communication overhead. We show that our implementation ...
2009-09-25
International Nuclear Information System (INIS)
Buffer layers with 100% lattice match with YBa2Cu3O7 - ? (YBCO) were prepared from mixed rare-earth-oxides applying a simple sol-gel process and dip-coating method. Structural analysis of the sol-gel derived powder by X-ray diffraction revealed that the mixing parameter, which eliminates the lattice mismatch with YBCO, is x = 0.2382, 0.1852, 0.1252, 0.0906, 0.0793 and 0.0395 in (Eu1 - xHox)2O3, (Eu1 - xErx)2O3, (Eu1 - xYbx)2O3, (Gd1 - xHox)2O3, (Gd1 - xYx)2O3 and (Gd1 - xYbx)2O3, respectively. Microstructural investigations were carried out for Gd1.819Ho0.181O3 films epitaxially grown on cube-textured Ni (100) substrates by sol-gel dip-coating process. X-ray diffraction of the buffer showed strong out-of-plane orientation on Ni tape. The (Gd1 - xHox)2O3 (222) pole figure indicated a single cube-on-cube textured structure. The omega and phi scans revealed good out-of-plane and in-plane alne alignments. The full-width at half-maximum values of ...
2010-04-02
Late Archean intrusive charnockites from the west-central Wind River Mountains, Wyoming
Energy Technology Data Exchange (ETDEWEB)
Late Archean (ca. 2.5Ga) porphyritic granites to comprise about 25% of the crystalline rocks of the Wind River uplift. In most localities, they are typical biotite-hornblende granites but on the western margin of the range there is evidence that portions of at least one pluton were emplaced as charnockite. In the Burnt Lake area homogenous charnockite crops out over an area of at least 3km while in the Boulder Creek Canyon, 8km to the S.E. charnockite occurs locally as blotches in porphyritic biotite granite. One sample from Boulder Creek, 15 cm in the longest dimension, shows a complete transition from charnockite to biotite granite. Textures indicate that the transition occurred as subsolidus hydration, with hornblende and biotite replacing augite and orthopyroxene, respectively. Pryoxene geothermometry from this sample yields maximum temperatures of around 900/sup 0/C, with a cooling trend to 600/sup 0/. Fluid inclusion of both CO/sub 2/ (p = .85 to .95) and ...
1985-01-01
Energy Technology Data Exchange (ETDEWEB)
In order to fabricate high temperature superconducting tapes for power applications, the authors have analyzed different buffer layer architectures grown on textured Ni substrates suitable for YBCO deposition. Due to its optimal lattice matching the studied structures present as top layer a CeO{sub 2} film. The deposition of CeO{sub 2} on Ni substrates was performed by pulsed laser ablation and by e-beam evaporation at different temperatures. The films obtained by the two deposition techniques have not optimal structural properties, having a polycrystalline component. The misorientation of CeO{sub 2} is probably due to the formation of NiO at the interface between the film and the substrate during the deposition process even if no oxygen is introduced. In order to prevent Ni oxidation an intermediate 2000 {angstrom} Pd thick film was deposited by e-beam. Furthermore, the lattice mismatch between Pd and CeO{sub 2} is smaller than that between Ni and CeO{sub 2}. The ...
1999-04-20
Dismembered Archean ophiolite in the SE. Wind River Mountains, Wyoming
Energy Technology Data Exchange (ETDEWEB)
Ophiolitic rocks occur as wall rocks of the 2.7 Ga Louis Lake batholith near Atlantic City, Wyoming. All of the Archean rocks are strongly deformed and metamorphosed to a greenschist and amphibolite facies, but relict structures and textures are commonly preserved. These include the following, from west to east: (1) metadiabase with rare coarse-grained metagabbro; (2) ultramafic rocks and metagabbro; (3) amphibolite, locally pillowed, overlain(.) by pelitic schist, banded iron formation, and quartzite; and (4) pillow lavas, massive sills or flows, and minor metasedimentary rocks. Slice 1 locally contains parallel dike margins and rare metagabbro screens; these features suggest that it may represent a sheeted dike complex. Slice 2 locally contains ultramafic rocks having relict cumulus textures and igneous layering, corresponding to the cumulus portion of an ophiolite. The pillow lavas of slice 4 and possibly slice 3 are interpreted as ...
1985-01-01
Energy Technology Data Exchange (ETDEWEB)
Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager (`Vision`, Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of ...
1996-03-01
Computed tomography whole body imaging in multi-trauma: 7 years experience
International Nuclear Information System (INIS)
AIM: To assess the impact of the introduction of a computed tomography (CT) imaging protocol for multi-trauma patients on the workload, overall diagnostic yield, and effect on detection of cervical spine injury and pneumothorax. METHOD: Between February 1997 and April 2004, all patients presenting acutely to the Emergency Department (ED) with haemodynamically stable trauma (Abbreviated Injury Scale 3 or more) involving more than two body systems were imaged with a comprehensive pre-set helical CT protocol (including non-contrast head, cervical spine: cranio-cervical and cervico-thoracic junctions; and oral and intravenous contrast-enhanced thoracic, abdomen and pelvis) after initial triage and a standard trauma series of radiographs (chest, lateral C-spine and pelvis). Diagnosis of cervical spine fracture and pneumothorax was noted before and after the CT protocol was carried out and findings from all studies were recorded prospectively. RESULTS: Over the 7-year ...
2006-04-01
Vapor fraction measurements in a steam-water duct at atmospheric pressure using neutron radiography
Energy Technology Data Exchange (ETDEWEB)
Real-time neutron radiography has been used to study the dynamic behavior of two-phase flow and measure vapor fractions in a steam-water duct at atmospheric pressure. This unique experimental technique offers one the opportunity to observe and record on videotape now Patterns and transient behavior of two-phase flow inside opaque containers without perturbing the environment. The neutron radiographic technique is non-intrusive and requires no special transparent window region. Data are recorded simultaneously over a large area of interest. Image processing of the video data can be employed to measure bubble velocities and time-averaged and Instantaneous vapor fractions.
1994-11-11
International Nuclear Information System (INIS)
A prospective study was performed on 50 patients suffering from osteochondritis dissecans of the knee and ankle to define criteria for stability and fixation of osteochondral lesions. Morphological parameters in MRI (size, fragmentation, cartilage, interface) and conventional radiology (separation, fragmentation) were registered and compared with arthroscopical staging. MRI staging based on different types of interfaces was demonstrated on T_1- and T_2-weighted images. MRI could correctly predict a Grade 1 lesion in 50%, a Grade 2 lesion in 90%, a Grade 3 lesion on 0%, and a Grade 4 lesion in 79%. Stable lesions were differentiated from unstable lesions in 90%. Radiographic findings corresponded with arthroscopic staging in only 56% of the cases because fibrotic connection may guarantee stability in case of bony separation. (orig./MG).
British Library Electronic Table of Contents (United Kingdom)
The objective of this study is to test the validity of sex determination in children and adolescents using lateral radiographic cephalometry and discriminant function analysis. Fifty male and 50 female cephalograms of Taiwanese children were used (males and females with mean age of 15.52???1.38 and 15.67???1.54?years, respectively). Twenty-two cephalometric measurements were performed using computerized cephalometry. Statistical analysis shows that all measurements were sexually dimorphic (p?0.05). Nine measurements, statistically validated and clinically relevant, were used for discriminant function analysis. A stepwise discriminant procedure selected seven of the nine variables, producing 95% accuracy in sex determination. Resubstitution classification reveals the same discriminant rat...
2010-01-01
Revisited the mathematical derivation wall thickness measurement of pipe for radiography
Energy Technology Data Exchange (ETDEWEB)
Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the Pythagoras theorem and geometrical principles. In order to ...
2007-07-01
Retinue of the beans roots growth by using neutron radiography technique
International Nuclear Information System (INIS)
Agricultural practices frequently cause the development of a soil compacted layer below the surface. These compacted layers restrict the root penetration into deeper layers of soil, in search for water. It is proposed to monitor, using Non Destructive Test, the roots growth due to the planting of standard seeds in different agricultural soils, in function of their compactness and humidity. It will be used the neutrons beams derived from an irradiation channel called J-9 of the Reactor Argonauta (IEN/CNEN), so that the neutron radiographic images of the soil-plant system can be obtained. Each root can be evaluated for its ability to penetrate into compacted soil layers; this fact would mean an optimization of agricultural harvests. (author)
2002-08-11
Removal of scattered thermal neutrons using antiscatter grid
International Nuclear Information System (INIS)
One of the significant factors of neutron radiographic image degradation is scattering blur from the object. A practical method is described to enhance image quality by eliminating the overlapping of scattered thermal neutrons component from the objects in ETRR-2 neutron radiography facility, using aluminum Gd-coated antiscatter grid. The MCNP code was used to determine the optimum grid dimensions that will reduce the scattered thermal neutrons from the object. An experiment was performed to determine the optimum grid height and irradiation time that gives the best image with acceptable geometric unsharpness. Using the MCNP code it was found that 97% of the scattered neutrons were removed by the grid. The wall dimensions and Gd coating are so small that the facility resolution cannot detect the image pattern superposition on the film.
2006-12-01
Real time neutron radioscopy - trends and applications
International Nuclear Information System (INIS)
Real Time Radiography (RTR) finds extensive applications for inspection of objects on assembly lines for rapid inspection. A typical RTR widely used includes a image intensifier, CCD camera, image processor and high resolution TV monitor in addition to radiographic source. Image intensifiers used in X-radiography employ CsI as the input detector. With the increased use of neutrons as radiation source, real time neutron radiography is also being practised widely. Image intensifiers used in neutron radiography employ gadolinium as the input screen. The neutron image intensifier system at the authors laboratory essentially consists of a 9 inch Trifield image intensifier tube, motorised zoom lens, CCD camera and a high resolution TV monitor
2003-11-12
Orthognathic treatment case after severe root resorption in the early treatment stage
British Library Electronic Table of Contents (United Kingdom)
This article presents an orthognathic treatment case after severe apical root resorption of maxillary anterior teeth using anterior segmental osteotomy. This case involved a 20-year-old female with the chief complaint of maxillary protruding and irregularly aligned mandibular anterior teeth. Her medical history showed no allergies or medical problems. The overbite was +3.0mm, and the overjet +3.0mm. After extraction of the four first premolars, a multi-bracket treatment was started. A severe root resorption of the maxillary anterior teeth was found 12 months after active treatment. The maxillary anterior segmental osteotomy was chosen as the compensatory treatment. The total treatment period was 2 years and 7 months. The post-retention panoramic radiograph showed no developmental root reso...
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
Reliable facility of cyclotron-based real time neutron radiography system has been developed and applied to some industrial components. The equipment for neutron fluoroscopy is based on a sub-compact cyclotron and a LiF/ZnS (Ag) fluorescent screen viewed by a silicon intensifier target TV camera. The real time image is monitored on a CRT, recorded with a standard video recorder and processed by a digital image processor. The effectiveness of our real time neutron radiograph has been demonstrated to be applicable to not only the dynamic observation but also the magnifying and stereoscopic observation of fluoroscopic images.
1987-03-01
Imaging automation and volume tomographic visualization at Texas Neutron Imaging Facility
Energy Technology Data Exchange (ETDEWEB)
A thermal neutron imaging facility for real-time neutron radiography and computed tomography has been developed at the University of Texas reactor. The facility produced a good-quality radiographs and two-dimensional tomograms. Further developments have been recently accomplished. Further developments have been recently accomplished. A computer software has been developed to automate and expedite the data acquisition and reconstruction processes. Volume tomographic visualization using Interactive Data Language (IDL) software has been demonstrated and will be further developed. Volume tomography provides the additional flexibility of producing slices of the object using software and thus avoids redoing the measurements.
1999-07-01
British Library Electronic Table of Contents (United Kingdom)
PurposeAlthough the safety and feasibility of partial adrenalectomy in patients with von Hippel-Lindau syndrome have been established, long-term outcomes have not been examined. In this study we evaluate the recurrence and functional outcomes in a von Hippel-Lindau syndrome cohort treated for pheochromocytoma with partial adrenalectomy with a followup of at least 5 years. Materials and MethodsWe reviewed the records of patients with von Hippel-Lindau syndrome treated with partial adrenalectomy for pheochromocytoma at the National Cancer Institute. Demographic, germline mutation status, surgical indication, oncologic and functional outcome data were collected. Local recurrence was defined as radiographic evidence of recurrent tumor on the ipsilateral side of partial adrenalectomy. Patients ...
2010-01-01
Five-year Changes in Periodontal Parameters after Apical Surgery
British Library Electronic Table of Contents (United Kingdom)
IntroductionMost clinical studies on the outcome of apical surgery concentrate on periapical healing based on radiographic and clinical characteristics (signs and symptoms). This study focuses on long-term changes in periodontal parameters after apical surgery. MethodsPeriodontal parameters (ie, probing depth [PD], level of gingival margin [GM], and calculated clinical attachment level [CAL]) were collected at baseline and at 1 and 5 years after apical surgery. Changes in PD, GM, and CAL were calculated over time and were also evaluated in relation to patient-, tooth-, and treatment-related covariables. ResultsOne hundred eighty-six of 242 initially identified teeth could be evaluated. Significant changes in GM and CAL were observed at facial sites during the first year after surgery (mean...
2011-01-01
Extrinsic allergic alveolitis induced by the yeast Debaryomyces hansenii.
A 65-yr-old female developed cough, fever and dyspnoea following repeated exposure to a home ultrasonic humidifier. High-resolution computed tomography showed ground-glass opacity in both lung fields. Arterial blood gas analysis gave an oxygen tension of 8.38 kPa (63 Torr). Pulmonary function testing revealed restrictive ventilatory impairment with a reduction in the diffusing capacity. The diagnosis of extrinsic allergic alveolitis (EAA) was confirmed by radiographic findings, pathological evidence of alveolitis and reproductive development by a provocation test to the humidifier water. The yeast Debaryomyces Hansenii was the only microorganism cultured from the water of the humidifier. The double diffusion precipitating test and lymphocyte proliferative response was positive for an extract of D. Hansenii, providing evidence to incriminate this fungus. This is the first described case of EAA caused by D. Hansenii. PMID:12449192
2002-11-01
International Nuclear Information System (INIS)
Digital radiography for diagnosis of chest diseases using Fuji Computed Radiography (FCR) was evaluated. The results were as follows; 1. Compared to the conventional chest X-ray films, various types of image enhancement could be made by manipulation of the digital information such as tone conversion, spatial frequency modification etc. 2. Digital radiography lessens the X-ray exposure dose and will ultimately permit speedy transmission of image data from outlying clinics to central processing hospitals. 3. Digital radiographic images are useful in chest X-ray diagnosis especially in mass surveys for lung cancer and in primary care medicine because of its full imaging capability. (author).
1983-01-01
Digital radiography of pulmonary abnormalities using Fuji computed radiography (FCR)
Energy Technology Data Exchange (ETDEWEB)
Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best practical conditions were determined. (author).
1991-12-01
Digital radiography of pulmonary abnormalities using Fuji computed radiography (FCR)
International Nuclear Information System (INIS)
Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best practical conditions were determined. (author).
1991-01-01
British Library Electronic Table of Contents (United Kingdom)
Aims The aim of this study is to examine the dose?response relationships between age, ?lifestyle factors?? (body mass index, tobacco smoking, sports), and symptomatic knee osteoarthritis in a population-based case?control study. Additionally, the study aims to investigate the mode of interaction between body mass index (BMI) and physical workload (occupational kneeling/squatting and lifting/carrying of loads) with respect to the risk of symptomatic knee osteoarthritis. Methods In five orthopedic clinics and five practices, 295 male patients aged 25?70 with radiographically confirmed knee osteoarthritis associated with chronic complaints were recruited. The control group comprised 327 male control subjects. In a structured personal interview, body weight at different ages, body height, cumu...
2010-01-01
CF findings of bowel infarction in 56 surgical patients, 5 of whom with reversible ischemia
International Nuclear Information System (INIS)
Bowel infarction is a rare and typical condition of the elderly; despite improvements in diagnostic imaging and vascular surgery, bowel infarction remains a major cause of acute abdomen, with mortality rates ranging 70-80%. Diagnosis on often late because clinical sings, laboratory data and radiologic findings are a specific. The authors investigated radiographic and particular CT patterns of intestinal infraction in 56 patients submitted to surgery within 12 hours of admission. We also report the CT findings of 5 of these patients who had reversible mesenteric ischemia. CT is more sensitive than radiography and does not exhibit the limitations of angiography (i.e., invasiveness, radiation exposure an complex organization. Therefore CT can presently be considered the method of choice in patients with suspected bowel infarction.
1999-04-01
International Nuclear Information System (INIS)
Ten patients with traumatic femoral neck fracture were studied with MR imaging (0.5 T, Magnetom, Siemens): unenhanced (multiecho, TR/TE = 1,600/30--240 [repetition time/echo time, msec]; gradient echo, TR/TE = 315/14, #theta# = 90 degrees) and Gd-DTPA enhanced (0.1 mM/kg body weight, Magnevist, Schering; gradient echo, TR/TE = 315/14, #theta# = 90 degrees). MR images were compared with clinical-radiographic findings. Digital subtraction angiography of the femoral head (FH) in five patients showed complete interruption of blood supply to the FH in three patients (signal intensity of FH did not increase on postcontrast images) and intact FH arteries in two patients (FH signal increased on postcontrast images, as did the healthy-side signal).
Abces du muscle iliopsoas : complication rare de la sacro-iliite a pyogene chez lenfant
British Library Electronic Table of Contents (United Kingdom)
Pyogenic sacroiliitis is a rare entity in children. Diagnosis is often delayed because of its variable clinical presentation, low suspicion by the examining physician, and rare findings on radiographs. Delayed diagnosis, however, results in complications such as iliopsoas abscess. We report the case of a 12-year-old girl hospitalized with a 21-day history of fever, pain in the left iliac fossa, and flexion contracture of the hip. On examination, she had fever (38.9 ^oC), psoitis, localized tenderness at the left sacroiliac joint, and pain elicited by lateral compression of the pelvis. The abdominal examination was normal. The erythrocyte sedimentation rate was 130mm in the first hour, C-reactive protein was 186mg/l, and the white blood cell count was 18,400/mm^3, with 79% neutrophils. Urin...
2010-01-01
The progression of hip dysplasia was investigated in 116 military working dogs. Medical records were reviewed for any clinical history of hind-limb lameness. Pelvic radiographs were studied for evidence and degree of hip dysplasia, degenerative joint disease, or both. The number of months each dog worked was determined. Each dog's age at termination from service and cause of death (or euthanasia) were recorded. The mean months of work for normal and dysplastic dogs were evaluated using the Student's t-test. No significant difference was found in the total number of months worked between normal and dysplastic dogs (p greater than 0.05). PMID:8875358
The progression of hip dysplasia was investigated in 116 military working dogs. Serial pelvic radiographs were graded for degree of dysplasia and degenerative joint disease (DJD). Norberg angles, angles of inclination, and joint space widths were measured. There was a significant correlation between the Norberg angle and the degree of dysplasia (p less than 0.0001). Angles of inclination and joint space width measurements did not demonstrate a correlation to canine hip dysplasia. Dysplastic dogs had a significant estimated risk for development of DJD compared to normal dogs (p less than 0.0001; odds ratio of 70.2). Dogs with normal hip conformation at 24 months of age or older did not develop moderate nor severe DJD. PMID:8875357
Energy Technology Data Exchange (ETDEWEB)
Purpose: Reconstruction of radiation doses for the thoracoabdominal babygram and the abdomen X-ray from radiographic settings and exposure data acquired at Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007; comparison of these dose values with values reported in the literature; recommendation of a reference dose value for the thoracoabdominal babygram. Materials and Methods: The data from all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 1493 thoracoabdominal babygrams and 3632 abdomen X-rays of newborns and young infants. With the computer program PAeDOS, a specific dose reconstruction algorithm was developed. Results: the entrance dose values of thoracoabdominal babygrams and abdomen ...
2010-06-15
International Nuclear Information System (INIS)
Purpose: Reconstruction of radiation doses for the thoracoabdominal babygram and the abdomen X-ray from radiographic settings and exposure data acquired at Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007; comparison of these dose values with values reported in the literature; recommendation of a reference dose value for the thoracoabdominal babygram. Materials and Methods: The data from all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 1493 thoracoabdominal babygrams and 3632 abdomen X-rays of newborns and young infants. With the computer program PAeDOS, a specific dose reconstruction algorithm was developed. Results: the entrance dose values of thoracoabdominal babygrams and abdomen X-rays in DvHK could ...
2010-06-01
Health-hazard evaluation report HETA 88-108-2146, Asarco New Market/Young Mines, Mascot, Tennessee
Energy Technology Data Exchange (ETDEWEB)
In response to a request from the International Chemical Workers Union, Akron, Ohio, an investigation was made into possible hazardous working conditions at two American Smelting and Refining Company (SIC-1031) zinc mines (New Market and Young) in Mascot, Tennessee. Specifically, exposures to asbestos (1332214), silica (14808607), and diesel emissions were determined. At both mines overexposures were found to nitrogen-dioxide (10102440) (NO2) and coal-tar pitch volatiles. Twenty-four percent of the NO2 measurements taken were above the NIOSH recommended ceiling of 1 part per million (ppm), but none exceeded the Mine Safety and Health Administration's (MSHA) ceiling of 5ppm. Exposure to diesel particulates ranged from 0.24 to 1.06mg/cu m. None of the 52 respirable dust samples collected exceeded the calculated MSHA limits for free silica exposure. A medical evaluation was offered and 83 of the 400 current employees and one retired employee participated. Seven underground ...
1991-10-01
Fuji computed radiography (FCR) for the diagnosis of spinal disorders
Energy Technology Data Exchange (ETDEWEB)
Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the ...
1987-04-01
Energy Technology Data Exchange (ETDEWEB)
The topics of these short lectures on the subject of cyclic stress were: Microstructural mechanisms of damage accumulation under a multistage cyclic stress until incipient cracking; influence of surface decarbonizing phenomena on the failure behaviour of steel construction parts subjected to cyclic stress; thermocyclic fatigue of pipe samples of austenitic steel 1.4436; studies on surface structuring, microstructure and fatigue in LCF area. The short lectures on effects of quasi-static and creep stress were: Shear fracture in AlMg alloys as a result of local plastic instability; study of formation and growth of pores for an early recognition of damage and the course of damage in heat-resistant steels under creep test; experimental and numeric studies of the infuence of the microstructure on the course of damage during shear fractures of steel; numerical modelling of ductile fractures on the basis of micromechanical models. Under the topic of tribological stress the following lectures ...
1989-01-01
Distinguishing benign notochordal cell tumors from vertebral chordoma
Energy Technology Data Exchange (ETDEWEB)
The objective was to characterize imaging findings of benign notochordal cell tumors (BNCTs). Clinical and imaging data for 9 benign notochordal cell tumors in 7 patients were reviewed retrospectively. Conventional radiographs (n = 9), bone scintigrams (n = 2), computed tomographic images (n = 7), and magnetic resonance images (n = 8) were reviewed. Eight of the 9 lesions were stained with hematoxylin-eosin and microscopically examined. There were 3 male and 4 female patients with an age range of 22 to 55 years (average age, 44 years). Two patients had two lesions at different sites. The lesions involved the cervical spine in 4 patients, the lumbar spine in 2, the sacrum in 2, and the coccyx in 1. The most common symptom was mild pain. The lesions of 2 patients were found incidentally during imaging studies for unrelated conditions. Five patients underwent surgical procedures. One patient died of surgical complications. All other patients have been well without ...
2008-04-15
Computed tomography in the diagnosis of cavum septum pellucidum
Energy Technology Data Exchange (ETDEWEB)
The cavum septum pellucidum is an anatomical variants of the septum pellucidum, and lying between two lateral ventricles and this is referred to as the fifth ventricle. Occasionally, posterior extension of the cavum septum pellucidum towards the splenium is seen and this is known as the cavum vergae, or sixth ventricle. The septum is double membrane and occasionally a narrow cavity containing CSF is present between these membrane. The roof of the cavum septum pellucidum is formed by the corpus callosum and its floor by the anterior pillars of the fornix. This cavum outlined with air is occasionally seen in the pneumoencephalography. Brain CT scans of 1000 patients were performed, and the diagnosis could be made on the basis of the characteristic shape, density and location. Other diagnostic procedure are not necessary in these cases. Patients were examined with CT scanner from June-80' to Dec-80', at department of radiology, Maryknoll Hospital, and 13 cases were ...
1981-09-15
International Nuclear Information System (INIS)
Ischemic bowel disease is a rare disorder whose incidence is increasing as the mean age of the population increases. Diagnosis by clinical, laboratory and radiologic means is often difficult, and delay in definitive therapy results in substantial morbidity and mortality. A series of 26 consecutive patients, with proved acute superior mesenteric ischemia, was retrospectively reviewed: the authors reports the diagnostic methods performed preoperatively, the site and the cause of infarction and the time passed between the first radiograph and surgery. Plain abdominal radiographs were performed in 25 of 26 patients, screening abdominal US in 23 cases and CT in 19 cases. All radiological examinations were retrospectively reviewed by the three authors, independently, to recognize the different signs of infarction. On plain abdominal films, the findings warranting a presumptive diagnosis of bowel infarction were air-fluid levels (84% of cases), ...
1997-01-01
International Nuclear Information System (INIS)
Purpose: To report our clinical experiences with on-board imager (OBI) kV image verification for cranial stereotactic radiosurgery (SRS) and radiotherapy (SRT) treatments. Methods and Materials: Between January 2007 and May 2008, 42 patients (57 lesions) were treated with SRS with head frame immobilization and 13 patients (14 lesions) were treated with SRT with face mask immobilization at our institution. No margin was added to the gross tumor for SRS patients, and a 3-mm three-dimensional margin was added to the gross tumor to create the planning target volume for SRT patients. After localizing the patient with stereotactic target positioner (TaPo), orthogonal kV images using OBI were taken and fused to planning digital reconstructed radiographs. Suggested couch shifts in vertical, longitudinal, and lateral directions were recorded. kV images were also taken immediately after treatment for 21 SRS patients and on a weekly basis for 6 SRT patients to assess any ...
2009-02-01
Energy Technology Data Exchange (ETDEWEB)
Thalassaemic patients are in need of frequent assessment of bone age because of growth failure and pubertal disorders. To compare the ''rapid'' Greulich and Pyle (G and P) method with the third edition of the Tanner and Whitehouse (TW3) method for determining skeletal maturity and predicting final height in thalassaemic patients. A total of 191 radiographs from 58 patients (28 male, 30 female) were retrospectively evaluated by two investigators, one for each method. In 47 radiographs from 15 patients having attained their adult height, predicted final height was calculated according to each method. The mean bone ages determined by both the G and P and TW3 methods were lower than mean chronological age, although the differences were not statistically significant (10.04 {+-} 3.69 years and 9.98 {+-} 3.39 years vs. 10.78 {+-} 3.96 years, respectively). Both methods had a tendency to over-estimate final height. ...
2007-12-15
Energy Technology Data Exchange (ETDEWEB)
Hepatocellular carcinoma (HCC) is characterized by tumor vascularization from the hepatic artery. The objective of our work was to compare color Doppler ultrasonography (CDU), including power Doppler ultrasonography (PDU) with radiographic imagings with contrast medium in regard to the detection of the arterial tumor vascularity of small hepatocellular carcinomas (HCC). We examined 42 small HCC lesions 2 cm or less in diameter in 37 patients for arterial tumor vascularity by conventional CDU, PDU, dynamic computed tomography (dCT), digital subtraction angiography (DSA), and CT hepatic arteriography (CTA). Color images were detected in 25 (59.5%) and 28 (66.7%) of the 42 lesions with conventional CDU and PDU, respectively, and tumor vascularity was detected in 26 (61.9%) by dCT, 23 (54.8%) by DSA, and 29 (69.0%) by CTA. Tumor vascularity could be detected in 51.9% by PDU and CTA, more than by conventional CDU, dCT, and DSA (44.4, 44.4, and 33.3%, respectively) in ...
2000-10-01
Energy Technology Data Exchange (ETDEWEB)
The oxidative dehydrogenation (ODH) of light alkanes is an alternative way for the production of olefins. A wide variety of catalytic systems has been investigated. Vanadium oxide based catalysts were described in the literature as effective catalysts for the ODH of propane. The catalytic activity and selectivity depend on the kind of support material, the kind of dopants and the formation of complex metal oxide phases. In recent papers it was claimed that both orthovanadate and/or pyrovanadate species are selective for the ODH of propane. Niobia based materials were investigated as catalysts for acidic and selective oxidation type reactions. In the ODH of propane niobia exhibited a high selectivity to propene but the conversion of propane was low. V{sub 2}O{sub 5}-Nb{sub 2}O{sub 5} catalysts proved to be catalytically active and selective and showed no formation of oxygenates. In the present study the influence of the niobia dopant of the catalytic properties of V{sub 2}O{sub ...
1998-12-31
Energy Technology Data Exchange (ETDEWEB)
The intention of this study is to show the high potential of remote sensing data to keep an eye on longterm processes in large regions with widespread tasks and questions. The results of two projects (sponsored by the BMBF - Ministry of Education and Science, Germany and the country of Saxony-Anhalt) are taken into account to give an impression of the chances provided by the application of hyperspectral airborne scanner data and satellite images. So these two projects focus at the applicability of various methods to use remote sensing data for a long- term monitoring of former lignite open-cast mining areas. Apart from the traditional pixelorientated analysis, the application and combination of new object orientated methods (e.g. segmentation, texture analysis) were investigated to distinguish between the following typical vegetation types: Spontaneous revegetation of plant communities; reforestation areas; recultivated grass seeding areas; area patterns of ...
2001-07-01
Steganography using wavelet compressed images
Internet bandwidth is in high demand, and one way that web sites lower the amount of bandwidth they use is by compressing their site's images. This lowers the amount of bandwidth used, and makes the site load much faster. There are of course many other useful applications for compressed images. Bit Plane Complexity Segmentation (BPCS) digital picture steganography is a technique to hide data inside an image file. BPCS achieves high embedding rates with low distortion based on the theory that noise-like regions in a bit-plane can be replaced with noise-like secret data without discernible loss in image quality. This is possible because the human eye, while very good at distinguishing anomalies in areas of homogenous texture, is bad at distinguishing anomalies in visually complex areas. However, BPCS is not a robust embedding scheme, and any lossy compression usually destroys the data. Wavelet image compression using the Discreet Wavelet Transform (DWT) is the basis ...
2001-08-01
Energy Technology Data Exchange (ETDEWEB)
This report presents the status of development of a three-dimensional conceptual model for the unconfined aquifer system at Hanford. A conceptual model is needed to support development of a realistic three-dimensional numerical model for predicting ground-water flow and the transport of contaminants. The report focuses on developing a hydrogeologic framework, assessing available hydraulic property data, describing flow-system boundaries, and evaluating areal recharge and leakage. Geologic descriptions of samples obtained during well drilling were used to prepare cross sections that correlate relatively continuous layers. The layers were defined based on textural differences that are expected to reflect differences in hydraulic properties. Assigning hydraulic properties to the layers is a critical part of the conceptual model. Available hydraulic property data for the study area were compiled and were correlated with the geologic layers where possible. Flow-system ...
1992-11-01
Review of progress in quantitative NDE. Abstracts
Energy Technology Data Exchange (ETDEWEB)
The meeting was arranged into the following sessions: introductory; advanced ceramics and ceramic composites; ceramic and metal matrix composites; electronic materials and devices; acoustoelasticity, stress, and texture; composites-porosity, strength, and UT propagation; process modeling and monitoring; thermal wave physics; material properties, composites, surfaces, and interfaces; acoustic emission; ferromagnetic materials; new sensors; NDE reliability assessment; elastic wave scattering and propagation; image analysis, data storage, and signal processing; UT transducers; weldments and bonded materials; eddy current models; unified life cycle engineering; x rays, CT, and NMR; eddy current probes and instruments; acoustic microscopy imaging, and reconstruction; signal processing, measurement techniques, and systems; NDE applications of artificial intelligence; crack behavior influenced by history; inversion procedures for UT and EC; process control and material ...
1986-01-01
Results of in-house cone-cup testing of low to high temperature SPF-alloys
Energy Technology Data Exchange (ETDEWEB)
Material testing of SPF-sheet is usually done with coupon hot tensile testing. The optimum range of strain rates is determined with stepped strain tests. To overcome the problem of very few available testing facilities and time consuming and costly procedure, cone cup testing has been developed since long. This test can be generated directly in the workshop, no machining of samples is necessary and it is very much related to the real SPF-process. The analysis of suitable temperature and strain rate is done by simple measurement of resulting cone height. This paper describes a unique and novel variant of the above mentioned baseline design. It provides on-line data of the actual status of the cone cup forming resulting from the applied, constant pressure. Strain rate variations as a result from texture or from the alloy-related behaviour is detectable. Thinning and ''hardening'' behaviour of different alloys up to maximum failure ...
2004-07-01
Radiation decontamination of dry food ingredients and processing aids
International Nuclear Information System (INIS)
Radiation decontamination of dry ingredients, herbs and enzyme preparations is a technically feasible, economically viable and safe physical process. The procedure is direct, simple, requires no additives and is highly efficient. Its dose requirement is moderate. Radiation doses of 3-10 kGy (0.3-1 mrad) have proved sufficient to reduce the viable counts to a satisfactory level. Ionising radiations do not cause any significant rise in temperature. The flavour, texture or other important technological or sensory properties of most ingredients are not influenced at radiation doses necessary for satisfactory decontamination, and radiation obviates the chemical residue problem. The microflora surviving radiation decontamination of dry ingredients are more susceptible to subsequent antimicrobial treatments. Recontamination can be prevented as the product can be irradiated in its final packaging. Irradiation could be carried out in commercial containers and would result ...
Energy Technology Data Exchange (ETDEWEB)
As a parameter for execution control of confirming a bearing stratum, which is most important in a bored precast pile method, discussions were made on the relativity between the product AT'' of a load current value A'' in an electric motor driving an auger used to drill pit holes with an excavation time T'' and a value N,'' a result of the standard penetration test of the ground. As a result, although the relativity of the N'' value has some variance in the ground of diluvial clay, they correspond well to each other in other kinds of ground. In pile bearing strata in particular, they correspond very well to each other regardless of soil textures of the ground, proving clearly that the AT'' value can be used as an effective parameter for confirmation of and penetration into the bearing stratum. Therefore, tips of all the piles used in one construction site can ...
1991-07-25
Producing Production Level Tooling in Prototype Timing
Energy Technology Data Exchange (ETDEWEB)
A new rapid solidification process machine will be able to produce eight-inch diameter by six-inch thick finished cavities at the rate of one per hour - a rate that will change the tooling industry dramatically. Global Metal Technologies, Inc. (GMTI) (Solon, OH) has signed an exclusive license with Idaho National Engineered and Environmental Laboratories (INEEL) (Idaho Falls, ID) for the development and commercialization of the rapid solidification process (RSP tooling). The first production machine is scheduled for delivery in July 2001. The RSP tooling process is a method of producing production level tooling in prototype timing. The process' inventor, Kevin McHugh, describes it as a rapid solidification method, which differentiates it from the standard spray forming methods. RSP itself is relatively straightforward. Molten metal is sprayed against the ceramic pattern, replicating the pattern's contours, surface texture and details. After ...
2001-03-01
Microstructure engineering from metallic powder blends for enhanced mechanical properties
International Nuclear Information System (INIS)
The present work focuses on the transformation of high-purity Ni powder blends of controlled volume fractions (40 and 60 %) of nanometre-sized (100 nm) and micrometre-sized (544 nm) particles into bulk samples as part of a strategy for producing ultrafine-grained materials usefully exhibiting both strength and ductility. The process involved cold isostatic pressing at 1.5 GPa and sintering. The resulting bulk samples had relative densities near 95 %, were texture-free, and exhibited two different grain size distributions with an average value of 600 #+-# 30 nm. The mechanical properties were investigated by compression and microhardness tests, both at room temperature, and compared to the behaviour of a sample processed from micrometre-sized powder only. Samples prepared from the blends exhibited high yield stresses of 440 and 550 MPa after compression, and they did sustain work hardening. Tests conducted before and after compression up to 50 % deformation showed ...
2010-07-01
Energy Technology Data Exchange (ETDEWEB)
The microstructure of the secondary deformation zone (SDZ) near the cutting surface in metal chips of Ti-6Al-4V formed during machining was investigated using focused ion beam (FIB) specimen preparation and transmission electron microscopy (TEM) imaging. Use of the FIB allowed precise extraction of the specimen across this region to reveal its inhomogeneous microstructure resulting from the non-uniform distribution of strain, strain rate, and temperature generated during the cutting process. Initial imaging from conventional TEM foil preparation revealed microstructures ranging from heavily textured to regions of fine grains. Using FIB preparation, the transverse microstructure could be interpreted as fine grains near the cutting surface which transitioned to coarse grains toward the free surface. At the cutting surface a 10 nm thick recrystallized layer was observed capping a 20 nm thick amorphous layer.
2011-01-01
International Nuclear Information System (INIS)
Spices and packaging materials were exposed to gamma irradiation at a dose of 10 KGy. Luncheon was prepared with irradiated or non-irradiated spices. Prepared luncheon was packaged in irradiated or non-irradiated packaging materials. Packaged luncheon was treated with 2 KGy. Treated and untreated packaged luncheon were kept in a refrigerator (1-4 Centigrade) for 12 months. Microbiological, nutritive and chemical characteristics of luncheon were evaluated after processing and during storage; whereas, sensory quality was evaluated only after irradiation. Gamma irradiation decreased the microorganisms counts of spices, packaging materials and packed luncheon and increased the shelf-life of packaged luncheon products. No major differences in moisture, protein, fat, ph value, total acidity, lipid peroxide and volatile basic nitrogen were observed due to irradiation. Sensory evaluation showed that all the combination treated luncheon were acceptable regarding sensory quality. However, the ...
Energy Technology Data Exchange (ETDEWEB)
The influence of high energy electron (23 MeV) irradiation on the electrical characteristics of p-channel polysilicon thin film transistors (PSTFTs) was studied. The channel 220 nm thick LPCVD (low pressure chemical vapor deposition) deposited polysilicon layer was phosphorus doped by ion implantation. A 45 nm thick, thermally grown, SiO{sub 2} layer served as gate dielectric. A self-alignment technology for boron doping of the source and drain regions was used. 200 nm thick polysilicon film was deposited as a gate electrode. The obtained p-channel PSTFTs were irradiated with different high energy electron doses. Leakage currents through the gate oxide and transfer characteristics of the transistors were measured. A software model describing the field enhancement and the non-uniform current distribution at textured polysilicon/oxide interface was developed. In order to assess the irradiation-stimulated changes of gate oxide parameters the gate oxide tunneling ...
2006-08-15
International Nuclear Information System (INIS)
The influence of high energy electron (23 MeV) irradiation on the electrical characteristics of p-channel polysilicon thin film transistors (PSTFTs) was studied. The channel 220 nm thick LPCVD (low pressure chemical vapor deposition) deposited polysilicon layer was phosphorus doped by ion implantation. A 45 nm thick, thermally grown, SiO_2 layer served as gate dielectric. A self-alignment technology for boron doping of the source and drain regions was used. 200 nm thick polysilicon film was deposited as a gate electrode. The obtained p-channel PSTFTs were irradiated with different high energy electron doses. Leakage currents through the gate oxide and transfer characteristics of the transistors were measured. A software model describing the field enhancement and the non-uniform current distribution at textured polysilicon/oxide interface was developed. In order to assess the irradiation-stimulated changes of gate oxide parameters the gate oxide tunneling conduction ...
2006-08-01
Energy Technology Data Exchange (ETDEWEB)
This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of structured water layers, developed in the ...
2008-01-15
British Library Electronic Table of Contents (United Kingdom)
The effects of anthropogenic (nitrogen fertilization) and natural [soil texture, pH content of humus, ammonium nitrogen (N-NH4), and the available forms of phosphorus (P), potassium (K), magnesium (Mg)] factors on nitrate nitrogen (NO3-N) content and distribution were shown. The dependencies between these factors and the content of NO3-N in soil were estimated in three soil layers: 0-30 cm; 31-60 cm; 61-90 cm. The research was carried out in 2004-2006, and the soil samples were taken from 411 places throughout eastern Poland in two seasons: spring and autumn. The concentration of NO3-N significantly depended on the year of investigation, season of the year, and depth of sampling. Distribution of NO3-N in the soil profile indicates possibility of NO3 leaching during winter and early spring....
2011-01-01
Deposition of Cu film on SiO_2 using a partially ionized beam
International Nuclear Information System (INIS)
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO_2 substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio I(111)/I(200) reaches its maximum value indicating a strong left-angle 111 right-angle texture, while the impurity concentration and resisitivity are minimum. The correlation between the structural, compositional and electrical properties are discussed in the ...
1990-01-01
Deposition of Cu film on SiO sub 2 using a partially ionized beam
Energy Technology Data Exchange (ETDEWEB)
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. The correlation between the structural, compositional and electrical properties are ...
1990-05-01
Deposition of Cu film on SiO sub 2 using a partially ionized beam
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. The correlation between the structural, compositional and electrical properties are ...
1990-05-01
Crud removal performance with ion exchange resins in BWR plants
Energy Technology Data Exchange (ETDEWEB)
It is needless to say that one of the most important roles of the condensate demineralizer in Japanese boiling water reactors (BWR) is to eliminate such impurities during accidental occurrence of sea water leakage from condensate cooling system. Ion exchange resins packed in condensate demineralizer have also been expected to decrease crud, or corrosion products (CP) in condensate water in order to finally reduce activated corrosion products (ACP) in the reactor coolant loop. It is perceived that crud removal ability of a condensate demineralizer has been improved year by year. And we call this phenomenon as `Aging Effect`. Typical property changes of aged cation exchange resin consisted of an increase of water retention capacity and a change of surface texture. Based on these findings, we formulated a new concept and developed new gel type ion exchange resins for the better crud removal. The results from column tests using actual condensate water for approximately ...
1996-01-01
Energy Technology Data Exchange (ETDEWEB)
To attain reproducible and stable contacts to compound semiconductor devices, it is necessary to achieve thermodynamically stable phases after the reaction of metals with the compound semiconductor. In this study, the final phases produced by the reactions between GaAs and thin metal films of Co, Rh, Ir, Ni, Pd, and Pt have been investigated. They are identified as MGa for M = Co, Rh, Ni, Pd, and Pt, monoarsenides of Co and Ni, diarsenides of Rh, Ir, Pd, and Pt, and Ir/sub 3/Ga/sub 5/. These phases, if deposited directly onto GaAs, will produce thermally stable contacts. In addition to the identification of these stable phases, analyses of the products of thin-film M/GaAs reactions by transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry reveal the distribution, grain size, and crystallographic texture of these end phases. Trends in these observations across the six metal/GaAs reactions studied are explained by considering ...
1987-09-01
ent-Rosane and abietane diterpenoids as cancer chemopreventive agents
British Library Electronic Table of Contents (United Kingdom)
Two ent-rosane- (cuzcol, 1 and 6-dehydroxycuzcol, 2) and a abietatriene- (salvadoriol, 3) type diterpenoids have been isolated from Maytenus cuzcoina and Crossopetalum uragoga, respectively, along with five known diterpene compounds (4-8). Their stereostructures have been elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, and computational data. The absolute configuration of cuzcol was determined by application of Riguera ester procedure. This is the first instance of isolation of ent-rosane diterpenoids from species of the Celastraceae. The isolated diterpenes were found to be potent anti-tumour-promoter agents, and carnosol (7) also showed a remarkable chemopreventive effect in an in vivo two-stage carcinogenesis model.
2011-01-01
Turbulent flow in a channel with transverse rib heat transfer augmentation
Turbulent flow in a 2D channel with repeated rectangular rib roughness was numerically simulated using a low Reynolds number form of the k-epsilon turbulence model. Friction factors and average Stanton numbers were calculated for various pitch to rib height ratios and bulk Reynolds numbers. Comparisons with experiment were generally adequate, with the predictions of friction superior to those for heat transfer. The effect of variable properties for channel flow was investigated, and the results showed a greater effect for friction than for heat transfer. Comparison with experiment yielded no clear conclusions. The turbulence model was also validated for a related problem, that of flow downstream of an abrupt pipe expansion.
1993-04-01
Tissue Heterogeneity in IMRT Dose Calculation for Lung Cancer
British Library Electronic Table of Contents (United Kingdom)
The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the gamma function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the l...
2011-01-01
The new computer program for three dimensional relativistic hydrodynamical model
An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.
2006-01-01
The Dynamical Interaction of AGN with their Galaxian Environments
Jet-driven shocks are responsible for an important fraction of the emission of the narrow-line regions (NLRs) in many classes of AGN. However, this cannot explain all observations. It is clear that the remaining sources are photoionised by the active nucleus. The 2-d hydrodynamic models from the RSAA group support an evolutionary scenario whereby the shock-excited NLRs are initially jet-driven but later, ionizing photons from the central engine replace shocks as the main excitation mechanism and shock induced star formation may also become important. In their photoionized phase, dusty and radiation-pressure dominated evolution produces a self-regulated NLR spectrum. This model aso explains the coronal emission lines and fast (3000 km s$^{-1}$) outflows seen in some Seyferts.
2003-01-01
British Library Electronic Table of Contents (United Kingdom)
A novel method of simultaneous realization of optical carrier-suppression and single-sideband modulation using fiber Fabry-Perot tunable filter is presented. In order to enhance transmission performance of radio over fiber links, we use a fiber Fabry-Perot tunable filter to filter out one sideband as well as suppress the optical carrier power. The results demonstrate 20.5dB and 14.2dB improvement in the signal noise ratios when 18GHz and 10GHz microwave signals carrying 5Mbit/s quadrature-phase-shift-keyed (QPSK) format data is transmitted over 35 km single mode fiber, respectively.
2006-01-01
Surface-loss power calculations for the LANSCE DTL
Energy Technology Data Exchange (ETDEWEB)
The surface losses in the drift-tube linac (DTL) tanks 3 and 4 of the LANSCE linear accelerator are calculated using 3-D electromagnetic modeling with the CST MicroWave Studio (MWS). The results are used to provide more realistic power estimates for the 201.25MHz RF upgrade design within the LANSCE-R project. We compared 3-D MWS results with those from traditional 2-D Superfish computations for DTL cells and their simplified models and found differences on the level of a few percent. The differences are traced to a 3-D effect consisting in a redistribution of the surface currents on the drift tubes (DT) produced by the DT stem. The dependence of MWS results on the mesh size used in computations is also discussed.
2008-01-01
Road Interpretation for Driver Assistance Based on an Early Cognitive Vision System
DEFF Research Database (Denmark)
In this work, we address the problem of road interpretation for driver assistance based on an early cognitive vision system. The structure of a road and the relevant traf?c are interpreted in terms of ego-motion estimation of the car, independently moving objects on the road, lane markers and large scale maps of the road. We make use of temporal and spatial disambiguation mechanisms to increase the reliability of visually extracted 2D and 3D information. This information is then used to interpret the layout of the road by using lane markers that are detected via Bayesian reasoning. We also estimate the ego-motion of the car which is used to create large scale maps of the road and also to detect independently moving objects. Sample results for the presented algorithms are shown on a stereo image sequence, that has been collected from a structured road.
2009-01-01
Quantum coherence in ion channels: resonances, transport and verification
Energy Technology Data Exchange (ETDEWEB)
Recently it was demonstrated that long-lived quantum coherence exists during excitation energy transport in photosynthesis. It is a valid question up to which length, time and mass scales quantum coherence may extend, how one may detect this coherence and what, if any, role it plays in the dynamics of the system. Here we suggest that the selectivity filter of ion channels may exhibit quantum coherence, which might be relevant for the process of ion selectivity and conduction. We show that quantum resonances could provide an alternative approach to ultrafast two-dimensional (2D) spectroscopy to probe these quantum coherences. We demonstrate that the emergence of resonances in the conduction of ion channels that are modulated periodically by time-dependent external electric fields can serve as signatures of quantum coherence in such a system. Assessments of experimental feasibility and specific paths towards the experimental realization of such ...
2010-08-15
Production of plutonium, yttrium and strontium tracers for using in environmental research
International Nuclear Information System (INIS)
Summary of cyclotron production methods of "2"3"7Pu (45,2 d), "8"8Y (106,65 d) and "8"5Sr (64,84 d) tracers via nuclear reactions with protons and alphas on "2"3"5U, "8"8Sr and "8"5Rb targets in wide energy range is given. Chemical methods of separation and purification of the tracers from the irradiated uranium, strontium and rubidium targets are described. The tracers were used for determination of Pu (239-240), Sr-90 and Am-241 in the samples (soil, plants, underground waters) from Semipalatinsk Test Site. Obtained results are discussed.
2001-12-12
Probing the origin of inertia behind spacetime deformation
To investigate the origin and nature of inertia, we introduce a new concept of hypothetical 2D, so-called, "master-space" (MS), subject to certain rules. The MS, embedded in the background 4D-spacetime, is an indispensable individual companion to the particle of interest, without relation to every other particle. We argue that a deformation/(distortion of local internal properties) of MS is the origin of inertia. With this perspective in sight, we construct the alternative relativistic theory of inertia (RTI), which allows to compute the relativistic inertial force acting on an arbitrary point-like observer due to its "absolute acceleration". We go beyond the hypothesis of locality with an emphasis on distortion of MS, which allows to improve essentially the standard metric and other relevant geometrical structures related to the noninertial reference frame of an arbitrary accelerated observer. We compute the inertial force exerted on the ...
2011-01-01
Premnalatifolin A, a novel dimeric diterpene from Premna latifolia Roxb
British Library Electronic Table of Contents (United Kingdom)
Premnalatifolin A (1), a unique icetexane diterpene dimer was isolated from the stem-bark of Indian medicinal plant, Premna latifolia. Its structure and relative stereochemistry were elucidated on the basis of detailed spectroscopic analysis, including HRESIMS and 2D NMR (COSY, HSQC, HMBC, and NOESY) spectra. The compound has dimeric carbon skeleton composed of two icetexane skeletal diterpenes linked via ether bond. Further, premnalatifolin A (1) was also evaluated for its cytotoxicity against cancer cell lines (HT-29, A-431, MCF-7, Hep-G2, PC-3, A-549, B-16 F10, and ACHN), which displayed potent activity against HT-29 and MCF-7 cell lines with the IC50 values of 12.15 and 1.11mg/mL, respectively.
2011-01-01
Optimization of band gap of photonic crystals fabricated by holographic lithography
Generally the photonic band gap (PBG) is a multi-variable function of several parameters related to the shape and size of the dielectric columns of photonic crystals (PhCs), and a time-consuming step-by-step scanning process for each parameter has to be used to find their best combination yielding maximum PBG. In this letter, the widely used Nelder-Mead simplex algorithm is introduced to optimize these parameters simultaneously to find a larger PBG for a new kind of two-dimensional (2D) hexagonal GaAs-Air PhC. This structure can be conveniently produced by the single-exposure holographic lithography, and the specific holographic design is also systematically investigated. This study reveals that the band gaps of PhCs made by holographic lithography may be widened by introducing irregularity of the columns and lowering the symmetry of the structure.
2008-01-01
British Library Electronic Table of Contents (United Kingdom)
For optimal performances, proton exchange membrane fuel cells require fine water and thermal management. Accurate modelling of the physical phenomena occurring in the fuel cell is a key issue to improve fuel cell technology. Here, an analytic steady state diphasic 2D model of heat and mass transfer is presented. Through this model, the aim of this work is to study the influence of local events on the global performances of a fuel cell. A part of the complete model is a microscopic representation of the coupling between water transport and charge transfers in the electrodes. The thickness of the liquid layer around the reactive agglomerates is deduced from the saturation. The evolution of the quantity of water within the catalyst layer is monitored and its influence on the global performanc...
2010-01-01
Numerical Simulations of the Thermal Instability Collapse in Radiation Pressure Dominated Disks
We show that accretion disks, both in the subcritical and supercritical accretion rate regime, may exhibit significant amplitude luminosity oscillations. The luminosity time behavior has been obtained by performing a set of time-dependent 2D SPH simulations of accretion disks with different values of ? and accretion rate. An explanation of this luminosity behavior is proposed in terms of limit-cycle instability: the disk oscillates between a radiation pressure dominated configuration (with a high luminosity value) and a gas pressure dominated one (with a low luminosity value). The origin of this instability is the difference between the heat produced by viscosity and the energy emitted as radiation from the disk surface (the well-known thermal instability mechanism). We support this hypothesis showing that the limit-cycle behavior produces a sequence of collapsing and refilling states of the innermost disk region.
2005-10-01
Normalized noise power spectrum of full field digital mammography detector system
International Nuclear Information System (INIS)
Full text: A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through de trending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (author)
Normalized Noise Power Spectrum of Full Field Digital Mammography System
International Nuclear Information System (INIS)
A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through detrending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality.
2010-01-05
An algorithm for creating synthetic telescope images of Smoothed Particle Hydrodynamics (SPH) density fields is presented, which utilises the adaptive nature of the SPH formalism in full. The imaging process uses Monte Carlo Radiative Transfer (MCRT) methods to model the scattering and absorption of photon packets in the density field, which then exit the system and are captured on a pixelated image plane, creating a 2D image (or a 3D datacube, if the photons are also binned by their wavelength). The algorithm is implemented on the density field directly: no gridding of the field is required, allowing the density field to be described to an identical level of accuracy as the simulations that generated it. Some applications of the method to star and planet formation simulations are presented to illustrate the advantages of this new technique, and suggestions as to how this framework could support a Radiative Equilibrium algorithm are also given ...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
The percolated or active triple phase boundary (TPB) length per unit volume of Ni-YSZ anode hollow fibers (HFs) containing 60wt.% initial NiO and a spatially varying microstructure were measured using a focused ion beam (FIB)-SEM technique. The measured values of contiguous TPB density were interfaced with a 2-D distributed finite element model of a hollow fiber solid oxide fuel cell. The model was applied to simultaneously solve the ionic and electronic charge balances in the electrodes, which were modelled as overlying continuum materials with effective electronic and ionic conductivities. The model was used to predict the effects of anode microstructure on the distribution of current density, and anode activation polarization. Active TPB lengths of 2.63-8.63 m^-^2 were measured for the ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The forward modelling and the prestack reverse time migration of seismic P-SV wave field was carried out in 2-D models of isotropic and anisotropic media which allow separation of P-SV and SH motion. The P-SV wave field can be described by a system of hyperbolic, first order differential equations in terms of particle velocity and stress. The system of five equations and five unknowns, namely horizontal (U) and vertical (V) velocity components, and three components of stress (T{sub xx}, T-z{sub z} and T{sub xz}) was solved numerically using second order space and forth order time finite differences operators. In order to attenuate numerical dispersion, a staggered grid was used. (author). 48 refs., 5 figs
1993-12-31
Luminosity oscillations in accretion discs around compact objects
We show that accretion disks, both in the subcritical and supercritical accretion rate regime, may exhibit significant amplitude luminosity oscillations. The luminosity time behavior has been obtained by performing a set of time-dependent 2D SPH simulations of accretion disks with different values of ? and accretion rate. An explanation of this luminosity behavior is proposed in terms of limit-cycle thermal instability: the disk oscillates between a radiation pressure dominated configuration (with a high luminosity value) and a gas pressure dominated one (with a low luminosity value). We support this hypothesis showing that the limit-cycle behavior produces a sequence of collapsing and refilling states of the innermost disk region.
2005-08-01
International Nuclear Information System (INIS)
The values of spins, parities, and spectroscopic factors for neutron transfer have been determined for many low-lying states in "9"7Mo and "1"0"1Mo by a study of the (t, d) and (d, p) reactions on the neighbouring even-mass isotopes. Eighteen new values of J"#pi# have been obtained for these nuclei. Values of the fullness and emptiness parameters V"2 and U"2 have been suggested for the 3s_1_/_2 and 2d_5_/_s orbitals in "1"0"0Mo. (Nuclear structure "9"7Mo, "1"0"1Mo, measured J, #pi#, and spectroscopic factors for states up to #approx#2.0 MeV using (d, p) and (t, d) reactions.) (author).
1990-11-01
Kriging analysis of soil properties
British Library Electronic Table of Contents (United Kingdom)
Background, aim, and scope Soil as a landscape body contains wide ranges of physical, chemical, morphological, and mineralogical properties, both laterally and vertically. Soils with similar properties and environments are expected to behave similarly. A statement on land use potential will depend in part on the precision and accuracy of the statements that can be made about the soils. This information has some practical applications in optimizing land management and productivity improvement. The spatial patterns and dependence of some selected physicochemical properties of brackish marsh and surrounding soils were investigated using a 2-D kriging analysis in conjunction with a geostatistical (GS+, Michigan) model. Materials and methods Composite (four subsamples) surface samples (0?20?cm)...
2008-01-01
British Library Electronic Table of Contents (United Kingdom)
Purpose Video-assisted thoracic surgery (VATS) has recently been adopted for complicated anatomical lung resections. During these thoracoscopic procedures, surgeons view the operative field on a two-dimensional (2-D) video monitor and cannot palpate the organ directly, thus frequently encountering anatomical difficulties. This study aimed to estimate the usefulness of preoperative three-dimensional (3-D) imaging of thoracic organs. Methods We compared the preoperative 64-row three-dimensional multidetector computed tomography (3DMDCT) findings of lung cancer-affected thoracic organs to the operative findings. Results In comparison to the operative findings, the branches of pulmonary arteries, veins, and bronchi were well defined in the 3D-MDCT images of 27 patients. Conclusion 3D-MDCT imag...
2009-01-01
Impedance Spectra of Mixed Conductors: a 2D Study of Ceria
In this paper we develop an analytical framework for the study of electrochemical impedance of mixed ionic and electronic conductors (MIEC). The framework is based on first-principles and it features the coupling of electrochemical reactions, surface transport and bulk transport processes. We utilize this work to analyze two dimensional systems relevant for fuel cell science via finite element method (FEM). Alternate current Impedance Spectroscopy (IS) of a ceria symmetric cell is simulated near equilibrium condition (zero bias) for a wide array of working conditions including variations of temperature and $H_2$ partial pressure on a two dimensional fuel cell sample with patterned metal electrodes. The model shows agreement of IS curves with the experimental literature with the relative error on the impedance being consistently below 2%. Important two-dimensional effects such the effects of thickness decrease and the influence of variable electronic and ionic diffusivities on the ...
2009-01-01
Gauge effects on phase transitions in superconductors
Classic and recent results for gauge effects on the properties of the normal-to-superconducting phase transition in bulk and thin film superconductors are reviewed. Similar problems in the description of other natural systems (liquid crystals, quantum field theory, early universe) are also discussed. The relatively strong gauge effects on the fluctuations of the ordering field at low spatial dimensionality D and, in particular, in thin (quasi-2D) films are considered in details. A special attention is paid to the fluctuations of the gauge field. It is shown that the mechanism in which these gauge fluctuations affect on the order of the phase transition and other phase transition properties varies with the variation of the spatial dimensionality D. The problem for the experimental confirmation of the theoretical predictions about the order of the phase transitions in gauge systems is discussed.
2006-01-01
Fundamental concepts of digital image processing
The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the patient is still under ...
1983-03-01
Flutter control effect and mechanism of central-slotting for long-span bridges
British Library Electronic Table of Contents (United Kingdom)
The flutter control effect and mechanism of central-slotting, which have gradually been adopted in the design and construction of long-span bridges as an effective flutter controlling measure, were investigated with theoretical analysis and wind tunnel test. Five basic girder cross-sections representing five typical aerodynamic configurations were selected and central-slotted with two different slot widths. Then, a series of sectional model tests and theoretical analyses based on the two-dimensional three-degrees-of-freedom coupling flutter analysis method (2 dimension-3 degrees of freedom method, 2d-3DOF method) were carried out to investigate the aerody namic performance, flutter mechanism and flutter modality of the five basic sections and their corresponding central-slotted sections. T...
2007-01-01
Flow mapping for assessment of native and repaired valves
International Nuclear Information System (INIS)
Color Doppler flow mapping (CDFM) was performed in 47 normal women ages 18-41 mean (m) 28 to determine the normal flow phenomena across each of the 4 heart valves. The group included: 15 elite marathon runners average run (ave.) 70 miles/week, heart rate (HR) 35-54 (m 45); 14 joggers ave. 40 mi/wkm HR 40-69 (m 53); and 17 controls 0 mi/wk, HR 49-93 (m 77). 2-D echo and CDFM defined the motion of each valve, including the presence of mitral valve prolapse (MVP), the ventricular inflow and outflow patterns and the presence of regurgitation.
British Library Electronic Table of Contents (United Kingdom)
Extraction of 25 L fermentation broth of the newly isolated Streptomyces sp. strain TN58 and various separation and purification steps led to the isolation of five bioactive metabolites, namely brevianamide F (C1), reported from a streptomycete for the first time, N?-acetyltryptamine (C2), thiazolidomycin (C3), and two rhamnopyranosides (C4 and C5). These two rhamnopyranosides were produced directly, without precursor addition. The chemical structure of these five active compounds was established on the basis of 1H, 13C/APT and 2D NMR spectra, ESI and EI-MS data, and by comparison with data from the literature. According to the biological studies, we show in this work that the compounds C1, C2, C4 and C5 possess antimicrobial activities.
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
The ground state of a three-dimensional (3D) rotating trapped superfluid Fermi gas in the BCS-BEC crossover is mapped to finite N v -body vortex states by a simple ansatz. The total vortex energy is measured from the ground-state energy of the system in the absence of the vortices. The vortex state is stable since the vortex potential and rotation energies are attractive while the vortex kinetic energy and interaction between vortices are repulsive. By combining the analytical and numerical works for the minimal vortex energy, the 2D configurations of N v vortices are studied by taking into account of the finite size effects both on xy-plane and on z-direction. The calculated vortex numbers as a function of the interaction strength are appropriate to the renew experimental results by Zwier...
2011-01-01
Extraction methods of phase information for X-ray diffraction enhanced imaging
Energy Technology Data Exchange (ETDEWEB)
X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of refraction-angle values than existing methods.
2007-08-21
Extraction methods of phase information for X-ray diffraction enhanced imaging
International Nuclear Information System (INIS)
X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of refraction-angle values than existing methods.
2007-08-21
British Library Electronic Table of Contents (United Kingdom)
The endophytic fungus Trichothecium roseum LZ93 from Maytenus hookeri was found to antagonize other pathogenic fungi in vitro. To identify which compound contributed substantially to the antagonism, we fermented the strain and purified its fermentation products. Eleven compounds were obtained, including two trichothecenes, five rosenonolactones, two cardiotonic cyclodepsipeptides, and two sterols. Compound 11?-hydroxyrosenonolactone (1) was assigned according to 1D and 2D-NMR data for the first time. At the same time, the 1H and 13C-NMR assignments for 6?-hydroxyrosenonolactone (2) were revised. Of all of them, only trichothecin (6) showed strong antifungal activity. Based on our observations of the antagonistic activity and the other experimental results, we suggest that the antifungal co...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
Polyacrylonitrile (PAN)-based carbon fabric (CF) was modified with strong HNO3 oxidation and then introduced into polyimide (PI) composites. The friction and wear properties of the carbon fabric reinforced polyimide composites (CFRP), sliding against GCr15 stainless steel rings, were investigated on an M-2000 model ring-on-block test rig under dry sliding. Experimental results revealed that the carbon fiber surface treatment largely reduced the friction and wear of the CFRP. Compared with the untreated ones, the surface-modified CF can enhance the tribological properties of CFRP efficiently due to the improved adhesion between the CF and the PI matrix. Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) study of the carbon fiber surface showed that the fiber surfa...
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
To improve the friction and wear behavior of carbon fabric reinforced polymer composites (CFRP), nano-SiO2 was deposited on the fabric surface. The friction and wear behavior of the resulting composites were investigated on a model ring-on-block test rig. Experimental results revealed that fiber surface treatment contributed to largely improve the tribological properties of the CFRP composites. Scanning electron microscope (SEM) investigation showed that the worn surface of the surface modified CFRP composite was smoother under given load and sliding rate. Field emission scanning electron microscopy (FESEM), FTIR and X-ray photoelectron spectroscopy (XPS) studies of the carbon fiber surface showed that nanostructured Sio2 thin film can be obtained by SiO2 sols deposition, which improved th...
2009-01-01
Development of in-vessel reflood instrumentation at ORNL
International Nuclear Information System (INIS)
A program under the sponsorship of the United States Nuclear Regulatory Commission was intiated at the Oak Ridge National Laboratory (ORNL) in late 1977. The program, Advanced Instrumentation for Reflood Studies (AIRS), is charged with developing instrumentation for measurement of in-vessel fluid phenomena in pressurized water reactor reflood facilities. The goal of the ORNL program is to develop techniques and systems for measuring fluid flow in-core, deentrainment in the upper plenum and liquid fallback from the upper plenum into the core. A large portion of the development at ORNL is devoted to the impedance probes for measurement of two-phase flow velocities and void fractions. Film probe development at ORNL is limited to adapting the present techniques to the environment of a reflood facility. As the development progresses on all the measurement techniques, ORNL will fabricate and supply instrument systems to the reflood facilities included in the ...
2004-09-06
Development of a 1D neutron transport code employing the method of characteristics
International Nuclear Information System (INIS)
To investigate the 2D/1D fusion core analysis method, a 1D neutron transport problem solver, PEACH-ID, is developed. It is a code of method of characteristics (MOC), both the usual fiat-source step characteristics (SC) scheme and linear source (LS) approximation scheme are adopted for tracking calculation along the neutron flying trajectory. Exponential function interpolation table and fission source extrapolation are adopted as two major methods to accelerate the computational process. Numerical results demonstrate that PEACH-1D is accurate and efficient, and the proposed LS scheme is able to handle quite larger mesh division and deserves much more application in the MOC codes. (authors)
2009-09-01
International Nuclear Information System (INIS)
The objective of this project is to develop multi-dimensional computational models in order to improve the operation of uranium electrorefiners currently used in pyroprocessing technology. These 2-D (US) and 3-D (ROK) mathematical models are based on the fundamental physical and chemical properties of the electrorefiner processes. The validated models by compiled and evaluated experimental data could provide better information for developing advanced electrorefiners for uranium recovery. The research results in this period are as follows: - Successfully assessed a common computational platform for the modeling work and identify spatial characterization requirements. - Successfully developed a 3-D electro-fluid dynamic electrorefiner model. - Successfully validated and benchmarked the two multi-dimensional models with compiled experimental data sets
2008-08-01
Designed defects in 2D antidot lattices for quantum information processing
DEFF Research Database (Denmark)
We propose a new physical implementation of spin qubits for quantum information processing, namely defect states in antidot lattices defined in the two-dimensional electron gas (2DEG) at a semiconductor heterostructure. Calculations of the band structure of a periodic antidot lattice are presented. A point defect is created by removing a single antidot, and calculations show that localized states form within the defect, with an energy structure which is robust against thermal dephasing. The exchange coupling between two electrons residing in two tunnel-coupled defect states is calculated numerically. We find results reminiscent of double quantum dot structures, indicating that the suggested structure is a feasible physical implementation of spin qubits.
2008-01-01
Energy Technology Data Exchange (ETDEWEB)
The paper describes the chemical constituents isolated from aerial parts of the plant Galianthe brasiliensis. From a methanol extract, the iridoid glycosides asperuloside, deacetylasperuloside, mixture of Z- and E-6-O-p-coumaroylscandoside methyl ester, the triterpene ursolic acid and the steroids stigmasterol, campesterol, b-sitosterol and 3-O-b-glucopyranosyl sitosterol were isolated. The structures of the natural products were identified on the basis of spectral data, including 2D NMR experiments. The antiproliferative properties of the crude methanolic extract were investigated against a series of nine human cancer cell lines. (author)
2006-05-15
Characterization of surface defects after flanging of metallic sheets
British Library Electronic Table of Contents (United Kingdom)
This paper deals with surface defects of automobile outer panels, which alter significantly the vehicle quality. Such defects occur during springback, after forming or flanging steps, and are characterized by concave depression of small amplitude over the convex shape of the part. The aim of this work is to reproduce at the laboratory scale a surface defect that occurs after flanging on a geometry similar to a door upper corner. A dedicated device has been designed in order to generate small size surface defects during flanging of metallic thin sheets. The outer surface of the sample was digitalized and the spatial geometry of the defect was evaluated from curvature change along 2D profiles. This study shows that the flanging height does not influence significantly the surface defect geome...
2011-01-01
Characterization and effect of using cotton methyl ester as fuel in a LHR diesel engine
International Nuclear Information System (INIS)
In the present study, surfaces of cylinder head, piston, exhaust and inlet valve of a four-stroke, direct injection, single cylinder diesel engine were coated with molybdenum (Mo) by plasma spray method. Thus, thermal barrier characteristic was brought to these parts. Variances in performance and emission values of cotton methyl ester and 2D fuel mixtures were studied in the ceramic coated and uncoated engines under the same running conditions. Performance (6.0% for specific fuel consumption) and emission values (up to 18.0% for CO, 8.0% for smoke density) of the test fuel were improved in the coated engine compared with the uncoated engine. NO_x increase (4.5%) with the increased temperatures expected in the coated engine.
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Characteristics of batch rotor-stator mixer performance are elucidated by shaft torque and angle resolved 2D PIV measurements obtained in a full-scale, custom build, bottom-mounted, rotor-stator mixer unit operating in the turbulent regime with water as working fluid. Measurements have been acquired at various rotor speeds corresponding to impeller based Reynolds numbers between 2.0--105 and 8.5--105. The use of a transparent Plexiglas stator facilitated PIV measurements inside and outside the stator as well as into the stator slots themselves. The governing mechanisms controlling the complex flow structures, flow rates, power dissipation, velocity fields, strain rate fields and turbulence intensity fields are explained, highlighting the influence on rotor-stator mixer performance...
2011-01-01
Brown diamonds from an eclogite xenolith from Udachnaya kimberlite, Yakutia, Russia
British Library Electronic Table of Contents (United Kingdom)
Abstract: We have performed petrographic and spectroscopic studies of brown diamonds from an eclogite xenolith from the Udachnaya pipe (Yakutia, Russia). Brown diamonds are randomly intermixed with colorless ones in the rock and often located at the grain boundaries of clinopyroxene and garnet. Brown diamonds can be characterized by a set of defects (H4, N2D and a line at 490.7nm) which are absent in colorless diamonds. This set of defects is typical for plastically deformed diamonds and indicates that diamonds were likely annealed for a relatively short period after deformation had occurred. Excitation of brown colored zones with a 632.8nm He-Ne laser produced the typical diamond band plus two additional bands at 1730cm^-^1 and 3350cm^-^1. These spectral features are not genuine Raman ban...
2011-01-01
Automated three-dimensional X-ray analysis using a dual-beam FIB
International Nuclear Information System (INIS)
We present a fully automated method for three-dimensional (3D) elemental analysis demonstrated using a ceramic sample of chemistry (Ca)MgTiO_x. The specimen is serially sectioned by a focused ion beam (FIB) microscope, and energy-dispersive X-ray spectrometry (EDXS) is used for elemental analysis of each cross-section created. A 3D elemental model is reconstructed from the stack of two-dimensional (2D) data. This work concentrates on issues arising from process automation, the large sample volume of approximately 17x17x10 #mu#m"3, and the insulating nature of the specimen. A new routine for post-acquisition data correction of different drift effects is demonstrated. Furthermore, it is shown that EDXS data may be erroneous for specimens containing voids, and that back-scattered electron images have to be used to correct for these errors.
2007-08-01
Antibacterial iridoid glucosides from Eremostachys laciniata
British Library Electronic Table of Contents (United Kingdom)
Eremostachys laciniata (L) Bunge (family: Lamiaceae alt. Labiatae; subfamily: Lamioideae) is one of the 15 endemic Iranian herbs of the genus Eremostachys. A decoction of the roots and flowers of E. laciniata has traditionally been taken orally for the treatment of allergies, headache and liver diseases. Three antibacterial iridoid glucosides, phloyoside I (1), phlomiol (2) and pulchelloside I (3) have been isolated from the rhizomes of this plant. The structures of these compounds were elucidated unequivocally by a series of 1D and 2D NMR analyses. The antibacterial activity and brine shrimp toxicity of these compounds were assessed using the resazurin microtitre assay and the brine shrimp lethality assay, respectively. All three iridoid glycosides 1-3 exhibited from low to moderate level...
2009-01-01
Analysis of mixing in a Twin Cam mixer using smoothed particle hydrodynamics
British Library Electronic Table of Contents (United Kingdom)
Smoothed Particle Hydrodynamics (SPH) is a Lagrangian, particle-based method that is well suited to industrial mixing simulations. Mass transport is simply the motion of the particles, and its grid-free nature means that it can easily accommodate complicated geometries involving moving parts and sharp corners. This article describes 2D SPH simulations of a Twin Cam mixer and compares the results against experimental data and results from two published finite element method (FEM) simulations. To analyze the mixing processes in the Twin Cam mixer, we present a method for calculating the Finite-Time Lyapunov Exponent (FTLE) using SPH particle data. The FTLEs can be used to locate the unstable and stable manifolds in the flow and indicate where mixing is either promoted or inhibited in the flo...
2008-01-01
Algebraic structures and eigenstates for integrable collective field theories
International Nuclear Information System (INIS)
Conditions for the construction of polynomial eigen-operators for the Hamiltonian of collective string field theories are explored. Such eigen-operators arise for only one monomial potential v(x)=#mu#x"2 in the collective field theory. They form a w_#infinity#-algebra isomorphic to the algebra of vertex operators in 2d gravity. Polynomial potentials of orders only strictly larger or smaller than 2 have no non-zero-energy polynomial eigen-operators. This analysis leads us to consider a particular potential #nu#(x)=#mu#x"2+g/x"2. A Lie algebra of polynomial eigen-operators is then constructed for this potential. It is a symmetric 2-index Lie algebra, also represented as a subalgebra of U(sl(2)). (orig.).
1992-02-01
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
A new method of imaging particle tracks in solid state nuclear track detectors
British Library Electronic Table of Contents (United Kingdom)
Summary Solid state nuclear track detectors are used to determine the concentration of a particles in the environment. The standard method for assessing exposed detectors involves 2D image analysis. However 3D imaging has the potential to provide additional information relating to angle as well as to differentiate clustered hit sequences and possibly energy of a particles but this could be time consuming. Here we describe a new method for rapid high-resolution 3D imaging of solid state nuclear track detectors. A `LEXT' OLS3100 confocal laser scanning microscope (Olympus Corporation, Tokyo, Japan) was used in confocal mode to successfully obtain 3D image data on four CR-39 plastic detectors. Three-dimensional visualization and image analysis enabled characterization of track features. This ...
2010-01-01
International Nuclear Information System (INIS)
Thienyl oxazoles and thienyl isoxazoles, are composite molecules having two subsystems thiophene and oxazole molecules connected together by a single bond that they have 13 isomers. They are potential candidates for many kinds of applications such as OLED and nonlinear optical materials. Initially equilibrium geometries of title compounds have been obtained without any restriction using density functional theory with 6-311++g(2d,p) basis set. We obtained structural parameters, dipole moment and electronic energy. At the second stage, we have calculated some electronic and nonlinear optical properties such as HOMO and LUMO energies, polarizability, anisotropic polarizability and hyper polarizability using same level of theory.
2008-08-25
3-D depth migration via McClellan transformations
Energy Technology Data Exchange (ETDEWEB)
Three-dimensional seismic wavefields may be extrapolated in depth, one frequency at a time, by two-dimensional convolution with a circularly symmetric, frequency- and velocity-dependent filter. This depth extrapolation, performed for each frequency independently, lies at the heart of 3-D finite-difference depth migration. The computational efficiency of 3-D depth migration depends directly on the efficiency of this depth extrapolation. McClellan transformations provide an efficient method for both designing and implementing two-dimensional digital filters that have a particular form of symmetry, such as the circularly symmetric depth extrapolation filters used in 3-D depth migration. Given the coefficients of one-dimensional, frequency- and velocity-dependent filters used to accomplish 2-D depth migration, McClellan transformations lead to a simple and efficient algorithm for 3-D depth migration. 21 refs., 12 figs.
1990-01-01
2D Thermal Hydraulic Analysis and Benchmark in Support of HFIR LEU Conversion using COMSOL
Energy Technology Data Exchange (ETDEWEB)
The research documented herein was funded by a research contract between the Research Reactors Division (RRD) of Oak Ridge National Laboratory (ORNL) and the University of Tennessee, Knoxville (UTK) Mechanical, Aerospace and Biomedical Engineering Department (MABE). The research was governed by a statement of work (SOW) which clearly defines nine specific tasks. This report is outlined to follow and document the results of each of these nine specific tasks. The primary goal of this phase of the research is to demonstrate, through verification and validation methods, that COMSOL is a viable simulation tool for thermal-hydraulic modeling of the High Flux Isotope Reactor (HFIR) core. A secondary goal of this two-dimensional phase of the research is to establish methodology and data base libraries that are also needed in the full three-dimensional COMSOL simulation to follow. COMSOL version 3.5a was used for all of the models presented throughout this report.
2010-09-01
Energy Technology Data Exchange (ETDEWEB)
In this article is reviewed the role of Computed Tomography (CT) in thoracic complications following ortho topic liver transplantation (OLT). In a post-OLT population of 567 patients transplanted in the Italian institutions, 100 patients (17.6%) were examined with chest CT. It was reviewed data relative to the total number of examinations, clinical and/or radiographic indications, the CT technique-i.e., conventional (with (out) intravenous, i.v., contrast material) or high-resolution (HRCT). It also reviewed the radiologic patterns and their correlation with the other clinical, bronchoscopic and/or laboratory results. Of 152 chest CT examinations, 45 (29.6%) were performed because of clinical indications, 31 (20.4%) because of a radiographic abnormality, 64 (42.1%) because of clinical and radiographic abnormality, 64 (42.1%) because of clinical and radiographic indications, while in 12 cases (7.9%) the ...
2000-12-01
Variation of phytoplankton biomass and primary production in Daya Bay during spring and summer
International Nuclear Information System (INIS)
Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m"-"3 in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mgC m"-"2 d"-"1 in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate ...
2004-12-01
Energy Technology Data Exchange (ETDEWEB)
The organization of organic semiconductor molecules in the active layer of organic electronic devices has important consequences to overall device performance. This is due to the fact that molecular organization directly affects charge carrier mobility of the material. Organic field-effect transistor (OFET) performance is driven by high charge carrier mobility while bulk heterojunction (BHJ) solar cells require balanced hole and electron transport. By investigating the properties and device performance of three structural variations of the fluorenyl hexa-peri-hexabenzocoronene (FHBC) material, the importance of molecular organization to device performance was highlighted. It is clear from {sup 1}H NMR and 2D wide-angle X-ray scattering (2D WAXS) experiments that the sterically demanding 9,9-dioctylfluorene groups are preventing {pi}-{pi} intermolecular contact in the hexakis-substituted FHBC 4. For ...
2010-03-24
International Nuclear Information System (INIS)
The implementation of wind energy conversion systems in the built environment renewed the interest and the research on Vertical Axis Wind Turbines (VAWT), which in this application present several advantages over Horizontal Axis Wind Turbines (HAWT). The VAWT has an inherent unsteady aerodynamic behavior due to the variation of angle of attack with the angle of rotation, perceived velocity and consequentially Reynolds number. The phenomenon of dynamic stall is then an intrinsic effect of the operation of a Vertical Axis Wind Turbine at low tip speed ratios, having a significant impact in both loads and power. The complexity of the unsteady aerodynamics of the VAWT makes it extremely attractive to be analyzed using Computational Fluid Dynamics (CFD) models, where an approximation of the continuity and momentum equations of the Navier-Stokes equations set is solved. The complexity of the problem and the need for new design approaches for VAWT for the built environment has driven the ...
2007-07-01
Self-interstitial diffusion and clustering with impurities in crystalline silicon
International Nuclear Information System (INIS)
In this work the diffusion of ion-beam-injected self-interstitials (Is) and their interaction with impurities in crystalline Si are presented. In particular, the I penetration into a molecular beam epitaxy grown Si structure was studied by means of diffusion effects induced on B spikes, analyzed by a developed simulation code. Trapping effects at sample-surface and bulk are evidenced and modeled. The B marker approach was extended to the two-dimensional (2D) I-diffusion occurring as a consequence of ion implantation through a sub-micron dimension patterned oxide mask. I-source size effects on the I penetration have been found and modeled, quantitatively describing the 2D I-diffusion. The I-substitutional carbon interactions have been also studied, showing the C ability to effectively retain Is. The I-trapping mechanism was quantitatively studied by the simulation code, showing that one I is able to ...
2004-02-01
Preliminary Simulations of CO2 Transport in the Dolostone Formations in the Ordos Basin, China
Energy Technology Data Exchange (ETDEWEB)
This report summarizes preliminary 2-D reactive-transport simulations on the injection, storage and transport of supercritical CO{sub 2} in dolostone formations in the Ordos Basin in China. The purpose of the simulations was to evaluate the role that basin heterogeneity, permeability, CO{sub 2} flux, and geochemical reactions between the carbonate geology and the CO{sub 2} equilibrated brines have on the evolution of porosity and permeability in the storage reservoir. The 2-D simulation of CO{sub 2} injection at 10{sup 3} ton/year corresponds to CO{sub 2} injection at a rate of 3 x 10{sup 5} ton/year in a 3-D, low permeable rock. An average permeability of 10 md was used in the simulation and reflects the upper range of permeability reported for the Ordos Basin Majiagou Group. Transport and distribution of CO{sub 2} between in the gas, aqueous, and solid phases were followed during a 10-year injection ...
2009-04-30
Optimizing an analytical dose calculation algorithm for fast 2D calculations
International Nuclear Information System (INIS)
Previously, an analytical dose calculation algorithm for MLC-based radiotherapy was developed and commissioned, which includes a detailed model of various MLC effects as a unique feature [1]. The algorithm was originally developed as an independent verification of the treatment planning system's dose calculation and it explicitly modeled spatial and depth dependent MLC effects such as interleaf transmission, the tongue-and-groove effect, rounded leaf ends, MLC scatter, beam hardening, and gradual MLC transmission fall-off with increasing off-axis distance. Originally the algorithm was implemented in Mathematica trademark (Wolfram). To speed up the calculation time and to be able to calculate high resolution 2D dose distributions within a reasonable time frame (<2 s) the algorithm needs to be optimized and to be embedded in a user friendly environment. To achieve this goal, the dose calculation model is implemented in Visual Basic 6.0, which ...
Isolation of imidacloprid degrading bacteria from industrial sites
International Nuclear Information System (INIS)
Immidacloprid is a cyclodiene organochlorine used as an insecticide all over the world and possessing a serous environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria, two soil samples were collected from industrial contaminated sites of Kala Shah Kahu district sheikupura, having ten year history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Eight bacterial strains, S/sub 1-a/ S/2-2-b/ S/2-c/ S/2-d/ S/2-e/ S/sub 2-f/ and S/sub 2-g/ and S/sub e-a/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically, physiologically and biochemically. Gram staining was done and Gram negative strain were confirmed on MacConkey agar and Eosin Methylene Blue. Bacterial strains were also checked for ...
Isobaric analog resonances in "8"9Y
International Nuclear Information System (INIS)
Three resonances at the proton energies 7.0, 7.08, and 7.53 MeV on the target "8"8Sr were chosen to investigate the possibility of determining the amplitudes of the weak coupling experimentally. The corresponding "8"9Sr levels under investigation were 1.93 MeV ("5/_2"+), 2.00 MeV ("3/_2"+), and 2.46 MeV ("3/_2"+). Angular distributions were measured on resonance at 7.0, 7.08, and 7.53 MeV from proton inelastic scattering to the 1.84 MeV (2"+) state of "8"8Sr for differential cross section, analyzing power, spin-flip probability, and spin-flip asymmetry. A polarized beam of protons was used to obtain the analyzing power. The spin-flip probability was obtained from the coincidence of the prompt gamma rays from the (p,p'#gamma#) reaction with the scattered protons. With the polarized beam, the gamma coincidence technique was further used to obtain a spin-flip asymmetry measurement. From these measurements, the polarization was calculated, and the first clear experimental examples of the ...
Energy Technology Data Exchange (ETDEWEB)
A new three-dimensional (3D) acoustic modelling method was developed using a first-order hyperbolic wave system which was solved with explicit finite dfferences. The numerical solution of the 3D wave system provides a useful method for simulating evolution of a pressure field corresponding to compressional type waves. Existing two-dimensional (2D) elastic modelling algorithms were modified and fine-tuned for computationally efficient and realistic wave propagation simulations in complex structures. An original formulation of the 3D reverse time migration method was developed which is very accurate, does not suffer from unwanted evenescent energy, can image dips beyond 90{degree}, and does not generate multiple energy. Two case studies were performed that involved steam stimulation projects in the Cold Lake deposit. Simulations were performed during different phases of the steam stimulation process to examine the relation between reservoir ...
1994-12-31
Energy Technology Data Exchange (ETDEWEB)
In rare cases, large adrenal masses with a suspicion of malignancy exhibit tumor extension into the adrenal vein and inferior vena cava. When planning surgery, the relationship of the extension to the inferior vena cava is of decisive improtance. We describe in two cases on the detection of a tumor thrombus in the inferior vena cava arising from a malignant adrenal mass by means of MR angiography (TOF, coronary 2D GRE images [FLASH], 3 slices acquired during 15 second apnea). The angiograms correlated well with the results of DSA venacavography and with the intraoperative findings. Thus, MRA has been demonstrated to be suitable for the certain proof of a venous tumor thrombus not only in cases of renal cell carcinomas but also in cases of malignant adrenal masses. The method should be applied whenever there is evidence of a venous involvement in the adrenal MR images. (orig.) [Deutsch] Grosse malignomverdaechtige Nebennierentumoren zeigen in ...
1995-11-01
Effect of vitamin D on the intestinal absorption of 203Pb and 47Ca in chicks
Energy Technology Data Exchange (ETDEWEB)
The transfer of 203Pb and/or 47Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). 203Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of 203Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of 203Pb by intestinal tissue but did accelerate 203Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased 47Ca tissue levels and increased 47Ca absorption. In rachitic chicks, the rate of absorption of 203Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in al segments was similar, indicting the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum greater than ileum. An acute dose of 1,25(OH)2D3 ...
1982-03-01
Effect of vitamin D on the intestinal absorption of /sup 203/Pb and /sup 47/Ca in chicks
Energy Technology Data Exchange (ETDEWEB)
The transfer of /sup 203/Pb and/or /sup 47/Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). /sup 203/Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of /sup 203/ Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of /sup 203/Pb by intestinal tissue but did accelerate /sup 203/Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased /sup 47/Ca tissue levels and increased /sup 47/Ca absorption. In rachitic chicks, the rate of absorption of /sup 203/Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in all segments was similar, indicating the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum > ileum. An acute dose of ...
1982-03-01
Approaches to Modeling Coupled Flow and Reaction in a 2-D Cementation Experiment
Energy Technology Data Exchange (ETDEWEB)
Porosity evolution at reactive interfaces is a key process that governs the evolution and performances of many engineered systems that have important applications in earth and environmental sciences. This is the case, for example, at the interface between cement structures and clays in deep geological nuclear waste disposals. Although in a different transport regime, similar questions arise for permeable reactive barriers used for biogeochemical remediation in surface environments. The COMEDIE project aims at investigating the coupling between transport, hydrodynamics and chemistry when significant variations of porosity occur. The present work focuses on a numerical benchmark used as a design exercise for the future COMEDIE-2D experiment. The use of reactive transport simulation tools like Hytec and Crunch provides predictions of the physico-chemical evolutions that are expected during the future experiments in laboratory. Focus is given in ...
2008-04-01
High gradient magnetic separation (HGMS) of magnetic materials from fluids or waste products has many established industrial applications. However, there is currently no technology employing HGMS for ex-vivo biomedical applications, such as for the removal of magnetic drug- or toxin-loaded spheres from the human blood stream. Importantly, human HGMS applications require special design modifications as, in contrast to conventional use where magnetic elements are permanently imbedded within the separation chambers, medical separators need to avoid direct contact between the magnetic materials and blood to reduce the risk of blood clotting and to facilitate convenient and safe treatment access for many individuals. We describe and investigate the performance of a magnetic separator prototype designed for biomedical applications. First, the capture efficiency of a prototype HGMS separator unit consisting of a short tubing segment and two opposing magnetizable fine wires along the outside ...
2007-03-30
International Nuclear Information System (INIS)
Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a potential for medical application of this method, we conducted evaluation of the images of the American Collage ...
2002-03-01
British Library Electronic Table of Contents (United Kingdom)
PurposeThis prospective study followed 61 patients who were partially dentulous and considered to have insufficient bone volume for routine implant treatment and consequently underwent sinus inlay bone grafting.Patients and MethodsThe patients were treated with maxillary sinus floor augmentation with particulated autogenous bone from the mandibular ramus/corpus. After a healing period, dental implants (n = 180) were installed.ResultsRadiographic examination revealed average residual vertical bone heights of 6.5 mm in the first premolar region, 3.8 mm in the second premolar region, 3.5 mm in the first molar region, and 2.6 mm in the second molar region. The average implant lengths were 12 mm in the first premolar region and 11 mm in the second premolar, first, and second molar regions. All ...
2008-01-01
Energy Technology Data Exchange (ETDEWEB)
Six patients with eosinophilic granuloma were studied retrospectively in order to correlate the MRI appearances with the pathology. Ages ranged from 2 years 6 months to 11 years. The bones involved were the humerus, ulna, radius, femur, clavicle and ilium. Plain films, MRI and pathology specimens were obtained. A lytic lesion with indistinct margins, endosteal erosions and periosteal reaction was seen in all cases on plain radiographs. Bone marrow signal was decreased on T1-weighted images and increased on T2-weighted images throughout the bony lesion in all cases. T2-weighted images showed extensive soft-tissue abnormalities suggesting inflammatory changes in four cases. In two cases abnormalities were limited. Extensive changes correlated histologically with an early phase lesion. Localized minor changes were associated with a mid-phase lesion. Inflammatory soft-tissue changes could be associated with eosinophilic granuloma. The size of the soft tissue mass ...
1994-09-01
Root canal preparation with the NiTi systems K3, Mtwo and ProTaper
British Library Electronic Table of Contents (United Kingdom)
Abstract The aim of this paper was to examine the result of rotary root canal preparation with the nickel-titanium (NiTi) systems K3, ProTaper and Mtwo. One hundred and fifty curved artificial root canals and 60 mesial canals of human mandibular molars were selected. In the group of curved artificial canals, all canals were prepared to size 35/0.04 taper with the three systems. In the group of human mandibular molars, the teeth with mature root canals were radiographed with silver points inserted in bucco-lingual and in mesio-distal positions. In the artificial root group, one K3 instrument separated. Mtwo (20%) showed significantly (P = 0.003) less zips than K3 (46.9%) or ProTaper (50%). There were no significant differences in ledge and elbow formation. K3 and Mtwo had the lowest percent...
2007-01-01
Energy Technology Data Exchange (ETDEWEB)
One aspect of the research program SFB 570 'Distortion engineering' is the in situ X-Ray diffraction analysis of phases and residual stresses during complete heat treatment cycles. These investigations result in experimental evidence available for the extensive computations. The optimisation of the instrumentation will be reported. A surface decarburisation of samples made from the ball bearing steel 100Cr6 could be avoided for a temperature range from 800 to 900 C and a holding time of one hour by a combination of evacuate the furnace and using a certain nitrogen flow as protective gas. At lower temperatures small amounts of ferrite caused by an increased diffusion rate of carbon lead again to a surface decarburisation up to a depth of 2 {mu}m. It was proved that with an evacuation of the X-Ray beam path at constant power of the X-Ray source the intensity of diffraction lines could be increased by more than a factor of 4. The use of nitrogen as protective gas instead ...
2007-07-01
Prognostic precision in postoperative /sup 99m/Tc-MDP scintimetry after femoral neck fracture
Energy Technology Data Exchange (ETDEWEB)
A 2-year follow-up regarding healing complications, such as redisplacement, nonunion, and segmental collapse of the femoral head, was performed in 306 patients operated on for femoral neck fracture and examined with /sup 99m/Technetium-MDP scintimetry within 2 weeks postoperatively. Scintimetric evaluation was performed by selecting regions of interest over the femoral head on the fracture side and the intact side and by comparing the uptake. A femoral head ratio fractured/intact side thus was obtained. Of 199 patients with an intact femoral head uptake (ratio less than or equal to 1.0), 181 showed no signs of healing complications at 2 years, whereas 18 had developed healing complications. Of 107 cases with a deficient femoral-head uptake (ratio < 1.0), 96 had developed healing complications within 2 years from the operation, while 11 cases had no signs of radiographic complications. We conclude that /sup 99m/Tc-MDP scintimetry performed within 2 weeks from ...
1987-01-01
Prognostic precision in postoperative "9"9"mTc-MDP scintimetry after femoral neck fracture
International Nuclear Information System (INIS)
A 2-year follow-up regarding healing complications, such as redisplacement, nonunion, and segmental collapse of the femoral head, was performed in 306 patients operated on for femoral neck fracture and examined with "9"9"mTechnetium-MDP scintimetry within 2 weeks postoperatively. Scintimetric evaluation was performed by selecting regions of interest over the femoral head on the fracture side and the intact side and by comparing the uptake. A femoral head ratio fractured/intact side thus was obtained. Of 199 patients with an intact femoral head uptake (ratio #<=# 1.0), 181 showed no signs of healing complications at 2 years, whereas 18 had developed healing complications. Of 107 cases with a deficient femoral-head uptake (ratio < 1.0), 96 had developed healing complications within 2 years from the operation, while 11 cases had no signs of radiographic complications. We conclude that "9"9"mTc-MDP scintimetry performed within 2 weeks from femoral neck fracture ...
Physics of electron beam therapy
International Nuclear Information System (INIS)
A book has been written to introduce the physical aspects of the radiotherapy electron beam by presenting a summary of the developments in this field. The first chapter is a brief introduction to the technology of medical accelerators with emphasis on the electron beam production facilities. Chapter 2 describes the interaction processes at the atomic level once the electron beam enters the medium. Chapter 3 is concerned with the various properties of the electron beam purely from the clinical point of view. The electron beam algorithms and models for distribution calculations are covered in Chapter 4 with inclusion of age diffusion and multiple scattering approaches. The factors affecting the beam distribution in a patient, with inhomogeneities, surface irregularities, backscattering etc. are discussed in Chapter 5. The last two chapters are devoted to electron beam dosimetry including various dosimetric methods, specification and measurement of beam energy, radiation output and beam ...
Phantom and animal imaging studies using PLS synchrotron X-rays
Ultra-high resolution radiographs can be obtained using synchrotron X-rays. A collaboration team consisting of K-JIST, POSTECH and YUMC has recently commissioned a new beamline (5C1) at Pohang Light Source (PLS) in Korea for medical applications using phase contrast radiology. Relatively simple image acquisition systems were set up on 5C1 beamline, and imaging studies were performed for resolution test patterns, mammographic phantom, and animals. Resolution test patterns and mammographic phantom images showed much better image resolution and quality with the 5C1 imaging system than the mammography system. Both fish and mouse images with 5C1 imaging system also showed much better image resolution with great details of organs and anatomy compared to those obtained with a conventional mammography system. A simple and inexpensive ultra-high resolution imaging system on 5C1 beamline was successfully implemented. The authors were able to acquire ultra-high resolution ...
2001-01-01
On the determination of the dose-area product during X-ray examinations
International Nuclear Information System (INIS)
Despite its great usefulness in the performance of the recording procedures prescribed by the X-Ray Ordinance the dose-area product is much less frequently measured for X-ray exposures than during fluorscopic examinations. The great multitude of measuring units, mainly on account of different scales of the measuring equipments themselves, is a cause of uncertainty in clinical routine and should be eliminated as far as the circumstances would permit. As the determination of the organ dose is relevant only in very few cases and does not necessarily require previous measurements of the dose-area product, these are of limited practical value in the assessment of individual radiation exposures during radiographic examinations. The measurements may, however, be very helpful in determinations of the radiation dose to the total population, if the future retrievability of the values obtained is ensured. In addition to some measuring values showing past and present ...
Low field magnetic resonance imaging of femoral neck fractures
International Nuclear Information System (INIS)
Fourteen patients with cervical hip fractures were treated with internal fixation using titanium screws. The femoral head vitality was evaluated with "9"9Tc"m-MDP scintigraphy and scintimetry within 2 weeks postoperatively and by serial low field magnetic resonance imaging (MR). Two patients with reduced radionuclide uptake (femoral head ratio =# 1.0), MR revealed a focal decrease of the signal intensity in the femoral head or neck at 2, 3 and 7 months after fracture, respectively. The radiographs in one of these patients were normal at 7 months after fracture. The second one showed signs of necrosis at 16 months and the last one developed delayed/non-union. With a non-ferromagnetic osteosynthesis the healing course after femoral neck fracture can be studied with low field MR equipment without disturbing artifacts. The time period between ischaemia and definite abnormalities on MR may embrace several months. (orig.).
International Nuclear Information System (INIS)
Ewing's sarcoma is a highly malignant neoplasm of the bone whose origin is still uncertain. A strong relationship exists between Ewing's sarcoma and tumors of neural origin (Ewing family of tumors). Ewing's sarcoma must be distinguished from other round-cell tumors like lymphoma and neuroblastoma and also must be differentiated from osteogenic sarcomas. On plain radiographs, Ewing's sarcoma appears as a lytic or mixed lytic-sclerotic, rarely as predominantly sclerotic lesion with margins Lodwick grade III. It is located primarily in the diaphyseal and metadiaphyseal regions of the long bones of the lower extremities. A large soft tissue tumor is usually present. Magnetic resonance imaging is the imaging modality of choice to evaluate the extent of the primary lesion, to monitor the response to neoadjuvant chemotherapy and to follow up non-resected Ewing's sarcomas. Bone scintigraphy is necessary to detect skeletal metastasis, and "2"0"1thallium scanning has been ...
1998-06-01
Femoral head viability following hip fracture. Prognostic role of radionuclide bone imaging
Energy Technology Data Exchange (ETDEWEB)
A retrospective study was made of all radionuclide (RN) bone images performed at our institution over a two-year period to evaluate femoral head viability after nonpathologic fracture of the femoral neck. Twelve patients had avascular femoral heads during the perioperative period, of which nine had adequate follow-up. Seven of these nine patients had follow-up bone images. Revascularization occurred in four patients, while three had persistent absence of femoral head uptake. With clinical follow-up ranging from four to 29 months (median: 14 months), only two of these nine patients developed clinical or radiographic evidence of osteonecrosis. RN bone imaging performed in the perioperative period does not reliably predict the development of post-traumatic osteonecrosis of the femoral head and, at present, should not be used to determine prospectively method of treatment of femoral neck fracture.
1985-03-01
Femoral head viability following hip fracture. Prognostic role of radionuclide bone imaging
International Nuclear Information System (INIS)
A retrospective study was made of all radionuclide (RN) bone images performed at our institution over a two-year period to evaluate femoral head viability after nonpathologic fracture of the femoral neck. Twelve patients had avascular femoral heads during the perioperative period, of which nine had adequate follow-up. Seven of these nine patients had follow-up bone images. Revascularization occurred in four patients, while three had persistent absence of femoral head uptake. With clinical follow-up ranging from four to 29 months (median: 14 months), only two of these nine patients developed clinical or radiographic evidence of osteonecrosis. RN bone imaging performed in the perioperative period does not reliably predict the development of post-traumatic osteonecrosis of the femoral head and, at present, should not be used to determine prospectively method of treatment of femoral neck fracture.
Ewing's sarcoma. Evaluation of radiotherapy and control of the primary tumor
International Nuclear Information System (INIS)
From 1964 to 1973 at the Institute of Oncology and Radiobiology, Havana City, 18 clinical histories were studied, all of them from patients with Erwing's sarcoma, histologically diagnosticated by biopsy. Age, sex, race, traumatism background, hemogram disturbances, radiographic signs, primary tumor localization, and early treatment, were exposed. Early treatment in 14(83%) patients as radiotherapy. Local recurrence or metastasis was presented in 10(55,5%) patients during the two first years following attack treatment. Five (35,7%) patients was the survival rate within five years starting early treatemt. After five years, three (21,4%) patients were alive: for 18 and 14 year, and 64 month period; two patients died at 62 and 64 months. It is concluded that this survival may be increased by initial behaviour enclosed at the technologic therapeutic patterns of the the Institute of Oncology and Radiobiology, of Havana City. (author).
Energy Technology Data Exchange (ETDEWEB)
The effects of therapeutic levels of radiation on the axial properties of the primate vertebral column were studied. Seven male rhesus monkeys (Macaca mulatta) were irradiated with a single does of 1300 cGy to the specific lumbar vertebrae of L2, L3, and L4. Three additional animals served as controls. Radiographs were taken before the radiation treatment and just prior to sacrifice to determine density changes in the bone. The animal subjects were sacrificed 105 days following the radiation exposure. Biomechanical testing was completed on lumbar levels 2 and 3 to identify changes in strength characteristics following radiation treatment. Histomorphometric analysis of lumbar vertebrae level 4 was completed to identify volume and surface density changes as well as cellular changes. Tetracycline, dicarbomethylaminomethyl fluorescein (DCAF), and xylenol orange were used as bone labeling agents to aid in the histomorphometry and to obtain dynamic parameter changes.
1990-01-01
Do gender and torus mandibularis affect mandibular cortical index? A cross-sectional study
BackgroundThe interactions between torus and several factors such as age, gender, and dental status have not been studied comprehensively. The purpose of this study was to determine the effect of gender on the mandibular cortical index (MCI) and to investigate a possible association between torus mandibularis (TM) and MCI.MethodsThe study consisted of 189 consecutive patients referred to Department of Oral Diagnosis and Radiology of Hacettepe University within 30 workdays. Patients who did not have systemic disorders affecting bone density were included; and the age, gender, dental status and existing TM of the patients were recorded. Morphology of the mandibular inferior cortex was determined according to Klemitti's classification on panoramic radiographs.ResultsMCI was affected by age and gender (P 0.05).ConclusionIn the study population, MCI was affected by age and gender. As age increased, semilunar defects could be seen on the cortex of the mandible and MCI ...
2007-10-30
International Nuclear Information System (INIS)
Present day mammography has not been able to make use of the advantages of digital luminescence radiography because of the limited spatial resolution. The recent development of electromagnetic focusing X-ray tube with effective focal spot sizes from 0.04 to 0.12 mm allows radiographic direct magnification with less geometric blur. It is now possible to combine direct magnification mammography with digital luminescence radiography. By combining high quality storage phosphor screens with an HQ-workstation a spatial resolution of 8 lp/mm is possible for 1.7-fold magnification. For 4-fold spot magnification views spatial resolution can be theoretically increased to approx. 20 lp/mm. One important advantage of digital radiography is the possibility of image-postprocessing. This article presents two sets of standard parameters and three sets of image dependent parameters for better imaging of specific lesions, such as microcalcifications. The introduction of the storage ...
British Library Electronic Table of Contents (United Kingdom)
Blomqvist M, Ahadi S, Fernell E, Ek U, Dahllf G. Dental caries in adolescents with attention deficit hyperactivity disorder: a population-based follow-up study. Eur J Oral Sci 2011; 119: 381-385. 2011 Eur J Oral Sci This study tested the hypothesis that adolescents with attention deficit hyperactivity disorder (ADHD) exhibit a higher prevalence of caries than adolescents in a control group. Thirty-two adolescents with ADHD and a control group of 55 adolescents from a population-based sample, all 17-yr of age, underwent a clinical and radiographic dental examination. The mean--SD number of decayed surfaces (DS) was 2.0--2.2 in adolescents with ADHD and 0.9--1.4 in adolescents of the control group. Thirty-one per cent of the adolescents in the ADHD group had no new caries lesions (DS-=-0) co...
2011-01-01
International Nuclear Information System (INIS)
Objective: To evaluate the quality and usefulness of direct digital radiography system in roentgenogram of chest in clinical practice. Methods: 1000 cases of chest roentgenograms with digital radiography and high kV conventional radiography were selected for analysis by 3 senior radiologists. Results: 1. With digital radiography system, the quality of chest film was assessed as grade A in 50.6%, grade B in 38.5%, grade C in 10.9%, and no waste film. 2. With conventional high kV radiography, the quality of chest film was assessed as grade A in 41.1%, grade B in 44.1%, grade C in 13.3%, and waste film in 1.5%. The direct digital radiography was statistically superior to the conventional high kV radiography. 3. The fine structure of the lungs could be revealed in 100.0% of chest roentgenogram with direct digital radiograph system, which was significantly higher than that acquired with the conventional high KV radiography (78.6%, P < 0.001). Conclusion: Direct ...
2003-02-01
Body dose conversion factors for computerized tomography
International Nuclear Information System (INIS)
While there have been many experimental and calculational investigations on absorbed dose distribution in the patient resulting from conventional X-ray procedures, such data for computerized tomography (CT) are still sparse. As this diagnostic procedure has shown a rapid increase in application during recent years, we have determined absorbed dose to body organs in a human phantom resulting from CT examinations. The exposure model consists of the heterogeneous MIRD-5 phantom and a suitable Monte-Carlo method to calculate absorbed dose to organs of interest. The exposure conditions are specified according to the exposure specifications of a CT-scanner currently in use. The calculations cover the range of body tissues of interest in terms of organ absorbed doses as well as a risk weighted absorbed dose. A detailed example showing the calculation of red bone marrow dose is given and a somatic effective dose equivalent Hsub(ES) is calculated for different conventional and CT-scanning ...
1980-10-31
International Nuclear Information System (INIS)
Mammography has emerged as a reliable non-invasive technique for the early detection of breast cancer--the second leading cause of cancer-related mortality among American women. The radiographic appearance of the female breast consists of radiolucent (dark) regions due to fat and radiodense (light) regions due to connective and epithelial tissue. The amount of radiodense tissue can be used as a marker for predicting breast cancer risk. This paper presents the development of an algorithm for estimating the percentage of radiodense tissue in a digitized mammogram. The technique involves determining a dynamic threshold for segmenting radiodense indications in mammograms. Both the mammographic image and the threshold are modeled as Gaussian random variables. This work is intended to support a concurrent study at the Fox Chase Cancer Center (FCCC) exploring the association between dietary patterns and breast cancer risk. Mammograms have been obtained from an existing ...
2002-05-25
Assessment of the effects of pixel loss on image quality in direct digital radiography
Energy Technology Data Exchange (ETDEWEB)
Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, NPS and DQE can ...
2004-03-21
Assessment of the effects of pixel loss on image quality in direct digital radiography
International Nuclear Information System (INIS)
Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, NPS and DQE can reveal small changes in image quality ...
2004-03-21
Website Policies and Important Links Comments
WorldWideScience.org is maintained by the U.S. Department of Energy's
Office of Scientific and Technical Information as the Operating Agent
for the WorldWideScience Alliance.
