WorldWideScience
1

Phase imaging using laser-produced X-ray sources  

International Nuclear Information System (INIS)

A possible novel application of hard x-ray emitted during laser-plasma interaction was discussed. The authors established an Optical Transform Function to study the joint effect of the spectral distribution and temporal profile of the laser-produced x-ray on x-ray phase imaging. Though the laser-produced x-ray pulse duration is short and incoherent, the analysis confirms that the current x-ray phase imaging theory still holds for laser-produced x-ray phase imaging

2000-08-01

2

Future of X-ray phase imaging in medical imaging technology  

International Nuclear Information System (INIS)

Weakly absorbing materials, such as biological, soft tissues, can be imaged by generating contrast due to the phase shift of X-rays. In the past decade, several methods for X-ray phase imaging were proposed and demonstrated. The performance of X-ray phase imaging is attractive in the field of medical imaging technology, and its development for practical use is expected. Many methods, however, have been developed under the assumption of the use of synchrotron radiation, which is an obstacle to practical use. The method based on Talbot (-Lau) interferometry enables us to use a compact X-ray source, and its development is expected as a breakthrough for medical applications. (author)

2007-04-01

3

X-ray phase imaging using a X-ray tube with a small focal spot. Improvement of image quality in mammography  

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 ...

2002-03-01

4

Application of imaging plate technology for NDT; Imaging plate gijutsu to sono oyo  

Energy Technology Data Exchange (ETDEWEB)

This paper describes Fuji computed radiography (FCR) of Fuji Film for NDT (non-destructive testing). Imaging plate (IP) is a two-dimensional detector of X-ray, and shows higher photographic sensitivity than X-ray film. The output emission of IP provides a good linear relationship to X-ray intensity in a wide intensity range. When this emission can be digitized, the X-ray intensity can be also digitized. IP is applied to NDT as an inspection using X-ray. FCR provides higher photographic sensitivity than the conventional X-ray film method, which results in one-fifth to one-twentieth of irradiation time. Images with stable density can be obtained independent of the intensity. Since IP has a wide dynamic range, the variation of X-ray intensity of 1:500 can be expressed in a single ...

1998-10-01

5

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

6

X-ray Phase Imaging Microscopy using a Fresnel Zone Plate and a Transmission Grating  

International Nuclear Information System (INIS)

We report on a hard X-ray phase imaging microscopy (a phase-difference microscopy) that consists of an objective and a transmission grating. The simple optical system provides a quantitative phase image, and does not need a wave field mostly coherent on the objective. Our method has a spatial resolution almost same as that of the absorption contrast microscope image obtained by removing the grating. We demonstrate how our approach provides a phase image from experimentally obtained images. Our approach is attractive for easily appending a quantitative phase-sensitive mode to normal X-ray microscopes, and has potentially broad applications in biology and material sciences.

2010-06-23

7

Theoretical considerations for X-ray phase contrast mammography by Thomson source  

Energy Technology Data Exchange (ETDEWEB)

The advent, in the near future, of compact X-ray sources like Thomson Back-Scattering (TBS) will allow the clinical application of advanced X-ray imaging techniques, such as phase contrast, with higher sensitivity and lower impact in terms of dose delivery. In this work, we theoretically investigated the possibility of using such sources for phase contrast imaging of micro-calcifications included in a breast tissue. In our study we analyzed the phase and amplitude distribution of the TBS source and we showed that this source can be used for phase contrast imaging since the source coherence at the sample position is sufficiently high for achieving good contrast and micrometer spatial resolution. Indeed the spatial coherence of a TBS source is closer to that of a synchrotron radiation source, and much better than that of a laboratory source. Moreover, we showed ...

2009-09-01

8

Radionuclide X-ray fluorescence analysis. 1: Excitation of X-ray fluorescense radiation by nuclear radiation  

Science.gov (United States)

The principles of radionuclide excitation of X-ray fluorescence radiation and its application in

1972-01-01

9

High-energy x-ray microscopy techniques for laser-fusion plasma research at the National Ignition Facility  

Energy Technology Data Exchange (ETDEWEB)

Multi-kilo-electron-volt x-ray microscopy will be an important laser-produced plasma diagnostic at future megajoule facilities such as the National Ignition Facility (NIF). However, laser energies and plasma characteristics imply that x-ray microscopy will be more challenging at NIF than at existing facilities. We use analytical estimates and numerical ray tracing to investigate several instrumentation options in detail, and we conclude that near-normal-incidence single spherical or toroidal crystals may offer the best general solution for high-energy x-ray microscopy at NIF and similar large facilities. Apertured Kirkpatrick{endash}Baez microscopes using multilayer mirrors may also be good options, particularly for applications requiring one-dimensional imaging over narrow fields of view. {copyright} 1998 Optical Society of America

1998-04-01

10

Multiple imaging radiography at LNLS  

Energy Technology Data Exchange (ETDEWEB)

An analyzer-based X-ray phase-contrast imaging (ABI) setup has been mounted at the Brazilian Synchrotron Light Laboratory (LNLS) for multiple imaging radiography (MIR) purposes. The algorithm employed for treating the MIR data collected at LNLS is described, and its reliability in extracting the distinct types of contrast that can be obtained with MIR is demonstrated by analyzing a test sample (thin polyamide wire). As a practical application, the possibility of studying ophthalmic tissues, corneal sequestra in this case, via MIR is investigated.

2008-01-11

11

Possibilities of rayleigh-taylor instability measurement by X-ray phase imaging  

International Nuclear Information System (INIS)

X-ray imaging is a very useful plasma diagnostic method. A theoretical analysis of the x-ray phase imaging in the method based on Fresnel diffraction is given. The authors show it is a linear band pass filter, a property suit for Rayleigh-Taylor (R-T) instability measurement. The evaluation permits the possibility of R-T instability measurement in x-ray phase imaging

12

Radionuclide X-ray fluorescence analysis. 3: Examples of application in practice  

Science.gov (United States)

Examples are given of the applicability and importance of radionuclide fluorescence analysis as a

1973-01-01

13

Position-sensitive proportional counter for space-based X-ray imaging studies  

International Nuclear Information System (INIS)

ASTROSAT, India's first dedicated astronomy satellite is slated for launch in 2007. The primary science objective of ASTROSAT is to explore the Universe using broad-band instruments covering optical, UV, soft X-ray and hard X-ray studies

2005-03-01

14

Phantom and animal imaging studies using PLS synchrotron X-rays  

CERN Document Server

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 ...

2001-01-01

15

Microstructures for high-energy x-ray and particle-imaging applications  

Energy Technology Data Exchange (ETDEWEB)

Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emissions (2-20 keV) and 3.5 MeV Alpha particle emissions from laser driven micro-implosions. Image resolution in these experiments was 3-8 ..mu..m. Extension of this coded imaging capability to higher energy x-rays (approx. 100 keV) and more penetrating charged particles (e.g. approx. 15 MeV protons) requires the fabrication of very thick (50-200 ..mu..m), high aspect ratio (10:1), gold Fresnel zone plates with narrow linewidths (5-25 ..mu..m) for use as coded aperatures. A reactive ion etch technique in oxygen has been used to produce thick zone plate patterns in polymer films. The polymer patterns serve as electroplating molds for the subsequent fabrication of the free-standing gold zone plate structures.

1981-05-01

16

Microstructures for high-energy x-ray and particle imaging applications  

Energy Technology Data Exchange (ETDEWEB)

Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emission (2--20 keV) and 3.5 MeV Alpha particle emissions from laser driven micro-implosions. Image resolution in these experiments was 3--8 ..mu..m. Extension of this coded imaging capability to higher energy x rays (approx.100 KeV) and more penetrating charged particles (e.g., approx.15 MeV protons) requires the fabrication of very thick (50--200 ..mu..m), high aspect ratio (10:1), gold Fresnel zone plates with narrow linewidths (5--25 ..mu..m) for use as coded apertures. A reactive ion etch technique in oxygen has been used to produce thick zone plate patterns in polymer films. The polymer patterns serve as electroplating molds for the subsequent fabrication of the free-standing gold zone plate structures.

1981-11-01

17

NASA Technical Reports Server - Radionuclide X-ray fluorescence ...  

Science.gov (United States)

Aug 1, 1972 ... The principles of radionuclide excitation of X-ray fluorescence radiation and its application in analytic chemistry are discussed.

18

Three-dimensional image display of brain tumor utilizing a modified voxel method  

Energy Technology Data Exchange (ETDEWEB)

The patch and voxel methods are representative examples of the ways in which multi-slice images may be displayed three-dimensionally by means of computer-graphics. Each of them have advantages and disadvantages and they are mutually complementary. We have developed algorithms for a modified voxel method which incorporates the advantages of the patch methods. We have applied this to the three-dimensional image display of brain tumor with excellent results. The three-dimensional reconstructions used for clinical application in this study were derived from X-ray CT images.

1988-08-01

19

Studies of crystalline CdZnTe radiation detectors and polycrystalline thin film CdTe for X-ray imaging applications  

CERN Document Server

The development of a replacement to the conventional film based X-ray imaging technique is required for many reasons. One possible route for this is the use of a large area film of a suitable semiconductor overlaid on an amorphous silicon readout array. A suitable semiconductor exists in cadmium telluride and its tertiary alloy cadmium zinc telluride. In this thesis the spectroscopic characteristics of commercially available CZT X- and gamma-radiation detectors are established. The electronic, optical, electro-optic, structural and compositional properties of these detectors are then investigated. The attained data is used to infer a greater understanding for the carrier transport in a CZT radiation detector following the interaction of a high energy photon. Following this a method used to fabricate large area films of CdTe on a commercial scale is described. This is cathodic electrodeposition from an aqueous electrolyte. The theory and ...

2001-01-01

20

X-Ray Phase Imaging for Breast Cancer Detection  

Science.gov (United States)

... Accession Number : ADA535309. Title : X-Ray Phase Imaging for Breast Cancer Detection. Descriptive Note : Annual rept. 1 Sep 2009-31 Aug 2010 ...

2010-09-01

21

Noise Characterization of Polycrystalline Silicon Thin Film Transistors for X-ray Imagers Based on Active Pixel Architectures  

UK PubMed Central (United Kingdom)

An examination of the noise of polycrystalline silicon thin film transistors, in the context of flat panel x-ray imager development, is reported. The study was conducted in the spirit of exploring...Full Text Available

2008-01-01

22

Development of high resolution imaging detectors for X-ray astronomy  

Energy Technology Data Exchange (ETDEWEB)

High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.

1985-03-01

23

Development of high resolution imaging detectors for X-ray astronomy  

International Nuclear Information System (INIS)

High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.

1985-01-01

24

Metrological applications of X-ray waveguide thin film structures in X-ray reflectometry and diffraction  

International Nuclear Information System (INIS)

The effect of resonance, observed in X-ray waveguide layered structures in a characteristic way influences the scattering properties of the films. It is well known that the resonant region in the reflectivity shows a series of minima, usually very deep and extremely narrow. The positions and depths of the minima depend only on X-ray waveguide and quasi X-ray waveguide film structural properties, on the X-ray wavelength and on the incident beam divergence. In the present work we propose and discuss the application of the X-ray waveguide and quasi X-ray waveguide film structures as a tools to experimental evaluation of some quantities related to X-ray reflectometric and diffractometric measurements, like the beam divergence, wavelength, or angular distance. Examples of application of ...

2001-09-23

25

Quantitative phase imaging using hard x-rays  

International Nuclear Information System (INIS)

The quantitative imaging of a phase object using 16 keV x-rays is reported. The theoretical basis of the techniques is presented along with its implementation using a synchrotron x-ray source. It is found that the phase image is in quantitative agreement with independent measurements of the object. 13 refs., 5 figs.

2009-02-01

26

Microstructural transformations and kinetics of high-temperature heterogeneous gasless reactions by high-speed x-ray phase-contrast imaging  

Science.gov (United States)

Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 {mu}s exposure and spatial resolution of 10 {mu}m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were ...

2009-12-01

27

Microstructural transformations and kinetics of high-temperature heterogeneous gasless reactions by high-speed x-ray phase-contrast imaging  

International Nuclear Information System (INIS)

Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 #mu#s exposure and spatial resolution of 10 #mu#m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were ...

2009-12-01

28

Development of a dual-detector X-ray imaging system for phase retrieval study  

International Nuclear Information System (INIS)

Based on a recently introduced phase X-ray imaging approach, a dual-detector prototype was developed for in-line X-ray phase imaging and phase retrieval utilizing a micro-focus X-ray source and two computed radiography (CR) cassette detectors. The system was built on a horizontal optical rail to facilitate manual adjustment of the positions of the X-ray source, the sample and the detectors. The novel design of the detector-1 is essential, it detects a portion of radiation to form an attenuation image; allows the rest of radiation to reach the detector-2 to form a phase contrast image, and the two images are used to retrieve a phase map. The two detectors are balanced for optimal phase-retrieval with reasonable radiation dose to the object to be imaged. The system was examined in ...

2007-01-01

29

Position sensitive detection of individual nuclear particle scintillations using image intensifier tubes  

International Nuclear Information System (INIS)

An imaging position sensitive detector for charged particles, neutrons, X-and gamma rays has been developed. The novel feature of this scintillation imaging radiation detector is its ability to detect individual nuclear particle scintillations with a h igh degree of spatial resolution. The key elements of this detector system are a high gain, low noise image intensifier tube, a CCD camera and commercially available image processing hardware and software. This detector system is highly effective for applications such as low fluence and real time neutron radiography, mapping of radioactive contamination in nuclear reactor fuel rods, X-ray diffraction imaging, high speed autoradiography and in general position sensitive detection of nuclear radiation. Results of some of the exploratory experiments carried out using this detector system are ...

1996-01-01

30

Stabilization of synchrotron radiation x-ray beam by MOSTAB  

International Nuclear Information System (INIS)

Monochromator stabilization (MOSTAB) is a feedback control system to stabilize an x-ray beam of synchrotron radiation. It applies a feedback voltage to a piezo electric transducer attached to a double-crystal monochromator. We developed MOSTAB modules and examined their performances using SPring-8 beamlines. The x-ray beam position stabilization using MOSTAB was realized simultaneously with the x-ray beam intensity stabilization. As an example of its application, we performed EXAFS measurement with MOSTAB. (author)

2003-05-01

31

Investigation of morphology and chemical composition of self-organized semiconductor quantum dots and wires by X-ray scattering  

International Nuclear Information System (INIS)

X-ray scattering methods suitable for the investigation of the morphology and chemical composition of self-organized quantum dots and quantum wires are reviewed. Their application is demonstrated in experimental examples showing that a combination of small angle X-ray scattering with high-resolution X-ray diffraction can reveal both the shape and the chemical composition of the self-organized objects. (author)

2001-09-23

32

Application of digital radiography to diagnosis of laryngeal diseases  

International Nuclear Information System (INIS)

Fuji Computed Radiography (FCR) is a new system of digital radiography that is based on the latest computer technologies. We applied this FCR system to the X-ray diagnosis of the laryngeal disease. Twenty patients with various laryngeal diseases were evaluated by both FCR frontal tomography and conventional screen-film frontal tomography under the same exposure condition. Both tomograms were then compared on the subject of the clarity of delineation of laryngeal structures. As the result, FCR tomograms revealed the feature of the laryngeal lumen and cartilages more clearly than conventional tomograms. In addition, energy subtraction method, which is one of FCR image processing systems, was presented as a new technical procedure to extinguish cervical spine shadows in plain anteroposterior laryngeal X-photograph. We stress that FCR system is the suitable procedure for X-ray analysis of laryngeal diseases, especially in the ...

1986-01-01

33

Radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

The author's achievements in the title field are summarized and discussed. The following topics are dealt with: (i) principles of radionuclide X-ray fluorescence analysis; (ii) mathematical methods in X-ray fluorescence analysis; (iii) Ross differential filters; (iv) application of radionuclide X-ray fluorescence analysis in the coal industry (with emphasis on the determination of the ash content, sulfur content, and arsenic content of coal); and (v) evaluation of the X-ray fluorescence analyzer from the radiological safety point of view. (P.A.).

1994-01-01

34

8. Application of radionuclide X-ray fluorescence analysis in other fields of science and technology  

International Nuclear Information System (INIS)

Certain applications are described of radionuclide X-ray fluorescence analysis in the ore dressing industry, in the manufacture of building materials, in metallurgy, pharmacy, in the chemical, photographic and paper industries, in space exploration, in archeology and for measuring the thicknesses of thin layers of coatings. (ES).

1983-12-01

35

Anode length optimization in a modified plasma focus device for optimal x-ray yields  

International Nuclear Information System (INIS)

The effect of anode length and operating gas pressure on the x-ray emission from a nitrogen-filling modified plasma focus device has been investigated. The time-resolved investigation of x ray was carried out by using a five-channel photodiode x-ray spectrometer. The maximum x-ray yield is seen to increase with the increase in the anode length from 110 to 125 mm. Further increase in the anode length to 130 mm causes the x-ray yields to decrease. The highest x-ray yield of 4.5 J into 4#pi# sr was found for 125 mm anode length, which is 0.2% of the input energy. The average x-ray photon energy was estimated by using half-value thickness method and found to be 8.4 keV. The electron temperature of the plasma was estimated to be around 3 keV by x-ray intensity ratio method. The space-resolved ...

2006-01-01

36

Applications of Cerius2, software of molecular simulation; Aplicaciones de Cerius2, software de simulacion molecular  

Energy Technology Data Exchange (ETDEWEB)

Most of the investigations have a theoretical sustenance based on molecular simulation. The area of application of molecular simulation is very wide, in the Materials Technology Department assigned to the Applied Sciences Management have been treated problems about metallic nano structures, glasses, interfaces, and molecules, to sustain and to explain some of the experimental results. Energy calculations are carried out to determine minimum energy structures, for later on to carry out calculations of some of their properties; as well as the images simulation of Electron microscopy and X-ray diffraction. (Author)

2007-07-01

37

Grating-based X-ray phase imaging using multiline X-ray source  

International Nuclear Information System (INIS)

Differential phase-contrast X-ray imaging has been performed in a Talbot-Lau configuration, where a multiline X-ray source was used instead of a combination of a hard-X-ray multiple slit and a normal focus X-ray generator. When the multiple slit is used, a high aspect ratio structure is needed and slit width should be below 10 ?m for its function. The fabrication and use of such a multislit can be omitted using the presented configuration. The multiline X-ray source was developed by making grooves on a tungsten rotating anode, which was irradiated by an electron beam to generate X-rays. An array of 10?m line sources with a pitch of 30?m was formed and combined with a 4.5 ?m pitch phase grating and a 5.3 ?m pitch amplitude grating to generate differential phase contrast. With a total exposure time of 40 s, a differential phase ...

2009-07-01

38

Broad-band hard X-ray reflectors  

DEFF Research Database (Denmark)

Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of the supermirror is superior to that of gold, extending the band of reflection at least a factor of 2.8 beyond that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted.

1997-01-01

39

From tomography to voludensitometry: radiation detectors for industrial control and medical instrumentation; De la tomographie a la voludensitometrie: les capteurs pour le controle industriel et l`instrumentation medicale  

Energy Technology Data Exchange (ETDEWEB)

In this article, the author presents the main technological solutions, available or in development, on X-ray detectors in order to obtain a digital image in biomedical radiography or in industrial radiography: linear x-ray detectors and bidimensional x-ray detectors (memory radioluminescent screens, matrix plan detectors).

1993-12-01

40

Radiation exposure due to X-rays of the hip joint in babies  

International Nuclear Information System (INIS)

Exact anatomic knowledge about the location of the gonads and the application of corresponding measures of radiation protection are the preconditions for an efficient reduction of the danger of a possible genetic damage as a result of radiation exposition during X-ray examination of the hip joint of newborns. (VJ).

41

Design of a GaAs X-ray imaging sensor with integrated HEMT readout circuitry  

CERN Document Server

A new monolithic semi-insulating (SI) GaAs sensor design for X-ray imaging applications between 10-100keV has been proposed. Monolithic pixel detectors offer a number of advantages over hybrid bump-bonded detectors, such as high device yield, low costs and are easier to produce large scale arrays. In this thesis, an investigation is made of the use of a SI GaAs wafer as both a detector element and substrate for the epitaxially grown High Electron Mobility Transistors (HEMTs). The design of the HEMT transistors, optimised for this application, were produced with the aid of the Silvaco 'Virtual Wafer Fab' simulation package. It was determined that the device characteristics would consist of a small positive threshold voltage, a low off-state drain current and high transconductance. The final HEMT transistor design, that would be integrated to a pixel detector, had a threshold voltage of 0.17V, an ...

2002-01-01

42

Use of x-ray imaging for evaluation of superconducting ceramics fabricated by PIT method  

Energy Technology Data Exchange (ETDEWEB)

High-spatial-resolution microfocus-based X-ray imaging technology, both real-time and film, has been used to study the thickness variation that occurs in the oxide core of silver-sheathed BSCCO ribbons produced by the powder-in-tube method. This thickness variation (also called ``sausaging``) occurs during incremental rolling and degrades the critical current densities of the ribbons. Using X-ray image data the authors determined the onset and severity of sausaging. Onset occurred at a ribbon thickness of 203 {micro}m, and the severity increased with subsequent rolling reductions. Scanning electron microscopy was used to confirm the X-ray image data. X-ray imaging provides several advantages over more traditional methods for characterizing the superconductors such as optical or scanning electron microscopy. The ...

1993-08-01

43

Determination of radiation exposure and significance of its influential factors for X-rayed children in the GDR  

International Nuclear Information System (INIS)

After having discussed the peculiarities of children in X-ray diagnosis the application of the effective as well as the mean equivalent doses as to the determination of the radiation exposure in children is represented. In using computerized tomograms to determine position and extent of an organ the exposure by repeated X-raying was calculated referring to the entrance dose. Entrance dose measurements for all types of X-ray examination in hospitals and ascertainments of the frequency of radiograms in 20 X-ray departments were used to determine per capita and collective doses, resp., in several age groups. Alltogether, the per capita dose of children in the GDR amounts to 30% of that of adults. Conclusions were drawn as to taking measures to further reduction of radiation exposure: (1) Technical measures, such as positioning of patients, shielding of organs, quality assurance; (2) ...

1988-01-01

44

Visibility of tumor-like details in inline phase contrast mammography using quasimonochromatic X-ray sources  

Energy Technology Data Exchange (ETDEWEB)

A new generation of quasimonochromatic high-flux X-ray sources, based on the X-ray radiation produced through Compton scattering between an electron beam and a laser beam, is under development. One of the possible applications of this source is inline phase contrast mammography, based on the observation of the edge-enhancement effect that can be observed at the border of structures inside the breast in images produced using a partially or totally coherent X-ray beam. In this work we present the results of a set of simulations of inline phase contrast mammography using typical inverse Compton scattering sources parameters. The simulated sample was a tumour-like mass having spherical shape, diameter between 200 {mu}m and 5 mm, placed inside a breast-like matrix, 4 cm thick, and a standard composition of 50% glandular tissue and 50% adipose tissue. We discuss the minimum requirements ...

2009-09-01

46

Evaluation of diagnostic digital radiography of the chest in comparison with conventional chest x-ray films  

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

47

X-ray findings in patients with miliary appearance of metallic mercury after suicide attempt  

Energy Technology Data Exchange (ETDEWEB)

This case report evaluates X-ray findings in patients with miliary accumulation of mercury observed after parenteral application of metallic mercury in a suizide attempt. There are certain discrepancies between clinical symptoms and the X-ray findings. A clear demonstration of mercury in coronary blood vessels is possible by fluoroscopy.

1985-03-01

48

Present state of radionuclide X-ray fluorescence analysis in coal mining  

International Nuclear Information System (INIS)

Applications of X-ray fluorescence analysis in coal mining and geology are briefly described based on results published in Czechoslovakia as well as abroad over the past 3 years. Particular attention is paid to the rapid determination of the ash content of coal using portable radionuclide X-ray fluorescence analyzers that are being developed in Czechoslovakia. (author).

1990-01-01

49

Multi-mirror system, 2. Application of inverse Compton Scattering for lithography X-ray sources  

Energy Technology Data Exchange (ETDEWEB)

A brilliant X ray source is proposed for lithography instruments with use of a multi-mirror system. The inverse Compton scattering between the stored electron beam in the storage ring and the stored photon beam in the multi-mirror system, is applied for the X-ray generation. (author)

2000-07-01

50

Portable fluid X-ray diagnostic system  

Energy Technology Data Exchange (ETDEWEB)

A portable X-ray image system is described comprising: (a) a base assembly including panels and hinges joining the panels together along edges, and compression stops for biasing the hinges to compensate for the weight of payload when mounted on the base assembly, the compression stops being located for interaction with the hinges for biasing the panels to exhibit upward bowing when laid upon a flat surface prior to loading, and to provide resiliency for facilitating the base assembly assuming a substantially flat configuration when a predetermined payload is placed upon the base assembly; (b) an X-ray member; (c) apparatus for detachably mounting a table member to the base assembly to hold the table member at a location above the base; (d) an X-ray source; (e) means for sensing X-rays to form an image; (f) means for mounting the X-ray source ...

1989-02-14

51

X-ray imaging dose due to the digital imaging devices used in radiation therapy for patient positioning and repositioning: How to take it into account?; Les doses dues a l'imagerie numerique pour le controle de positionnement du patient en radiotherapie: comment les prendre en compte?  

Energy Technology Data Exchange (ETDEWEB)

The patient positioning and repositioning control in radiation therapy all along the treatment can be conducted using a variety of X-ray sources and imaging detector devices. The development of image guided radiation therapy techniques leads to more frequent use of this imaging control. In this article we summarize the current methods for measuring the dose delivered by X-ray imaging devices used in radiation therapy, as well as basic proposals to take account of these imaging doses for prescribing, recording and reporting radiation therapy treatment. (authors)

2008-12-15

52

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 ...

2007-08-21

53

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 ...

2007-08-21

54

Fluid flow visualization with neutron radiography. [Using collimated beam of neutrons  

Energy Technology Data Exchange (ETDEWEB)

A technique was developed that permits fluid flow to be visualized even where the flow is completely shrouded by metal. The technique employs real-time neutron radiography, which is similar to x-ray radiography except a collimated beam of neutrons is used. Various combinations of neutron-opaque tracer materials were tested with neutron-transparent fluid. Neutron opaque tracers, such as solid particles, fluid droplets, and streaklines were imaged through metal walls as they convected in neutron-transparent ambient fluid. Visualization of bubbles/voids were evaluated for possible future applications. Surface-flow patterns were also imaged by using neutron-opaque tufts. These techniques were evaluated for image contrast, resolution, and the ability to accurately track fluid flow fields. The techniques were also modeled to optimize contrast in various flow configurations. ...

1991-01-01

55

Fluid flow visualization with neutron radiography  

International Nuclear Information System (INIS)

A technique was developed that permits fluid flow to be visualized even where the flow is completely shrouded by metal. The technique employs real-time neutron radiography, which is similar to x-ray radiography except a collimated beam of neutrons is used. Various combinations of neutron-opaque tracer materials were tested with neutron-transparent fluid. Neutron opaque tracers, such as solid particles, fluid droplets, and streaklines were imaged through metal walls as they convected in neutron-transparent ambient fluid. Visualization of bubbles/voids were evaluated for possible future applications. Surface-flow patterns were also imaged by using neutron-opaque tufts. These techniques were evaluated for image contrast, resolution, and the ability to accurately track fluid flow fields. The techniques were also modeled to optimize contrast in various flow configurations. ...

1764-01-01

56

A summary of neutron radiography and neutron radioscopy applications at the University of Michigan Phoenix Memorial Laboratory  

International Nuclear Information System (INIS)

Neutron radiography and neutron radioscopy are rapidly becoming the valuable tools for nondestructive testing and basic research. The Phoenix Memorial Laboratory has developed a neutron facility capable of both film neutron radiography and real time neutron radioscopy, and has used this facility to study several phenomena of interest to the researchers in many areas. Neutrons can be used for imaging the phenomena that X-ray cannot image, such as the presence, absence or movement of hydrogenous materials inside metals such as aluminum or steel. There are three basic methods for obtaining images using neutrons: high resolution film neutron radiography, real-time neutron radioscopy and transfer film neutron radiography. The neutron radiography facility at Phoenix Memorial Laboratory, the neutron radioscopic imaging systems, the neutron radiographic detectors, lubrication studies, spray ...

1992-03-01

57

Hard X-ray identification of Eta Carinae and steadiness close to periastron  

CERN Document Server

Context: The colliding-wind binary Eta Car exhibits soft X-ray thermal emission that varies strongly around periastron, and non-thermal emission seen in hard X-rays and gamma-rays. Aims: To definitively identify Eta Car as the source of the hard X-ray emission, to examine how changes in the 2-10 keV band influence changes in the hard X-ray band, and to understand more clearly the mechanisms producing the non-thermal emission using new INTEGRAL observations obtained close to periastron. Methods: A Chandra observation encompassing the ISGRI error circle was analysed, and all other soft X-ray sources (including the outer shell of Eta Car itself) were discarded as likely counter-parts. New hard X-ray images of Eta Car were studied close to periastron, and compared to previous observations far from periastron. Results: The INTEGRAL component, ...

2010-01-01

58

A Remarkable Low-Mass X-ray Binary within 0.1 pc of the Galactic Center  

CERN Document Server

Recent X-ray and radio observations have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and infrared observations of the transient and its surroundings. Chandra bservations detect the source at a flux of F_X = 2e-12 erg cm^-2 s^-1 (2-8 keV). After accounting for absorption both in the interstellar medium and in material local to the source, the implied luminosity of the source is only L_X = 4e34 erg/s (2-8 keV; D=8 kpc). However, the diffuse X-ray emission near the source also brightened by a factor of 2. The enhanced diffuse X-ray emission lies on top of a known ridge of dust and ionized gas that is visible infrared images. We interpret the X-ray emission as scattered flux from the outburst, and ...

2005-01-01

59

Recent Progress in CdTe and CdZnTe Detectors  

CERN Document Server

Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) have been regarded as promising semiconductor materials for hard X-ray and Gamma-ray detection. The high atomic number of the materials (Z_{Cd} =48, Z_{Te} =52) gives a high quantum efficiency in comparison with Si. The large band-gap energy (Eg ~ 1.5 eV) allows us to operate the detector at room temperature. However, a considerable amount of charge loss in these detectors produces a reduced energy resolution. This problem arises due to the low mobility and short lifetime of holes. Recently, significant improvements have been achieved to improve the spectral properties based on the advances in the production of crystals and in the design of electrodes. In this overview talk, we summarize (1) advantages and disadvantages of CdTe and CdZnTe semiconductor detectors and (2) technique for improving energy resolution and photopeak efficiencies. Applications of these ...

2001-01-01

60

Diffraction applications using the energy dispersive beamline X6A at the National Synchrotron Light Source  

Energy Technology Data Exchange (ETDEWEB)

The energy dispersive beamline X6A at the National Synchrotron Light Source employs a curved crystal monochromator (polychromator) which focuses a range ([similar to]1 keV) of x-ray energies into a narrow (100--120 [mu]m) line image. Although this beamline was constructed primarily for time-dependent EXAFS experiments, we have begun to explore the use of this instrument for energy dispersive diffraction experiments with different types of sample including macromolecular crystals. The tunability ([ital E]=6.5 to 21 keV) and flexibility ([Delta][ital E]=100--1000 eV) of the instrument makes the beamline ideal as a test bed for the application of polychromatic single-crystal diffraction techniques to different chemical or biological materials.

1995-02-01

62

Imaging properties of the Medipix2 system exploiting single and dual energy thresholds  

CERN Document Server

Low noise, high resolution and high dose efficiency are the common requirements for most X-ray imaging applications. Especially in medical applications the dose efficiency is a necessity for detector systems. We present the imaging performance of the Medipix2 readout chip bump bonded to a 300 mu m thick Si detector as a function of the detection threshold, a free parameter not available in conventional integrating imaging systems. Spatial resolution has been measured using the modulation transfer function (MTF) and it varies between 8.2 Ip/mm and 11.0 Ip/mm at 70%. An associated measurement of noise power spectrum (NPS) permits us to derive the detective quantum efficiency (DQE) which can be as a high as 25.5 % for a broadband incoming spectrum. The influence of charge diffusion in the sensor together with threshold variation in the readout chip is discussed. ...

2006-01-01

63

Study of Stent Deployment Mechanics Using a High-Resolution X-ray Imaging Detector  

UK PubMed Central (United Kingdom)

To treat or prevent some of the 795,000 annual strokes in the U.S., self-expanding endo-vascular stents deployed under fluoroscopic image guidance are often used. Neuro-interventionalists need...Full Text Available

2011-03-01

64

General fundamentals of radiological diagnostics. Specific diagnostic radiology: Throat, mediastinum, diaphragm, mammary gland, infant thorax. 7. rev. ed.  

International Nuclear Information System (INIS)

The fundamentals and the technical application methods of the imaging procedures are discussed in detail with regard to their application in medicine. The development of the X-ray contrast media has led to a better tolerance and a significant reduction of risks. Problems relating to radiation protection and radiation exposure are discussed critically. The general point gives an overview of the radiological examination methods and is meant to deepen the understanding of the special techniques and their rationally determined application. The following special part deals with diagnosing of organs in the region of the neck and the thorax. The general basis is the conventional radiological examination. The great increase in information achieved by means of the new imaging methods becomes clear if we look at the diagnostics of the soft tissue of the neck. Computerized ...

65

A comparison of x-ray detectors for mouse CT imaging  

International Nuclear Information System (INIS)

There is significant interest in using computed tomography (CT) for in vivo imaging applications in mouse models of disease. Most commercially available mouse x-ray CT scanners utilize a charge-coupled device (CCD) detector coupled via fibre optic taper to a phosphor screen. However, there has been little research to determine if this is the optimum detector for the specific task of in vivo mouse imaging. To investigate this issue, we have evaluated four detectors, including an amorphous selenium (a-Se) detector, an amorphous silicon (a-Si) detector with a gadolinium oxysulphide (GOS) screen, a CCD with a 3:1 fibre taper and a GOS screen, and a CCD with a 2:1 fibre taper and both GOS and thallium-doped caesium iodide (CsI:Tl) screens. The detectors were evaluated by measuring the modulation transfer function (MTF), noise power spectrum (NPS), detective quantum efficiency (DQE), stability over multiple ...

2004-12-07

66

Soft x-ray microradiography and lithograph using a laser produced plasma source. Final report  

Energy Technology Data Exchange (ETDEWEB)

Considering the hardware characteristics of the laser-induced plasma X-ray source and the limitations of the conventional cone-beam reconstruction algorithm, a general cone-beam reconstruction algorithm has been developed at our laboratory, in which the motion locus of the X-ray source is an arbitrary curve corresponding to at least a 2{pi} continuous horizontal angular displacement in the coordinate system of the specimen. The preliminary simulation shows that the general cone-beam reconstruction algorithm consistently results in visually satisfactory images.

1992-03-01

67

Soft x-ray microradiography and lithograph using a laser produced plasma source  

Energy Technology Data Exchange (ETDEWEB)

Considering the hardware characteristics of the laser-induced plasma X-ray source and the limitations of the conventional cone-beam reconstruction algorithm, a general cone-beam reconstruction algorithm has been developed at our laboratory, in which the motion locus of the X-ray source is an arbitrary curve corresponding to at least a 2{pi} continuous horizontal angular displacement in the coordinate system of the specimen. The preliminary simulation shows that the general cone-beam reconstruction algorithm consistently results in visually satisfactory images.

1992-01-01

68

Tolerance limits of X-ray image intensity  

International Nuclear Information System (INIS)

Evaluation of the tolerance limits of X-ray image density accepted by the radiologist shows that for different kinds of examinations, deviations of more than 50% from optimal density lead to images which cannot be used diagnostically. Within this range diagnostic accuracy shows a distinct maximum and diminishes to the limits by 20%. These figures are related to differences in the intensifying factor of screens, sensitivity of films, sensitometric parameters of film processing as well as the doses employed with automatic exposure control devices, measured in clinical conditions. Maximum permissible tolerance limits of the whole imaging system and of its constituents are discussed using the Gaussian law of error addition. (author).

69

Recent progress in energy-filtered high energy X-ray photoemission electron microscopy using a Wien filter type energy analyzer  

International Nuclear Information System (INIS)

Energy-filtered X-ray photoemission electron microscopy (EXPEEM) is a microscopy technique which has the potential to provide surface chemical mapping during surface chemical processes on the nanometer scale. We studied the possibilities of EXPEEM using a Wien filter type energy analyzer in the high energy X-ray region above 1000 eV. We have successfully observed the EXPEEM images of Au islands on a Ta sheet using Au 3d_5_/_2 and Ta 3d_5_/_2 photoelectron peaks which were excited by 2380 eV X-rays emitted from an undulator (BL2A) at Photon Factory. Our recent efforts to improve the sensitivity of the Wien filter energy analyzer will also be discussed.

2004-10-15

70

Particle and X-ray damage in pn-CCDs  

Energy Technology Data Exchange (ETDEWEB)

The fully depleted pn-junction charge coupled device (pn-CCD) has been developed as a detector for X-ray imaging and high-resolution spectroscopy for the X-ray satellite missions XMM and ABRIXAS. If the detector is exposed to a particle radiation environment, the energy resolution is degraded due to charge transfer losses and a dark current increase. In a first experiment, prototype devices were irradiated with 10 MeV protons. After completion of the detector development, the proton irradiation was repeated for a quantitative study of the radiation damage, relevant for the satellite missions. The irradiation test was extended by a 5.5 MeV {alpha}-particle and a 6 keV X-ray exposure of the pn-CCD, including the CAMEX preamplifier chip.

2000-01-11

71

Phase formation sequence in the Pd-GaAs system  

Energy Technology Data Exchange (ETDEWEB)

The morphological aspects of ternary phase formation during the Pd-GaAs reaction have been studied by application of transmission electron microscopy (TEM) and Rutherford backscattering (RBS) techniques. The TEM images show that the first product phase, ''phase I'', forms during deposition of Pd onto (100) GaAs and exhibits the preferred orientation (0001)/sub I/ approx. // (01 anti 1)/sub GaAs/. In the presence of unreacted Pd, the second phase, ''phase II'', nucleates at large-angle grain boundaries in the phase I film as the annealing temperature increases above approx.250C. Energy dispersive analysis of x-rays and RBS suggest the nominal compositions Pd3GaAs and Pd4GaAs for phases I and II, respectively.

1985-12-01

72

Application of nuclear analytical methods in determining heavy metals in a welder's working environment  

International Nuclear Information System (INIS)

The problems are discussed of using radionuclide X-ray fluorescence analysis (the most frequently used source is "2"4"1Am) and neutron activation analysis for monitoring the chemical quality of the working environment of a welder. Elements determinable by these methods are listed and the advantages of the methods stated with regard to speed, simplicity and appropriate accuracy of measurement together with commercial availability of the instruments. Welding as a source of harmful substances is assessed by determination of the amount of chromium in aerosols generated by welding austenitic chromium-nickel steels. The described methods allow to obtain a complex image of the chemical nature of welding aerosols and to understand the mechanism of their impact on the human organism. (J.C.).

1986-01-01

73

Advantages of magnification in digital phase-contrast mammography using a practical X-ray tube  

Energy Technology Data Exchange (ETDEWEB)

Phase-contrast imaging with a practical cone-beam X-ray tube has been realized for clinical use in digital mammography using computed radiography (CR). To perform phase-contrast imaging, the X-ray detector must be distanced from an object so that the phase-contrast image achieves magnification; in a mammography unit dedicated to phase-contrast imaging, the magnification ratio is 1.75. When using an X-ray tube with a 0.1-mm focal spot, it appears that the penumbra in magnification blurs both projected images and the phase contrast, which generates an edge effect. However, where the sampling pitch of the CR plate is 43.75 {mu}m, the blur stretches the width of the phase contrast so that unit pixels in the detector can capture it. Note that the width of an ideal phase contrast using an X-ray point ...

2008-12-15

74

Radiological protection. Textbook for radiographers and reference book for radiological safety officers  

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).

75

Patient doses in the Netherlands. [X-ray diagnosis and radiotherapy  

Energy Technology Data Exchange (ETDEWEB)

Contributions to the population dose due to medical applications of ionising radiation are presented. It appears that contributions due to radiotherapy and X ray diagnosis are of comparable magnitude. To account for the age dependency of the radiation risks, contributions in terms of somatically significant dose equivalent are calculated as 0.3 mSv per caput per annum for X ray diagnosis and as 0.2 mSv per caput per annum for radiotherapy, the latter referring to only doses to organs outside the target volume. (author).

1991-01-01

76

Applications of X-ray scattering in pharmaceutical science  

British Library Electronic Table of Contents (United Kingdom)

The use of X-ray scattering techniques in pharmaceutical science is increasing, in part through increased collaborations with the materials science community, and through increased availability of instrumentation, particularly synchrotron sources. The ability to understand not only the biopharmaceutical outcome, but also arguably, more importantly, the structural aspects of drugs and drug delivery systems, is essential to progressing pharmaceutical science; this review serves as an introduction to the major techniques and the wide range of areas in which X-ray scattering may be applied in understanding and controlling structure in pharmaceutical systems.

2011-01-01

77

Magnified x-ray phase imaging using asymmetric Bragg reflection: Experiment and theory  

International Nuclear Information System (INIS)

X-ray imaging using asymmetric Bragg reflection in the hard x-ray regime opens the way to improve the spatial resolution limit below 1 #mu#m by magnifying the image before detection, simultaneously providing a strong phase contrast. A theoretical formalism of the imaging process is established. Based on this algorithm, numerical simulations are performed and demonstrate that both Fresnel propagation and Bragg diffraction contribute to contrast formation. The achievable resolution of this technique is investigated theoretically; the results obtained can be used to improve future experimental setups. Furthermore, the minimum detectable phase gradient is estimated, for comparison with other phase sensitive imaging techniques. Results from biological objects demonstrate that the technique is viable for imaging both in two and three dimensions. ...

2006-08-01

78

What can we learn about extragalactic radio jets from X-ray data?  

CERN Document Server

We review the current status of resolved X-ray emission associated with extragalactic radio jets and hotspots. The primary question for any particular jet is to decide if the X-rays come from the synchrotron process or from inverse Compton scattering. There is considerable evidence supporting synchrotron emission for knots in the jets of FRI galaxies. For FRII terminal hotspots detected in the X-ray band, synchrotron self-Compton emission continues to provide viable models with one possible exception (so far). Inverse Compton scattering on photons of the cosmic microwave background is indicated for a few powerful jets, and is expected to be an important contributor if not the dominating mechanism for higher redshift objects. The application of a model generally yields physical parameters and in many cases, these include the Doppler boosting factor.

2003-01-01

79

Pulse source of electron and X-ray radiations of subnanosecond duration  

International Nuclear Information System (INIS)

The time and dose characteristics of the electron and X-ray radiations of a tube, connected to a subnanosecond mega volt accelerator, are measured. By the pulse of the accelerating voltage of #>=# 600 kV with duration of #approx =# 0.3 ns the tube generates approximately 5 x 10"1"2 electrons pulse. The current amplitude equals approximately 5 kA/pulse and the radiation dose-about 5 kGy/pulse. The X-ray radiation dose from the tantalum external target constitutes 0.15 Gy/pulse. The prototypes of the electron and X-ray tubes sufficiently lower volumes, opening new applications in the technique and medicine, are developed

80

Noise suppression in scatter correction for cone-beam CT  

UK PubMed Central (United Kingdom)

Scatter correction is crucial to the quality of reconstructed images in x-ray cone-beam computed tomography (CBCT). Most of existing scatter correction methods assume smooth scatter distributions. The...Full Text Available

2009-03-01

81

In vivo Visualization of the Water-refilling Process in Xylem Vessels Using X-ray Micro-imaging  

UK PubMed Central (United Kingdom)

Background and AimsXylem vessels containing gases (embolized) must be refilled with water if they are to resume transport of water through the plant, so refilling is of great importance...Full Text Available

2008-03-01

82

Feasibility study of the iterative x-ray phase retrieval algorithm  

International Nuclear Information System (INIS)

An iterative phase retrieval algorithm was previously investigated for in-line x-ray phase imaging. Through detailed theoretical analysis and computer simulations, we now discuss the limitations, robustness, and efficiency of the algorithm. The iterative algorithm was proved robust against imaging noise but sensitive to the variations of several system parameters. It is also efficient in terms of calculation time. It was shown that the algorithm can be applied to phase retrieval based on one phase-contrast image and one attenuation image, or two phase-contrast images; in both cases, the two images can be obtained either by one detector in two exposures, or by two detectors in only one exposure as in the dual-detector scheme.

2009-01-01

83

The Micro-X Imaging Spectrometer Instrument  

Science.gov (United States)

The Micro-X instrument is a NASA funded, rocket borne X-ray imaging spectrometer planned for launch in January 2011. An array of Transition Edge Sensors (TESs) will observe incoming photons in the 0.2-3 keV energy band with an energy resolution of 2-4 eV at 1 keV. This will be a substantial improvement over current non-dispersive detectors for X-ray spectroscopy of extended sources and will be the first demonstration of a TES-based microcalorimeter in space. The TESs will utilize the 50 mK stage of an Adiabatic Demagnetization Refrigerator (ADR) as a heat sink, and will be read out by a SQUID time division multiplexer. X-rays will be focused onto the TES array of 128 pixels on a 600 micron pitch by a conically approximated Wolter optic with an effective area of 200 cm2. The spectrometer will have a field of view of 11.8 arcmin. We describe the design and development progress of the instrument.

2010-01-01

84

Radionuclide X-ray fluorescence analysis of solid aerosol particles on Synpor 4 collection filters  

International Nuclear Information System (INIS)

The feasibility was studied of the application of radionuclide X-ray fluorescence analysis to the identification and determination of chemical elements in the air. A description of the method is presented, the main stages of the analysis are discussed (sample preparation and standards, selection of radioactive radiation sources, geometry of measurement and evaluation of results). The method is illustrated on the determination of elements Fe, Cu, Zn, Br, and Pb in air samples taken in the city of Prague. (author) 2 tabs., 2 figs., 14 refs.

1992-01-01

85

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

86

Determination of Mn, Fe, Ni, Cu, Zn and Pb contents in samples of apple trees by radionuclide X-ray fluorescence analysis  

Energy Technology Data Exchange (ETDEWEB)

The applicability of the radionuclide X-ray fluorescence analysis (RXFA) for qualitative and quantitative evaluation of environmental plant samples is discussed and examples of determination of Mn, Fe, Ni, Cu, Zn, Pb in samples of apple trees are given. The instrumentation, the standard and sample preparation are also presented.

1982-12-01

87

The infrared-dominated jet of 3C401  

CERN Document Server

We present a Hubble Space Telescope image of the FRII radio galaxy 3C 401, obtained at 1.6 microns with the NICMOS camera in which we identify the infrared counterpart of the brightest region of the radio jet. The jet has a complex radio structure and brightens where bending occurs, most likely as a result of relativistic beaming. We analyze archival data in the radio, optical and X-ray bands and we derive its spectral energy distribution. Differently from all of the previously known optical extragalactic jets, the jet in 3C401 is not detected in the X-rays even in a long 48ksec X-ray Chandra exposure and the infrared emission dominates the overall SED. We propose that the dominant radiation mechanism of this jet is synchrotron. The low X-ray emission is then caused by two different effects: i) the lack of any strong external photon field and ii) the shape of the electron ...

2005-01-01

88

Spherically bent crystal spectroscopy in laser-produced plasma  

International Nuclear Information System (INIS)

A curved crystal X-ray spectrographs of reflection type spherical geometry was required based on the Johann scheme. Due to their high efficiency and resolution, X-ray spectrographs of focusing spectrograph spatial resolution are suitable for detecting weak X-ray spectra in spectrometers for laser fusion research. Spherically bent mica crystal with a radius of curvature of 380 mm was used in the spectrometer. The Bragg angle of the crystal analyzer was 51 degree. The image plate was employed to obtain high spatial resolution and a narrow spectral band width, with an effective area of 30 mm x 80 mm. The designed optical path of the X-ray spectrometer beam was 980 mm long from the source to the crystal and the detector. The first experiment was carried out at the 20 J energy laser facility of Research Center of Laser Fusion, China Academy of Engineering Physics. ...

2008-02-01

89

Hard x-ray phase imaging using simple propagation of a coherent synchrotron radiation beam  

International Nuclear Information System (INIS)

Particularly high coherence of the x-ray beam is associated, on the ID19 beamline at ESRF, with the small angular size of the source as seen from a point of the sample (0.1-1 #mu#rad). This feature makes the imaging of phase objects extremely simple, by using a 'propagation' technique. The physical principle involved is Fresnel diffraction. Phase imaging is being simultaneously developed as a technique and used as a tool to investigate light natural or artificial materials introducing phase variations across the transmitted x-ray beam. They include polymers, wood, crystals, alloys, composites or ceramics, exhibiting inclusions, holes, cracks, ... . 'Tomographic' three-dimensional reconstruction can be performed with a filtered back-projection algorithm either on the images processed as in attenuation tomography, or on the phase maps retrieved from the images ...

1999-05-21

90

Construction of a homogeneous phantom for radiographic image standardization; Construcao de um fantoma homogeneo para padronizacao de imagens radiograficas  

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. ...

1996-12-31

91

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 ...

1986-01-01

92

Sensitization and radiation hardening of the photostimulable X-ray storage phosphor CsBr:Eu2+  

British Library Electronic Table of Contents (United Kingdom)

The X-ray storage phosphor CsBr:Eu2+ in form of needle image plates is believed to be a promising alternative to the granular BaFBr:Eu2+ with regard to PSL yield and spatial resolution. Unfortunately, CsBr:Eu2+ exhibits poor radiation hardness, which is caused by a migration of europium ions initiated by naturally existing defect centers like (Eu2+-VCs)-centers and X-ray generated MEu-centers. It will be shown that the formation of (Eu2+-O2?)-dipoles at the expense of (Eu2+-VCs)-dipoles, incorporated by thermal annealing in O2-containing and humid atmosphere, does not improve the radiation stability. There is, however, a strong improvement in the radiation hardness by codoping of CsBr:Eu2+ with lithium ions, which is accompanied by a complete suppression of the previously observed MEu-cent...

2009-01-01

93

Plasma Diagnostics in the Optical and X-ray regions on the Plasma Focus device PF-4 (Installation TYULPAN)  

International Nuclear Information System (INIS)

The results of experiments received on the plasma focus (PF) device with energy stored equal 4 kJ are represented. Photos of the current plasma sheath (CPS), pre-pinch, sphere-like plasma formations are produced with help of the electron-optical converter contained a gated micro-channel plate (MCP) and the CCD-camera imaging system in the visible region. The redial velocity of the CPS is about 107 cm/s. Neon plasma electron density measured with help of the interferograms in the visible region and the spectra in the soft X-ray region is equals to 3?1018 cm-3. Electron temperature is equal to about 200 eV. Discharge integral photos were obtained with help of the soft X-ray pinhole camera. Pictures with 2 ?s resolution of the plasma luminescence above PF anode region were made by CCD-camera.

2006-01-01

94

Nondestructive characterization of low-level transuranic waste  

Energy Technology Data Exchange (ETDEWEB)

The use of nondestructive evaluation (NDE) methods is proposed for characterization of transuranic (TRU) waste stored at the Radioactive Waste Management Complex. These NDE methods include real-time x-ray radiography, real-time neutron radiography, x-ray and neutron computed tomography, thermal imaging, container weighing, visual examination, and acoustic measurements. An integrated NDE system is proposed for characterization and certification of TRU waste destined for eventual shipment to the Waste Isolation Pilot Plant in New Mexico. Methods for automating both the classification waste and control of a complete nondestructive evaluation/nondestructive assay system are presented. Feasibility testing of the different NDE methods, including real-time x-ray radiography, and development of automated waste classification techniques are covered as part of a five year effort designed to yield a production ...

1981-10-01

95

Crystallization and preliminary X-ray studies of a galactose-specific lectin from the seeds of Spatholobus parviflorus  

British Library Electronic Table of Contents (United Kingdom)

A galactose-specific seed lectin was purified from the legume Spatholobus parviflorus and crystallized using the hanging-drop vapour-diffusion technique. Thecrystals belonged to space group P1, with unit-cell parameters a = 60.998, b=60.792, c = 78.179-, = 101.32, = 91.38, = 104.32. X-ray diffraction data were collected under cryoconditions (100-K) to a resolution of 2.04- using a MAR image-plate detector system mounted on a rotating-anode X-ray (Cu-K) generator. Molecular replacement using legume-lectin coordinates as a search model gave a tetrameric structure.

2011-01-01

96

Quantitative analysis of X-Ray Microtomography images of metal powders in the course of sintering  

Energy Technology Data Exchange (ETDEWEB)

In situ X-Ray microtomography offers new opportunities for analysing sintering mechanisms since it allows 3D observation of the microstructural evolution of the powder all along a sintering cycle. With synchrotron radiation at ESRF, a 3D image with a resolution of 2 {mu}m can be obtained in about one minute. In addition to the visual examination of the images, relevant microstructural parameters can be measured through quantitative image analysis using recently developed tools. In this paper the results obtained with two materials, loose copper powder and compacted steel powder, are resumed. For copper powder, the dispersion of local parameters such as particle co-ordination number and porosity is investigated. Concerning steel compacts, data about pore morphology evolution and on local strains provides clues for understanding the anisotropic shrinkage of such compacts. (authors)

2005-07-01

97

Radiotherapy for ocular lesions by electron beam therapy  

Energy Technology Data Exchange (ETDEWEB)

Radiotherapy can be very significant as the treatment for ocular lesions, eyes need to be preserved as properly as possible on their functions and cosmetics. The application of conventional X ray therapy has been gradually abandoned as conventional X ray therapy ceased to be accepted as the general treatment for malignant tumors. Consequently the necessity of electron beam therapy has been rising even as the substituted method for conventional X ray therapy. The department of radiology of Gunma University was obliged to establish a new therapy for ocular lesions, and has been trying electron beam therapy since 1973. It is concluded that electron beam therapy is not at all inferior to conventional X ray therapy as reported above. Basic therapeutic methods for ocular lesions are the following: 1) For ...

1981-11-01

98

Experimental Evaluation And Simulation Of Multi-pixel Cadmium-zinc-telluride Hard-x-ray Detectors  

CERN Document Server

This dissertation describes the evaluation of many-pixel Cadmium-Zinc-Telluride (CdZnTe) hard-X-ray detectors for future use with the High Energy Replicated Optics (HERO) telescope being developed at Marshall Space Flight Center. The detector requirements for the HERO application are good energy resolution (sufficient to resolve cyclotron features and nuclear lines), spatial resolution of ∼200 μm, minimal charge loss of absorbed X rays, and minimal sensitivity to the background environment. This research concentrates on assessing the suitability of these detectors for the focus of HERO, and includes the development of a simulation of the physics involved in an X-ray-detector interaction, a study of the intrinsic material properties, measurements with prototype detectors such as the energy and spatial resolution, charge loss, and X-ray background ...

2004-01-01

99

The use of lead isotopic abundances in trace uranium samples for nuclear forensics analysis  

International Nuclear Information System (INIS)

Secondary ion mass spectrometry (SIMS), secondary electron microscopy (SEM) and X-ray analysis have been applied to the measurement of U-bearing particles with the intent of gleaning information concerning their history and/or origin. The lead isotopic abundances are definitive indicators that U-bearing particles have come from an ore-body, even if they have undergone chemical processing. SEM images and X-ray analysis can add further information to the study that may allude to the extent of chemical processing. The presence of 'common' lead that does not exhibit a radiogenic signature is clear evidence of anthropogenic origin. (author)

2010-06-01

100

Dual-energy projection radiography using condenser discharge x-ray generator and FCR. Determination of technical factors  

Energy Technology Data Exchange (ETDEWEB)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique.

1987-04-01

101

Dual-energy projection radiography using condenser discharge x-ray generator and FCR  

International Nuclear Information System (INIS)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique. (author).

1987-01-01

102

Free-electron laser beam  

International Nuclear Information System (INIS)

The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by irradiation of 5.7#mu#m ...

2003-06-01

103

Determination of heptacaine hydrochloride in solution using nuclear analytical methods  

Energy Technology Data Exchange (ETDEWEB)

The applicability of two nuclear analytical methods: radionuclide X-ray fluorescence analysis and radiometric titrations based on precipitate formations was studied in order to determine the heptacaine hydrochloride in solutions. The applied methods were evaluated based on the obtained sensitivity values.

1984-01-20

104

Determination of heptacaine hydrochloride in solution using nuclear analytical methods  

International Nuclear Information System (INIS)

The applicability of two nuclear analytical methods: radionuclide X-ray fluorescence analysis and radiometric titrations based on precipitate formations was studied in order to determine the heptacaine hydrochloride in solutions. The applied methods were evaluated based on the obtained sensitivity values. (author).

1984-01-01

106

Nanofocusing refractive X-ray lenses  

Energy Technology Data Exchange (ETDEWEB)

This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is ...

2010-02-05

107

Non-destructive Imaging of Individual Bio-Molecules  

CERN Document Server

Radiation damage is considered to be the major problem that still prevents imaging an individual biological molecule for structural analysis. So far, all known mapping techniques using sufficient short wave-length radiation, be it X-rays or high energy electrons, circumvent this problem by averaging over many molecules. Averaging, however, leaves conformational details uncovered. Even the anticipated use of ultra-short but extremely bright X-ray bursts of a Free Electron Laser shall afford averaging over 10^6 molecules to arrive at atomic resolution. Here we present direct experimental evidence for non-destructive imaging of individual DNA molecules. In fact, we show that DNA withstands coherent low energy electron radiation with deBroglie wavelength in the Angstrom regime despite a vast dose of 10^8 electrons/nm^2 accumulated over more than one hour.

2009-01-01

108

A study of reconstruction algorithms and filters for an industrial X-ray tomography system  

Energy Technology Data Exchange (ETDEWEB)

Computed tomography (CT) has been incorporated in an industrial Diode-Array Digital Radiography (DADR) system. An input data size of 512 pixel points x 400 projections yielded a 400x400 output image matrix. Reconstruction algorithms used are the filtered backprojection (FBP) and the direct Fourier reconstruction (DFR). Various filters were used in the FBP reconstruction process and their effects on image quality were evaluated. A spatial resolution of 100 {mu}m was measured with a block of plates and a minimum detectable feature size in the range of 10-100 {mu}m was measured using thin wires. Industrial specimens imaged have included ceramic samples, ball bearings and integrated circuits. A number of engineering problems have been solved, such as adjustment of the X-ray source, centering of the rotator spindle in the view field and beam-hardening corrections. (orig.).

1990-12-20

109

An X-ray photoelectron spectroscopic study of B-N-Ti system  

International Nuclear Information System (INIS)

Composite nitrides (such as BN, TiN) are widely used in various industrial applications because of their extreme wear and corrosion resistance, thermal and electrical properties. in order to obtain composite materials with these optimal properties, it is important to elucidate whether any chemical reactions occur at nitride/metal interfaces, e.g., those involving BN-Ti/TiN. Materials of interest include the deposition by PVD of Ti and TiN on BN substrates. Some of these systems were then subjected to varying degrees of physical and thermal alteration. Detailed X-ray photoelectron spectroscopy (XPS) has therefore been rendered of these interfaces using cross-sectional display and sputter etching. Resulting structural and morphological features have been investigated with transmission electron microscopy (TEM) and X-ray diffraction (XRD). Diffusion of the nitridation, oxynitride formation and interfacial growth are of general ...

1997-04-04

110

Study of chest portable radiography using computed radiography. Removal effect of X-ray scatter by a copper plate  

Energy Technology Data Exchange (ETDEWEB)

When chest radiographs are obtained using an anti-scatter grid in a mobile x-ray unit by Fuji Computed Radiography (FCR), right lung densities may differ from left lung densities owing to misalignment caused by an oblique x-ray beam. Such misalignment is considered to be caused by factors such as the shape of the bed and angle of the x-ray tube. Misalignment is especially frequent when exposure is carried out in the sitting position. Although a low-ratio grid has been reported to offer improvement, the misalignment is not completely eliminated. Therefore, we used a copper plate without a lattice feature instead of grid, and examined the results. The copper plate was found to have the ability of a grid to eliminate radiation scatter, and, furthermore, to offer the physical capabilities of a grid as determined by Carlin's new grid assessment method. Image quality was demonstrated through contrast ...

2001-04-01

111

Study of chest portable radiography using computed radiography. Removal effect of X-ray scatter by a copper plate  

International Nuclear Information System (INIS)

When chest radiographs are obtained using an anti-scatter grid in a mobile x-ray unit by Fuji Computed Radiography (FCR), right lung densities may differ from left lung densities owing to misalignment caused by an oblique x-ray beam. Such misalignment is considered to be caused by factors such as the shape of the bed and angle of the x-ray tube. Misalignment is especially frequent when exposure is carried out in the sitting position. Although a low-ratio grid has been reported to offer improvement, the misalignment is not completely eliminated. Therefore, we used a copper plate without a lattice feature instead of grid, and examined the results. The copper plate was found to have the ability of a grid to eliminate radiation scatter, and, furthermore, to offer the physical capabilities of a grid as determined by Carlin's new grid assessment method. Image quality was demonstrated through contrast ...

2001-04-01

112

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 ...

113

Investigating the complex X-ray spectrum of a broad-line 2MASS red quasar: XMM-Newton observation of FTM 0830+3759  

CERN Document Server

We report results from a 50 ks XMM-Newton observation of the dust-reddened broad-line quasar FTM 0830+3759 (z=0.413) selected from the FIRST/2MASS Red Quasar survey. For this AGN, a very short 9 ks Chandra exposure had suggested a feature-rich X-ray spectrum and HST images revealed a very disturbed host galaxy morphology. Contrary to classical, optically-selected quasars, the X-ray properties of red (i.e. with J-Ks> 1.7 and R-Ks> 4) broad line quasars are still quite unexplored, although there is a growing consensus that, due to moderate obscuration, these objects can offer a unique view of spectral components typically swamped by the AGN light in normal, blue quasars. The XMM-Newton observation discussed here has definitely confirmed the complexity of the X-ray spectrum revealing the presence of a cold (or mildly-ionized) absorber with Nh ~10^{22} cm^-2 along the line of sight to the nucleus and ...

2010-01-01

114

Analysis of degradation in nickel-based alloys using focused ion beam imaging and specimen preparation combined with analytical electron microscopy  

International Nuclear Information System (INIS)

Focused ion beam (FIB) microscopes have become well-established in the semiconductor industry during the past decade, and are rapidly gaining attention in the field of materials science, both as a tool for producing site specific, parallel sided transmission electron microscope (TEM) specimens and as stand alone specimen preparation and imaging systems. FIB secondary electron imaging (SEI) of nickel-based alloys, such as commercially produced Alloy 600 (approximately Ni 15Cr 10Fe 0.5C), has been demonstrated to show a high degree of sensitivity to the presence of deformation in the alloy, and FIB secondary ion imaging (SII) is particularly useful for identifying the presence of grain boundary corrosion, as secondary ion yields from metallic specimens can increase by three orders of magnitude in the presence of oxygen. This 'oxygen enhanced yield', makes FIB SII ideal for detection of corrosion at grain boundaries down to ...

2002-09-23

115

Optical and structural properties of Ge films from ion-assisted deposition  

International Nuclear Information System (INIS)

The optical properties and microstructure of germanium (Ge) films, prepared by ion-assisted deposition (IAD) process, were investigated. The Ge films were deposited on sapphire and silicon substrates, with and without simultaneous Ar+ bombardment. Higher index films, with a refractive index 7.7% larger than that of the single crystalline Ge wafer, were obtained with the IAD process. The density of the IAD film could be 1.5% greater than that of the e-beam film. The results of the heat treatment indicated that the optical and structural properties of the IAD films were more stable. Ge nano-crystallites could be observed under high ion power density, which induced a crystalline structure in the Ge thin films. The average size of the nano-crystallites, as determined from both the X-ray diffraction data and the transmission electron microscopy images, showed that no systematic change had occurred. The results presented in this work suggest that the ...

2008-11-28

116

Portal localization images using computed radiography for high-energy electron beam therapy  

Energy Technology Data Exchange (ETDEWEB)

Portal localization images for high-energy electron beam therapy are necessary to confirm the treatment field by comparing them with a simulation image obtained before treatment or portal verification images after treatment. In this study, portal localization images were acquired using the computed radiography (CR) system and bremsstrahlung X-rays generated in the electron beam irradiations. All images obtained with phantom and the irradiations of in the electron energy of 8, 10, 12 and 15 MeV were feasible for clinical use. The CR system used in this study included general diagnostic imaging cassette and storage phosphor plate, but none of other special devices. The system can usually supply portal localization images, which maintains the quality assurance of high-energy electron beam therapy. (author)

2002-09-01

117

Application of 10 GeV electron driven x-ray laser in gamma-ray laser research  

Energy Technology Data Exchange (ETDEWEB)

The proposed short wavelength coherent light source driven by the SLAC 3 km linac might be used to induce transitions between nuclear isomeric states. If an isotope were found with energetically adjacent isomeric states, one short-lived and one long-lived, and it were possible to separate and concentrate the long-lived species, and other nuclear and solid-state parameters were favorable, it might be possible to convert sufficient population to the short-lived state to realize [gamma]-ray lasing. Even if the x-ray intensity were insufficient, study of such driven transitions would be quite valuable.

1992-01-01

118

Application of 10 GeV electron driven x-ray laser in gamma-ray laser research  

Energy Technology Data Exchange (ETDEWEB)

The proposed short wavelength coherent light source driven by the SLAC 3 km linac might be used to induce transitions between nuclear isomeric states. If an isotope were found with energetically adjacent isomeric states, one short-lived and one long-lived, and it were possible to separate and concentrate the long-lived species, and other nuclear and solid-state parameters were favorable, it might be possible to convert sufficient population to the short-lived state to realize {gamma}-ray lasing. Even if the x-ray intensity were insufficient, study of such driven transitions would be quite valuable.

1992-12-01

119

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

120

Energy Dispersive X-ray Analysis in the Electron Microscope  

CERN Document Server

Energy Dispersive X-ray Analysis in the Electron Microscope

2003-01-01

121

ASE FILE  

Science.gov (United States)

radionuclide X-ray fluorescence analysis: the resolving power of the ... The radiation detectors used in radionuclide X-ray fluorescence ...

122

Targeted drug delivery under MRI guidance  

British Library Electronic Table of Contents (United Kingdom)

The main goal of local drug delivery is to increase the concentration of a specific therapeutic agent in a target tissue with minimal nontarget distribution. Compared to systemic therapy, local drug delivery provides a high level of therapeutic efficacy with minimal systemic effects. The current primary imaging modality for drug delivery has been x-ray angiography, but it has major limitations including anatomical ambiguity and inability to visualize the targeted tissues. Due to these inherent problems, MR guidance has been explored as an alternative imaging modality for guiding and monitoring of drug therapy. Recently, interventional MR (XMR) systems have been implemented that have both dual x-ray and MRI capabilities in a single suite and allow for real-time interventional procedures to ...

2008-01-01

123

PET/MRI hybrid imaging: devices and initial results  

British Library Electronic Table of Contents (United Kingdom)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...

2008-01-01

124

Study of X-ray filter and peak kilovoltage in Fuji computed radiography in regard to the detection of simulated pulmonary nodules  

Energy Technology Data Exchange (ETDEWEB)

To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that (1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; (2) approximately equal detection rates were obtained ...

1994-10-01

125

Study of X-ray filter and peak kilovoltage in Fuji computed radiography in regard to the detection of simulated pulmonary nodules  

International Nuclear Information System (INIS)

To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that 1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; 2) approximately equal detection rates were obtained ...

1994-01-01

126

Large area, low capacitance Si(Li) detectors for high rate x-ray applications  

Energy Technology Data Exchange (ETDEWEB)

Large area, single-element Si(Li) detectors have been fabricated using a novel geometry which yields detectors with reduced capacitance and hence reduced noise at short amplifier pulse-processing times. A typical device employing the new geometry with a thickness of 6 mm and an active area of 175 mm 2 has a capacitance of only 0.5 pf, compared to 2.9 pf for a conventional planar device with equivalent dimensions. These new low capacitance detectors, used in conjunction with low capacitance field effect transistors, will result in x-ray spectrometers capable of operating at very high count rates while still maintaining excellent energy resolution. The spectral response of the low capacitance detectors to a wide range of x-ray energies at 80 K is comparable to typical state-of-the-art conventional Si(Li) devices. In addition to their low capacitance, the new devices offer other advantages over conventional detectors. Detector fabrication ...

1992-10-01

127

Determination of trace elements in Syrian medicinal plants and their infusions by energy dispersive X-ray fluorescence and total reflection X-ray fluorescence spectrometry  

Energy Technology Data Exchange (ETDEWEB)

X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise (Anisum vulgare), licorice root (Glycyrrhiza glabra), and white wormwood (Artemisia herba-alba)

2009-07-15

128

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-08-01

129

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

International Nuclear Information System (INIS)

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

1995-01-01

130

X-ray ablation measurements and modeling for ICF applications  

Energy Technology Data Exchange (ETDEWEB)

X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both ...

1996-09-01

131

CR portal imaging; A linac graphy using storage phosphor imaging systems  

Energy Technology Data Exchange (ETDEWEB)

In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable ...

1992-07-01

132

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 ...

1987-01-01

133

Methods and results of a representative analysis of the radiation exposure of the population by diagnostic radiology  

International Nuclear Information System (INIS)

From the frequency of diagnostic radiologic examinations and their radiation dose delivered to the population the risk of cancer induction and genetic damage is calculated on the basis of the risk factors given by the ICRP. Thus 0.38 % and 3 % of the total mortality for cancer and leukemia, resp., can be attributed to X-ray diagnostics. Chest examinations alone result in 0.07-0.7 damages per 100,000 persons depending on the imaging technique applied. (author).

1984-01-01

134

Lung studies with spiral CT. pitch 1 versus pitch 2  

International Nuclear Information System (INIS)

In Spiral CT, the pitch is the ratio of the distance to tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examination with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. The authors investigated the yield of pitch 2 in lung parenchyma studies, particular relative to diagnostic image quality.

1999-03-01

135

CR portal imaging  

International Nuclear Information System (INIS)

In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable ...

1992-01-01

136

Application of grazing incidence x-ray diffraction to polymer blends  

Energy Technology Data Exchange (ETDEWEB)

The physical properties of polymer blends consisting of one or more crystallizable components are affected by the microstructure of these materials. In particular, the degree of crystallinity can be influenced by processing parameters, and the crystallinity, as well as the phase distribution, may vary as a function of depth through an injection molded part Conventional x-ray diffraction techniques can provide information regarding both phase composition and degree of crystallinity, but, because of the relative transparency of these materials to wavelengths generally available in the laboratory, these techniques provide information representative of only the bulk. By employing parallel beam optics at varying grazing incidence angles, the x-ray sampling depth can be varied without loss of resolution. This technique can be used to vary the effective analysis depth from the top several hundred angstroms for low razing incidence to centimeters for ...

1992-01-01

137

Application of grazing incidence x-ray diffraction to polymer blends  

Energy Technology Data Exchange (ETDEWEB)

The physical properties of polymer blends consisting of one or more crystallizable components are affected by the microstructure of these materials. In particular, the degree of crystallinity can be influenced by processing parameters, and the crystallinity, as well as the phase distribution, may vary as a function of depth through an injection molded part Conventional x-ray diffraction techniques can provide information regarding both phase composition and degree of crystallinity, but, because of the relative transparency of these materials to wavelengths generally available in the laboratory, these techniques provide information representative of only the bulk. By employing parallel beam optics at varying grazing incidence angles, the x-ray sampling depth can be varied without loss of resolution. This technique can be used to vary the effective analysis depth from the top several hundred angstroms for low razing incidence to centimeters for ...

1992-10-01

138

Gamma and X-ray shielding compositions utilizing bauxite - Red Mud regional research laboratory (CSIR), Bhopal, India  

International Nuclear Information System (INIS)

Available in abstract form only. Full text of publication follows: The application spectrum of X-ray and Gamma radiation is increasing exponentially in the area of diagnostic, nuclear medicine, food preservation, nuclear power plants and strategic utilities. To prevent the harmful effects of these radiations, shielding materials based on lead metal and its compounds are being used historically, which are toxic in nature. To protect environment it has become necessary to develop non-toxic lead free shielding materials. The use of titanium metal and its compounds as synthetic rock i.e. SYNROC are reported to be very effective non-toxic shielding materials for various applications. Red mud waste generated in aluminum producing industries possesses a unique mineralogical compositions containing fairly high quantity of titanium oxide and iron oxide useful for making non toxic shielding compositions and therefore red mud has been ...

2007-09-02

139

X-Ray Fluorescence Analysis of Composite Propellants for ...  

Science.gov (United States)

... The constancy of the X-ray intensity ratio for each element in Table 8 as the X-ray tube settings were changed shows the excellent compensating ...

1977-06-03

140

Radionuclide X-ray fluorescence analysis. 2: Detection of the X-ray fluorescence radiation excited by radionuclide radiation  

Science.gov (United States)

This investigation describes the technique for the detection of the X-ray fluorescent radiation

1972-01-01

141

X-ray Microdiffraction and Strain Gradient Crystal Plasticity Studies of Geometrically Necessary Dislocations Near a Ni Bicrystal Grain Boundary  

Energy Technology Data Exchange (ETDEWEB)

We compare experimental measurements of inhomogeneous plastic deformation in a Ni bicrystal with crystal-plasticity simulations. Polychromatic X-ray microdiffraction, orientation imaging microscopy and scanning electron microscopy, were used to characterize the geometrically necessary dislocation distribution of the bicrystal after uniaxial tensile deformation. Changes in the local crystallographic orientations within the sample reflect its plastic response during the tensile test. Elastic strain in both grains increases near the grain boundary. Finite element simulations were used to understand the influence of initial grain orientation and structural inhomogeneities on the geometrically-necessary dislocations arrangement and distribution and to understand the underlying materials physics.

2009-01-01

142

The search for decaying Dark Matter  

CERN Document Server

We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry of the Universe. In super-WIMP models, the details of the ...

2009-01-01

143

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

144

Real-time cross-sectional averaged void fraction measurements in vertical annulus gas-liquid two-phase flow by neutron radiography and X-ray tomography techniques  

Energy Technology Data Exchange (ETDEWEB)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed Tomography (X-CT) system are used to determine the flow regime, the instantaneous cross-sectional averaged void fraction, and the time averaged void fraction in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements are obtained for gas flow rates form 0.0 to 30.0 l/min. The flow regimes observed by all three measurement systems via image analysis shows that the results agree well with each other. Both the RTNR and the X-CT systems show that the time averaged and cross-sectional averaged void fraction increases with increasing superficial gas velocity. Time and cross-sectional averaged void fractions determined by the RTNR system agree within 4% with those determined by the high speed X-ray CT technique. (orig.).

1995-03-11

145

Real-time cross-sectional averaged void fraction measurements in vertical annulus gas-liquid two-phase flow by neutron radiography and X-ray tomography techniques  

International Nuclear Information System (INIS)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed Tomography (X-CT) system are used to determine the flow regime, the instantaneous cross-sectional averaged void fraction, and the time averaged void fraction in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements are obtained for gas flow rates form 0.0 to 30.0 l/min. The flow regimes observed by all three measurement systems via image analysis shows that the results agree well with each other. Both the RTNR and the X-CT systems show that the time averaged and cross-sectional averaged void fraction increases with increasing superficial gas velocity. Time and cross-sectional averaged void fractions determined by the RTNR system agree within 4% with those determined by the high speed X-ray CT technique. (orig.).

1995-03-01

146

Integration and Testing of the Micro-X Rocket Payload  

Science.gov (United States)

The Micro-X instrument is a rocket borne, X-ray imaging spectrometer planned for launch in October 2011. An array of 128 Transition Edge Sensors (TESs) on a 600 micron pitch will observe incoming photons in the 0.2-3 keV energy band with an energy resolution of 2-4 eV at 1 keV. X-rays will be focused onto the TES array by a conically approximated Wolter optic with an effective area of 300 cm^2 giving the instrument a field of view of 11.8 arcmin. This performance will constitute a substantial improvement over current non-dispersive detectors for X-ray spectroscopy of extended sources and will be the first demonstration of a TES-based microcalorimeter in space. The TESs will utilize the 50 mK stage of an Adiabatic Demagnetization Refrigerator (ADR) as a heat bath, and will be read out by a SQUID time division multiplexer. The first flight of the Micro-X instrument will observe the Puppis A supernova ...

2011-05-01

147

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

148

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

149

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

150

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

151

''SEPIO NUANCE DT'' digital mammography system  

International Nuclear Information System (INIS)

In the past, the need for high quality images, i.e., very sharp and clear images, in mammography have prevented mammography equipment from being digitalized; however, recent advances in detection technology such as development of a high resolution digital X-ray detector have produced improvements in digital mammography. Digital mammography is expected to replace conventional film-screen mammography. We have developed a digital mammography system, named ''SEPIO NUANCE DT'', which is equipped with a direct conversion flat panel detector. The present paper describes the high basic performance and user-friendly functions of the system. (author)

2007-03-01

156

The X-ray Ordinance  

International Nuclear Information System (INIS)

The sections and provisions of the X-ray Ordinance of January 8, 1987 are discussed which are of relevance to dental radiology. (DG).

157

Study of the crystallographic architecture of corals at the nanoscale by scanning transmission X-ray microscopy and transmission electron microscopy.  

Science.gov (United States)

We have investigated the nanotexture and crystallographic orientation of aragonite in a coral skeleton using synchrotron-based scanning transmission X-ray microscopy (STXM) and transmission electron microscopy (TEM). Polarization-dependent STXM imaging at 40-nm spatial resolution was used to obtain an orientation map of the c-axis of aragonite on a focused ion beam milled ultrathin section of a Porites coral. This imaging showed that one of the basic units of coral skeletons, referred to as the center of calcification (COC), consists of a cluster of 100-nm aragonite globules crystallographically aligned over several micrometers with a fan-like distribution and with the properties of single crystals at the mesoscale. The remainder of the skeleton consists of aragonite single-crystal fibers in crystallographic continuity with the nanoglobules comprising the COC. Our observation provides information on the nm-scale processes ...

2011-05-05

158

Validity of the CT to attenuation coefficient map conversion methods  

International Nuclear Information System (INIS)

The most important commercialized methods of attenuation correction in SPECT are based on attenuation coefficient map from a transmission imaging method. The transmission imaging system can be the linear source of radioelement or a X-ray CT system. The image of transmission imaging system is not useful unless to replacement of the attenuation coefficient or CT number with the attenuation coefficient in SPECT energy. In this paper we essay to evaluate the validity and estimate the error of the most used method of this transformation. The final result shows that the methods which use a linear or multi-linear curve accept a error in their estimation. The value of mA is not important but the patient thickness is very important and it can introduce a error more than 10 percent in the final result.

2004-04-27

159

Polynomial curve fitting method for refraction-angle extraction in diffraction enhanced imaging  

International Nuclear Information System (INIS)

X-ray diffraction enhanced imaging (DEI) is applied to inspect internal structures of weakly absorbing low-Z sample. How to extract phase information from raw images measured in different positions of rocking curve is the key problem of DEI. In this paper, we present an effective extraction method called polynomial curve fitting method, in order to extract accurate information angular in a fast speed. It is com- pared with the existing methods such as multiple-images statistical method and Gaussian curve fitting method. The experiments results on a plastic cylinder and a black ant at the Beijing Synchrotron Radiation Facility prove that the polynomial curve fitting method can obtain most approximate refraction-angle values and its computation speed is 10 times faster than the Gaussian curve fitting method. (authors)

2009-11-01

160

Determination of the optimal speed of rotational display through an 180 degree arc in rotatostereoradiography and MR angiography  

International Nuclear Information System (INIS)

Rotatostereoradiographic (RSRG) images are displayed in an oscillating, rotational manner. While reviewing these rotating images, the radiologist may become psychologically irritated by the rotation. A rapidly rotating display of linear subjects gives one three-dimensional depth information. This three-dimensional sense is lost if the rotation speed is too slow. The authors of this paper determined the slowest possible rotating display speed that allows perception of three-dimensional depth information minimizing psychological irritation. In the RSRG device (Shimadzu ROTATO-360), an x-ray tube coupled with an image intensifier rotates through a 180 degrees arc in 1.8 or 2.25 seconds. Both rotation times could be doubled. The images were displayed at four different speeds, covering the 180 degrees arc in 1.8, 2.25, 3.6, and 4.5 seconds.

1990-11-25

161

3D Fourier synthesis of a new X-ray picture identical in projection to a previous picture  

Energy Technology Data Exchange (ETDEWEB)

A central problem in diagnostic radiology is to compare a new X-ray picture with a previous picture and from this comparison be able to decide if anatomical changes have occurred in the patient or not. It is of primary interest that these pictures are identical in projection. If not it is difficult to decide with confidence if differences between the pictures are due to anatomical changes or differences in their projection geometry. In this thesis we present a non invasive method that makes it possible to find the relative changes in the projection geometry between the exposure of a previous picture and a new picture. The method presented is based on the projection slice theorem (central section theorem). Instead of an elaborate search for a single new picture a pre-planned set of pictures are exposed from a circular orbit above the patient. By using 3D Fourier transform techniques we are able to synthesize a new X-ray picture from this set of ...

1993-11-01

162

Experimental and clinical studies on the usefulness and assessment of the angiographic images processed by a digital radiography system (FCR: Fuji Computed Tomography)  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to assess experimentally and clinically the usefulness of Fuji Computed Radiography (FCR) in angiographic examinations. FCR had a spatial resolution with much lower X-ray exposure doses, although the resolution of FCR was generally inferior to conventional films. When a contrast medium of 1% iodine concentration was used, FCR pinpointed a mass 1.5 mm in diameter; and conventional film could detect a mass 2.2 mm in diameter. The contrast of iodine in FCR examinations was stable. A high sensitivity of imaging plate allowed a wide range of visualization. In 148 selective angiographic examinatinons for 138 patients, FCR-subtraction images were superior to conventional film angiography for contrast resolution; it had a high sensitivity in detecting areas, such as the mediastimun and left lobe of the liver, and tumor stains in capillary phase. The capability of FCR arteriogram was as good as film ...

1989-06-01

163

Experimental and clinical studies on the usefulness and assessment of the angiographic images processed by a digital radiography system (FCR: Fuji Computed Tomography)  

International Nuclear Information System (INIS)

The purpose of this study was to assess experimentally and clinically the usefulness of Fuji Computed Radiography (FCR) in angiographic examinations. FCR had a spatial resolution with much lower X-ray exposure doses, although the resolution of FCR was generally inferior to conventional films. When a contrast medium of 1% iodine concentration was used, FCR pinpointed a mass 1.5 mm in diameter; and conventional film could detect a mass 2.2 mm in diameter. The contrast of iodine in FCR examinations was stable. A high sensitivity of imaging plate allowed a wide range of visualization. In 148 selective angiographic examinatinons for 138 patients, FCR-subtraction images were superior to conventional film angiography for contrast resolution; it had a high sensitivity in detecting areas, such as the mediastimun and left lobe of the liver, and tumor stains in capillary phase. The capability of FCR arteriogram was as good as film ...

1989-01-01

164

Chemical and morphological characterization of mesoporous material supported copper oxide nanoparticles for potential application  

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

165

Charge Redistribution in Pd-Ag Alloys from a Local Perspective  

Science.gov (United States)

Using Pd and Ag L3,2-edge x-ray-absorption near edge structures (XANES) and x-ray photoemission spectroscopy, we have investigated the charge distribution in a series of Pd-Ag alloys (Pd3Ag, PdAg, and PdAg3) from a local perspective. It is found that, relative to the pure element, both Pd and Ag gain d and lose non-d (s and p) charge upon alloying. The results are discussed in terms of band filling, rehybridization, electronegativity, and electroneutrality considerations. The possibility of using the L3,2-edge XANES white line to circumvent the need of an appropriate volume for charge transfer discussions and for other applications are noted.

1996-12-01

166

Beryllium coating on JET Inconel tiles  

International Nuclear Information System (INIS)

Full text: Institute for Nuclear Research, Pitesti-Mioveni, Romania in direct cooperation with the National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest studied and prepared for coating more than 1000 tiles made of Inconel with 7-9 #mu#m of beryllium for nuclear fusion applications at JET, Culham, UK. The principles of manufacturing processes using thermal evaporation and plasma ignited in pure metal vapors as well as by Thermionic Vacuum Arc (TVA) method and the properties of the Ni and Be coatings are presented. The prepared beryllium layers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy. (authors)

2009-10-12

167

Application of CaSO4:Dy (TLD-900) to diagnostic x-ray exposures  

International Nuclear Information System (INIS)

The properties of a new commercial thermoluminescent dosimeter, CaSO4:Dy without a LiF binder (TLD-900) was studied for low-exposure measurements in diagnostic radiology. The former TLD-900 had a LiF binder (herein referred to as ''TLD-900/LiF''). The principle features of this dosimeter are its high sensitivity to low-energy radiation and its relatively low fading which permits measurements down to less than 2.6 X 10(-8) C kg (0.1 mR) with an accuracy better than 20%. The characteristics, annealing procedures, light sensitivity, energy response, reproducibility, and fading, of TLD-900 are discussed and compared with TLD-900/LiF. When the precautions presented in this paper are used, the dosimeters can be used for the measurement of x-ray exposures.

168

Upgrade of X-ray Magnetic Diffraction Experimental System and Its Application to Ferromagnetic Material  

International Nuclear Information System (INIS)

We have performed X-ray magnetic diffraction (XMD) experiment of ferromagnets at the Photon Factory (PF) of the High Energy Accelerator Research Organization (KEK) in Tsukuba. In this study, we have upgraded the XMD experimental system in order to apply this method to as many samples as possible. Upgrade was made for (1) the X-ray counting system and related measurement program, (2) the electromagnet, and (3) the refrigerator. The performance of the system was enhanced so that (1) the counting rate capability was improved from 104cps to 105cps, (2) the maximum magnetic field was increased from 0.85T to 2.15T, and (3) the lowest sample temperature was reduced from 15K to 5K. The new system was applied to an orbital ordering compound of YTiO3, and we obtained spin magnetic form factor for the reflection plane (010) perpendicular to the b axis. The magnetic field of 2T was needed to saturate the magnetization of YTiO3 along the b axis. These are ...

2007-01-19

169

Evolution of surface roughness in silicon X-ray mirrors exposed to a low-energy ion beam  

International Nuclear Information System (INIS)

The possibility of smoothening aspherical X-ray mirrors by irradiation of the surface with a low-energy ion beam is investigated. Nanofocusing being the primary application of these mirrors the ion beam conditions must be optimized to achieve a surface roughness of the order of 0.1-0.2 nm. To address this issue a first study was performed on silicon flat substrates etched using ion energies ranging from 400 to 1200 eV. A second study consisted of eroding the silicon surface while varying the ion grazing incidence angle between 10 deg. and 90 deg. for a fixed value of the ion energy. The surface topography of the samples was characterized at various scales using atomic force microscopy (probed area: 1-10 ?m2), interferential optical microscopy (probed area: 1 mm2) and X-ray scattering (probed area: 100 mm2). Finally, a study by AFM of the evolution of the surface finish level of a silicon mirror after ion erosion at various ...

2010-05-01

170

Application of radionuclide X-ray fluorescence analysis to the monitoring of the quality of air  

International Nuclear Information System (INIS)

An X-ray fluorometric train was set up for analyzing gravitational fallout, and tested on standard reference samples of fly ashes from conventional power plants. Analysis of thin layers proved inappropriate, and therefore pelletization of the samples, either alone or together with the X-ray MIX binder, was applied. Sample grinding in an agate mortar was found sufficient to suppress the particle size effect. The optimum pressure was 20 MPa. The optimum geometry was sought for "1"0"9Cd source, and limits of detection of 2.78-0.47 #mu#g were achieved for Cr-Zr elements. Tominaga's method was employed for matrix effect correction. Ti, Fe, Cu, Zn, As, Rb, Sr, Zr and Pb were determined in the SRM's; the relative errors ranged from units per cent (for Zn, Rb, Sr and Zr present in concentrations about 100 ppm and for Fe in concentrations of units per cent) up to 45% (for Ti present in a concentration of 0.67%). The method developed was applied to the ...

1990-10-01

171

Total dose hardening of SIMOX buried oxides for fully depleted devices in rad-tolerant applications  

International Nuclear Information System (INIS)

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

1996-07-15

172

Reference values for X-ray diagnostic investigations. Some thoughts on the relation between expenditure and benefit  

International Nuclear Information System (INIS)

In the first part of this contribution, the definition of reference values is given and the theoretical and practical problems in the application of this concept are discussed. In this connection, the present resources on instrumentation and the technical requirements for dose assessment are described. In the second part, some consequences are taken and proposals for further actions are made. (orig.)

173

Crystallization and preliminary X-ray diffraction studies of two thermostable ?-galactosidases from glycoside hydrolase family 36  

UK PubMed Central (United Kingdom)

α-Galactosidases from thermophilic organisms have gained interest owing to their applications in the sugar industry. The α-galactosidases AgaA, AgaB and AgaA A355E mutant from Geobacillus...Full Text Available

174

Application of isotope-excitation x-ray fluorescence (XRF) analysis for aluminium production  

International Nuclear Information System (INIS)

An energy sensitive Si(Li) detector XRF analyzer built by ATOMKI, Hungary, has been applied for various analytical purposes in alumina production at the Almasfuezitoe Alumina Company, Hungary. Specifically, the CaO content in red mud was determined by the new XRF technique using isotope excitation sources. The analysis of other components is under way. (R.P.).

175

2. Nuclear analytical methods and environmental protection  

International Nuclear Information System (INIS)

The first step in the protection of the environment is the control of pollutant level in the components of the environment. The application is compared of radionuclide X-ray fluorescence analysis (RXFA) used for this purpose with polarographic and nuclear analytical techniques. The advantage of RXFA is its high sensitivity and selectivity, its low time and cost exactingness. The origins and development of RXFA are described. (Ha).

1983-12-01

176

Dosimetric properties of an applicator system for intraoperative electron-beam therapy utilizing a Clinac--18 accelerator  

International Nuclear Information System (INIS)

A prototype electron applicator system providing circular and rectangular fields for use in intraoperative electron beam therapy with a Varian Clinac 18 linear accelerator has been fabricated. The dosimetric properties of this system for a variety of electron-beam energies, applicator sizes, and x-ray collimator settings was documented. Significant findings include: (a) surface dose values are in excess of 90% for electron energies of 12 MeV and above; (b) for the 18-MeV beam, the deepest depth where the central axis dose is 90% of its maximum value is in excess of 50 mm for circular applicators whose diameters are in excess of 5 cm; and (c) the treatment time to deliver 1000 rads ''given dose'' (at a given dose rate of 300 MU/min) is on the order of 3--4 min. Cross-field behavior is acceptable for the intended application and x-ray contamination is less than 4% ...

177

Adaptive Image Processing A Computational Intelligence Perspective  

CERN Document Server

Adaptive image processing is one of the most important techniques in visual information processing, especially in early vision such as image restoration, filtering, enhancement, and segmentation. This work focuses on applications of advanced CI techniques in image processing applications

2009-01-01

178

PET/MRI hybrid imaging: devices and initial results  

International Nuclear Information System (INIS)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with ...

2008-06-01

179

Compressed-shell integrity measurements in spherical implosion experiments  

International Nuclear Information System (INIS)

The shell integrity near peak compression of spherical implosions using the 60-beam, 30-kJ UV OMEGA laser system [Opt. Commun. 133, 495 (1997)] has been measured. Hot core emission backlights a shell with a thin titanium-doped layer that is imaged at x-ray photon energies above and below the titanium K edge. The x-ray intensity ratio between the two images is related to perturbations in the cold, or absorbing, part of the shell. The measured cold-shell areal-density modulations, integrated over the time of peak compression, are of the order of 25% to 50% with nonuniformity spectra peaked at spatial wavelengths of 30 to 50 #mu#m and with the smallest detectable nonuniformity features extending down to spatial wavelengths of 12 to 15 #mu#m. Hot-shell areal-density modulations of the emitting part of the shell (inner edge) are of the order of 13% to 20%. The measured shell modulations are in agreement with ...

2001-06-01

180

The determination of optical conditions of Fuji computed radiography (FCR) in pelvimetry and the reduction of radiation dose to mother and fetus  

Energy Technology Data Exchange (ETDEWEB)

The determination of optical parameter type in x-ray pelvimetry was performed on 59 subjects using Fuji computed radiography (FCR). Excellent measurable images were obtained at GT (type A), RT (type P), GA (1.6) and RN (2.0). To reduce maternal and fetal exposure to radiation, the doses were progressively decreased to 50%, 25%, 12.5%, 6.3%, that of conventional screen/film system. One-eighth per cent of conventional radiation dose was minimum for FCR at which measurable images could be obtained. Thereby drastically reducing the radiological exposure to both mother and fetus was possible to obtain measurable images in FCR. (author).

1991-05-01

181

The determination of optical conditions of Fuji computed radiography (FCR) in pelvimetry and the reduction of radiation dose to mother and fetus  

International Nuclear Information System (INIS)

The determination of optical parameter type in x-ray pelvimetry was performed on 59 subjects using Fuji computed radiography (FCR). Excellent measurable images were obtained at GT (type A), RT (type P), GA (1.6) and RN (2.0). To reduce maternal and fetal exposure to radiation, the doses were progressively decreased to 50%, 25%, 12.5%, 6.3%, that of conventional screen/film system. One-eighth per cent of conventional radiation dose was minimum for FCR at which measurable images could be obtained. Thereby drastically reducing the radiological exposure to both mother and fetus was possible to obtain measurable images in FCR. (author).

1991-01-01

182

Identification of fatigue damage in cortical bone by diffraction enhanced imaging  

International Nuclear Information System (INIS)

In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.

2005-08-11

183

Similarity between the primary and secondary air-assisted liquid jet breakup mechanism  

CERN Document Server

we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide range of air speeds. This finding reveals the intrinsic connections of these two breakup regimes and has deep implications on the unified theoretical approach in treating the breakup mechanism of high speed liquid jet.

2007-01-01

184

Projection techniques in diagnostic radiography discussed with regard to required dose  

International Nuclear Information System (INIS)

The paper presents information in the form of data, tables and diagrams compiled to a broad but very up-to-date survey of required radiation for the various most frequently performed X-ray examinations of patients. The required dose is discussed from the point of view of radiation protection, defining the inevitably administered dose to the skin, the frequency of examinations, and the diagnostic image quality as the main three factors to be observed, as these determine the radiation dose to the patient and to the personnel. The somatic risks of radiography examinations are a point of main interest. (DG).

1990-09-01

185

Acute diaphragmatic paralysis caused by chest-tube trauma to phrenic nerve  

International Nuclear Information System (INIS)

A 3"1/_2-year-old child developed unilateral diaphragmatic paralysis after chest drain insertion. Plain chest X-ray demonstrated paravertebral positioning of the chest-tube tip, and magnetic resonance imaging revealed hematomas in the region of the chest-tube tip and the phrenic nerve fibers. The trauma to the phrenic nerve was apparently secondary to malposition of the chest tube. This is a rare complication and has been reported mainly in neonates. Radiologists should notify the treating physicians that the correct position of a chest drain tip is at least 2 cm distant from the vertebrae. (orig.)

2001-06-01

186

The influence of different SPECT reconstruction algorithms on cardiac ischemia with the use artificial neural networks  

International Nuclear Information System (INIS)

The aim of the study was the attempt to evaluate the influence of two different methods of cardiac perfusion SPECT reconstruction (FBP and ITW) on clinical efficacy in diagnosing the coronary artery disease as well as the cardiac ischemia detection in three areas of heart vascularized by main coronary arteries: LAD, LCX and RCA with the use of artificial neural networks (ANN). The study was performed retrospectively with the use of the diagnostic image records as well as clinical dataset of 43 patients. Myocardial perfusion stress/rest SPECT study and X-ray coronarography data were evaluated for each patient. The results of coronary angiography were considered the reference method. The cardiac SPECT data were reconstructed using the two different methods: filtered backprojection (FBP) and iterative Wallis method (ITW). The local perfusion deficits denominated in stress and rest study in three main vessel cardiac segments were the main input ...

187

Image-enhancement applications at the Lawrence Livermore National Laboratory  

Energy Technology Data Exchange (ETDEWEB)

A diverse set of digital image-processing applications exists at the Lawrence Livermore National Laboratory. While many of these include some sort of image analysis or restoration, virtually all of them require image-enhancement procedures. In this paper we describe the principal image-processing facility at the Laboratory, followed by a discussion of several of the major image-processing application areas.

1982-06-01

188

Nondestructive testing of metal coating thickness and control of chemical composition using radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

The principle is described of a method using low-activity emitters as the primary radiation source for analysis. The selection of the radiation source and the detection methods including the assessment of the applicability of various radiation detectors are discussed. The benefits and the constraints of the method are considered. Practical examples are presented showing the application possibilities of the method for testing the thickness of bearing layers, piston ring coats, lead layers, etc. The possibility is shown of applying the rapid test for the composition of tungsten and chromium alloyed metal materials in testing complex systems. (J.K.).

1974-12-03

189

X-ray magnetic circular dichroism measurements using an X-ray phase retarder on the BM25 A-SpLine beamline at the ESRF  

UK PubMed Central (United Kingdom)

Circularly polarized X-rays produced by a diamond X-ray phase retarder of thickness 0.5 mm in the Laue transmission configuration have been used for recording X-ray magnetic circular dichroism...Full Text Available

2010-05-01

190

Sampling and analytical methodologies for energy dispersive X-ray fluorescence analysis of airborne particulate matter  

International Nuclear Information System (INIS)

The present document represents an attempt to summarize the most important features of the different forms of ED-XFR as applied to the analysis of airborne particulate matter. It is intended to serve as a set of guidelines for use by participants in the IAEA's own programmes, and other scientists, who are not yet fully experienced in the application of ED-XRF to airborne particulate samples, and who wish either to make a start on using this technique or to improve their existing procedures. The methodologies for sampling described in this document are of rather general applicability. Emphasis is also placed on the sources of errors affecting the sampling of airborne particulate matter. The analytical part of the document describes the different forms of ED-XRF and their potential applications. Spectrum evaluation, a key step in X-ray spectrometry, is covered in depth, including discussion on several ...

1986-06-25

191

Computed radiography (FCR) with a dual side reading system. Comparison with conventional radiography for visualization of nodular lung cancers  

International Nuclear Information System (INIS)

To assess the diagnostic capability Fuji computed radiography (FCR) using a dual side reading system was compared to the conventional radiography using a film-screen system. Twenty-eight patients with lung cancer were examined with a new FCR system (FCR 5501D) and a conventional screen-film system concurrently. FCR utilizes a reading system that detects emissions from dual sides of imaging plate. Chest X-rays were obtained with same exposure factors in both systems. Image qualities of both systems were compared by two radiologists using a five-level score. There were no lesion that FCR images were inferior to film-screen images. The frequency of score +1 or +2 that FCR images were superior to film-screen images was 31% in large nodular shadows, 40% in accompanying shadows with a nodule, 67% of small nodular shadows, and 43% of the lymph node ...

2003-02-01

192

Introducing DeBRa: a detailed breast model for radiological studies  

Energy Technology Data Exchange (ETDEWEB)

Currently, x-ray mammography is the method of choice in breast cancer screening programmes. As the mammography technology moves from 2D imaging modalities to 3D, conventional computational phantoms do not have sufficient detail to support the studies of these advanced imaging systems. Studies of these 3D imaging systems call for a realistic and sophisticated computational model of the breast. DeBRa (Detailed Breast model for Radiological studies) is the most advanced, detailed, 3D computational model of the breast developed recently for breast imaging studies. A DeBRa phantom can be constructed to model a compressed breast, as in film/screen, digital mammography and digital breast tomosynthesis studies, or a non-compressed breast as in positron emission mammography and breast CT studies. Both the cranial-caudal and mediolateral oblique views can be modelled. The anatomical details ...

2009-07-21

193

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)

194

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

195

Estimating hip fracture risk from digital x-ray image data  

International Nuclear Information System (INIS)

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

196

Designing engineering upgradability into magnetic resonance imagers: Impact on future costs  

Energy Technology Data Exchange (ETDEWEB)

MRI is a powerful diagnostic modality of expanding availability. Equipment and installation amount to nearly $2M per site. An important component of diagnostic efficacy is not just equipment costs but also replacement costs, which for x-ray CT amount to 14-20% of the purchase cost per year; and in the early years of that technology reached 30-50%. The authors show how design choices made during the RandD stages of MRI development have allowed them to improve system performance parameters such as data reconstruction, archiving and display speeds, computational capabilities, operator interfaces, imaging sequence flexibility and signal-to-noise levels. Over the last four years these improvements have been made at a retrofit cost well below the target of 6-7% of the purchase price per year.

1987-02-01

197

X-ray stars in globular clusters  

Science.gov (United States)

The properties and kinetics of x-ray stars in globular clusters are described. Locations, configurations, star evolution, massive close binary systems, various mechanisms, and the x-ray burster properties are included. (JFP)

1977-10-01

198

X-ray dose enhancement effects  

International Nuclear Information System (INIS)

A brief description of the physical process of dose enhancement effects produced by X-ray radiation on materials is given, with emphasis on the influence on electronic devices. The damages caused by X-ray radiation dose enhancement is more serious than that of #gamma#-ray with higher energy.

199

Beam-induced damage on diffractive hard X-ray optics  

UK PubMed Central (United Kingdom)

The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both...Full Text Available

2010-11-01

200

Synthesis of novel high-voltage cathode material LiCoPO{sub 4} via rheological phase method  

Energy Technology Data Exchange (ETDEWEB)

For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO{sub 4}. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm{sup -2}. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g{sup -1}, respectively. The better electrochemical property should be ascribed to the ...

2010-07-23

201

Synthesis of novel high-voltage cathode material LiCoPO4 via rheological phase method  

International Nuclear Information System (INIS)

For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO4. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm-2. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g-1, respectively. The better electrochemical property should be ascribed to the better crystallized ...

2010-07-23

202

Soft X-ray holography of FIB nanostructured Co/Pt multilayers  

International Nuclear Information System (INIS)

Focused Ion Beam (FIB) milling is a powerful tool to produce ordered magnetic nanostructures. However, it is impossible to produce out-of-plane magnetized nanoscale structures from multilayer films by direct FIB writing. Co/Pt multilayers exhibit an out-of-plane easy axis due to strong perpendicular interface anisotropy. The interface contribution is known to be very sensitive to high energy ion irradiation. In case of 30 keV Ga ions it needs less than one ion per 100 surface atoms to destroy the perpendicular interface anisotropy. We demonstrate how this problem can be overcome by milling a Co/Pt multilayer, which has been deposited on a SiN membrane, from the rear side, through the SiN. The effect of the ions is determined as a function of applied dose utilizing the domain structure imaged by soft X-ray holography. When the magnetic material is removed we find only a very narrow range of destruction around the holes in contrast to the ...

2009-03-22

203

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

204

Cross-sectional void fraction distribution measurements in a vertical annulus two-phase flow by high speed X-ray computed tomography and real-time neutron radiography techniques  

Energy Technology Data Exchange (ETDEWEB)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed tomography (X-CT) system are compared for measurement of two-phase flow. Each system is used to determine the flow regime, and the void fraction distribution in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements obtained for gas flow rates from 0.0 to 30.01/min. The flow regimes observed by all three measurement systems through image analysis shows that the two-dimensional void fraction distribution can be obtained. The X-CT system is shown to have a superior temporal resolution capable of resolving the void fraction distribution in an (r,{theta}) plane in 33.0 ms. Void fraction distribution for bubbly flow and slug flow is determined.

1995-09-01

205

Cross-sectional void fraction distribution measurements in a vertical annulus two-phase flow by high speed X-ray computed tomography and real-time neutron radiography techniques  

International Nuclear Information System (INIS)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed tomography (X-CT) system are compared for measurement of two-phase flow. Each system is used to determine the flow regime, and the void fraction distribution in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements obtained for gas flow rates from 0.0 to 30.01/min. The flow regimes observed by all three measurement systems through image analysis shows that the two-dimensional void fraction distribution can be obtained. The X-CT system is shown to have a superior temporal resolution capable of resolving the void fraction distribution in an (r,#theta#) plane in 33.0 ms. Void fraction distribution for bubbly flow and slug flow is determined.

1995-09-01

206

Camera for coherent diffractive imaging and holography with a soft-x-ray free-electron laser  

International Nuclear Information System (INIS)

We describe a camera to record coherent scattering patterns with a soft-x-ray free-electron laser (FEL). The camera consists of a laterally graded multilayer mirror, which reflects the diffraction pattern onto a CCD detector. The mirror acts as a bandpass filter for both the wavelength and the angle, which isolates the desired scattering pattern from nonsample scattering or incoherent emission from the sample. The mirror also solves the particular problem of the extreme intensity of the FEL pulses, which are focused to greater than 10"1"4 W/cm"2. The strong undiffracted pulse passes through a hole in the mirror and propagates onto a beam dump at a distance behind the instrument rather than interacting with a beam stop placed near the CCD. The camera concept is extendable for the full range of the fundamental wavelength of the free electron laser in Hamburg (FLASH) FEL (i.e., between 6 and 60 nm) and into the water window. We have fabricated and tested various ...

2008-04-01

207

Automatic system for measuring dose-area product (DAP) in ROI fluoroscopy  

Energy Technology Data Exchange (ETDEWEB)

A computerized system for monitoring dose-area product (DAP) has been developed for region of interest (ROI) fluoroscopy in which patient exposure is reduced using an x-ray attenuating filter with an aperture. The system includes an IBM compatible computer which is connected through an IEEE-488 interface to an electrometer which measures the charge from a DAP ionization chamber. A digital input/output board connects the computer to the filter placement device to determine whether the filter is in or out of the beam, and to the x-ray generator to determine when the exposure is due to spot filming. The computer logs the DAP from conventional fluoroscopy, ROI fluoroscopy and spot filming separately, applying the appropriate calibration factor for each. Measured DAPs, fluoroscopic DAP rates and exposure times are displayed in real-time. The system has been installed in a GI fluoroscopic room so that the dose-reduction potential of ROI ...

1997-04-01

208

Photoacoustic response to X-ray absorption in copper and brass  

Energy Technology Data Exchange (ETDEWEB)

The X-ray photoacoustic spectra of copper and brass (64.7 wt.% Cu and 35.3 wt.% Zn) have been measured at XANES (X-ray absorption near-edge structure) regions using synchrotron radiation. These spectra were compared with optical density of X-ray spectra. It is shown that the information derived from XANES is also included in the X-ray photoacoustic spectrum which reflects the heat production processes in copper and brass. However, the results showed that the increases and changes of the photoacoustic signal were different from those of the X-ray absorption coefficient at XANES regions. (author).

1990-09-01

209

Generation of microwaves and hard X-rays in a flash X-ray tube  

Energy Technology Data Exchange (ETDEWEB)

High interelectrode voltage peaks have been observed simultaneously with the emission of hard X-ray bursts from a flash X-ray tube. The magnitude of the voltage peaks may exceed twice the initial charging voltage. It has also been observed that the discharge emits bursts of X-and P-band microwaves radiation which are coincident with the emission of the hard X-ray bursts. The results indicate that the microwaves and X-rays have a common origin in discharge plasma movements and an acceleration model for electrons in the plasma is presented as one possible explanation of the observed phenomena.

1982-01-01

210

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

International Nuclear Information System (INIS)

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

2010-12-15

211

Application of spectroscopic techniques for the study of paper documents: A survey  

International Nuclear Information System (INIS)

For many centuries paper was the main material for recording cultural achievements all over the world. Paper is mostly made from cellulose with small amounts of organic and inorganic additives, which allow its identification and characterization and may also contribute to its degradation. Prior to 1850, paper was made entirely from rags, using hemp, flax and cotton fibres. After this period, due to the enormous increase in demand, wood pulp began to be commonly used as raw material, resulting in rapid degradation of paper. Spectroscopic techniques represent one of the most powerful tools to investigate the constituents of paper documents in order to establish its identification and its state of degradation. This review describes the application of selected spectroscopic techniques used for paper characterization and conservation. The spectroscopic techniques that have been used and will be reviewed include: Fourier-Transform Infrared spectroscopy, Raman ...

2009-06-01

212

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 ...

1987-04-01

213

x - NASA Technical Reports Server  

Science.gov (United States)

Mar 1, 2011 ... Radionuclide X-ray fluorescence analysis. 2: Detection of the X-ray fluorescence radiation excited by radionuclide radiation ...

215

A comparison of the X-ray properties of X Per and gamma Cas  

Energy Technology Data Exchange (ETDEWEB)

The X-ray properties of the main sequence Be stars conclude that they are a widely separated binary system containing an accreting neutron star.

1982-04-01

216

Radionuclide X-ray fluorescence analysis with environmental application  

International Nuclear Information System (INIS)

The purpose of this work is to present a comprehensive, instructive analysis of the basis of radionuclide XRFA, to describe methods of sample preparation for environmental analysis and to make the reader more familiar with the procedures, methods and instrumentation of radionuclide XRFA used in this field. This book discusses the use of radionuclide XRFA for solving analytical problems of the environment and information is presented concerning the current state of research and use of radionuclide XRFA in this significant area. The present volume will serve as a basic source of data and also as a laboratory handbook. refs.; figs.; tabs.

1990-01-01

217

Large-area metallic photonic lattices for military applications.  

Energy Technology Data Exchange (ETDEWEB)

In this project we developed photonic crystal modeling capability and fabrication technology that is scaleable to large area. An intelligent optimization code was developed to find the optimal structure for the desired spectral response. In terms of fabrication, an exhaustive survey of fabrication techniques that would meet the large area requirement was reduced to Deep X-ray Lithography (DXRL) and nano-imprint. Using DXRL, we fabricated a gold logpile photonic crystal in the <100> plane. For the nano-imprint technique, we fabricated a cubic array of gold squares. These two examples also represent two classes of metallic photonic crystal topologies, the connected network and cermet arrangement.

2007-11-01

218

Application of radionuclide X-ray fluorescence analysis in determining lanthanum content in tungsten and in iron by internal standard technique  

Energy Technology Data Exchange (ETDEWEB)

The use of the method is described on powder samples before and after sintering with a La content of up to 1%. For excitation of the K series of La a /sup 241/Am source with an activity of 1.11 GBq was used. The obtained results showed that the method is sufficiently accurate (error 7%) at a short period of measurement (100 s). It gives satisfactory results even in the comparison of the experimental relative count rate and the theoretically calculated value despite the fact that the analytical signal comes from the sample surface.

1983-05-01

219

Application of radionuclide X-ray fluorescence analysis in determining lanthanum content in tungsten and in iron by internal standard technique  

International Nuclear Information System (INIS)

The use of the method is described on powder samples before and after sintering with an La content of up to 1%. For excitation of the K series of La a _2_4_1Am source with an activity of 1.11 GBq was used. The obtained results showed that the method is sufficiently accurate (error 7%) at a short period of measurement (100 s). It gives satisfactory results even in the comparison of the experimental relative count rate and the theoretically calculated value despite the fact that the analytical signal comes from the sample surface. (Ha).

1983-01-01

220

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

221

Digital processing to improve image quality in real-time neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a ...

1985-01-01

222

Digital processing to improve image quality in real-time neutron radiography  

International Nuclear Information System (INIS)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a ...

1985-01-01

223

Sequential changes in the femoral head after intracapsular fracture of the femoral neck. MRI findings  

International Nuclear Information System (INIS)

Authors obtained T1-weighted MRI images of the femoral head after fracture of the femoral neck and classified the signals into four patterns to investigate the sequential changes of the femoral head. The T1-weighted MRI images obtained initially after femoral neck fracture showed a normal pattern in 10 of the 15 hip joints studied. MRI images obtained subsequently still showed the normal signal pattern in eight of the 10 hip joints which had shown the normal pattern in the first MRI, while two of the 10 joints subsequently showed a band pattern. The joint with the homogeneous pattern in the first MRI subsequently showed a band pattern. Of the three joints with an inhomogeneous pattern in the first MRI, two joints showed a subsequent band pattern, and the other a normal pattern. The joints which showed a band pattern continued to show a similar band pattern. Eventually, all hip joints studied showed a normal or band pattern ...

1998-07-01

224

A novel method to characterize the MTF in 3D for computed mammotomography  

Science.gov (United States)

A novel phantom has been developed to measure the modulation transfer function (MTF) in 3D for x-ray computed tomography. The phantom consists of three tungsten wires, positioned nearly orthogonal to each other. Simultaneous measurements of the MTF are taken at various locations along the three orthogonal reconstructed planes. Our computed mammotomography (CmT) system uses a Varian Paxscan 2520 digital x-ray detector which can be positioned anywhere in ~2pi steradian band and can have arbitrary trajectories. With a half-cone beam geometry and with the phantom positioned near the center of rotation, projection images are acquired over 360 degrees. Various 3D orbits are evaluated including vertical axis of rotation and saddle. Reconstructions were performed using an iterative ordered-subsets transmission algorithm on rebinned projection images, using various numbers of iterations. Rotation of ...

2006-03-01

225

Digital direct magnification mammography with storage phosphor screens. Standardized and image result dependent post-processing parameters  

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 ...

226

Radiation methods in research of ancient monuments  

Energy Technology Data Exchange (ETDEWEB)

A 'Laboratory of Quantitative Methods in Monument Research' is being built at the CTU Prague. Its primary orientation is the investigation of historic architecture, although other objects of art can also be investigated. In the first phase, two radiation methods are being established, but it is set up in such a way, that various other methods can readily be added in its future development. The radiation methods chosen for the initial development of the laboratory are: thermoluminescence dating and X-ray fluorescence analysis. The design of the automated TL-reader, built in our laboratories, is adjusted for the purpose of dating of historic brick architecture (which, of course, does not exclude applications for ceramics and other materials). The investigation of renaissance architecture in southern Bohemia and Moravia is under preparation as the first large campaign of this kind in the Czech Republic. Radionuclide ...

2000-11-15

227

Radiation methods in research of ancient monuments  

International Nuclear Information System (INIS)

A 'Laboratory of Quantitative Methods in Monument Research' is being built at the CTU Prague. Its primary orientation is the investigation of historic architecture, although other objects of art can also be investigated. In the first phase, two radiation methods are being established, but it is set up in such a way, that various other methods can readily be added in its future development. The radiation methods chosen for the initial development of the laboratory are: thermoluminescence dating and X-ray fluorescence analysis. The design of the automated TL-reader, built in our laboratories, is adjusted for the purpose of dating of historic brick architecture (which, of course, does not exclude applications for ceramics and other materials). The investigation of renaissance architecture in southern Bohemia and Moravia is under preparation as the first large campaign of this kind in the Czech Republic. Radionuclide X-ray ...

2000-11-15

228

Nanostructured p-CuIn3Se5/n-CdS heterojunction engineered using simple wet chemical approach at room temperature for photovoltaic application  

British Library Electronic Table of Contents (United Kingdom)

Herein, we report engineering of nanostructured p-CuIn3Se5/n-CdS heterojunction thin film on a glass substrate, which is prepared at room temperature using simple wet chemical approach involving ion exchange reactions between CdS and Cu^+, In^3^+ and Se^2^- ions in alkaline medium. The uniform deposition of heterojunction thin films is achieved by optimizing the pH, temperature and molarity of the reactant bath. The as-deposited thin-films were annealed at 200^oC in air for 1h and further characterized for structural, optical and electrical properties using UV-Vis spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Hall effect for type of conductivity, and I-V measurement to investigate the char...

2011-01-01

229

Measuring head for radionuclide X-ray fluorescence analyzer  

International Nuclear Information System (INIS)

The design of a gaging head for a portable radionuclide X-ray fluorescence analyzer is described. The gaging head is designed as a construction unit system which enables the application of lateral reflexion geometry as well as of coaxial geometry. It is designed so that adjustment from one geometry to the other is labour and time saving. The selection of characteristic radiation is performed by a couple of Ross' differential filters. These filters are prepared by a novel technique developed by our laboratory. The filter exchange is effected by the longitudinal move of the couple of filters encapsulated in a holder. The shift of the filters is controlled by means of a triggering mechanism situated in the body of the gaging head handle. This design makes is possible to handle the gaging head during measurements with one hand. A simple interchange of the absorption filter for the transmissive filter allows the operator to avoid any unwanted shift ...

1976-05-21

230

Luminescence properties of europium and terbium activated yttrium niobium/tantalate phosphors under VUV-UV excitation  

International Nuclear Information System (INIS)

Various compositions of Y(Ta,Nb)O4:Eu3+,Tb3+ with different Nb and activator concentrations have been investigated under UV and VUV excitation. Some compounds with very strong emission under VUV excitation were found. Such phosphors could be proposed as very good emissive materials for Displays and Lightings. The growing interest in luminescence spectroscopy of rare earth ions in the vacuum ultraviolet (VUV) and the visible (VIS) spectral range is due to industrial demands for new applications. YTaO4 and YNbO4 phosphors are a perspective class of efficient materials that are generally used in X-ray intensifying screens. These phosphors exhibit satisfying luminescence whenever excited by UV light, cathode radiation or X ray. However, to our knowledge, no work has been published on the VUV-excited luminescence for Eu3+ and Tb3+ double activated yttrium niobate and yttrium tantalate based phosphors. In ...

231

Characterization and gas-sensing behavior of an iron oxide thin film prepared by atomic layer deposition  

International Nuclear Information System (INIS)

In this work we investigate an iron oxide thin film grown with atomic layer deposition for a gas sensor application. The objective is to characterize the structural, chemical, and electrical properties of the film, and to demonstrate its gas-sensitivity. The obtained scanning electron microscopy and atomic force microscopy results indicate that the film has a granular structure and that it has grown mainly on the glass substrate leaving the platinum electrodes uncovered. X-ray diffraction results show that iron oxide is in the #alpha#-Fe_2O_3 (hematite) phase. X-ray photoelectron spectra recorded at elevated temperature imply that the surface iron is mainly in the Fe"3"+ state and that oxygen has two chemical states: one corresponding to the lattice oxygen and the other to adsorbed oxygen species. Electric conductivity has an activation energy of 0.3-0.5 eV and almost Ohmic current-voltage dependency. When exposed to O_2 ...

2008-07-31

232

Broad-band stigmatic spectrograph for the soft x-ray range  

International Nuclear Information System (INIS)

We describe a panoramic stigmatic spectrograph comprising a grazing-incidence toroidal mirror and a large-aperture free-standing transmission diffraction grating (5000 lines mm-1 ). Two spectrograph versions were constructed, with grazing angles of 7.6 and 40 and the short-wavelength spectral limits near 4 and 1.5 nm. The spectrograph aberrations were studied by numerical ray tracing. The spectrograph was used to record line and quasi-continuous spectra (1.5 - 30 nm) of multiply charged ions in a plasma generated by the second-harmonic pulses of an yttrium aluminate laser (Q = 0.15 J, ? = 5 ns, ? = 0.54 ?m, repetition rate = 0.5 Hz). In combination with a laser-produced plasma radiation source, the arrangement was used to characterise soft x-ray optical components and to generate collimated beams of polarised radiation in the 14 - 20 nm range. (laser applications and other topics in quantum electronics)

1998-09-30

233

Determination of two-phase flow parameters for nuclear fuel channels using a real-time neutron radiography method  

Energy Technology Data Exchange (ETDEWEB)

Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10{sup 6}n/cm{sup 2}-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,{integral}dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and CANDU-type nuclear fuel flow channels are investigated. Measurements of flow ...

1995-07-01

234

Determination of two-phase flow parameters for nuclear fuel channels using a real-time neutron radiography method  

International Nuclear Information System (INIS)

Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10"6n/cm"2-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,#integral#dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and CANDU-type nuclear fuel flow channels are investigated. Measurements of flow regime, void ...

1346-01-01

237

Spin evolution in wind-fed X-ray binaries  

International Nuclear Information System (INIS)

Global angular momentum balance suggests that the neutron stars in Be/X-ray binaries are not spinning in equilibrium. This requires an X-ray lifetime ''approx <'' 10"5 yr, and suggests that there are many 'dead' Be/X-ray binaries in the Galaxy. Some of these may be turned up as millisecond radio pulsars with Be star companions. (author).

243

Radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Slovak 1973. 164 p. Czechoslovakia Havranek, E. Bumbalova, A. Svitel,

1973-01-01

244

NONDESTRUCTIVE DETERMINATION OF AIRBORNE LEAD ...  

Science.gov (United States)

... NONDESTRUCTIVE DETERMINATION OF AIRBORNE LEAD PARTICULATES BY THE RADIONUCLIDE X-RAY FLUORESCENCE ANALYSIS. ...

246

Ectopic Ureter  

Science.gov (United States)

... such as renal flow scan or a formal kidney X-ray, called an intravenous pyelogram ( IVP ), may help ...

250

DoseWatchers - A computer based X ray dose monitoring project in paediatric radiology  

International Nuclear Information System (INIS)

Full text: Introduction. Children, especially premature infants and neonates, are at a much higher risk to obtain an X ray induced disturbance of life - particularly cancer. On the one hand this is due to their longer life expectancy and on the other hand it is due to their higher cell proliferation rate. The paediatric radiology unit of the Inselspital Bern recently installed some of the most advanced X ray equipment nowadays available. It is based on the two latest digital technologies: double read computed radiography (CR) and direct digital radiography (DR). Only the implementation of these digital radiography systems permits the digital acquisition and additionally the analysis of acquired data. The systematic analysis of large amounts of biometric data and exposition data is the basis for further dose reduction and a systematic quality control (QC). Patients are increasingly critical concerning ...

2006-11-13

251

Are Optically-Selected Quasars Universally X-Ray Luminous? X-Ray/UV Relations in Sloan Digital Sky Survey Quasars  

CERN Document Server

We analyze archived Chandra and XMM-Newton X-ray observations of 536 Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) quasars (QSOs) at 1.7 <= z <= 2.7 in order to characterize the relative UV and X-ray spectral properties of QSOs that do not have broad UV absorption lines (BALs). We constrain the fraction of X-ray weak, non-BAL QSOs and find that such objects are rare; for example, sources underluminous by a factor of 10 comprise $\\la$2% of optically-selected SDSS QSOs. X-ray luminosities vary with respect to UV emission by a factor of $\\la$2 over several years for most sources. UV continuum reddening and the presence of narrow-line absorbing systems are not strongly associated with X-ray weakness in our sample. X-ray brightness is significantly correlated with UV emission line properties, so that relatively X-ray weak, non-BAL ...

2008-01-01

252

Upper Limits from HESS Observations of AGN in 2005-2007  

CERN Document Server

Very high energy (VHE; >100 GeV) observations of a sample of selected active galactic nuclei (AGN) were performed between January 2005 and April 2007 with the High Energy Stereoscopic System (HESS), an array of imaging atmospheric-Cherenkov telescopes. Significant detections are reported elsewhere for many of these objects. Here, integral flux upper limits for twelve candidate very high energy (VHE; >100 GeV) gamma-ray emitters are presented. In addition, results from HESS observations of four known VHE-bright AGN are given although no significant signal is measured. For three of these AGN (1ES 1101-232, 1ES 1218+304, and Mkn 501) simultaneous data were taken with the Suzaku X-ray satellite.

2007-01-01

253

The unusual host galaxy of the BL Lac object PKS 1413+135  

CERN Document Server

The BL Lacertae object PKS 1413+135 is associated with a disk dominated galaxy which heavily absorbs the BL Lac nucleus at optical and X-ray wavelengths. It has been argued whether this galaxy is actually the host galaxy of PKS 1413+135 or whether the BL Lac is a background QSO, gravitationally lensed by the apparent host galaxy. We have obtained deep high resolution H-band images of this unusual BL Lac object using the UKIRT IRCAM3. Our observations show that the BL Lac nucleus is centered within < 0.05 arcsec of the galaxy. Based on this result we assess the probability for the lensing scenario and come to the conclusion that the disk galaxy is indeed the host of PKS 1413+135. The galaxy shows peanut-shaped isophotes, suggesting the presence of a central bar which is a common feature of AGN

1999-01-01

254

The temporal evolution of coronal loops observed by GOES-SXI  

CERN Document Server

We study the temporal evolution of coronal loops using data from the Solar X-ray Imager (SXI) on board of GOES-12. This instrument allows us to follow in detail the full lifetime of coronal loops. The observed light curves suggest three somewhat distinct evolutionary phases: rise, main, and decay. The durations and characteristic timescales of these phases are much longer than a cooling time and indicate that the loop-averaged heating rate increases slowly, reaches a maintenance level, and then decreases slowly. This suggests that a single heating mechanism operates for the entire lifetime of the loop. For monolithic loops, the loop-averaged heating rate is the intrinsic energy release rate of the heating mechanism. For loops that are bundles of impulsively heated strands, it is an indication of the frequency of occurrence of individual heating events, or nanoflares. We show that the timescale of the loop-averaged heating rate is proportional ...

2006-01-01

255

Studies of technetium chemistry. Pt. 13: The relationship between solvation free energies and brain uptakes of "9"9Tc"m complexes  

International Nuclear Information System (INIS)

Based on the X-ray crystallographic data of Tc-complexes for brain imaging agents, geometry optimizations in vacuo of TcO-BAT, TcO-MAMA, TcO-L, L-ECD, TcN-BAT and TcN-L, L-ECD complexes are performed with Hartree-Fock method and LANL 2 DZ basis set of G98W program. Then solvation free energy for each Tc-complex mentioned above in water is calculated by polarizable continuum method (PCM) including models of CPCM and IEFPCM. The results show that solvation free energy of Tc-complex is not only an indicator of lipophilicity but also one of the important factors that influence the brain uptake

2002-02-01

256

In situ synthesis of silver chloride nanoparticles into bacterial cellulose membranes  

British Library Electronic Table of Contents (United Kingdom)

In situ synthesis of silver chloride (AgCl) nanoparticles was carried out under ambient conditions in nanoporous bacterial cellulose (BC) membranes as nanoreactors. The growth of the nanoparticles was readily obtained by alternating dipping of BC membranes in the solution of silver nitrate or sodium chloride followed by a rinse step. X-ray diffraction (XRD) patterns indicated the existence of AgCl nanoparticles in the BC and scanning electron microscopy (SEM) images showed that the AgCl nanoparticles well dispersed on the surface of BC and penetrated into the BC network. The AgCl nanoparticle-impregnated BC membranes exhibited high hydrophilic ability and strong antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The preparative proced...

2009-01-01

257

High resolution electron microscopy study of as-prepared and annealed tungsten-carbon multilayers  

International Nuclear Information System (INIS)

A series of sputtered tungsten-carbon multilayer structures with periods ranging from 2 to 12 nm in the as-prepared state and after annealing at 500 degrees C for 4 hours has been studied with high resolution transmission electron microscopy. The evolution with annealing of the microstructure of these multilayers depends on their period.As-prepared structures appear predominantly amorphous from TEM imaging and diffraction. Annealing results in crystallization of the W-rich layers into WC in the larger period samples, and less complete or no crystallization in the smaller period samples. X-ray scattering reveals that annealing expands the period in a systematic way. The layers remain remarkably well-defined after annealing under these conditions.

258

Comparative evolution of various CCD image sensors hardening techniques with ionizing radiation  

International Nuclear Information System (INIS)

This paper reviews various techniques to harden Charged Coupled Device (CCD) sensors and the results after irradiation of three Thomson n buried channel CCDs having a different degree of hardening. It describes the major irradiation effects on CCD performances and it makes a comparison of the results between the different hardening levels. It shows good results on dark voltage after ionizing radiation for TH 7863M device hardened both by design and by operating conditions (MPP mode) with respect to the standard device TH 7863A. The irradiations were performed with "6"0Co or X-ray (10 keV) sources on devices in operating mode. (author). 3 refs., 8 figs.

259

Diagnosis of plasmocytomas using magnetic resonance imaging  

International Nuclear Information System (INIS)

Background. In multiple myeloma 5 different infiltration patterns can be differentiated: 1. Normal appearance of bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. 'salt-and pepper' pattern with inhomogeneous bone marrow with interposition of fat islands. Methods. For the fast and total acquisition of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique is superior. The focal involvement is clearly demonstrated as areas of high signal intensity on e.g. STIR images. Diffuse involvement can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. MRI is superior to X-ray in focal and diffuse involvement. With ultrafast sequences a 'screening' of the whole red bone marrow as for myeloma infiltration is possible. Prognosis. In prognosis studies diffuse infiltration is ...

2000-08-01

260

Development of Intelligent Setting System for Fracture Based on X-Ray Image  

Energy Technology Data Exchange (ETDEWEB)

In order to achieve micro-wound, intelligence and high efficiency for fracture setting, intelligent setting system for fracture is proposed in accordance with biomechanics and fracture therapy theory. In the comprehensive medical system based on C-shape-arm X-machine, image processing and analysis is the core, programmable logical controller and stepping motor are important driving parts controlling mechanical parts. Six degree of freedom dynamics sensor ensures to control accurately force and moment. On the foundation of analyzing X-ray image peculiarities, method of processing and analysis is put forward, combining time domain with frequency domain. After mining domain knowledge in depth, setting actions is quantized into three non-continuous steps and is parameterized into two angles and one distance aiming at femoral-neck fracture. Objective features are extracted by virtue of three power polymerization curved surface ...

2006-10-15

261

Determination of ash content in coal by means of backscattered X-ray radiation and X-ray fluorescence analysis, and devices manufactured by the PAR company  

Energy Technology Data Exchange (ETDEWEB)

Discusses methods for determining ash content in coal using backscattering in X-ray fluorescence. The following aspects are evaluated: principle of ash content determination, energy sources, factors that influence measurement accuracy, reliability. Types of X-ray fluorescence analyzers developed in Czechoslovakia and manufactured in the Czech Republic are comparatively evaluated. Operation of the RPM 113.1 radionuclide X-ray fluorescence analyzer developed by the PAR company and used for measuring ash content in coal and coal calorific value is discussed. 7 refs.

1993-09-01

262

An Apparent Hard X-ray Decline of CH Cygni  

CERN Document Server

CH Cygni is a symbiotic star consisting of an M giant and an accreting white dwarf, which is known to be a highly variable X-ray source with a complex, two-component, spectra. Here we report on two Suzaku observations of CH Cyg, taken in 2006 January and May, during which the system was seen to be in a soft X-ray bright, hard X-ray faint state. Based on the extraordinary strength of the 6.4 keV fluorescent Fe K-alpha line, we show that the hard X-rays observed with Suzaku are dominated by scattering.

2006-01-01

263

Nuclear analytical techniques in Cuban sugar industry  

Energy Technology Data Exchange (ETDEWEB)

This paper is a review concerning the application of Nuclear Analytical Techniques in the Cuban sugar industry. The most complete elemental composition of final molasses (34 elements) and natural zeolites (38) this last one employed as an auxiliary agent in sugar technological processe4s has been performed by means of instrumental Neutron Activation Analysis (INAA) and X-Ray Fluorescence Analysis (XRFA). The trace elemental sugar cane soill-plant relationship and elemental composition of different types of Cuban sugar (raw, blanco-directo and refine) were also studied. As a result, valuable information referred to the possibilities of using these products in animal and human foodstuff so as in the other applications are given. (author). 34 refs., 6 figs., 1 tab.

1997-12-01

264

Development of nanocomposite polymer materials for electrical and electronic applications  

International Nuclear Information System (INIS)

Some results and experimental procedures of laboratory are reported in the frame of researches conducted for the development of new nanostructured composite materials. These new materials, which are constituted by an organic phase: the polymer and an inorganic phase: the silicate, are being strongly investigated nowadays so it is expected that they could provide, among other, better electrical insulation properties and flame-delay in electrical and electronic applications. The laboratory experimental work has been developed from two families of polymers, thermoplastics and thermosets and clays silicates providing lamellar type. There are now some preliminary results, such as obtaining thin films of these nanocomposite materials, their complete characterization by X-ray diffraction, scanning microscopy and thermogravimetric analysis, they do well to wait for future research activities. (author)

2007-01-01

265

Radiological protection. Textbook for radiographers and reference book for radiological safety officers; Strahlenschutz. Lehrbuch fuer Personen, die nach den Bestimmungen der Roentgenverordnung vom 8. Januar 1987 als medizinisch-technische Radiologieassistenten taetig sind und zur Unterweisung fuer Strahlenschutzbeauftragte  

Energy Technology Data Exchange (ETDEWEB)

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) [Deutsch] Das vorliegende Lehrbuch, das sich vor allem an das technische Personal und an Strahlenschutzbeauftragte wendet, unterrichtet ueber die derzeit gueltigen Bestimmungen der Roentgenverordnung, die Anwendung von Roentgenstrahlen, ueber Qualitaetssicherung, die Organisation der ...

1996-12-31

266

Depth-profiling of vertical sidewall nanolayers on structured wafers by grazing incidence X-ray flourescence  

Energy Technology Data Exchange (ETDEWEB)

The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, developed an alignment strategy to specify elemental depth profiling in vertical sidewall layers on structured wafers. For this purpose, PTB's irradiation chamber for 200 mm and 300 mm silicon wafers was used to combine total-reflection X-ray fluorescence (TXRF) and grazing incidence XRF (GIXRF) techniques by employing monochromatized undulator radiation of the BESSY II electron storage ring. 3-D test structures were fabricated to develop an optimal alignment strategy allowing for depth profiling in such nanolayers. The test structures consisted of silicon bars with widths/spacings either in the {mu}m or in the nm range. In order to be able to differentiate the sidewalls more easily from the remainder of the structures, they were provided with an additional silicon nitride layer. Four structure types of different bar width and density parameters on two 200 mm ...

2008-12-15

267

Depth-profiling of vertical sidewall nanolayers on structured wafers by grazing incidence X-ray flourescence  

International Nuclear Information System (INIS)

The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, developed an alignment strategy to specify elemental depth profiling in vertical sidewall layers on structured wafers. For this purpose, PTB's irradiation chamber for 200 mm and 300 mm silicon wafers was used to combine total-reflection X-ray fluorescence (TXRF) and grazing incidence XRF (GIXRF) techniques by employing monochromatized undulator radiation of the BESSY II electron storage ring. 3-D test structures were fabricated to develop an optimal alignment strategy allowing for depth profiling in such nanolayers. The test structures consisted of silicon bars with widths/spacings either in the ?m or in the nm range. In order to be able to differentiate the sidewalls more easily from the remainder of the structures, they were provided with an additional silicon nitride layer. Four structure types of different bar width and density parameters on two 200 mm silicon wafers were ...

2008-12-01

268

Scatter measurements for optical cone-beam computed tomography  

Energy Technology Data Exchange (ETDEWEB)

Both x-ray and optical cone-beam CT (CBCT) scanners are limited by scattered photons that contaminate the primary images. Transparent radiochromic gels and plastics are anticipated to produce less scattering than polymerization gels and hence result in reconstructed dose distributions with greater contrast and dynamic range. Four methods of scatter measurement were investigated to quantify scatter fractions using an in-house optical CBCT scanner. The methods consisted of generating either 'coin' shadows or primary beamlets in transmission images. The four methods generated similar results of 10% scatter fractions in gel transmission images for this particular scanner configuration with both leuco crystal violet and carbon black micelle gels. The scatter contributions were distributed as 5% from micelle gel, 2% from Teflon wall, 2% from refractive index matching liquid and 1% other ...

2009-05-01

269

Real-time neutron radiography at the Iea-R1 m nuclear research reactor  

International Nuclear Information System (INIS)

A LIXI (Light Intensifier X-ray Image) device has been employed in a real-time neutron radiography system. The LIXI is coupled to a video camera and the real-time images can be observed in a TV monitor, and processed in a computer. In order to get the real-time system operational, the neutron radiography facility installed at the IEA-R1 m nuclear research reactor of the IPEN-CNEN/S P has been optimized. The most important improvements were the neutron/gamma ratio, the effective energy of the neutron beam, decrease of the scattered radiation at the irradiation position, and the additional shielding of the video camera. Several one-frame as well as computer processed images are presented. The overall Modulation Transfer Function for the real-time system was obtained from the resolution parameter p = 0:44 +- 0:04 mm; the system sensitivity, evaluated for a Perspex step wedge, was determined and the average ...

2003-06-01

270

Radionuclide imaging of the acutely painful scrotum  

International Nuclear Information System (INIS)

This paper discusses the clinical application and main objective of testicular imaging. The authors present cases that represent a spectrum of the abnormalities which might be detected by testicular imaging, with special attention given to testicular torsion and the acute diseases which may mimic it clinically. Accuracy of the test is noted.

271

Nonnegative Factorization of Diffusion Tensor Images and Its Applications  

UK PubMed Central (United Kingdom)

This paper proposes a novel method for computing linear basis images from tensor-valued image data. As a generalization of the nonnegative matrix factorization, the proposed method aims to approximate...Full Text Available

2011-01-01

272

Compact Image Slicing Spectrometer (ISS) for hyperspectral fluorescence microscopy  

UK PubMed Central (United Kingdom)

An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated...Full Text Available

2009-07-20

273

A BPF-FBP tandem algorithm for image reconstruction in reverse helical cone-beam CT  

UK PubMed Central (United Kingdom)

Purpose: Reverse helical cone-beam computed tomography (CBCT) is a scanning configuration for potential applications in image-guided radiation therapy in which an accurate anatomic image...Full Text Available

2010-01-01

274

Signal and imaging sciences workshop proceedings  

Energy Technology Data Exchange (ETDEWEB)

Papers are presented in the areas of: Medical Technologies; Non-Destructive Evaluation; Applications of Signal/Image Processing; Laser Guide Star and Adaptive Optics; Computational Electromagnetic, Acoustics and Optics; Micro-Impulse Radar Processing; Optical Applications; TANGO Space Shuttle.

1997-11-01

275

A submillimeter wavelength space-based imaging radar  

Science.gov (United States)

This report considers the use of a submillimeter wavelength space-based imaging radar. The main application envisioned is midcourse decoy discrimination for strategic defense, for which it would have the capability of producing a series of images, in real time, at strategic ranges, with less than meter scale resolution and with modest power requirements. Undoubtedly, there are other applications. The requirements for a SAR and ISAR imaging radar at submillimeter wavelength are determined, and the prospect for the development of RF sources to power the radar is examined.

1988-05-01

276

High-resolution beta imaging; L'imagerie beta haute resolution  

Energy Technology Data Exchange (ETDEWEB)

For many years, {beta} radioactivity has been used to label molecules and follow them in various biological processes. {beta} imaging is obtained by autoradiography. Classically made on films or on photographic emulsions, autoradiography is now supplanted by radio-imagers which are very performing. The phosphor-imager, {beta}-imager and {mu}-imager are the systems mainly used today and their operating principles and properties are compared. The great advantages of these imagers are: their rapidity to obtain results and their reliability for absolute quantification. All emitters ({beta}{sup -}, {beta}{sup -} -{gamma} and {beta}{sup +}) are detectable as well as the gamma emitters of nuclear medicine, by means of their low energy electrons ejected during y emission. Phosphor-imager is well suited to energetic tracers and large series of ...

2007-04-15

277

MER-DIMES : a planetary landing application of computer vision  

Science.gov (United States)

During the Mars Exploration Rovers (MER) landings, the Descent Image Motion Estimation System

2005-01-01

278

A comparison of patient doses in lumbar spine radiography from various X-ray units in Poland  

Energy Technology Data Exchange (ETDEWEB)

A number of diagnostic X-ray units in Poland were subjected to analysis. The air kerma on X-ray tables was measured for the X-ray parameters used routinely during lumbo-sacral spine radiography of standard adult patient. Measurements of air kerma were performed using TLD made of lithium-fluoride. The doses received by patients in different X-ray departments can differ more than two orders of magnitude (from 0.42 mGy up to 72.11 mGy), for the same X-ray examination. The dose can be significantly reduced if fluorescent screens made from components of rare earth are used. (author). 10 refs, 1 fig., 2 tabs.

1995-12-31

279

Tuning the spin state of iron phthalocyanine by ligand adsorption  

International Nuclear Information System (INIS)

The future use of single-molecule magnets in applications will require the ability to control and manipulate the spin state and magnetization of the magnets by external means. There are different approaches to this control, one being the modification of the magnets by adsorption of small ligand molecules. In this paper we use iron phthalocyanine supported by an Au(111) surface as a model compound and demonstrate, using x-ray photoelectron spectroscopy and density functional theory, that the spin state of the molecule can be tuned to different values (S #approx# 0, 1/2, 1) by adsorption of ammonia, pyridine, carbon monoxide or nitric oxide on the iron ion. The interaction also leads to electronic decoupling of the iron phthalocyanine from the Au(111) support. (fast track communication)

2010-12-01

280

The duke XUV FEL storage ring facility  

Energy Technology Data Exchange (ETDEWEB)

In this paper we present status and developments of the Duke storage ring facility. The Duke storage ring facility provides the unique combination of phase-locked light sources ranging from high power OK-4 XUV FEL to quasimonochromatic {gamma}-ray beam and IR/X-ray spontaneous radiation. The XUV OK-4 FEL, which is collaborative project with BlNP, Novosibirsk, is in operation since November, 1996. The OK-4 UV FEL is also used for production of nearly monochromatic {gamma}-ray s with tunable energy. We present the results of UV lasing with the OK4 FEL and selected results of its applications. We will discuss our future plans for extension of this source and status of the construction of dedicated used facility adjacent to the FEL building. (author)

1998-11-01

281

The Use of Weighting in Periodicity Searches in All-Sky Monitor Data: Applications to the GLAST LAT  

Energy Technology Data Exchange (ETDEWEB)

The light curves produced by all-sky monitors, such as the Rossi X-ray Timing Explorer All-Sky Monitor and the Swift Burst Alert Telescope (BAT), generally have non-uniform error bars. In searching for periodic modulation in this type of data using power spectra it can be important to use appropriate weighting of data points to achieve the best sensitivity. It was recently demonstrated that for Swift BAT data a simple weighting scheme can actually sometimes reduce the sensitivity of the power spectrum depending on source brightness. Instead, a modified weighting scheme, based on the Cochran semi-weighted mean, gives improved results independent of source brightness. We investigate the benefits of weighting power spectra in period searches using simulated GLAST LAT observations of {gamma}-ray binaries.

2009-06-25

282

Synthesis and characterization of undoped and TM (Co, Mn) doped ZnO nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Antibacterial activity of Transition metals (Mn, Co) doped ZnO nanopowders prepared by a DC thermal plasma method against Escherichia coli and Staphylococcus aureus are investigated. The phase and morphology studies have been carried out by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. All the samples of the present investigation are found to have hexagonal wurtzite structure and crystallite sizes are found to vary from 25nm to 30nm. Our bacteriological study showed the enhanced antibacterial activity of transition metals doped ZnO nanoparticles than undoped ZnO indicating the great potential of ZnO nanoparticles in relevant clinical and biomedical applications.

2011-01-01

283

Study of the application of BATAN's equipment for nuclear forensic activities  

International Nuclear Information System (INIS)

Nuclear forensic activities, such as in illicit trafficking, can solve a problem who did it and can gain the basis for a response. Other than that, the forensics can be also applied to solve on what are materials, who is responsible, is there more, where was material diverted and what route did the material taken. BATAN, in fact , owns a lot of equipment which can be supported for nuclear forensics activities, such as, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM) as well as X-Ray Diffraction (XRD). For the first step, BATAN has to be an active, participate member of The International Technical Working Group on Nuclear Smuggling (ITWG). BATAN can then collaborate not only with Indonesia Arm Forces and Police, but also with other foreign institutions to develop this activity with mutual advantages agreement.

2005-10-01

284

Stress-induced martensitic transformation of metastable #beta#-titanium alloy  

International Nuclear Information System (INIS)

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

2007-03-25

285

Silver nanoparticles prepared by chemical reduction-protection method, and their application in electrically conductive silver nanopaste  

Energy Technology Data Exchange (ETDEWEB)

Ag nanoparticles were prepared in a water-phase system with a mixture of silver-ammonia complex, sodium borohydride, and lauric acid according to molar feed ratio of approximately 6:3:1. The mechanism of preparation and separation by chemical reduction-protection method was explored. The as-synthesized Ag nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-vis spectroscopy, respectively. It was found that the size of high purity Ag particles was ranging from 30 to 50 nm with slight agglomeration. In addition, the as-synthesized wet Ag nanoparticles were dispersed stably in organic vehicle to formulate electrically conductive nanopaste. Upon direct-written and sintered, the array pattern of the nanopaste with the resolution of about 30 {mu}m was achieved with the electrical resistivity in the order of magnitude of 10{sup -5} {Omega} cm.

2010-04-02

286

Reference values for X-ray diagnostic investigations. Some thoughts on the relation between expenditure and benefit; Referenzwerte fuer roentgendiagnostische Untersuchungen. Teil 2. Ueberlegungen zur Verhaeltnismaessigkeit von Nutzen und Aufwand  

Energy Technology Data Exchange (ETDEWEB)

In the first part of this contribution, the definition of reference values is given and the theoretical and practical problems in the application of this concept are discussed. In this connection, the present resources on instrumentation and the technical requirements for dose assessment are described. In the second part, some consequences are taken and proposals for further actions are made. (orig.) [German] Im ersten Teil des Aufsatzes werden Definitionen von Referenzwerten in der radiologischen Diagnostik untersucht und die theoretischen und praktischen Probleme der Umsetzung des gesamten Konzepts eroertert. In diesem Zusammenhang werden auch der gegenwaertige Geraetebestand und die technischen Voraussetzungen zur Dosisermittlung beschrieben. Im zweiten Teil werden daraus Schlussfolgerungen gezogen und Vorschlaege zum weiteren Vorgehen gemacht. (orig.)

2001-07-01

287

Reference values for X-ray diagnostic investigations. Some thoughts on the relation between expenditure and benefit; Referenzwerte fuer roentgendiagnostische Untersuchungen. T. 1. Ueberlegungen zur Verhaeltnismaessigkeit von Nutzen und Aufwand  

Energy Technology Data Exchange (ETDEWEB)

In the first part of this contribution, the definition of reference values is given and the theoretical and practical problems in the application of this concept are discussed. In this connection, the present resources on instrumentation and the technical requirements for dose assessment are described. In the second part, some consequences are taken and proposals for further actions are made. (orig.) [German] Im ersten Teil des Aufsatzes werden die Definition von Referenzwerten in der radiologischen Diagnostik untersucht und die theoretischen und praktischen Probleme der Umsetzung des gesamten Konzepts eroertert. In diesem Zusammenhang werden auch der gegenwaertige Geraetebestand und die technischen Voraussetzungen zur Dosisermittlung beschrieben. Im zweiten Teil werden daraus Schlussfolgerungen gezogen und Vorschlaege zum weiteren Vorgehen gemacht. (orig.)

2000-07-01

288

Plasma nitriding of microalloyed steel  

Energy Technology Data Exchange (ETDEWEB)

Microalloyed or high strength low alloy (HSLA) steels are carbon-manganese steels containing small amounts of Nb, V or Ti. The excellent mechanical properties of these alloys, particularly high yield strength, usually obviate the need for expensive quench and tempering operations. Furthermore, the presence of a significant amount of nitride-forming elements in some microalloyed steels has generated interest in the applicability of these alloys as a new generation of nitriding steels. In this paper, a study of the plasma nitriding behaviour of a commercially available microalloyed steel MAXIMA{sup TM} is reported. A comparison is made with a traditional quenched and tempered nitriding steel (En19), plasma nitrided under similar conditions. Optical and scanning electron microscopy in conjunction with microhardness measurements and X-ray diffraction were utilized to characterize the nitrided surfaces. The observed differences in the thickness and ...

1995-03-01

289

Increased osteoblast adhesion on nanograined Ti modified with KRSR  

British Library Electronic Table of Contents (United Kingdom)

Peptide sequences such as lysine-arginine-serine-arginine (KRSR) selectively bind transmembrane proteoglycans (e.g. heparin sulfate) of osteoblasts (bone-forming cells) and are, therefore, actively being investigated for orthopedic applications. Further, nanophase materials (or materials with grain or particle sizes less than 100 nm) are promising new materials that promote new bone growth more than compared to conventional (that is, micron grain or particle size) materials. To combine the above two promising approaches for improving orthopedic implants, the objective of this in vitro study was to functionalize titanium (Ti) surfaces (both nanophase and conventional) with KRSR peptides and study their osteoblast cell adhesive properties. Materials were characterized by X-ray photoelectron ...

2007-01-01

290

In-vitro evaluation of corrosion resistance of nitrogen ion implanted titanium simulated body fluid  

International Nuclear Information System (INIS)

Titanium and its alloy Ti6Al4V enjoy widespread use in various biomedical applications because of favourable local tissue response, higher corrosion resistance and fatigue strength than the stainless steels and cobalt-chromium alloy previously used. The study reported in this paper aims to optimize the conditions of nitrogen ion implantation on commercially pure titanium and to correlate the implantation parameters to the corrosion resistance. X-ray photoelectron spectroscopy was used to analyse surface concentration and the implantation processes. An improvement in the electrochemical behaviour of the passive film was shown to occur with nitrogen ion implantation on titanium, in simulated body fluids. (UK).

291

Exploring the binding of the strong organic acceptor F{sub 4}TCNQ to coinage metals  

Energy Technology Data Exchange (ETDEWEB)

Organic/metal interface properties are of high interest for the application of molecular (sub)monolayers to modify surface properties. They are applied for, e.g., molecular electronics, chemical sensing, or the tuning of injection barriers in organic electronic devices. We present a joint theoretical and experimental study of F{sub 4}TCNQ adsorbed on Cu(111). The electronic and structural properties were determined by ultraviolet photoelectron spectroscopy (UPS) and X-ray standing wave (XSW) measurements. To better understand the complex process of binding, we modelled the system using density-functional theory. We find forward-donation from the lone pairs of the molecule into metallic states and back-donation from the metal into the LUMO of the molecule. The data on Cu(111) are compared to F4TCNQ on Au(111) and Ag(111) as well as to investigations of pyrenetetraone on various coinage metals.

2008-07-01

292

Design and microstructural analysis of magnesium alloys for dynamical applications  

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

293

Cumulative effect of X-ray radiation and inflammatory reaction on the circadian rhythm of tyrosine aminotransferase in the liver of mice  

International Nuclear Information System (INIS)

The activity of tyrosine aminotransferase (TAT) in the liver of mice subjected simultaneously to ionizing radiation and to local inflammatory process showed in the first 24 hours of the experiment statistically significant changes resulting from summation of the harmful effects of both factors. In the second 24-hour period an evident tendency was observed for return of a normal circadian rhythm of the enzyme. This points to presence of an endogenous mechanism of suppression of the manifestations of significant desynchronization of the circadian rhythm. The paper contains also a trial of mathematical analysis of changes in TAT activity in the circadian rhythm, a description and analysis or the suppression process, qualitative and quantitative determination of the phenomenon of cumulation of the effects of powerful stress factors acting on the animal organism. The obtained results were compared with the results of investigations of TAT activity changes obtained in the case of separate ...

1980-01-01

294

Chemically bonded phosphate ceramics : part III : reduction mechanism and its application to iron phosphate ceramics.  

Energy Technology Data Exchange (ETDEWEB)

In this, the last of a series of three papers, we discuss a method of forming iron phosphate ceramics by a reduction process. We report the formation of iron oxide ceramics by reducing hematite with iron in a phosphoric acid solution. The reaction results in a rapid-setting ceramic (at room temperature) with a compressive strength of 3700 psi and a density of 1.7 g/cm{sup 3}. Although the exact mineral form of the binder is difficult to determine because it is mostly amorphous and hence is not amenable to X-ray diffraction analyses, this material is expected to consist of iron hydrophosphates. The reduction process is very useful in recycling several industrial wastes that are rich in hematite, including iron mine tailings, red mud (a caustic waste from the alumina industry), and machining swarfs. Formation of ceramics with red mud and swarfs is also discussed.

2003-11-01

295

Chemical, electrical and electrochemical characterization of hybrid organic/inorganic polypyrrole/PW12O40^3^- coating deposited on polyester fabrics  

British Library Electronic Table of Contents (United Kingdom)

A study of the stability of conducting fabrics of polyester (PES) coated with polypyrrole/PW12O40^3^- (organic/inorganic hybrid material) in different pH solutions (1, 7, 13) has been done. Washing tests were also done in views of its possible application in electronic textiles such as antistatic clothing. X-ray photoelectron spectroscopy (XPS) studies have been done to quantify the amount of counter ion that remains in the polymer matrix and determine the doping ratio (N^+/N) after the different tests. Scanning electron microscopy (SEM) was also used to observe morphological differences after the different tests. Surface resistivity changes were measured by means of electrochemical impedance spectroscopy (EIS). Scanning electrochemical microscopy (SECM) was employed to measure changes in ...

2011-01-01

296

Charging a Battery-Powered Device with a Fiber-Optically Connected Photonic Power System for Achieving High-Voltage Isolation  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the development and testing of a system to provide isolated power to the cathode-subsystem electronics of an x-ray tube. These components are located at the cathode potential of several hundred kilovolts, requiring a supply of power isolated from this high voltage. In this design a fiber-optically connected photonic power system (PPS) is used to recharge a lithium-ion battery pack, which will subsequently supply power to the cathode-subsystem electronics. The suitability of the commercially available JDSU PPS for this application is evaluated. The output of the ppe converter is characterized. The technical aspects of its use for charging a variety of Li-Ion batteries are discussed. Battery charge protection requirements and safety concerns are also addressed.

2008-01-01

297

CHARACTERIZATION OF DEXTRIN PREPARED BY COMMON NEUTRAL AND THERMOSTABLE a-AMYLASES  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT With corn starch as raw material, dextrin was prepared by the combined application of common neutral and thermostable a-amylases in this study. The effects of reaction temperature, reaction time, addition of common neutral and thermostable a-amylases on dextrose equivalent (DE)-value of dextrin were investigated. The obtained dextrin with a DE value of 20.43 was evaluated for morphology, crystallography, particle size distribution and thermal property by scanning electron microscope, X-ray diffractometer, light scattering particle size analyzer and thermogravimetric analyzer. The results showed that the amorphous regions in the core part of corn starch were completely hydrolyzed and only the fractured crystalline surface remained. The particle size of the dextrin change significan...

2010-01-01

298

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-08-15

299

Study of porous silicon morphologies for electron transport  

International Nuclear Information System (INIS)

Field emitter devices are being developed for the gigatron, a high-efficiency, high frequency and high power microwave source. One approach being investigated is porous silicon, where a dense matrix of nanoscopic pores are galvanically etched into a silicon surface. In the present paper pore morphologies were used to characterize these materials. Using of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images of both N-type and P-type porous layers, it is found that pores propagate along the <100> crystallographic direction, perpendicular to the surface of (100) silicon. Distinct morphologies were observed systematically near the surface, in the main bulk and near the bottom of N-type (100) silicon lift-off samples. It is seen that the pores are not cylindrical but exhibit more or less approximately square cross sections. X-ray diffraction spectra and electron diffraction patterns verified that bulk porous ...

1993-05-17

300

Probing the Large-Scale Structure Around the Most Distant Galaxy Clusters from the Massive Cluster Survey  

CERN Document Server

We present maps of the cosmic large-scale structure around the twelve most distant galaxy clusters from the Massive Cluster Survey (MACS) as traced by the projected surface density of galaxies on the cluster red sequence. Taken with the Suprime-Cam wide-field camera on the Subaru telescope, the images used in this study cover a 27x27 arcmin^2 area around each cluster, corresponding to 10 x 10 Mpc^2 at the median redshift of z = 0.55 of our sample. We directly detect satellite clusters and filaments extending over the full size of our imaging data in the majority of the clusters studied, supporting the picture of mass accretion via infall along filaments suggested by numerical simulations of the growth of clusters and the evolution of large-scale structure. A comparison of the galaxy distribution near the cluster cores with the X-ray surface brightness as observed with Chandra reveals, in several cases, significant offsets ...

2008-01-01

301

Magnetic imaging of ion-irradiation patterned Co/Pt multilayers using complementary electron and photon probes  

Energy Technology Data Exchange (ETDEWEB)

The three-dimensional magnetic structure and reversal mechanism of patterned Co/Pt multilayers, were imaged using complementary Lorentz transmission electron microscopy (LTEM) (in-plane component) and magnetic transmission x-ray microscopy (M-TXM) (perpendicular magnetization). The Co/Pt films with perpendicular anisotropy were patterned by ion irradiation through a stencil mask to produce in-plane magnetization in the irradiated regions. The boundaries of the patterns, defined by the transition from out-of-plane to in-plane magnetization, were found to be determined by the stencil mask, whilst the scale of the magnetic reversal by the physical microstructure. The nucleation fields were substantially reduced to 50 Oe for the in-plane regions and 1 kOe for the perpendicular regions, comparing to 4.5 kOe for the as-grown film. The perpendicular reversals were found to always originate at the pattern boundaries.

2001-04-01

302

Experience in using Fuji computed radiography (FCR), 1  

Energy Technology Data Exchange (ETDEWEB)

New experiment of radiography in using Fuji Intelligent Diagnostic X-ray System was first reported in XV International Congress of Radiology, 1981. By utilizing this system instead of traditional screen/film system, high density imaging plate in conjunction with computed image processor was developed, this is FCR. However, as the numerous problems in regard to the basic side of FCR system are found, it is expected that these are solved by investigators at their earliest opportunities. The purpose of this study is to reduce the radiation doses of the patients at radiography of the chest by using FCR system installed in our Department of Radiology in July, 1984. Experimentally we measured the radiation doses of the patient having the each breast of 18, 20, 22 and 24cm in thickness at radiography of the chest by using VICTOREEN MODEL 666 survey meter. The results obtained were as follows: 1) By using FCR system the radiation ...

1984-12-01

303

Experience in using Fuji computed radiography (FCR), 1  

International Nuclear Information System (INIS)

New experiment of radiography in using Fuji Intelligent Diagnostic X-ray System was first reported in XV International Congress of Radiology, 1981. By utilizing this system instead of traditional screen/film system, high density imaging plate in conjunction with computed image processor was developed, this is FCR. However, as the numerous problems in regard to the basic side of FCR system are found, it is expected that these are solved by investigators at their earliest opportunities. The purpose of this study is to reduce the radiation doses of the patients at radiography of the chest by using FCR system installed in our Department of Radiology in July, 1984. Experimentally we measured the radiation doses of the patient having the each breast of 18, 20, 22 and 24cm in thickness at radiography of the chest by using VICTOREEN MODEL 666 survey meter. The results obtained were as follows: 1) By using FCR system the radiation ...

1984-01-01

304

X-ray dosimetry of TlGaSe_2 single crystals  

International Nuclear Information System (INIS)

TlGaSe_2 compound belongs to group of layered semiconductors of A"3B"3C_2"6-type. Photoelectric and optical properties of TlGaSe_2 single crystals were investigated in detail. Influence of gamma-, electron and neutron radiation on photoelectric properties of TlGaSe_2 single crystals is investigated too. The present work deals with experimental results relative to X-ray dosimetric characteristics of TlGaSe_2 crystals at 300 K. X-ray conductivity and X-ray dosimetric characteristic measurements are carried out in low load resistance regime. The source of X-ray radiation is the installation of X-ray diffraction analysis (URS-55a) with the BCV-2(Cu). Intensity of X-ray radiation (E) is regulated by measurement with current variation in tube at each given value of X-ray radiation dose E (R/min) are measured by crystal dosimeter DRGZ-02. ...

305

Target Diagnostic Instrument-Based Controls Framework for the National Ignition Facility  

Energy Technology Data Exchange (ETDEWEB)

NIF target diagnostics are being developed to observe and measure the extreme physics of targets irradiated by the 192-beam laser. The response time of target materials can be on the order of 100ps--the time it takes light to travel 3 cm--temperatures more than 100 times hotter than the surface of the sun, and pressures that exceed 109 atmospheres. Optical and x-ray diagnostics were developed and fielded to observe and record the results of the first 4-beam experiments at NIF. Hard and soft x-ray spectra were measured, and time-integrated and gated x-ray images of hydrodynamics experiments were recorded. Optical diagnostics recorded backscatter from the target, and VISAR laser velocimetry measurements were taken of laser-shocked target surfaces. Additional diagnostics are being developed and commissioned to observe and diagnose ignition implosions, including various neutron and activation diagnostics. ...

2007-05-07

306

Focused ion beam assisted three-dimensional rock imaging at submicron scale  

Energy Technology Data Exchange (ETDEWEB)

Computation of effective flow properties of fluids in porous media based on three dimensional (3D) pore structure information has become more successful in the last few years, due to both improvements in the input data and the network models. Computed X-ray microtomography has been successful in 3D pore imaging at micron scale, which is adequate for many sandstones. For other rocks of economic interest, such as chalk and diatomite, submicron resolution is needed in order to resolve the 3D-pore structure. To achieve submicron resolution, a new method of sample serial sectioning and imaging using Focused Ion Beam (FIB) technology has been developed and 3D pore images of the pore system for diatomite and chalk have been obtained. FIB was used in the milling of layers as wide as 50 micrometers and as thin as 100 nanometers by sputtering of atoms from the sample surface. The focused ion beam, consisting of ...

2003-05-09

307

Tissue oxygenation in a murine SCC VII tumor after X-ray irradiation as determined by EPR spectroscopy  

UK PubMed Central (United Kingdom)

PurposeThe goal of this study was to clarify the dynamics of tumor oxygen (partial pressure of oxygen, pO2) in SCC VII murine tumors in mice after X-ray...Full Text Available

2008-03-01

308

Subacute neuropathological effects of microplanar beams of x-rays from a synchrotron wiggler.  

UK PubMed Central (United Kingdom)

Microplanar beam radiation therapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and...Full Text Available

1995-09-12

309

Small-Angle X-ray Scattering of Reduced Ribonuclease A: Effects of Solution Conditions and Comparisons with a Computational Model of Unfolded Proteins  

UK PubMed Central (United Kingdom)

The disulfide-reduced form of bovine ribonuclease A (RNAse A), with the Cys thiols irreversibly blocked, was characterized by small-angle x-ray scattering (SAXS). To help resolve the conflicting...Full Text Available

2008-04-11

310

Radionuclide X-ray fluorescence analysis of waste water from the production of citric acid  

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid.

1982-02-18

311

Radionuclide X-ray fluorescence analysis of waste water from the production of citric acid  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid. (author).

1982-02-01

312

PIXE analysis of GaAs and ZnSe  

Energy Technology Data Exchange (ETDEWEB)

The optoelectronic compounds of GaAs and ZnSe are difficult to analyze by PIXE (particle-induced X-ray emission) due to the strong absorption of the As and Se K{sub {alpha}} X-rays. As part of a program to investigate optoelectronic materials using ion beam techniques, we have explored the possibility of using the high sensitivity of PIXE to check these materials for stoichiometry and dopant concentrations. The K{sub {alpha}} X-ray intensity ratios of Ga to As and Zn to Se have been investigated using H beams of 0.5 to 2.5 MeV and He beams of 1.0 to 2.5 MeV. The variation in the X-ray intensity ratio with beam energy and target thickness is modelled in terms of the cross section for X-ray production and the absorption coefficients of the X-rays in the target. The results of this model show the experimental conditions that must be satisfied in order that the ...

1990-01-01

313

PIXE analysis of GaAs and ZnSe  

International Nuclear Information System (INIS)

The optoelectronic compounds of GaAs and ZnSe are difficult to analyze by PIXE (particle-induced X-ray emission) due to the strong absorption of the As and Se K_#alpha# X-rays. As part of a program to investigate optoelectronic materials using ion beam techniques, we have explored the possibility of using the high sensitivity of PIXE to check these materials for stoichiometry and dopant concentrations. The K_#alpha# X-ray intensity ratios of Ga to As and Zn to Se have been investigated using H beams of 0.5 to 2.5 MeV and He beams of 1.0 to 2.5 MeV. The variation in the X-ray intensity ratio with beam energy and target thickness is modelled in terms of the cross section for X-ray production and the absorption coefficients of the X-rays in the target. The results of this model show the experimental conditions that must be satisfied in order that the ...

1989-06-01

314

Numerical optimization of spherical variable-line-spacing grating X-ray spectrometers  

UK PubMed Central (United Kingdom)

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and...Full Text Available

2011-03-01

315

Method of describing dose distributions in computer design of teleradiotherapy  

International Nuclear Information System (INIS)

Method for description of X-ray radiation dose distribution based on semiempirical description of dose fields is suggested. At that dose field description parameters can be easily individualized for concrete X-ray device.

316

Measurements of accurate x-ray scattering data of protein solutions using small stationary sample cells  

UK PubMed Central (United Kingdom)

In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage...Full Text Available

2009-01-01

317

Magnetic fields of x-ray pulsars  

Energy Technology Data Exchange (ETDEWEB)

An analytic model of magnetic torques applied to an accreting neutron star is employed to evaluate the magnetic dipole moments of x-ray pulsars. A new type of close binary system containing a neutron star is suggested.

1982-09-01

318

Experimental X-ray intensity ratio L#beta#/L#alpha#  

International Nuclear Information System (INIS)

Experimental, relative intensities for the components of L X-ray were collected from literature, and atomic-number dependency of L#beta#/L#alpha# has been found. (author).

1980-01-01

319

Contribution to the radionuclide x-ray fluorescence analysis of human blood and plasma  

International Nuclear Information System (INIS)

A photon-induced x-ray fluorescence method allowing the simultaneous determination of iron, copper, zinc, bromine and rubidium in human blood and blood plasma samples is described. The method is reliable and has a good sensitivity for a wide range of elements. (author).

1986-04-01

320

Complex Spatio-Spectral Structure of Diffuse X-Ray emission in the ...  

Science.gov (United States)

SN 1987A: Soft X-Ray Intensity Ratio. 2002-12 to 2000-12. 2005-7 to 2002-12. Contours: 2002-12. (0.5 2 keV). (0.5 2 keV). Contours: 2005-7 ...

321

Chemical effects on K x-ray intensity ratios in chromium compounds  

International Nuclear Information System (INIS)

K_#beta#/ K_#alpha# x-ray intensity ratio of chromium were measured in different chromium compounds. The results show the variation of the intensity ratio as a function of the chemical environment around the metal ion. (author)

2003-02-10

322

Characterization and catalytic oxidation activity of uranium-bismuth mixed oxides  

International Nuclear Information System (INIS)

Bi-U mixed oxides were synthesized by two methods and characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The samples were tested for the catalytic oxidation of carbon monoxide by oxygen. A stepwise redox mechanism consistent with the kinetic results is proposed. (orig.).

323

Chandra Observations of Nuclear X-ray Emission from a Sample of Radio Sources  

CERN Document Server

We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the unresolved cores. The sample includes 16 quasars (11 core-dominated and 5 lobe-dominated) in the redshift range z=0.30--1.96, and one low-power radio-galaxy at z=0.064. No diffuse X-ray emission is present around the cores of the quasars, except for the nearby low-power galaxy that has diffuse emission on a scale and with a luminosity consistent with other FRIs. No high-amplitude, short-term variability is detected within the relatively short Chandra exposures. However, 1510-089 shows low-amplitude flux changes with a timescale of $\\sim$25 minutes. The X-ray spectra of the quasar cores are generally well described ...

2003-01-01

324

APOD: 2002 July 11 - M51: X Rays from the Whirlpool  

Science.gov (United States)

picture will download the highest resolution version available. M51: X-Rays from the Whirlpool Credit: A. Wilson (UMD) et al., CXC, NASA Explanation: Fresh from yesterday's...

2011-10-07

325

A comparison of iterative algorithms and a mixed approach for in-line x-ray phase retrieval  

UK PubMed Central (United Kingdom)

Previous studies have shown that iterative in-line x-ray phase retrieval algorithms may have higher precision than direct retrieval algorithms. This communication compares three iterative phase...Full Text Available

2009-08-15

328

Superconducting properties of metallic superlattices  

Energy Technology Data Exchange (ETDEWEB)

The preparation by sputtering of artificial metallic superlattices is described, as are the results of x-ray structural determinations. Tunneling and resistivity measurements on these materials are reported.

1987-01-01

329

Radionuclide X-ray fluorescence analysis using semiconductor detectors  

International Nuclear Information System (INIS)

Czech May 1979. p. 32-33. Czechoslovakia Benada, J. Spacek, B. Ustav

1979-05-01

330
331

Plasma diagnostics in the optical and X-ray regions on the plasma focus device PF-4 (TULIP)  

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

2006-09-11

332

Microcomputers in radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Czech Apr 1986. p. 51. Czechoslovakia Cechak, T. Kluson, J. Ceske

1986-04-01

333

Experimental study of X-ray vidicon  

International Nuclear Information System (INIS)

(1972). USSR Sviryakin, DI Manets, AI Kolupaev, AN v. 213 p. 111-114.

335

Electron-induced luminescence and x-ray spectrometer development: progress report  

Science.gov (United States)

The progress in the development of a surface analysis tool based on the excitation of characteristic

2003-01-01

336

Electron-Induced Luminescence and X-Ray Spectrometer (ELXS) System for Life Detection  

Science.gov (United States)

The ELXS concept is a novel, portable, micro-instrument targeted for the detection of mineralogic

2002-01-01

338

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds  

Energy Technology Data Exchange (ETDEWEB)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L{sub {gamma}1} X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L{sub {gamma}1}/L{sub {beta}1} X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).

1990-12-20

339

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds  

International Nuclear Information System (INIS)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L_#gamma#_1 X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L_#gamma#_1/L_#beta#_1 X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).

1990-12-01

340

The evolution of x-ray binaries  

International Nuclear Information System (INIS)

These proceedings represent papers presented at the Astrophysics Conference in Maryland, USA. The topic of the Conference was the evolution of x-ray binaries and the papers encompass a wide range of subjects on x-ray astronomy. There were one hundred eighteen papers presented at the Conference and out of these three have been abstracted for the Energy Science and Technology database.

1993-10-11

341

Radionuclide X-ray fluorescence analysis of components of the environment  

International Nuclear Information System (INIS)

The physical foundations and methodology are described of radionuclide X-ray fluorescence analysis. The sources are listed of air, water and soil pollution, and the transfer of impurities into biological materials is described. A detailed description is presented of the sampling of air, soil and biological materials and their preparation for analysis. Greatest attention is devoted to radionuclide X-ray fluorescence analysis of the components of the environment. (ES).

1983-01-01

342

Pd-Na/F double exploding foil photoionization experiment  

Science.gov (United States)

The achievement of inner-shell photoionization of Zn-like Pd by means of two exploding foils is described. This resulted in the soft X-ray transition 3d94s2-3d104p at 46 A. It is shown that the photoionization of inner shell electrons in highly stripped ions can lead to X-ray transitions which may be candidates for X-ray lasers under 50 A.

1990-03-01

343

Nondestructive determination of airborne lead particulates by the radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Airborne lead particulates collected on a membrane filter were determined by the nondestructive X-ray fluorescence method. The gamma/X radionuclide source "2"4"1Am/Ag and a scintillation detector with a NaI/Tl crystal were used for the excitation and detection, respectively, of L X-rays of Pb. One can say, with reference to the obtained results, that the sensitivity and accuracy of the measurement is more than adequate for monitoring the Pb level in air. (author).

1980-01-01

344

Measurement of the K?/K? ratio for muon alpha sticking X-rays in muon catalyzed d-t fusion at the RIKEN-RAL Muon Facility  

International Nuclear Information System (INIS)

At the RIKEN-RAL Muon Facility, ?- to ? sticking K? X-rays were observed for the first time taking advantage of the pulsed beam structure. The precision of the present measurements was insufficient to distinguish between theoretical models, however the observed K?/K? X-ray intensity ratio tends to be smaller than most of these theoretical predictions.

1999-06-01

345

Genetic and somatic risks in X-ray diagnosis  

International Nuclear Information System (INIS)

Based on a literature study an actual summary of the risk-utility problems in X-ray diagnosis is outlined due to the Recommendations of the International Commission for Radiation Protection (ICRP publication 26/1977). Papers demonstrating quantitative assessment of the somatic and genetical risk in X-ray examination are preferably cited and evaluated. It is concluded that the somatic and genetical risk is low in diagnostic ratiology. However, it must not be neglected and has always to be compared to the utility of an examination as well as to other risks of the examination. (author).

1982-01-01

346

Determination of ash in coal by X-ray backscattering and X-ray fluorescence analysis and apparatus by the PAR company  

International Nuclear Information System (INIS)

The basic principles of determination of the ash content of coal by the title methods are outlined. A brief technical characteristic of the ash meters and radionuclide X-ray fluorescence analyzers manufactured by the PAR company is presented. (Z.S.). 4 figs., 7 refs.

1993-01-01

347

Contribution to the in vitro multielement X-ray fluorescence analysis of human soft tissues  

International Nuclear Information System (INIS)

Determination of Mn, Fe, Ni, Cu, Zn, and Pb in human soft tissues by radionuclide X-ray fluorescence analysis (using "2"3"8Pu and "1"0"9Cd sources) is described. The results of multielement XRS analysis of selected human tissues are tabulated. They are in good agreement with the literature data. It is concluded that X-ray fluorescence technique is a suitable method for trace element determination. (author).

1986-11-01

348

Post-mortem fetal MRI: What do we learn from it?  

International Nuclear Information System (INIS)

Post-mortem magnetic resonance (MR) imaging is of increasing interest not only as an alternative to autopsy but as a research tool to aid the interpretation and diagnosis of in utero MR images. The information from the post-mortem MR has allowed the development of imaging sequences applicable to in utero imaging and neonatal imaging. It has established brain development during gestation and has provided data on this to which in utero MR can be compared. The detail available from the post-mortem images is such that brain development can be studied in a non-invasive manner, a permanent record on the normal and abnormal areas is available and a greater understanding of developmental abnormalities is possible.

2006-02-01

349

Synchrotron PES and NEXAFS studies of self-assembled aromatic thiol monolayers on Au(1 1 1)  

Energy Technology Data Exchange (ETDEWEB)

Self-assembled monolayers (SAMs) on various metal, semiconductor or insulator substrates can be easily modified with specific functional groups of interest and have promising applications in surface wetting (hydrophobic/hydrophilic modification), tribology, corrosion protection, sensor electrodes modification, molecular and biomolecular recognition, protein adsorption, cell adhesion, and molecular- or organic-electronic device fabrications. In this paper, we highlight recent progress in the development of SAMs on solid substrates as well as their practical applications, with particular emphasis on the characterization of self-assembled aromatic thiol monolayers with different functional groups on Au(1 1 1) using synchrotron-based photoemission spectroscopy and near-edge X-ray absorption fine structure measurements. The SAM-related molecular orientation, electronic structures, and chemical bonding are presented. Using ...

2009-05-15

350

National and International Security Applications of Cryogenic Detectors - Mostly Nuclear Safeguards  

International Nuclear Information System (INIS)

As with science, so with security--in both arenas, the extraordinary sensitivity of cryogenic sensors enables high-confidence detection and high-precision measurement even of the faintest signals. Science applications are more mature, but several national and international security applications have been identified where cryogenic detectors have high potential payoff. International safeguards and nuclear forensics are areas needing new technology and methods to boost speed, sensitivity, precision and accuracy. Successfully applied, improved nuclear materials analysis will help constrain nuclear materials diversion pathways and contribute to treaty verification. Cryogenic microcalorimeter detectors for X-ray, gamma-ray, neutron, and alpha-particle spectrometry are under development with these aims in mind. In each case the unsurpassed energy resolution of microcalorimeters reveals previously invisible spectral features of ...

2009-12-16

351

PET and MRI in cardiac imaging: from validation studies to integrated applications  

International Nuclear Information System (INIS)

Positron emission tomography (PET) is the gold standard for non-invasive assessment of myocardial viability and allows accurate detection of coronary artery disease by assessment of myocardial perfusion. Magnetic resonance imaging (MRI) provides high resolution anatomical images that allow accurate evaluation of ventricular structure and function together with detection of myocardial infarction. Potential hybrid PET/MR tomography may potentially facilitate the combination of information from these imaging modalities in cardiology. Furthermore, the combination of anatomical MRI images with the high sensitivity of PET for detecting molecular targets may extent the application of these modalities to the characterization of atherosclerotic plaques and to the evaluation of angiogenetic or stem cell therapies, for example. This article reviews studies using MRI and PET in parallel to ...

2009-03-01

352

Fundamental concepts of digital image processing  

Science.gov (United States)

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) ...

1983-03-01

353

GaAs detector optimization for different medical imaging applications  

International Nuclear Information System (INIS)

We have investigated the detection performance of GaAs detectors made with different thickness and contact geometries. A comparison is made between these detection capabilities and the imaging requirements for the following medical applications: digital mammography, digital chest radiography and nuclear medicine. Experimental results and preliminary images are presented and discussed. (author)

1999-09-11

354

MR imaging of musculoskeletal trauma to the pelvis and the lower limb  

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging can be used in the trauma setting to detect fractures and associated soft tissue injuries of the musculoskeletal system. Magnetic resonance imaging complements plain radiography and CT for evaluating cancellous bone, cartilage and growth-plate injuries, and intra- and extraarticular supporting soft tissue structures. This review outlines typical applications and imaging consideration for injuries of the pelvis and lower extremity. (orig.) With 12 figs., 78 refs.

1999-03-01

355

Optimization of X-ray energy resolution from a horizontally focused single-crystal monochromator  

Energy Technology Data Exchange (ETDEWEB)

A method has been developed to optimize the energy resolution of a horizontally focusing monochromator. The method consists of determining the optimum radius of curvature of the cylindrically bent monochromator crystal by minimizing the total diffracted X-ray flux measured through an X-ray absorption foil. When measured at an absorption edge a global minimum can be identified, which corresponds to the minimum energy band accepted along the entire length of the crystal. Experimental verification of this method has been validated by comparing X-ray fluorescent scans taken for a series of crystal curvatures and by directly measuring the X-ray beam profiles at the corresponding points. The actual optical configuration and asymmetric-cut parameter of the focusing monochromator on beamline X4C at the National Synchrotron Light Source are modeled and ray tracing simulations of the optical system are compared ...

2009-02-11

356

Miniature x-ray source  

Energy Technology Data Exchange (ETDEWEB)

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

2000-01-01

357

Influence of the X-ray radiation on the lifetime of carriers in the p-n junctions of Si and Ge  

International Nuclear Information System (INIS)

Lifetime of minority charae carriers in the Si and Ge p-n unctions has been measured by pulse method of conductivity modulation of base. Its dependence on the X-ray radiation dose has been investigated. Dependence of current transmission coefficients on the dose has been measured and their sharp decrease at low doses and the following saturation at high doses have been observed. Linear dependence of lifetime on X-ray radiation dose has been obtained. Resulting from the comparison of regularities of the change of lifetime due to current characteristics, it has been shown that X-ray radiation leads to the formation of the surface defects, influencing the change of current characteristics as well as to stationary structural defects, causing the decrease of lifetime of the charge carriers with the increase of X-ray radiation dose.

358

Gauging film thickness: A comparison of an x-ray diffraction technique with Rutherford backscattering spectrometry  

Energy Technology Data Exchange (ETDEWEB)

An x-ray diffraction technique for determining thin-film thickness is presented which should prove to be a valuable alternative to the array of spectroscopies (Rutherford backscattering spectrometry, Auger electron spectroscopy, etc.) currently favored for these measurements. Some of the virtues of this x-ray diffraction approach are its nondestructive nature, fast data acquisition rate (enabling in situ observations), thickness resolution better than 5 nm, and conventional equipment requirements. Results are shown for Pd/sub 2/Si thin films grown during isothermal annealing of Pd coatings (100 nm) on Si at 200 /sup 0/C for various amounts of time. A comparison of these x-ray measurements with Rutherford backscattering spectrometry data taken from the same specimens is used to demonstrate the validity of the x-ray technique.

1985-01-15

359

Fully Coherent X-ray Pulses from a Regenerative Amplifier Free Electron Laser  

Energy Technology Data Exchange (ETDEWEB)

We propose and analyze a novel regenerative amplifier free electron laser (FEL) to produce fully coherent x-ray pulses. The method makes use of narrow-bandwidth Bragg crystals to form an x-ray feedback loop around a relatively short undulator. Self-amplified spontaneous emission (SASE) from the leading electron bunch in a bunch train is spectrally filtered by the Bragg reflectors and is brought back to the beginning of the undulator to interact repeatedly with subsequent bunches in the bunch train. The FEL interaction with these short bunches not only amplifies the radiation intensity but also broadens its spectrum, allowing for effective transmission of the x-rays outside the crystal bandwidth. The spectral brightness of these x-ray pulses is about two to three orders of magnitude higher than that from a single-pass SASE FEL.

2006-02-17

360

Measurement of the L sub 2 - L sub 3 Coster-Kronig transition probability in Tm( Z =69)  

Energy Technology Data Exchange (ETDEWEB)

The {ital L}{sub 2}-{ital L}{sub 3} Coster-Kronig transition probability ({ital f}{sub 23}) in Tm was measured by multiparameter {ital K} versus {ital L} x-ray coincidence techniques. The Tm x rays were obtained from a radioactive source of {sup 169}Yb and were detected with cooled germanium and silicon detectors of high-energy resolution. Corrections were applied for the contribution of {ital K}{alpha}{sub 1} x rays to the {ital K}{alpha}{sub 2} x-ray peak and for the contribution of unresolved {ital L}{eta} x rays to the {ital L}{alpha}{sub 1,2} x-ray peak. The contribution of {ital K}{alpha}{sub 1} x rays to the {ital K}{alpha}{sub 2} x-ray peak was determined solely from the results of the coincidence measurements using a method of ...

1989-11-01

361

Measurement of the L sub 2 - L sub 3 Coster-Kronig transition probability in Tm( Z =69)  

Science.gov (United States)

The {ital L}{sub 2}-{ital L}{sub 3} Coster-Kronig transition probability ({ital f}{sub 23}) in Tm was measured by multiparameter {ital K} versus {ital L} x-ray coincidence techniques. The Tm x rays were obtained from a radioactive source of {sup 169}Yb and were detected with cooled germanium and silicon detectors of high-energy resolution. Corrections were applied for the contribution of {ital K}{alpha}{sub 1} x rays to the {ital K}{alpha}{sub 2} x-ray peak and for the contribution of unresolved {ital L}{eta} x rays to the {ital L}{alpha}{sub 1,2} x-ray peak. The contribution of {ital K}{alpha}{sub 1} x rays to the {ital K}{alpha}{sub 2} x-ray peak was determined solely from the results of the coincidence measurements using a method of ...

1989-11-01

362

X-ray production with sub-picosecond laser pulses  

Energy Technology Data Exchange (ETDEWEB)

The interaction of intense, sub-picosecond laser pulses with solid targets produces intense picosecond x-ray pulses. With focused laser pulses of several 10 {sup 18} W/cm{sup 2}, He-like and H-like line radiation from targets such as aluminum and silicon has been produced. The energy conversion efficiency from the laser pulse energy to the 1--2 keV line x-rays is nearly one percent. The duration of the line x-ray radiation is of the order of ten picoseconds, although this may be an upper estimate because of the temporal resolution of the x-ray streak camera. The spatial extent of the x-ray source region is only slightly larger than the laser focal spot, or about 10 {mu}m in diameter. With these characteristics, such x-ray sources emit an intensity of nearly 10{sup 14} W/cm{sup 2}. Experiments and modeling which led to the above conclusions will be discussed.

1993-12-31

363

X-ray and UV-light irradiation effects on oxide superconducting thin films  

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 ...

364

Energetic electrons in impulsive and extended solar flares as deduced from flux correlations between hard X-rays and microwaves  

Energy Technology Data Exchange (ETDEWEB)

The peak flux relationship between hard X-rays and microwaves from solar flares is studied using about 400 events simultaneously recorded with the hard X-ray burst spectrometer on the SMM satellite and the Nobeyama 17 GHz radiometer. The data indicate that the hard X-ray and microwave peak fluxes correlate best for X-ray energies of less than about 80 keV for impulsive flares and greater than about 360 keV for extended flares. By postulating that electrons responsible for microwave emission at 17 GHz are those emitting hard X-rays at these photon energies, it is concluded that: (1) in impulsive flares, microwaves at about 20 GHz are emitted mainly by electrons of less than about 200 keV from a layer through which the electrons stream down into the thick-target hard X-ray source; and (2) in extended flares, microwaves are emitted mainly by MeV electrons trapped ...

1988-01-01

365

DETECTION OF AN X-RAY PULSATION FOR THE GAMMA-RAY PULSAR CENTERED IN CTA 1  

International Nuclear Information System (INIS)

We report the detection of X-ray pulsations with a period of ?315.87 ms from the 2009 XMM-Newton observation for the radio-quiet ?-ray pulsar, LAT PSR J0007+7303, centered in the supernova remnant CTA 1. The detected pulsed period is consistent with the ?-ray periodicity at the same epoch found with the Fermi Gamma-ray Space Telescope. The broader sinusoidal structure in the folded light curve of the X-ray emission is dissimilar to that of the ?-ray emission, and the phase of the peak is about 0.5 shifting from the peak in the ?-ray bands, indicating that the main component of the X-rays originates from different sites of the pulsar. We conclude that the main component of the X-ray pulsation is contributed by the thermal emission from the neutron star. Although with a significantly different characteristic age, PSR J0007+7303 is similar to Geminga in emission properties of X-rays ...

2010-12-10

366

Subject-specific, multiscale simulation of electrophysiology: a software pipeline for image-based models and application examples  

UK PubMed Central (United Kingdom)

Many simulation studies in biomedicine are based on a similar sequence of processing steps, starting from images and running through geometric model generation, assignment of tissue properties, numerical...Full Text Available

2009-06-13

367

Doppler imaging using spectrally-encoded endoscopy  

UK PubMed Central (United Kingdom)

The capability to image tissue motion such as blood flow through an endoscope could have many applications in medicine. Spectrally encoded endoscopy (SEE) is a recently introduced technique...Full Text Available

2008-09-15

368

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-10-15

369

Star Formation Activities of Galaxies in the Large-Scale Structures at z=1.2  

CERN Document Server

Recent wide-field imaging observations of the X-ray luminous cluster RDCSJ1252.9-2927 at z=1.24 uncovered several galaxy groups that appear to be embedded in filamentary structure extending from the cluster core. We make a spectroscopic study of the galaxies in these groups using GMOS on Gemini-South and FORS2 on VLT with the aim of determining if these galaxies are physically associated to the cluster. We find that three groups contain galaxies at the cluster redshift and that they are probably bound to the cluster. This is the first confirmation of filamentary structure as traced by galaxy groups at z>1. We then use several spectral features in the FORS2 spectra to determine the star formation histories of group galaxies. We find a population of relatively red star-forming galaxies in the groups that are absent from the cluster core. While similarly red star forming galaxies can also be found in the field, the average strength of the hd ...

2009-01-01

370

Microstructural observation of focused ion beam modification of Ni silicides/Si thin films  

International Nuclear Information System (INIS)

Focused ion beam (FIB) irradiation of a thin Ni_2Si layer deposited on a Si substrate was carried out and studied using an in-situ transmission electron microscope (in-situ TEM). Square areas on sides of 4 by 4 and 9 by 9 microm were patterned at room temperature with a 25 keV Ga"+-FIB attached to the TEM. The structural changes of the films indicate a uniform milling, sputtering of the Ni_2Si layer and the damage introducing to the Si substrate. Annealing at 673 K results in the change of the Ni_2Si layer into an epitaxial NiSi_2 layer outside the FIB irradiated area, but several precipitates appear around the treated area. Precipitates was analyzed by energy dispersive X-ray spectroscopy (EDS). Larger amount of Ni than the surrounding matrix was found in precipitates. Selected area diffraction (SAD) patterns of the precipitates and the corresponding dark field images imply the formation of a Ni rich silicide. The relation between the FIB tail ...

1996-12-02

371

Establishing a Connection Between Active Region Outflows and the Solar Wind: Abundance Measurements with EIS/Hinode  

CERN Document Server

One of the most interesting discoveries of the X-ray Telescope and EUV Imaging Spectrometer (EIS) on board the Hinode solar observatory is the presence of persistent high temperature high speed outflows from the edges of active regions. Measurements by EIS indicate that the outflows reach velocities of 50 km/s with spectral line asymmetries approaching 200 km/s. It has been suggested that these outflows may lie on open field lines that connect to the heliosphere, and that they could potentially be a significant source of the slow speed solar wind. A direct link has been difficult to establish, however. In this letter, we use EIS measurements of spectral line intensities that are sensitive to changes in the relative abundance of Si and S as a result of the first ionization potential (FIP) effect, to measure the chemical composition in the outflow regions of AR 10978 over a period of 5 days in December 2007. We find that Si is always enhanced ...

2010-01-01

372

Electrochemical properties of Cu{sub 2}O/Cu composite particles prepared by a novel and facile method  

Energy Technology Data Exchange (ETDEWEB)

In this study, Cu{sub 2}O/Cu composite particles were synthesized using an innovative chemical reduction method without any template and surfactant. X-ray diffraction (XRD) analysis revealed that the product mainly consisted of Cu{sub 2}O phase coexisting with a Cu phase. FE-SEM images showed that the octahedral shaped particles were Cu{sub 2}O. The electrochemical performance of the Cu{sub 2}O/Cu particles was investigated with regards to the working electrode material in alkaline solution. The particles had a maximum discharge capacity of 222.9 mAh/g at a discharge current density of 60 mA/g and a high value of 109.1 mAh/g after 50 charge-discharge cycles. Cyclic voltammetry revealed that the reaction between Cu{sub 2}O and Cu is the major electrochemical reaction during the charging and discharging process. Electrochemical impedance spectroscopy revealed that the formation of Cu{sub 2}O on the surface of Cu particles increased the contact ...

2010-07-01

373

Detection of Second-Layer Corrosion in Aging Aircraft Fuselage  

International Nuclear Information System (INIS)

A Digital X-ray imaging system using Compton backscattering has been developed to obtain a cross-sectional profile and mass loss of corroded lap-splices of aging aircraft from density variation. A slit-type camera was designed to focus on a small scattering volume inside the material, from which the backscattered photons are collected by a collimated scintillator detector for interpretation of material characteristics. The cross section of the lap-joint is scanned by moving the scattering volume through the thickness direction of the specimen. The mass loss of each layer has been estimated from a Compton backscatter A-scan to obtain the thickness of each layer including the aluminum sheet, the corrosion layer and the sealant. Quantitative information such as location and width of planar corrosion in the lap splices of fuselages is obtained by deconvolution using a nonlinear least-square error minimization method(BFGS method): A simple ...

2006-12-01

374

Computed Tomography in staging and follow-up of thoracic Hodgkin's diseases  

International Nuclear Information System (INIS)

As yet, the role of Computed Tomography (CT) as a routine imaging technique in the staging and follow-up of thoracic Hodgkin's disease has not been assessed. The authors reported the results obtained in 120 patients affected with thoracic Hodgkin's disease, staged and followed by means af chest X-rays and CT. CT better identified intrathoracic involvement of mediastinal nodes, of lung parenchyma, of pleura, and of pericarcial and chest walls in 54/120 patients (45%), with staging modifications in 18 (15%) of them only. Treatment was changed only in 12 patients (19%) where radiation therapy had been planned. The clinical value of the additional information yielded by CT was especially evident in the follow-up: CT allowed the correct evaluation of persistent/ recurrent disease in 51/117 patients (43.5%), a figure high enough to suggest the use of CT in the routive follow-up of patients affected with thoracic Hodgkin's disease.

1990-01-01

375

Comparative examinations of serum pepsinogen I, II and gastric area using computed radiography in the atrophic gastritis  

Energy Technology Data Exchange (ETDEWEB)

The relationship between serum PG I, PG II levels and extent of atrophic gastritis was examined. The subjects were 64 patients (male: 32, female: 32, 51.9 years old on average) with established diagnosis of either atrophic gastritis or normal. In the X-ray gastric examination, Fuji Computed Radiography (FCR) was used to obtain clear-cut images of the gastric area. Concerning the serum PG I level, patients in the group with atrophic gastritis showed lower levels than those of the people in the group with no atrophic change, but the variation was wide, and no definite tendency was seen in the relationship between the atrophic change and the serum PG I levels. Concerning the serum PG II level, as the atrophic change progresses, the serum PG II level tended to increase gradually. A significant reduction in the PG I/II ratio was seen in the group with atrophic changes (p<0.01) in comparison with the group with no atrophic changes, and the PG I/II ...

1995-11-01

376

Comparative examinations of serum pepsinogen I, II and gastric area using computed radiography in the atrophic gastritis  

International Nuclear Information System (INIS)

The relationship between serum PG I, PG II levels and extent of atrophic gastritis was examined. The subjects were 64 patients (male: 32, female: 32, 51.9 years old on average) with established diagnosis of either atrophic gastritis or normal. In the X-ray gastric examination, Fuji Computed Radiography (FCR) was used to obtain clear-cut images of the gastric area. Concerning the serum PG I level, patients in the group with atrophic gastritis showed lower levels than those of the people in the group with no atrophic change, but the variation was wide, and no definite tendency was seen in the relationship between the atrophic change and the serum PG I levels. Concerning the serum PG II level, as the atrophic change progresses, the serum PG II level tended to increase gradually. A significant reduction in the PG I/II ratio was seen in the group with atrophic changes (p<0.01) in comparison with the group with no atrophic changes, and the PG I/II ...

1995-01-01

377

An investigation of the capacitance dispersion on the fractal carbon electrode with edge and basal orientations  

Energy Technology Data Exchange (ETDEWEB)

Capacitance dispersion on the fractal carbon electrode with edge and basal orientations was investigated using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and a.c.-impedance spectroscopy. For this purpose, four types of as-received pyrolytic graphite electrode, as-received, mechanically polished, and as-activated glassy carbon electrodes were prepared with different surface irregularities and amounts of edge orientations. The apparent self-similar fractal dimensions of the carbon electrodes were determined from the analyses of AFM images based upon triangulation method. The amounts of edge orientations on the surface of the carbon electrodes were qualitatively estimated from the XPS analysis of surface acidic functional groups that were preferably formed on the edge planes by the heat treatment of the carbon electrodes. The values of the constant phase element exponent {alpha} determined from the apparent self-similar ...

2003-10-15

378

A new fuel cell electrocatalyst based on carbonized polyacrylonitrile foam: The nature of platinum-support interactions  

Energy Technology Data Exchange (ETDEWEB)

X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) have been conducted on a new fuel cell electrocatalytic material based on a highly porous carbonized polyacrylonitrile (PAN) microcellular foam with very low platinum loading ({approximately}13 to 23 {micro}g/cm{sup 2}). TEM images of this material clearly show the existence of nanometer size platinum particles which are homogeneously distributed in the highly porous carbonized PAN matrix. An XPS study of Pt-loaded PAN indicates that C 1s, O 1s, and N 1s peaks shift to lower binding energies, compared to virgin PAN. It was concluded that special metal-support interaction exists, through the formation of a charge-transfer complex between platinum and pyridine-type nitrogen atoms of PAN support. This interaction leads to the enhancement of the catalytic activity, and the improvement of the long-time stability of this electrocatalyst.

1997-01-01

379

4U 1907+09: a HMXB running away from the Galactic plane  

CERN Document Server

We report the discovery of a bow shock around the high-mass X-ray binary (HMXB) 4U 1907+09 using the Spitzer Space Telescope 24 $\\mu$m data (after Vela X-1 the second example of bow shocks associated with HMXBs). The detection of the bow shock implies that 4U 1907+09 is moving through the space with a high (supersonic) peculiar velocity. To confirm the runaway nature of 4U 1907+09, we measured its proper motion, which for an adopted distance to the system of 4 kpc corresponds to a peculiar transverse velocity of $\\simeq 160 \\pm 115$ km/s, meaning that 4U 1907+09 is indeed a runaway system and supporting the general belief that most of HMXBs possess high space velocities. The direction of motion of 4U 1907+09 inferred from the proper motion measurement is consistent with the orientation of the symmetry axis of the bow shock, and shows that the HMXB is running away from the Galactic plane. We also present the Spitzer images of the bow shock ...

2011-01-01

380

Real-time neutron radiography; Radiografia com neutrons em tempo-real  

Energy Technology Data Exchange (ETDEWEB)

The main objective of the present thesis was develop and get operational a real-time neutron radiography system, at the IPEN-CNEN/SP. This system is installed inside the shielding of an old facility, designed in 1988, for film radiography, which is installed at the beam-hole 08 of the 5 MW, IEA-R1 Nuclear Research Reactor. The most important modifications at the such facility were the increase of the {gamma}-radiation filter thickness, increase of the inner area of the shielding, design of a neutron collimator and a light tight box. The main characteristics of the neutron beam at the irradiation position are: flux: 1 x 10{sup 6}n/cm{sup 2}s, collimation ratio 70, effective energy 7 meV, diameter 20 cm, neutron/{gamma} ratio {approx} 10{sup 6}n/cm{sup 2}mrem. The real-time images have been obtained by means of an imaging system that consists of a screen scintillator, a light intensifier, a video camera, a digitizing frame grabber and a computer. ...

2000-07-01

381

Real-time neutron radiography  

International Nuclear Information System (INIS)

The main objective of the present thesis was develop and get operational a real-time neutron radiography system, at the IPEN-CNEN/SP. This system is installed inside the shielding of an old facility, designed in 1988, for film radiography, which is installed at the beam-hole 08 of the 5 MW, IEA-R1 Nuclear Research Reactor. The most important modifications at the such facility were the increase of the #gamma#-radiation filter thickness, increase of the inner area of the shielding, design of a neutron collimator and a light tight box. The main characteristics of the neutron beam at the irradiation position are: flux: 1 x 10"6n/cm"2s, collimation ratio 70, effective energy 7 meV, diameter 20 cm, neutron/#gamma# ratio #approx# 10"6n/cm"2mrem. The real-time images have been obtained by means of an imaging system that consists of a screen scintillator, a light intensifier, a video camera, a digitizing frame grabber and a computer. The device composed ...

2000-01-01

382

Surfactant based sol-gel approach to nanostructured LiFePO{sub 4} for high rate Li-ion batteries  

Energy Technology Data Exchange (ETDEWEB)

Porous nanostructured LiFePO{sub 4} powder with a narrow particle size distribution (100-300nm) for high rate lithium-ion battery cathode application was obtained using an ethanol based sol-gel route employing lauric acid as a surfactant. The synthesized LiFePO{sub 4} powders comprised of agglomerates of crystallites <65nm in diameter exhibiting a specific surface area ranging from 8m{sup 2}g{sup -1} to 36m{sup 2}g{sup -1} depending on the absence or presence of the surfactant. The LiFePO{sub 4} obtained using lauric acid resulted in a specific capacity of 123mAhg{sup -1} and 157mAhg{sup -1} at discharge rates of 10C and 1C with less than 0.08% fade per cycle, respectively. Structural and microstructural characterization were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray (EDX) analysis while ...

2007-01-01

383

Exact and variational calculations of eigenmodes for three-dimensional free electron laser interaction with a warm electron beam  

International Nuclear Information System (INIS)

I present an exact calculation of free-electron-laser (FEL) eigenmodes (fundamental as well as higher order modes) in the exponential-gain regime. These eigenmodes specify transverse profiles and exponential growth rates of the laser field, and they are self-consistent solutions of the coupled Maxwell-Vlasov equations describing the FEL interaction taking into account the effects due to energy spread, emittance and betatron oscillations of the electron beam, and diffraction and guiding of the laser field. The unperturbed electron distribution is assumed to be of Gaussian shape in four dimensional transverse phase space and in the energy variable, but uniform in longitudinal coordinate. The focusing of the electron beam is assumed to be matched to the natural wiggler focusing in both transverse planes. With these assumptions the eigenvalue problem can be reduced to a numerically manageable integral equation and solved exactly with a kernel iteration method. An approximate, but more ...

1995-08-21

384

Mechanisms controlling the leaching kinetics of fixated flue gas desulfurization (FGD) material under neutral and acidic conditions.  

Science.gov (United States)

A number of agricultural and engineering uses for fixated flue gas desulfurization (FGD) material exist; however, the potential for leaching of hazardous elements has limited widespread application and the processes controlling the leaching of this material are poorly understood. In this study, a flow-through rotating-disk system was applied to elucidate the relative importance of bulk diffusion, pore diffusion, and surface chemical reaction in controlling the leaching of fixated FGD material under pH conditions ranging from 2.2 to 6.8. Changing the hydrodynamics in the rotating disk system did not affect the leaching kinetics at both pH 2.2 and 6.8, indicating that bulk diffusion was not the kinetic-limiting step. Application of the shrinking core model (SCM) to the data suggested a surface reaction-controlled mechanism, rather than a pore diffusion mechanism. The leaching of fixated FGD material increased with decreasing pH, suggesting it can ...

2007-05-07

385

Apoferritin-Templated Yttrium Phosphate Nanoparticle Conjugates for Radioimmunotherapy of Cancers  

Energy Technology Data Exchange (ETDEWEB)

We report a templated-synthetic approach based on apoferritin to prepare radionuclide nanoparticle (NP) conjugates. Non-radioactive yttrium (89Y) was used as model target and surrogate for radioyttrium (90Y) to prepare the nanoparticle conjugate. The center cavity and multiple channel structure of apoferritin offer a fast and facile method to precipitate yttrium phosphate by diffusing yttrium and phosphate ions into the cavity of apofrritin, resulting a core-shell nanocomposite. The yttrium phosphate/apoferritin nanoparticle was functionalized with biotin for further application. The synthesized nanoparticle was characterized by transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS). We found that the resulting nanoparticles were uniform in size, with a diameter of around 8 nm. We tested the pre-targeting capability of the biotin-modified yttrium phosphate/apoferritin nanoparticle (yttrium phosphate/apoferritin ...

2008-05-01

386

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

387

Real-time neutron coded aperture imaging: A technique for nondestructive three-dimensional imaging  

Energy Technology Data Exchange (ETDEWEB)

Neutron Coded Aperture Imaging is a nondestructive imaging technique that utilizes neutrons scattered from an object through specially designed apertures. Coded Aperture Imaging is an alternative technique to Computed Tomography for three-dimensional imaging. Coded Aperture Imaging has the advantage that all of the three-dimensional information is contained in a single image, whereas Computed Tomography requires several images or projections. This technique has been implemented by other using photographic film as an image recording medium and optical reconstruction or decoding of the images. In this work, the possibility of using a real-time neutron video camera to record the images, followed by digital decoding methodology has been investigated. Because only a small fraction of ...

1992-01-01

388

Postfire soil burn severity mapping with hyperspectral image unmixing  

Science.gov (United States)

Sep 28, 2011... to assess the application of high resolution imagery for burn severity mapping and to compare it to standard burn severity mapping methods. ...

389

Measurement of K x-ray intensity ratio of tin, gadolinium and dysprosium  

International Nuclear Information System (INIS)

Full text: Measurement of K_#beta# to K_#alpha# x-ray intensity ratios are important not only in the field of atomic physics, radiation physics and medical physics, but also to test the validity of assumptions made in the theoretical prediction. The intensity ratios can also give information on the effect of physical and chemical environment of the element in the compound. Many investigators have adopted a single and double reflection geometries to measure the K_#beta# to K_#alpha# x ray intensity ratios to understand the effect of physical and chemical environment on x-ray fluorescence. The targets are excited by a radioactive source of having activity of the order 100 MBq. in order to carry out accurate measurement K_#beta# to K_#alpha# x-ray intensity ratios, we have develop 2#pi# geometrical configuration method : placing a target right on the surface of the detector facing the ...

2003-11-01

390

Approximate fuzzy C-means (AFCM) cluster analysis of medical magnetic resonance image (MRI) data  

International Nuclear Information System (INIS)

The authors describe the application of an approximate fuzzy C-means (AFCM) clustering algorithm as a data dimension reduction approach to medical magnetic resonance images (MRI). Image data consisted of one T1-weighted, two T2-weighted, and one T2*-weighted (magnetic susceptibility) image for each cranial study and a matrix of 10 images generated from 10 combinations of TE and TR for each body lymphoma study. All images were obtained with a 1.5 Tesla imaging system (GE Signa). Analyses were performed on over 100 MR image sets with a variety of pathologies. The cluster analysis was operated in an unsupervised mode and computational overhead was minimized by utilizing a table look-up approach without adversely affecting accuracy. Image data were first segmented into 2 coarse clusters, each of which ...

391

Document image retrieval with morphology-based segmentation and features combination  

Science.gov (United States)

Digital libraries need more than just a retrieval based on keywords, which can be inefficient for some applications. Thus, a document retrieval based on content of the digitized image version of the document can be a more appropriated approach. This paper discusses the retrieval of document images by means of identifying a variety of elements present in the document's image body. We propose a new strategy to identify and combine features extracted from a document image. We also consider the task of constructing an optimized feature set to improve the retrieval performance and to validate our experiments on an assorted database. Experimental results show that the proposed segmentation together with a wisely feature combination increase the overall retrieval performance. Moreover the retrieved images demonstrate the generality and effectiveness of our approach for ...

2011-01-01

392

Injuries of the tibio-talar joint and preoperative planning. Verletzungen des oberen Sprunggelenks aus unfallchirurgischer Sicht  

Energy Technology Data Exchange (ETDEWEB)

The treatment of bony, osteochondral, and ligamentous injuries of the tibio-talar requires precise preoperative planning by radiological investigation. This is essential to a correct understanding of the underlying pathology and will allow a proper classification of the injury, which is the basis of treatment. Conventional radiography using anteroposterior and lateral X-rays with comparative views of the noninjured side and, if necessary, rotated spot views and tomography are of high value especially in osteochondral fractures of the talus. Intraoperative control images in both planes after osteosynthesis are mandatory. For evaluation of the postoperative course and severity of arthrosis formation, the classification system of Bargon has proved its worth. In addition, tomography of the tibio-talar joint in two planes is useful especially in tibial pilon fractures, some malleolar fractures, and peripheral talar fractures. In talar fracture ...

1991-12-01

393

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

394

A convolution/superposition method using primary and scatter dose kernels formed for energy bins of X-ray spectra reconstructed as a function of off-axis distance: a theoretical study on 10-MV X-ray dose calculations in thorax-like phantoms  

British Library Electronic Table of Contents (United Kingdom)

A convolution/superposition method is proposed for use with primary and scatter dose kernels formed for energy bins of X-ray spectra reconstructed as a function of off-axis distance. It should be noted that the number of energy bins is usually about ten, and that the reconstructed X-ray spectra can reasonably be applied to media with a wide range of effective Z numbers, ranging from water to lead. The study was carried out for 10-MV X-ray doses in water and thorax-like phantoms with the use of open-jaw-collimated fields. The dose calculations were made separately for primary, scatter, and electron contamination dose components, for which we used two extended radiation sources: one was on the X-ray target and the other on the flattening filter. To calculate the in-air beam intensities at po...

2011-01-01

395

X-ray fluorescence analysis as auxiliary method of restorers  

International Nuclear Information System (INIS)

The principle is described of X-ray fluorescence analysis and the manner of detecting the emitted characteristic radiation. The advantages are presented of radionuclide X-ray fluorescence analysis which consist primarily in the possibility of conducting a totally non-destructive analysis, and of accurate and relatively narrow localization of the analyzed area, the simultaneous qualitative and quantitative determinations of a large number of elements in the order of concentrations 10"1 to 10"-"4%, stability of excitation radiation flux, simple design and relatively low capital costs. The so-called matrix effect is pointed to. A number of examples is given of the use of the cited method, including its use in the analysis of art objects. (J.B.).

1987-09-07

396

Standard samples for X-ray radiometric analysis of substance composition  

International Nuclear Information System (INIS)

Some aspects of metrological provision of X-ray radiometric analyzers for mineral raw composition and gamma-gamma-logging equipment are considered. Standard samples (SS) based on the phenol-formaldehyde resin with the introduced quantities calculated of element compositions in the form of oxides and salts are described. Principles of metrological provision developed are used when carrying out state acceptance tests of X-ray radiometric analyzer RAL-M-102 ''Ehkran'' and gamma-gamma-logging equipmnt RSK-102. Economic benefit from introduction of an SS set is #approx# 60-100 thousand roubles per year.

397

Role of nuclear medicine bone scans in evaluating pain in athletic injuries  

Energy Technology Data Exchange (ETDEWEB)

The utilization of nuclear medicine bone scanning examinations early in the diagnostic process allows physicians to render prompt and correct treatment in urgent or difficult athletic cases. Bone scanning should be performed for athletic injuries whenever (1) x-rays are normal but bone or joint pain persists; (2) x-rays are positive but it cannot be determined if the findings are acute or chronic; (3) soft-tissue injuries present and x-rays are not useful; and (4) bone pain or joint impairment present without a history of trauma.89 references.

1987-10-01

398

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

399

Measurement of the K{sub {beta}}/K{sub {alpha}} ratio for muon alpha sticking X-rays in muon catalyzed d-t fusion at the RIKEN-RAL Muon Facility  

Energy Technology Data Exchange (ETDEWEB)

At the RIKEN-RAL Muon Facility, {mu}{sup -} to {alpha} sticking K{sub {beta}} X-rays were observed for the first time taking advantage of the pulsed beam structure. The precision of the present measurements was insufficient to distinguish between theoretical models, however the observed K{sub {beta}}/K{sub {alpha}} X-ray intensity ratio tends to be smaller than most of these theoretical predictions.

1999-06-15

400

Measurement of M shell X-ray production cross sections and fluorescence yields for the elements in the atomic range 70#<=#Z#<=#92 at 5.96 keV  

International Nuclear Information System (INIS)

Total M X-ray cross sections for 12 elements in atomic range 70#<=#Z#<=#92 were measured at 5.96 keV Mn K X-ray photon energy. The average M shell fluorescence yields (anti #omega#_M) of these elements have also been observed using the presently measured cross section values and the theoretical M shell photoionisation cross section values. (orig.).

401

L-subshell and total M-shell X-ray production cross sections of Ta, W, Pt, Au, Pb and Bi by 0.7-2.4 MeV protons  

International Nuclear Information System (INIS)

The L-subshell and total M-shell X-ray production cross sections of Ta, W, Pt, Au, Pb and Bi have been measured by protons of energy between 0.7 and 2.4 MeV. The obtained results for X-ray production cross sections have been compared with the existing experimental data, prediction of the ECPSSR theory and also with fitted empirical cross sections of Strivay and Weber.

2006-06-01

402

Inner-shell excitation of intrinsic luminescence and resonantly excited X-ray fluorescence at Be 1s edge in oriented BeO crystals  

International Nuclear Information System (INIS)

The results of studies of the time-resolved luminescence of self-trapped excitons (STE) with different multiplicity as well as the X-ray emission in oriented BeO crystals under excitation in the vicinity of the 1 s Be photoabsorption edge are presented. The branching of the electronic excitations relaxation depends strongly on the crystal orientation after the inner-shell excitation. The common features between the processes of the STE luminescence and resonantly excited X-ray fluorescence have been discussed.

2007-05-21

403

Estimation of X-rays dose in the crystals of final thickness  

International Nuclear Information System (INIS)

A calculation method of the X-ray radiation dose (energy of gamma- radiation remains in the range of energies where the mechanism of photoelectric absorption is the prevailing one) absorbed in the absorbers of final thickness is suggested. Calculations of resorption of secondary radiation (characteristic fluorescences) in the substance and kinetic energy of photoelectrons caused by this resorption (it would be enough to consider one or two hard series) are presented. Calculation of the spectrum of photoelectron energy yield in TeInSe_2 monocrystal for 0.1-0.5 A range of X-ray radiation is conducted by the developed methods.

404

Emission Line Spectra in the Soft X-Ray Region 20-75 (Angstrom)  

Energy Technology Data Exchange (ETDEWEB)

As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.

2002-06-18

405

Analytic description of X-ray fluorescence intensity as a function of the particle size in powder samples and pulp upon X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Analytic expression is derived for X-ray fluorescence dependence on the particle size of powder and slurry media. The expression is obtained for a model of powder medium containing particles of different size and random distribution in the bulk of the sample. Limiting cases of homogeneous and slurry-like media are considered and expressions for calculation of the fluorescence intensity are derived. The results reasonably match the experiment for binary powder mixtures and thus provide evaluation of the powder particle size on the fluorescence intensity for multicomponent polydisperse powder medium

2007-11-01

406

A Virtual Young's Double Slit Experiment for Hard X-ray Photons  

CERN Document Server

We have implemented a virtual Young's double slit experiment for hard X-ray photons with micro-fabricated bi-prisms. We observe fringe patterns with a scintillator, and quantify interferograms by detecting X-ray fluorescence from a scanned 30nm Cr metal film. The observed intensities are best modeled with a near-field, Fresnel analysis. The maximum fringe number in the overlap region is proportional to the ratio of real to imaginary parts refractive index of the prism material. The horizontal and vertical transverse coherence lengths at beamline APS 8-ID are measured.

2009-01-01

407

3. Physical foundations and methodology of radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

The physical foundations are described of radionuclide X-ray fluorescence analysis (RXFA) and the table shows the values of K- and L-absorption thresholds and the K- and L-line energies of elements. The calculation of the intensity of characteristic radiation during RXFA proceeds from relations derived for conventional X-ray fluorescence analysis. The choice of the radionuclide source is ruled by the nature of the analysed substance and the used detection technique. The diagram shows the areas of radionuclide sources and the energy of the fluorescence radiation of elements. The table shows the spectra of radionuclide sources suitable for the purposes of RXFA measured by semiconductor Si(Li) and Ge(Li) detectors. (ES).

1983-12-01

408

Vapor phase lubrication of a Ni-based superalloy  

Energy Technology Data Exchange (ETDEWEB)

In addition to ceramics, alloys such as tool steel and nickel- and iron-based superalloys are being considered for high temperature applications such as missile bearings and low heat rejection engines. Studies were made to lubricate a nickel-based superalloy at 500{degrees}C, by using a vaporized aryl phosphate ester, at a concentration of 0.1% in air. From deposition and wear studies it was found that it was impossible to form a good polymeric coating on the superalloy surface. Energy dispersive X-ray analyzer (EDXA) analysis showed that this was due to minute quantities of aluminum in the alloy segregating to the surface, upon being heated to 500{degrees}C, forming a passive oxide coating. It was necessary to activate the surface, in order to lubricate the material successfully. A method of activation by electrodepositing the surface with a layer of iron oxide was developed. Once activated, a good lubricous polymer was formed on the ...

1995-03-01

409

Thermodynamics and stability of the mixed-conducting Sr-Fe-Co-O system.  

Energy Technology Data Exchange (ETDEWEB)

Mixed-conducting Sr-Fe-Co oxides have potential applications in dense ceramic membranes for high-purity oxygen separation and/or methane conversion to produce syngas (CO + H{sub 2}), because of their combined high electronic/ionic conductivity and significant oxygen permeability. We studied the crystal structure and microstructure of the system in X-ray diffraction experiments and by using scanning electron microscopy, respectively. Thermogravimetric analysis was conducted on the SrFeCo{sub 0.5}O{sub x} sample in environments of various oxygen partial pressures (pO{sub 2}). Conductivity increased while weight decreased with increasing temperature. Activation energy decreased while conductivity increased with increasing pO{sub 2}. The pO{sub 2}-dependent conducting behavior of the SrFeCo{sub 0.5}O{sub x} system can be understood by considering the trivalent-to-divalent transition of transition-metal ions.

1999-04-28

410

The surface modification of tooth dentine with a Free Electron Laser (FEL)  

International Nuclear Information System (INIS)

Free Electron Laser (FEL) with the wide wavelength tunability has been developed and used for various applications. The FEL gives high efficiency for the photo-induced ablation when the laser is tuned to an absorption maximum of the target. The FEL was tuned to 9.4 #mu#m, which is an absorption maximum of phosphoric acid ion, a known major component of dentine. The FEL pulse length was several ps. The average output power was varied from 5 to 20 mW by filters. The change of irradiated dentine surface was analyzed by mass spectroscopy and Energy Dispersive X-ray (EDX) spectroscopy. Positive ions which correspond to Na"+, CO_3"+ and many phosphoric acid ions were measured. It was found that atomic ratio of P/Ca had reduced from 0.65-0.60. The atomic ratio of P/Ca, however had not changed with irradiation by Er:YAG laser (2.9 #mu#m), or CO_2 laser (10.6 #mu#m). These results indicate the selective ablation of phosphoric acid ion by the 9.4 mm FEL ...

1998-09-02

411

The potential of the baobab (Adansonia digitata L.) as a proxy climate archive  

Energy Technology Data Exchange (ETDEWEB)

The large girth and immense size of the baobab has caused many to speculate about its age. Unfortunately reliable age estimates cannot be determined from growth rates as the girth varies in response to different moisture regimes. In a similar way, ages cannot be determined from ring-width measurements or X-ray densitometry as the absorbent nature of the soft fibrous wood and distortion upon drying prevent the application of these techniques. The Southern Hemisphere bomb radiocarbon curve was used to demonstrate that the rings of a recently-fallen baobab (Adansonia digitata L.) from Kruger National Park appear to be annual. The detrended C isotope values of finely-ground wholewood from another baobab specimen were found to be highly associated with January precipitation (r = 0.72; p < 0.01). This study demonstrates that high resolution information about past climates may be obtained by analysing the C isotope values from baobab samples ...

2006-10-15

412

The potential of the baobab (Adansonia digitata L.) as a proxy climate archive  

International Nuclear Information System (INIS)

The large girth and immense size of the baobab has caused many to speculate about its age. Unfortunately reliable age estimates cannot be determined from growth rates as the girth varies in response to different moisture regimes. In a similar way, ages cannot be determined from ring-width measurements or X-ray densitometry as the absorbent nature of the soft fibrous wood and distortion upon drying prevent the application of these techniques. The Southern Hemisphere bomb radiocarbon curve was used to demonstrate that the rings of a recently-fallen baobab (Adansonia digitata L.) from Kruger National Park appear to be annual. The detrended C isotope values of finely-ground wholewood from another baobab specimen were found to be highly associated with January precipitation (r = 0.72; p < 0.01). This study demonstrates that high resolution information about past climates may be obtained by analysing the C isotope values from baobab samples even ...

2006-10-01

413

Synthesis and photo-degradation application of WO3/TiO2 hollow spheres  

British Library Electronic Table of Contents (United Kingdom)

A WO3/TiO2 composite, hollow-sphere photocatalyst with average diameter of 320nm and shell thickness of 50nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO3/TiO2 hollow spheres were red-shifted compared to the TiO2 hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO3 and TiO2 phases were confirmed by X-ray diffraction analysis. BET isotherms revealed that the specific surface area and average pore diameter of the hollow spheres were 40.95m^2/g and 19nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO3/TiO2 hollow spheres under visible light within 80min. Under the same conditions, only 24% MB can ...

2011-01-01

414

Surface improvement and biocompatibility of TiAl{sub 24}Nb{sub 10} intermetallic alloy using rf plasma nitriding  

Energy Technology Data Exchange (ETDEWEB)

The present work describes the surface improvement and biocompatibility of TiAl{sub 24}Nb{sub 10} intermetallic alloy using rf plasma nitriding. The nitriding process was carried out at different plasma power from 400 W to 650 W where the other plasma conditions were fixed. Grazing incidence X-ray diffractometry (GIXRD), Auger electron spectroscopy (AES), tribometer and a nanohardness tester were employed to characterize the nitrided layer. Further potentiodynamic polarization method was used to describe the corrosion behavior of the un-nitrided and nitrided alloy. It has been found that the Vickers hardness (HV) and corrosion resistance values of the nitrided layers increase with increasing plasma power while the wear rates of the nitrided layers reduce by two orders of magnitude as compared to those of the un-nitrided layer. This improvement in surface properties of the intermetallic alloy is due to formation of a thin modified layer which is composed of titanium ...

2007-09-30

415

Surface improvement and biocompatibility of TiAl_2_4Nb_1_0 intermetallic alloy using rf plasma nitriding  

International Nuclear Information System (INIS)

The present work describes the surface improvement and biocompatibility of TiAl_2_4Nb_1_0 intermetallic alloy using rf plasma nitriding. The nitriding process was carried out at different plasma power from 400 W to 650 W where the other plasma conditions were fixed. Grazing incidence X-ray diffractometry (GIXRD), Auger electron spectroscopy (AES), tribometer and a nanohardness tester were employed to characterize the nitrided layer. Further potentiodynamic polarization method was used to describe the corrosion behavior of the un-nitrided and nitrided alloy. It has been found that the Vickers hardness (HV) and corrosion resistance values of the nitrided layers increase with increasing plasma power while the wear rates of the nitrided layers reduce by two orders of magnitude as compared to those of the un-nitrided layer. This improvement in surface properties of the intermetallic alloy is due to formation of a thin modified layer which is composed of titanium nitride ...

2007-09-30

416

Study of transformation behavior in a Ti-4.4 Ta-1.9 Nb alloy  

International Nuclear Information System (INIS)

An alloy of composition Ti-4.4 wt.% Ta-1.9 wt.% Nb is being developed as a structural material for corrosion applications, as titanium and its alloys possess excellent corrosion resistance in many oxidizing media. The primary physical metallurgy database for the Ti-4.4 wt.% Ta-1.9 wt.% Nb alloy is being presented for the first time. Determination of the #beta# transus, M_s temperature and classification of the alloy have been carried out, employing a variety of microscopy techniques, X-ray diffraction (XRD), micro-hardness and differential scanning calorimetry (DSC). The #beta# transition temperature or #beta# transus determined using different experimental techniques was found to agree very well with evaluations based on empirical calculations. Based on chemistry and observed room temperature microstructure, the alloy has been classified as an #alpha# + #beta# titanium alloy. The high temperature #beta# transforms to either #alpha#' or #alpha# ...

2005-01-15

417

Studies on the development of mossy zinc electrodeposits from flowing alkaline electrolytes  

Energy Technology Data Exchange (ETDEWEB)

The initiation and characteristics of mossy zinc electrodeposits have been investigated. Batteries with zinc electrodes are candidates for electric vehicle applications; however, this electrode is prone to form non-compact deposits that contribute to capacity loss and battery failure. Moss is deposited when the current density is far from the limiting current. This morphology first appears only after the bulk deposit is approximately 1 {mu}m thick. In this investigation, the effects of flow rate (Re=0--4000), current density (0--50 mA/cm{sup 2}), concentration of the electroactive species (0.25 and 0.5 M), and the concentration of supporting electrolyte (3, 6, and 12 M) on the initiation of moss were examined. The rotating concentric cylinder electrode was employed for most of the experiments; and a flow channel was used to study the development of morphology. After the experiment, the deposit was characterized using microscopic, x-ray ...

1991-07-01

418

Silver nanoparticle-decorated carbon nanotubes as bifunctional gas-diffusion electrodes for zinc-air batteries  

Energy Technology Data Exchange (ETDEWEB)

Thin, lightweight, and flexible gas-diffusion electrodes (GDEs) based on freestanding entangled networks of single-walled carbon nanotubes (SWNTs) decorated with Ag nanoparticles (AgNPs) are tested as the air-breathing cathode in a zinc-air battery. The SWNT networks provide a highly porous surface for active oxygen absorption and diffusion. The high conductivity of SWNTs coupled with the catalytic activity of AgNPs for oxygen reduction leads to an improvement in the performance of the zinc-air cell. By modulating the pH value and the reaction time, different sizes of AgNPs are decorated uniformly on the SWNTs, as revealed by transmission electron microscopy and powder X-ray diffraction. AgNPs with sizes of 3-5 nm double the capacity and specific energy of a zinc-air battery as compared with bare SWNTs. The simplified, lightweight architecture shows significant advantages over conventional carbon-based GDEs in terms of weight, thickness and conductivity, and hence ...

2010-07-01

419

SIMS and XRD measurements for the critical review of carbon diffusivity derivation from hardness profiles  

Energy Technology Data Exchange (ETDEWEB)

Microhardness decarburization profiles are often used in the industry to estimate the carbon distribution in steels. For quantitative evaluation, an analysis based on diffusion theory must be performed, the fundamentals and mathematical basics of which are presented. If the relationship between hardness and carbon content is known, microhardness-distance curves of steels can be analyzed in this way. For martensitic grades, for instance, a linearized expression holds in the concentration range from 0.15 to 0.6 m.% C. Microhardness depth profiles of higher carbon steels and other microstructures, however, are also evaluated in the literature. The applicability of quantitative diffusion modeling is discussed in detail. Through hardenable rolling bearing steel 100Cr6 (1.3505, SAE 52100) serves as model material: carbon concentration-distance curves are measured with high accuracy by secondary ion mass spectrometry (SIMS) and compared with microhardness decarburization ...

2007-07-01

420

Pulse Shapes From Rapidly-Rotating Neutron Stars: Equatorial Photon Orbits  

CERN Document Server

We demonstrate that fitted values of stellar radius obtained by fitting theoretical light curves to observations of millisecond period X-ray pulsars can significantly depend on the method used to calculate the light curves. The worst-case errors in the fitted radius are evaluated by restricting ourselves to the case of light emitted and received in the equatorial plane of a rapidly-rotating neutron star. First, using an approximate flux which is adapted to the one-dimensional nature of such an emission region, we show how pulse shapes can be constructed using an exact spacetime metric and fully accounting for time-delay effects. We compare this to a method which approximates the exterior spacetime of the star by the Schwarzschild metric, inserts special relativistic effects by hand, and neglects time-delay effects. By comparing these methods, we show that there are significant differences in these methods for some applications, for example ...

2005-01-01

421

Non-isothermal oxidation of ceramic nanocomposites using the example of Ti-Si-C-N powder: Kinetic analysis method  

Energy Technology Data Exchange (ETDEWEB)

A method of kinetic analysis applicable to non-isothermal oxidation processes of ceramic nanocomposites is presented using Ti-Si-C-N powder as the substrate. The nanoparticle size and phase composition were determined using high-resolution transmission electron microscopy and X-ray diffraction (XRD). Thermogravimetric measurements were carried out for powder samples in dry air in the temperature range 298-1770 K. The following heating rates were applied: 3, 5, 10, 20 K min{sup -1}. Mass spectrometry was used to analyze gaseous oxidation products and solid products were identified by the XRD technique. The Coats-Redfern equation was applied for the kinetic analysis. For each stage of the oxidation kinetic models, the best accuracy was achieved using a series of criteria, and then the A and E parameters of the Arrhenius equations were estimated. Both linear regression and artificial neural networks were applied in testing kinetic models.

2008-08-15

422

Ni, Pd, and Pt on GaAs: A comparative study of interfacial structures, compositions, and reacted film morphologies  

Energy Technology Data Exchange (ETDEWEB)

The reactions between (100) GaAs and the near-noble metals Ni, Pd, and Pt have been investigated by application of high-resolution transmission electron microscopy (TEM), energy-dispersive analysis of x rays in the scanning TEM and Rutherford backscattering spectrometry. Emphasis is placed on the evolution of the phase distributions, film compositions, and interface morphologies during annealing at temperatures up to 480 /sup 0/C. The first phase in the Ni/GaAs reaction is shown to have the nominal composition Ni/sub 3/GaAs. Ternary phases of the type Pd/sub x/GaAs are also found to be the dominant products of the Pd/GaAs reaction. Conversely, only binary phases result from the Pt/GaAs reaction. These observations are used to construct isothermal sections of the M--Ga--As thin-film phase diagrams. The behavior of a thin (1--2 nm) native oxide--hydrocarbon layer during the Ni/GaAs, Pd/GaAs, and Pt/GaAs reactions is also ...

1987-03-01

423

Modeling of the relaxation kinetics of metastable tensile strained Si:C alloys  

Energy Technology Data Exchange (ETDEWEB)

In order to enhance the performance of CMOS transistors, embedded epitaxial layers of Si:C can be used. In the present work, Si:C layers with Carbon contents up to 1.9 at-% and in-situ Phosphorus doping up to 4 x 10{sup 20}At/cm{sup 3} have been investigated. Due to the low solubility of Carbon in Silicon (0.0004 at.-% at the melting point), all layers considered in this work are metastable and tend to relax. Since it is crucial to the application to retain the strain of those layers, the responsible mechanisms must be understood. The relaxation during thermal treatment was studied by high resolution X-ray diffraction and was found to behave differently, depending on Carbon content and Phosphorus doping concentration. In this work, we propose a relaxation mechanism based on a kick-out reaction of substitutional Carbon which is accelerated by Phosphorus content through transient enhanced diffusion. We simulate the time evolution of layer ...

2010-07-01

424

Microstructure modifications and modulated piezoelectric responses in PLZT/Al{sub 2}O{sub 3} composites  

Energy Technology Data Exchange (ETDEWEB)

Piezoelectric ceramics for acoustic applications have been prepared by mixing the piezoelectric phase Pb{sub 1-1.5x}La{sub x}{open_square}{sub x/2}(Ti{sub 1-y}Zr{sub y})O{sub 3} (PLZT) with variable fractions of Al{sub 2}O{sub 3}. The samples are in form of pellets and polarized at high temperature. After thermal treatment, X-ray diffraction and scanning electron microscopy have been used to determine the phase and morphological modifications. The morphotropic PLZT initial phase disproportionates into modified PLZT and ZrO{sub 2} phases. Using electrical impedance spectroscopy, the resonance frequencies of the composite system have been determined and analyzed. As the Al{sub 2}O{sub 3} volume fractions increase, the resonance frequency and the amplitude of the electrical response both decrease. An interpretation of the role of Al{sub 2}O{sub 3} additions is proposed in terms of phase and microstructure modifications. Using LRC electrical ...

2003-01-15

425

Inductively coupled plasma nitriding of chromium electroplated AISI 316L stainless steel for PEMFC bipolar plate  

Energy Technology Data Exchange (ETDEWEB)

Chromium electroplated AISI 316L stainless steel was nitrided using inductively coupled plasma (ICP) for application in the bipolar plate of a polymer electrolyte membrane fuel cell (PEMFC). A continuous and thin chromium nitride layer was formed at the surface of the samples after ICP nitriding for 2 h at 400 C. The interfacial contact resistance (ICR) and corrosion resistance in simulated PEMFC operating conditions were higher than the required values, while they varied with the applied dc bias voltage during the nitriding process. The ICR value decreased with an increase in bias voltage. Potentiodynamic polarization measurements showed that all of the nitrided samples had excellent corrosion resistance with a current density of {proportional_to}10{sup -7} A cm{sup -2} at the cathode. It was also found that the oxygen content at the surface was not increased after the corrosion test. X-ray diffractometry (XRD), field emission scanning ...

2009-03-15

426

Improved adhesion for thermoplastic polymers using oxyfluorination  

Energy Technology Data Exchange (ETDEWEB)

Industrial applications of thermoplastic polymers are often limited by their poor adhesion properties. In this work the effect of surface oxyfluorination on the adhesion properties was investigated for polyethylene (PE), polyoxymethylene (POM), polybutylene terephthalate (PBT) and polyamide 6 (PA6). The adhesive joint strength was quantified using lap-shear tests. These results were correlated with the changes in the chemical composition of the surface, determined by X-ray photoelectron spectroscopy (XPS), in the surface free energy, measured by the contact angle method, and in the topography, using white-light confocal microscopy. The adhesive strength is strongly improved for all four polymers, but the degree of this increase depends on the polymer type. The surface free energy shows a similar trend for all four polymers. A high surface free energy exceeding 50 mN/m was observed after oxy-fluorination, whereby the polar component was strongly ...

2008-03-15

427

Ferroelectric and magnetic properties of Ho{sub 2}CuTiO{sub 6} double perovskite  

Energy Technology Data Exchange (ETDEWEB)

Ho{sub 2}CuTiO{sub 6} double pervoskite is synthesized by solid state reaction method and the phase formation was confirmed by X-ray diffraction. Ho{sub 2}CuTiO{sub 6} crystallizes in space group P63 cm and are isostructural in AMnO{sub 3} structure. We have investigated the effect of the presence of a magnetic ion (Ho{sup 3+}{approx}10.4{mu}{sub B}) in Ho{sub 2}CuTiO{sub 6}, on the magnetic properties, compared to that of an isostructural double perovskite containing Y-ion (non-magnetic), i.e., Y{sub 2}CuTiO{sub 6}. Magnetization measurements on Ho{sub 2}CuTiO{sub 6} showed paramagnetic moment of 0.026{mu}{sub B}/Ho at room temperature in an applied field of 7 T although no saturation is observed at room temperature, whereas, at 5 K, the paramagnetic moment was 0.3{mu}{sub B}/Ho in the same field. Since this compound is non-centrosymmetric, it is of interest to look into the possibility of realizing multiferroicity (coexistence of magnetic and ferroelectric ...

2006-08-15

428

Facile synthesis of additive-assisted nano goethite powder and its application for fluoride remediation  

Energy Technology Data Exchange (ETDEWEB)

The present article describes a novel synthesis route for nano-sized goethite ({alpha}-FeOOH) using hydrazine sulphate as an additive. The X-ray diffraction (XRD) peaks of synthesized powder matched well with those of {alpha}-FeOOH. Transmission electron microscopy (TEM) showed the particles of irregular shape in the range of 1-10 nm. Batch adsorption experiments for fluoride uptake were performed to study the influence of various experimental parameters such as contact time (10 min to 7 h), initial fluoride concentration (10-150 mg L{sup -1}), pH (2-11.6) and the presence of competing anions. The time data fitted well to pseudo-second-order kinetic model. The fluoride removal passed through broad maxima in pH ranges of 6-8. High adsorption capacity of 59 mg g{sup -1} goethite was obtained. The isothermic data fitted well to Freundlich model. The presence of other ions namely chloride and sulphate adversely affected fluoride removal. Fluoride from contaminated ...

2010-02-15

429

FEM Analysis and Measurement of Residual Stress by Neutron Diffraction on the Dissimilar Overlay Weld Pipe  

International Nuclear Information System (INIS)

Much research has been done to estimate the residual stress on a dissimilar metal weld. There are many methods to estimate the weld residual stress and FEM (Finite Element Method) is generally used due to the advantage of the parametric study. And the X-ray method and a Hole Drilling technique for an experimental method are also usually used. The aim of this paper is to develop the appropriate FEM model to estimate the residual stresses of the dissimilar overlay weld pipe. For this, firstly, the specimen of the dissimilar overlay weld pipe was manufactured. The SA 508 Gr3 nozzle, the SA 182 safe end and SA376 pipe were welded by the Alloy 182. And the overlay weld by the Alloy 52M was performed. The residual stress of this specimen was measured by using the Neutron Diffraction device in the HANARO (High-flux Advanced Neutron Application ReactOr) research reactor, KAERI (Korea Atomic Energy Research Institute). Secondly, FEM Model on the ...

2010-10-01

430

Evaluation of passive films by photo and impedance spectroscopy; Bunkoho oyobi inpidansu ho ni yoru himaku hyoka  

Energy Technology Data Exchange (ETDEWEB)

The passive films formed on iron metal, alloys or stainless steel are extremely thin oxides or hydroxides and possess the properties of high chemical stability in the environment. These films show characteristics interested both electrical as well as electrochemical point of view due to the thin thickness of the films. Auger Electron Spectroscopy, X-ray Photoelectron spectroscopy and so on which are the conventional electrochemical measurement methods or the surface analysis methods are used for the analysis and evaluation of these films, however, at present, the application of research technique focusing the superconductor characteristics of the films are tried. Although, the potential modulation reflection spectroscopy method has merits like possibility of in-situ measurement, high precision, possibility of stable analysis even for extremely thin film and so forth, it has also demerits like difficulty to response the potential modulation of ...

1995-09-20

431

Electrical properties of ultra-thin oxynitrided layer using N{sub 2}O plasma in inductively coupled plasma chemical vapor deposition for non-volatile memory on glass  

Energy Technology Data Exchange (ETDEWEB)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics ...

2007-06-04

432

Electrical properties of ultra-thin oxynitrided layer using N_2O plasma in inductively coupled plasma chemical vapor deposition for non-volatile memory on glass  

International Nuclear Information System (INIS)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics ...

2007-06-04

433

Development of highly reliable screening by using x-ray fluorescence spectrometry. Applications to determine lead in tin plated and tin-bismuth plated samples  

International Nuclear Information System (INIS)

A highly reliable screening method was developed for the determination of lead in tin plated layers and tin-bismuth plated layers. The contents of lead in the layers of the various samples were determined by inductively coupled plasma optical emission spectrometry. The calibration curve for lead in the tin and tin-bismuth plated layers by using WD-XRF exhibited linear correlation from 130 #mu#g/g to 2070 #mu#g/g. Calibration curve of lead normalized with Pb-L#alpha#/Sn-K#alpha# intensity was more linear, and this method was possible to evaluate very small sample. The calibration curve for lead in the tin plated layers by using ED-XRF was good linearly, but it for lead in the tin-bismuth plated layers was affected by Pb-L#alpha# spectrum and Bi-L#alpha# spectrum overlap each other. It was effective for decreasing affect of Bi-L#alpha# spectrum by using curve fitting method. (author)

2009-03-01

434

Development and cytotoxicity evaluation of SiAlONs ceramics  

International Nuclear Information System (INIS)

SiAlONs are ceramics with high potential as biomaterials due to their chemical stability, associated with suitable mechanical properties, such as high fracture toughness and fracture resistance. The objective of this work was to investigate the mechanical properties and the cytotoxicity of these ceramic materials. Three different compositions were prepared, using silicon nitride, aluminum nitride and a rare earth oxide mixture as starting powders, yielding Si_3N_4-SiAlON composites or pure SiAlON ceramics, after hot-pressing at 1750 deg. C, for 30 min. The sintered samples were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Furthermore, hardness and fracture toughness were determined using the Vicker's indentation method. The biological compatibility was evaluated by in vitro cytotoxicity tests. Ceramic with elevated hardness, ranging between 17 and 21 GPa, and high fracture toughness of 5 to 6 MPa m"1"/"2 were obtained. ...

2007-01-01

435

Conversion of a plasma enhanced chemical vapor deposited silicon-carbon-nitride thin film at ultra-low temperature by oxygen plasma  

Energy Technology Data Exchange (ETDEWEB)

In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray photoelectron spectroscopy is reported for both the as-deposited and ...

2008-01-30

436

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 ...

1980-10-31

437

Application of neutron diffraction in chemistry. Pt. 2  

Energy Technology Data Exchange (ETDEWEB)

This article provides a survey of neutron scattering experiments in condensed matter research, which are of interest to chemistry. The theoretical background has been treated in a previous issue. The present article consists of two parts. The first part exhibits the range of experimental possibilities by means of a few selected examples. The starting point is classical neutron diffraction by which the position of atomic nuclei may be determined. Additional information on the spatial distribution in the outer electron shells may be obtained via combined X-ray/neutron-diffraction experiments or via the diffraction of polarized neutrons. Progress in instrumentation, due to the development of more intense sources, has influenced especially the fields of small angle scattering and spectroscopy. The second part features domains of research of current interest, where a combination of several neutron scattering techniques may prove to be necessary. Thus, the kinetics of ...

1982-01-01

438

An evaluation of low-dose single-slice helical CT in pulmonary CT scan  

International Nuclear Information System (INIS)

Objective: To investigate the feasibility of low-dose single-slice helical CT in pulmonary CT scan and evaluate the clinical application. Methods: Thirteen cases were selected out of 132 cases, in which low-dose (50mAs) single-slice helical CT scan of chest was performed. This set of cases included 7 cases of multiple metastatic nodules; 3 of solitary pulmonary, nodule; and 3 of pulmonary patchy lesions. Regular dose (170mAs) CT scan was also performed on all those patients. The regular dose and low dose CT scan were compared on sensitivity of detecting the lesions; the performance in demonstrating the details of the abnormalities; and the capability of revealing the segmental bronchi as well. Results: The same number and size of the pulmonary nodules were revealed with scan modalities loaded with different doses. No significant difference in demonstrating the details of the nodules and the segmental bronchi was found between both modalities (#chi#"2=0.123-3.39, ...

2006-04-01

439

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

Science.gov (United States)

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

2010-09-01

440

X-ray exposure in the teaching of science at junior and senior high schools  

Energy Technology Data Exchange (ETDEWEB)

A significant amount of X-rays were detected as a leakage from some of the Crooke`s tubes which were used in the teaching of science at junior and senior high schools in Japan. We measured the leaked dose of X-rays from the Crooke`s tubes with ionizing chambers, film badges and TLDs. The maximum leaked dose at 5cm distance from those tubes was estimated 143mSv/h. The effective energy of leaked X-rays was 19.3keV. The maximum dose of students exposed during the teaching of science were estimated 0.15mSv per experiment, which exceeded the value recommended in the ICRP publication 36. (author)

1995-10-01

441

X-ray Emission as a Probe of the Wind-Driven Shock in WR 140  

Science.gov (United States)

single star evolution. To understand the evolution of massive stars and their role in shaping the galaxy, understanding of the distribution of ...

443

Trace analysis in cadmium telluride by heavy ion induced X-ray emission and by SIMS  

International Nuclear Information System (INIS)

The possibilities of using both selective heavy ion induced X-ray emission and secondary ion mass spectroscopy (SIMS), for the identification of impurities present at low concentrations in cadmium telluride are examined. The relative concentrations of the impurities along CdTe crystals have been determined by exciting the X-ray emission of the elements in several slices with Ar and Kr ions and by comparing the relative characteristic X-ray emission yields. As a consequence of the quasimolecular inner shell ionization mechanism in heavy ion-atom collisions, Ar and Kr ions allow a strong excitation of the main impurities seen by SIMS namely Si, Cl and Ge, As, with only a minor contribution of Cd and Te. From the changes of the concentrations of the various impurities along the crystal, informations about segregation coefficients and compensation can be obtained.

2007-02-01

444

Thermal and Electromigration-Induced Strains in Polycrystalline Films and Conductor Lines X-ray Microbeam Measurements and Analysis  

CERN Document Server

Thermal and Electromigration-Induced Strains in Polycrystalline Films and Conductor Lines

2006-01-01

445

The investigations on K and L X-ray fluorescence parameters of gold compounds  

British Library Electronic Table of Contents (United Kingdom)

The study aimed to determine the chemical effects on the K and L X-ray intensity ratios and the K and L X-ray production cross sections for gold compounds. The K shell fluorescence yields and L shell average yields were also investigated. The samples were excited by 59.5keV ?-rays from an 241Am annular radioactive source and 123.6keV ?-rays from a 57Co annular radioactive source. K and L X-rays emitted from samples were counted by an Ultra-LEGe detector with a resolution of 0.150keV at 5.9keV. The experimental values were compared with theoretical, the semi-empirical and other experimental values.

2010-01-01

447

The Effects of Long Term Storage on Special Purpose Lead ...  

Science.gov (United States)

... Special Purpse Lead Azide Lot #I3A-4-62 ... Standard X-ray techniques are not sufficiently sensitive ... the National Bureau of Standards, and examined ...

1972-10-01

448

Structure and morphology changes during nylon 66 fiber deformation via synchrotron x-ray scattering techniques  

Energy Technology Data Exchange (ETDEWEB)

Morphological and structural changes of nylon 66 were evaluated during a continuous heat-draw process. Results are discussed.

1996-12-31

449

Strong-interaction effect measurements in sigma hyperonic atoms of W and Pb  

Energy Technology Data Exchange (ETDEWEB)

Strong-interaction effects have been observed in the x-ray spectra of atoms formed with [Sigma][sup [minus

1993-03-01

450

Resonant inelastic soft x-ray scattering of CdS: a two-dimensional electronic structure map approach  

Energy Technology Data Exchange (ETDEWEB)

Resonant inelastic x-ray scattering (RIXS) with soft x-rays is uniquely suited to study the elec-tronic structure of a variety of materials, but is currently limited by low (fluorescence yield) count rates. This limitation is overcome with a new high-transmission spectrometer that allows to measure soft x-ray RIXS"maps." The S L2,3 RIXS map of CdS is discussed and compared with density functional calculations. The map allows the extraction of decay channel-specific"absorp-tion spectra," giving detailed insight into the wave functions of occupied and unoccupied elec-tronic states.

2008-09-24

453

Radiation exposure to patients during hepatic interventional procedure  

International Nuclear Information System (INIS)

Objective: To investigate the X-ray radiation dose patients dealt with the hepatic intervention. Methods: Thermoluminescence and tissue-equivalent anthropomorphic phantom were used to measure the X-ray radiation dose in patients dealt with the hepatic intervention in 85 patients. Results: The peak skin dose in the patients who accepted hepatic intervention was from 179.95 to 1759.00 mGy, effective dose approached 29.22 mSv (male), 29.27 mSv (female). Conclusion: Hepatic intervention is now regarded as an important therapeutic method for liver cancer. However, the patients were exposed to too much X-ray radiation during interventional procedures. Some more effective protection should be taken to decrease the X-ray radiation dose accepted by patients. (authors)

2005-05-01

454

Photon-induced L-shell x-ray intensity ratio for elements with 73 #<=# Z #<=#83 in the energy range 17 #<=# E #<=# 47 keV  

International Nuclear Information System (INIS)

The L-shell x-ray intensity ratios I(L_#beta#)/I(L_#alpha#) and I(L_#gamma#)/I(L_a_l_p_h_a) for elements with 73 #<=# Z #<=# 83 have been measured at photon incident energies of 17.8, 25.8 and 46.9 keV. The emitted x-rays were measured with a Si(Li) detector system. The results for Re, Pt and Tl are being reported for the first time. A comparison is made of the experimental results with the calculated values obtained by using the theoretical x-ray emission rates, subshell ionisation cross sections, subshell fluorescence yields and Coster-Kronig transition probabilities. The experimental results are in reasonable agreement with the theoretical values. (author).

1988-01-01

455

PRICES SUBJECT To CHq.G - NASA Technical Report Server (NTRS)  

Science.gov (United States)

by the radionuclide X-ray fluorescence analysis into several groups according to the atomic number of the determined element. Table I documents this. ...

456

On the Z-dependence of K#alpha#_1/K#beta#_1 X-ray intensity ratio  

International Nuclear Information System (INIS)

1976. Germany Ramaswamy, MK Birla Inst. of Tech. and Science, Pilani

1976-03-29

457

Measurements and calculations of M-shell X-ray production in Er, Yb and Lu by 0.75-6 MeV He ions  

Energy Technology Data Exchange (ETDEWEB)

M-shell X-ray production cross sections for the light rare-earth elements of {sup 68}Er, {sup 7}Yb and {sup 71}Lu have been measured for incident {sup 4}He{sup +} ions in the energy range from 0.75 to 6 MeV. The measured X-ray production cross sections are compared to the predictions of the First Born approximation, the ECPSSR theory and the ECUSAR theory. A comparison of the ytterbium M-shell X-ray production cross sections with these theories is made for two different sets of fluorescence yields and Coster-Kronig factors that are further modified for multiple ionization.

2005-12-15

458

Magnetospheric particle acceleration and X-ray emission of pulsars  

CERN Document Server

The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the surface of neutron star and trigger the acceleration of particles. The charged particles are accelerated mainly in the field of magneto-dipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magneto-dipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.

2007-01-01

459

Luminescence and x-ray absorption measurements of persistent SrAl2O4:Eu,Dy powders: Evidence for valence state changes  

Science.gov (United States)

The development of new efficient afterglow phosphors is currently hampered by a limited understanding of the persistent luminescence mechanism. Radioluminescence (RL) and x-ray absorption measurements on the persistent phosphor SrAl2O4:Eu,Dy were combined to reveal possible valence state changes for the rare earth (co)dopants. Traps in the phosphor material are quickly filled when exposing thermally emptied SrAl2O4:Eu,Dy powder to x rays. On the same time scale a partial oxidation of Eu2+ to Eu3+ is observed by x-ray absorption near-edge spectroscopy (XANES), while for the trivalent dysprosium the valence state remains unchanged. The impact of these observations on the recently proposed models for persistent luminescence is discussed.

2011-08-01

460

Koji Mukai's Bibliography - Astrophysics Science Division Staff ...  

Science.gov (United States)

Jul 25, 2011 ... Koji Mukai's Bibliography. Invited Reviews. Mukai, K. 1994, "ASCA PV Phase Observations of Cataclysmic Variables," in "New Horizon of X-ray ...

461

K_#beta#/K_#alpha#X-ray intensity ratio in the region of 15#<=#Z#<=#22  

International Nuclear Information System (INIS)

The X-ray intensity ratio K_#beta#/K_#alpha# has been measured by using a 10 mCi "5"5Fe source (Mn K X-rays) and high resolution Si(Li) detector system coupled to a computer-controlled multichannel analyzer over the range of 15#<=#Z#<=#22. Correction have been made to the measured relative intensities (K_#alpha# and K_#beta# X-rays) for self-absorption in the sample, air, Be-window absorption and detection efficiency. The results are compared with those of other experiments and with the Scofield calculations. (author) 13 refs.; 3 figs.; 2 tabs.

1994-01-01

462

Ion-induced M X-ray emission from heavy lanthanides  

International Nuclear Information System (INIS)

Thick targets of several heavy lanthanide (Ho-Lu) compounds were bombarded by protons and "3He ions of 3 MeV/amu, and M_#alpha# and M_#beta# X-rays were measured with a crystal spectrometer. Ionization probabilities of the N-shell for zero impact parameter were obtained from the X-ray intensity ratio for proton and "3He ion impacts. A shell dependence of the ionization probability was found in a scaling plot. X-ray spectra of lanthanide compounds were compared and no chemical effect was observed. This result is considered to be due to the fact that the main component of M_#alpha# and M_#beta# lines is for radiative transition after the refilling of the 4f orbit (3d"-"14f"n"+"1 #-># 4f"n) where n denotes the number of 4f electrons of the target atom before ionization. (orig.).

1987-12-01

463

Future instrumentation for the study of the Warm-Hot Intergalactic Medium  

CERN Document Server

We briefly review capabilities and requirements for future instrumentation in UV- and X-ray astronomy that can contribute to advancing our understanding of the diffuse, highly ionised intergalactic medium.

2008-01-01

464

Feasibility analysis for attosecond X-ray pulses at FERMI@ELETTRA free electron laser  

Energy Technology Data Exchange (ETDEWEB)

We present preliminary analysis for the feasibility of the attosecond x-ray pulses at a proposed FERMI@ELETTRA free electron laser (FEL) [1]. In part 1 we restrict ourselves to minimal modifications to the proposed FEL and consider a scheme for attosecond x-ray production which can be qualified as a small add-on to a primary facility. We demonstrate that at 5-nm wavelength our scheme is capable for production of pulses with an approximate duration of 100 attoseconds at approximately 2 MW peak power and with an absolute temporal synchronization to a pump laser pulse. In part 2 we propose to use an FEL amplifier seeded by a VUV signal and to follow it by the scheme for attosecond x-ray production described in part 1.

2004-09-01

465

FUV and X-ray absorption in the Warm-Hot Intergalactic Medium  

CERN Document Server

The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas collapsing in large-scale filaments and probably harbours a substantial fraction of the baryons in the local Universe. Absorption-line measurements in the ultraviolet (UV) and in the X-ray band currently represent the best method to study the WHIM at low redshifts. We here describe the physical properties of the WHIM and the concepts behind WHIM absorption line measurements of H I and high ions such as O VI, O VII, and O VIII in the far-ultraviolet and X-ray band. We review results of recent WHIM absorption line studies carried out with UV and X-ray satellites such as FUSE, HST, Chandra, and XMM-Newton and discuss their implications for our knowledge of the WHIM.

2008-01-01

466

Electron-induced luminescence and x-ray spectrometer development  

Science.gov (United States)

Jan 22, 2011 ... dc.description.abstract, The progress in the development of a surface analysis tool based on the excitation of characteristic luminescence ...

467

Density Gradients for Isolation of Mononuclear Blood Cells for ...  

Science.gov (United States)

... to-continuum X-ray intensity ratio [5]. For ence in the means [7]. In addition, washing samples on thin films, the characteristic X- lymphocytes in NH ...

2011-05-15

469

Acceleration of particles in pulsar magnetosphere and the X-ray radiation  

CERN Document Server

The available data of single X-ray pulsars, their wind nebulae, and the SNRs which are connected to some of these sources are analysed. It is shown that electric field intensity of neutron stars tears off charged particles from the surface of neutron star and triggers the acceleration of particles. The charged particles are accelerated mainly in the field of magnetodipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magnetodipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.

2004-01-01

470

Preparation, properties, and application characteristics of metastable layers of the Ti-Si-C-N system; Herstellung, Aufbau, Eigenschaften und Anwendungsverhalten von metastabilen Schichten aus dem System Ti-Si-C-N  

Energy Technology Data Exchange (ETDEWEB)

In the Ti-Si-C and Ti-Si-C-N systems, metastable layers were precipitated by means of non-reactive magnetron sputtering of hot-pressed two-phase TiC/SiC and TiN/SiC targets with 20 mole% and 50 mole% SiC. The preparation parameters were varied as follows: ion bombardment during precipitation (bias sputtering), substrate temperature, and annealing times when annealing amorphous 50%:50% TiC/SiC and 50%:50% TiN/SiC layers. Sputtering of targets containing 20% SiC was found to result in monophase fcc layers (NaCl structure). This was documented on the basis of X-ray and electron diffraction patterns. Direct precipitation of targets with 50 mole% SiC resulted in amorphous layers. Increasing the ion bombardment during accretion, raising the substrate temperature, and annealing amorphous 50%:50% TiC/SiC and 50%:50% TiN/SiC (layers precipitated directly) resulted in the crystallization of TiC and TiN nanocrystallites, respectively, imbedded in an amorphous SiC matrix. ...

1992-10-01

471

Three-dimensional cranio-facial computed tomography  

International Nuclear Information System (INIS)

Computed tomography allows today to reconstruct three-dimensional (eD) images fram axial scans. The authors report their experience in cranio-facial pathology achived in two Departments of Radiology (University of Trieste, Italy and University of Standford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The application in maxillo-facial traumas, cranio-facial malformations and head tumours are disscussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demostration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.

1986-01-01

472

Application of the neutron television fluoroscopic system to neutron computed tomography  

Energy Technology Data Exchange (ETDEWEB)

Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter. (orig.).

1984-10-01

473

Application of the neutron television fluoroscopic system to neutron computed tomography  

Energy Technology Data Exchange (ETDEWEB)

Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter.

1984-10-01

474

An application of the neutron television fluoroscopic system to neutron computed tomography  

International Nuclear Information System (INIS)

Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter. (orig.).

1984-10-01

475

Parallel architecture for rapid image generation and analysis  

Energy Technology Data Exchange (ETDEWEB)

A multiprocessor architecture inspired by the Disney multiplane camera is proposed. For many applications, this approach produces a natural mapping of processors to objects in a scene. Such a mapping promotes parallelism and reduces the hidden-surface work with minimal interprocessor communication and low-overhead cost. Existing graphics architectures store the final picture as a monolithic entity. The architecture here stores each object's image separately. It assembles the final composite picture from component images only when the video display needs to be refreshed. This organization simplifies the work required to animate moving objects that occlude other objects. In addition, the architecture has multiple processors that generate the component images in parallel. This further shortens the time needed to create a composite picture. In addition to generating images for ...

1987-01-01

476

Radiology of facial injury  

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

477

Computer vision approaches to medical image analysis. Revised papers  

Energy Technology Data Exchange (ETDEWEB)

This book constitutes the thoroughly refereed post proceedings of the international workshop Computer Vision Approaches to Medical Image Analysis, CVAMIA 2006, held in Graz, Austria in May 2006 as a satellite event of the 9th European Conference on Computer Vision, EECV 2006. The 10 revised full papers and 11 revised poster papers presented together with 1 invited talk were carefully reviewed and selected from 38 submissions. The papers are organized in topical sections on clinical applications, image registration, image segmentation and analysis, and the poster session. (orig.)

2006-07-01

478

A high-sensitivity small animal SPECT system  

International Nuclear Information System (INIS)

Medical imaging using single gamma-ray-emitting radionuclides typically makes use of parallel hole collimators or pinholes in order to achieve good spatial resolution. However, a tradeoff in sensitivity is inherent in the use of a collimator, and modern preclinical single photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma rays, often less than 0.1%. A system for small animal SPECT imaging which uses no collimators could potentially achieve very high sensitivity-several tens of percent-with reasonably sized detectors. This would allow two significant improvements in preclinical studies: images could be obtained more rapidly, allowing higher throughput for screening applications, or for dynamic processes to be observed with very good time resolution; and images could be obtained with less radioactive tracer, making possible the in vivo ...

2009-03-07

479

Diagnosis of plasmocytomas using magnetic resonance imaging; Diagnostik des Plasmozytoms mit der MRT  

Energy Technology Data Exchange (ETDEWEB)

Background. In multiple myeloma 5 different infiltration patterns can be differentiated: 1. Normal appearance of bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. 'salt-and pepper' pattern with inhomogeneous bone marrow with interposition of fat islands. Methods. For the fast and total acquisition of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique is superior. The focal involvement is clearly demonstrated as areas of high signal intensity on e.g. STIR images. Diffuse involvement can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. MRI is superior to X-ray in focal and diffuse involvement. With ultrafast sequences a 'screening' of the whole red bone marrow as for myeloma infiltration is possible. Prognosis. In prognosis ...

2000-08-01

480

Clinical trial of NMR-CT, (4). Clinical evaluation of hybrid image  

Energy Technology Data Exchange (ETDEWEB)

In our evaluation we utilized the Asahi Mark-J NMR-CT system, with a resistive vertical quadrupolar electromagnet (0.1 Tesla) and a proton resonance frequency of 4.5 MHz. Our main imaging methods are the inversion-recovery or IR, saturation-recovery, or SR, and calculated T/sub 1/. Difference, or D images, constructed by subtracting the data of the IR signal from that of the SR signal, have also been obtained in some cases. The system allows averaging of raw data. Hybrid images were constructed from two or more images to obtain clear definition of areas of interest. By using the hybrid image, several tissues of different relaxation times can be shown in the same image. Application in our study of the newly developed hybrid image indicates its importance in the detection and diagnosis of lesion, especially the detection ...

1985-01-01

481

X-dosimetry of Tl(InS_2)_1_-_x(FeSe_2)_x single crystals  

International Nuclear Information System (INIS)

Tl(InS_2)_1_-_x(FeSe_2)_x single crystals (where x=0; 0.001; 0.005; 0.01 and 0.015) were grown by the Bridgman-Stockbarger method. Obtained single crystals were crystallized in monoclinic structure. The present paper deals with experimental results relative to X-ray dosimetric characteristics of the Tl(InS_2)_1_-_x(FeSe_2)_x solid solutions at 300 K. Installation URS-55a was the source of radiation. X-ray radiation dose (E) falling on the crystals is measured by the crystalline X-ray dosimeter DRGZ-02. The value of X-ray conductivity coefficient K_#sigma# characterising X-ray sensitivity is defined as K_#sigma#= (#sigma#_E-#sigma#_0)/E#sigma#_0. where #sigma#_E is conductivity under the effect of X-ray radiation by intensity E, #sigma#_0 is conductivity in the lack of radiation. Comparing X-ray dosimetric characteristics of TlInS_2 and ...

2003-09-15

482

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

International Nuclear Information System (INIS)

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

2000-12-01

483

Development of homogeneous mixing technology of dispersion nuclear fuel  

Energy Technology Data Exchange (ETDEWEB)

The measurement methods of homogeneity of dispersion fuel were analyzed. The effects of mixing method, rotating speed, particle shape, particle size and moisture content on homogeneity of U{sub 3}Si/Al powder mixture were characterized by the apparent density measurement. The effects of fuel particle shape on green properties and optimum compaction conditions were investigated in U{sub 3}Si{sub 2}/Al powder compacts. 3 kinds of measurement method on the homogeneity were analyzed by apparent density measurement method, x-ray image contrast method and image analysis method of mixed powders or fuel rods. The homogeneity of dispersed fuel powder mixture was analyzed using three kinds of mixing, by apparent density measurements method. The homogeneity of powder mixture increased with rotating speed of the V-shape tumbler mixer. The comminuted irregular shaped particles and smaller particle size of fuel powders showed homogeneity ...

2000-04-01

484

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-09-01

485

Applicator reconstruction and applicator shifts in 3D MR-based PDR brachytherapy of cervical cancer  

British Library Electronic Table of Contents (United Kingdom)

Purpose To evaluate the methods of applicator reconstruction in 3D MR-based planning for brachytherapy of cervical cancer, and to investigate applicator shifts and changes in DVH parameters during PDR treatment. Methods For each application MR scans with applicator in situ were made: three T2-weighted (4.5mm slices) Turbo Spin Echo (TSE) scans and a balanced Steady State Free Precession scan (1.5mm). Three observers tested two applicator reconstruction methods: (A) directly on the bSSFP scan and (B) on a resampled combination of the three T2-weighted scans. For 10 patients MR imaging was repeated on the second day of each PDR fraction to determine applicator shifts and changes in DVH parameters. Results For both applicator reconstruction methods the interobserver variation for the DVH para...

2009-01-01

486

Investigation of flora and fauna species of Lake Baikal by electron-probe microanalysis  

International Nuclear Information System (INIS)

Complete text of publication follows. Baikal is an ancient unique lake. The sweet water of Baikal is crystal clean; it concentrates oxygen and contains scarce silicon. This feature is provoked very particular interest for scientists and poses some awkward questions concerning the preservation of Baikal's ecosystem. A profound investigation of fish otholiths, animal teeth, sponges, valves of mollusks and diatom algae provides chronological information, possibility to reconstruct the events proceeding in the environment based on variations of their chemical composition. Because these study objects are small-sized, and some of them are micron-size, application of the electron-probe microanalysis turns to be quite productive. The goal of this study is to disclose performance capabilities of this method while investigating the Baikal flora and fauna. Investigations were performed by devices JCXA-733 and JXA-8200 using the electron microscope and ...

487

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-06-01

488

X-ray spectral microanalysis of component redistribution in finely dispersed two-phase alloys  

International Nuclear Information System (INIS)

It is shown that it is necessary to take into account locality of the analysis and to introduce additional corrections for partial capture of matrix and fluorescent subexcitation by matrix during quantitative X-ray spectral microanalysis of finely dispersed materials. Cast two-phase (#alpha#+#beta#) titanium alloy VT3-1 is chosen as an investigation object.

489

X-ray generation by the Smith-Purcell effect  

International Nuclear Information System (INIS)

Smith-Purcell (S-P) radiation is produced when electrons graze the surface of a grating. Calculations based on the theory of diffraction radiation show that, given severe restrictions on e"--beam quality, S-P radiation is highly efficient. Efficient S-P x-ray generation requires relativistic e"- beams having a transverse momentum and dimension whose product approaches the Heisenberg uncertainty limit.

490

X-ray diffraction studies of palladium silicide thin films  

Energy Technology Data Exchange (ETDEWEB)

The solid state reaction between a Pd thin film and a Si substrate produces a single new phase, Pd/sub 2/Si, for temperatures <700/sup 0/C. When the substrate is a single crystal of (111) surface orientation, this process is particularly interesting because the silicide grows epitaxially. Growth of epitaxial interfacial Pd/sub 2/Si was the focus of this study using X-ray diffraction techniques.

1985-01-01

491

Survey of radiation doses to patients from the diagnostic use of X-rays  

International Nuclear Information System (INIS)

The National Radiological Protection Board is to carry out a survey of doses received by patients from the diagnostic use of X-rays, beginning in June 1977, and carried out at over 100 National Health Service hospitals. Details are given of the reasons for carrying out the survey and the survey objectives. The survey working methods are discussed, together with methods of calculation of the genetically significant dose. The radiation doses will be measured by a thermoluminescent dosimeter developed specially for the survey. (U.K.).

1977-06-01

492

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-15

493

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

International Nuclear Information System (INIS)

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

2004-07-01

494

Structural intermediates in the assembly of taxoid-induced microtubules and GDP-tubulin double rings: time-resolved X-ray scattering.  

UK PubMed Central (United Kingdom)

We have studied the self-association reactions of purified GDP-liganded tubulin into double rings and taxoid-induced microtubules, employing synchrotron time-resolved x-ray solution scattering. The...Full Text Available

1996-05-01

495

M shell x-ray emission in Pb, Th and U due to L_3 to M sub shell transfer of vacancies  

International Nuclear Information System (INIS)

M shell x-ray production cross sections in thick targets of Pb, Th and U by K x-rays of Rb, Nb and Mo respectively have been measured. As the incident K x-ray energies are above the L_3 edge but below L_2 edge energies of the respective target elements under reference, the M x-rays are produced not only due to direct interaction of incident photons with M shell electrons but also due to the shift of the L_3 subshell vacancies to the M shell. The experiment has been performed using a double reflection geometrical setup with a 1 Curie"2"4"1Am gamma ray source and a Si (Li) x-ray spectrometer. The measured values have been compared with those calculated using known values of M and L_3 subshell photoionisation cross sections and fluorescence yields etc., wherever possible. The component of the percentage contribution due to shift of L_3 subshell vacancies to M shell to the total M shell ...

496

Improving airport explosives detection  

Energy Technology Data Exchange (ETDEWEB)

ORNL has developed the technology to detect hidden explosives in luggage using X ray and neutron detection devices. The Federal Aviation Administration has ordered the airlines to buy and install Thermal Neutron Analysis (TNA) units. The combined pulsed-neutron and X-ray interrogation inspection (CPNX) system developed at ORNL uses less radioactive materials as well as being more sensitive to weapons, electronic devices and plastic explosives.

1990-01-01

497

FLASH-the first soft x-ray free electron laser (FEL) user facility  

Energy Technology Data Exchange (ETDEWEB)

The free electron laser (FEL) FLASH at DESY in Hamburg is the first x-ray FEL ever built. Many new developments were necessary in order to exploit the unique properties of this novel light source for scientific experiments. The facility has constantly been improved and several major upgrades have been made or are currently underway. This paper reviews the main characteristics of the user facility as well as the major developments and upgrades.

2010-10-14

498

Changes in the profile structure of the sarcoplasmic reticulum membrane induced by phosphorylation of the Ca2+ ATPase enzyme in the presence of terbium: a time-resolved x-ray diffraction study.  

UK PubMed Central (United Kingdom)

The design of the time-resolved x-ray diffraction experiments reported in this and an accompanying paper was based on direct measurements of enzyme phosphorylation using [gamma-32P]ATP that were employed...Full Text Available

1994-05-01

499

Analysis of titanium and zirconium in red mud with energy dispersive x-ray spectrometry  

Energy Technology Data Exchange (ETDEWEB)

An energy dispersive x-ray fluorescence technique was used for the determination of Titanium (Ti) and Zirconium (Zr) in red mud by using a standard addition method. An annular {sup 241}Am source is employed for excitation of K shells of elements. 13 refs., 2 figs., 1 tab.

1996-11-01