WorldWideScience
2

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 ...

2006-04-01

3

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

4

Macromodular splenic tuberculosis in a medically-treated AIDS patient: diagnosis and management by CT  

International Nuclear Information System (INIS)

We used computerized tomography (CT) in the study of eight patients with macronodular splenic tuberculosis prior to the microbiological diagnosis. These patients underwent additional CT controls during and after tuberculostatic therapy. All the patients studed presented the acquired immunodeficiency syndrome (AIDS). Splenomegaly and numerosous round, hypodense lesions that showed no contrast uptake were found in all the subjects. Only three patients presented evidence of tuberculosis in plain radiography and/or chest X-ray. Two patients presented abdominal lymph nodes. None of them showed evidence of hepatic lesions or ascites. follow-up CT scans revealed a progressive reduction of the lesions, which eventually disappeared completely, and splenomegaly was considerably reduced. Anthough it is uncommon, we should suspect splenic involvement in tuberculosis if the clinical and ...

5

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

7

Radiation risk in computerized tomography (CT)  

Energy Technology Data Exchange (ETDEWEB)

The two main aspects of the concept proposed by the ICRP in recommendation 26 for the radiation risk, the differentiation of stochastic and non stochastic damages and the qualification of the stochastic risk, are discussed in its consequences for radiation protection in X-ray diagnostics. Quantitative results from the literature serve to demonstrate the risk factors for the various organs and their sum concerning the position of the layer. As special points of somatic risk appeared the mamma and the pelvic region. The particular risk of CT examination is determined by number and position of the layers and the scan parameters of the system. For typical CT examination the resulting risk factors are estimated in comparison with conventional X-ray diagnostics. The somatic risk of CT examination is relatively high and comparable to conventional examination with the highest risk, while ...

1984-01-01

8

Radiation risk in computerized tomography (CT)  

International Nuclear Information System (INIS)

The two main aspects of the concept proposed by the ICRP in recommendation 26 for the radiation risk, the differentiation of stochastic and non stochastic damages and the qualification of the stochastic risk, are discussed in its consequences for radiation protection in X-ray diagnostics. Quantitative results from the literature serve to demonstrate the risk factors for the various organs and their sum concerning the position of the layer. As special points of somatic risk appeared the mamma and the pelvic region. The particular risk of CT examination is determined by number and position of the layers and the scan parameters of the system. For typical CT examination the resulting risk factors are estimated in comparison with conventional X-ray diagnostics. The somatic risk of CT examination is relatively high and comparable to conventional examination with the highest risk, while ...

1984-01-01

9

Radiation risk in computerized tomography (CT)  

International Nuclear Information System (INIS)

The two main aspects of the concept proposed by the ICRP in recommendation 26 for the radiation risk, the differentiation of stochastic and non stochastic damages and the qualification of the stochastic risk, are discussed in its consequences for radiation protection in X-ray diagnostics. Quantitative results from the literature serve to demonstrate the risk factors for the various organs and their sum concerning the position of the layer. As special points of somatic risk appeared the mamma and the pelvic region. The particular risk of CT examination is determined by number and position of the layers and the scan parameters of the system. For typical CT examination the resulting risk factors are estimated in comparison with conventional X-ray diagnostics. The somatic risk of CT examination is relatively high and comparable to conventional examination with the highest risk, while ...

10

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 tube, the object and the screen-film system was determined for phase imaging of mammography. In order to ...

2002-03-01

11

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

12

CT scan findings in cerebral paragonimiasis  

International Nuclear Information System (INIS)

Computed tomography was performed on 5 patients with chronic cerebral paragonimiasis. CT showed solitary or multiple, amorphous, round, or oval calcifications, and ventricular enlargement in all 5 cases. A large low-density area is also found in 4 of the 5 cases. These CT findings are compatible with previously reported findings of simple X-ray films of the skull, pneumoencephalography, and pathological studies. (author).

1982-01-01

13

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

14

PET/CT cardiology: an area whose boundaries are still out of sight  

International Nuclear Information System (INIS)

Positron emission tomography (PET) and X-ray computed tomography (CT) performed with PET/CT cameras allow us to obtain concurrently information on the presence and degree of alterations of myocardial perfusion and metabolism and on coronary arteries calcification. Furthermore, by gated myocardial perfusion studies, PET may provide crucial information on regional coronary blood flow reserve and endothelial dysfunction. A number of recent papers provide some insight on the potential of PET/CT in cardiology and in the assessment of various cardiovascular diseases including various types of vasculitis and metabolic diseases.

2006-05-01

15

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

16

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

17

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

18

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

19

Computed Tomography of the spine in multiple myeloma  

International Nuclear Information System (INIS)

Computed Tomography (CT) of the spine was performed on 17 patients with myeloma in order to assess the role of the technique in recognizing and evaluating the extent of the lesions. Myelomatous lesions followed two patterns at CT: first of all, multiple focal lesions, whose density is either solid, liquid, or fatty; second, an extensive pattern involving the spongiosa of the vertebra, including the posterior arch. CT detected more lesions than conventional radiology; furthermore, the extent of the lesions was much better demonstrated by CT. CT should thus be performed: a) in case of pain and/or neurological findings in negative radiological examinations; b) to evaluate the extent of myelomatous lesions (mainly in the spine); c) in solitary myeloma CT may be performed on different bone segments with clinical symptomatology but normal X-ray ...

1988-01-01

20

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

UK PubMed Central (United Kingdom)

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

2009-09-16

21

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 ...

1995-03-11

22

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 ...

1995-03-01

23

Estimated fetal radiation dose from multislice CT studies  

International Nuclear Information System (INIS)

It is often necessary to estimate the dose of radiation to a fetus from a series of CT scans. To assist in making this process easier and more accurate, we measured fetal doses in an adult anthropomorphic phantom for four CT scanners: Picker 1200, Siemens DRH, GE 9800, and GE 8800. Measurements were made at four kilovoltages (100, 120, 130, and 140 kVp), for 2-, 5-, 8-, and 10-mm thicknesses, for two scanning angles (360 degrees and 398 degrees) and for two patient orientations (prone and supine). The fetal-dose estimates are based on the CT dose index measured by using a pencil ionization chamber at the center position of a 16-cm-diameter cylindrical phantom. Comparison with data from other investigators shows reasonable agreement when phantom differences, X-ray tube output, and equipment calibration are considered.

24

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 ...

2010-01-01

25

High resolution computed tomography in the study of cervical spine trauma  

International Nuclear Information System (INIS)

Correct ortopedic therapy for traumas of the cervical rachis requires perfect knowledge of the spatial balance of the fracture focus. The authors belive Computed Tomography (CT) to be the most suitable, and often indispensable, method for this purpose. Twenty-four patients were examined for traumatic pathology of the cervical rachis. In 7 cases with clinically minor traumas, the negative outcome of the traditional traumas, the negative outcome of the traditional exam was considered reliable and sufficient for therapeutic purposes. The extant 17 patients were examined also by means of CT, either to better dermine the characteristics of skeletal lesions already ascertained with traditional techniques or to asses the presence of clinically-suspected osteo-articular lesions, even with negative conventional X-rays. For 9 of these patients orthopedic treatment was considered sufficient, whereas 8 patients underwent surgery and ...

1989-01-01

26

X-ray observation of a. sqrt. 3 x. sqrt. 3 superlattice in KC/sub 8/ at high pressure  

Energy Technology Data Exchange (ETDEWEB)

A single-crystal x-ray study under pressure reveals a phase transition from an in-plane 2x2 commensurate potassium superstructure to a new ..sqrt..3x..sqrt..3 commensurate superstructure. This is the first such transition to be observed; it is related to the recently discovered staging transition of KC/sub 8/ under pressure. In addition this staging transition was observed to occur more slowly and at much lower pressures than in the reported neutron-scattering experiment on highly oriented pyrolytic graphite samples. 13 references, 2 figures.

1985-05-15

27

ROSAT observations of the RSCVn binary sigma Geminorum  

DEFF Research Database (Denmark)

X-ray observations of the RSCVn system sigma Geminorum have been undertaken with the ROSAT observatory. Several spectra of very good signal-to-noise ratio were obtained. Spectral fitting using metal abundances amounting to 50% of solar values reveal two temperature components at 2 MK and 12 MK. Previous EXOSAT observations showed another component at 40 MK. Particular interest is focused on the temporal variations of the X-ray emission. It is found that variations occur on time scales ranging from years to hours and minutes.

1997-01-01

28

Radiological diagnosis of lesions of intervertebral discs  

International Nuclear Information System (INIS)

During their life, intervertebral discs undergo degenerative changes which need not necessarily become lesions. Conventional X-rays do not provide information on the condition of the intervertebral discs, so MRT or CT are recommended as primary techniques as they are non-invasive. Invasive methods like myelography and especially discography should not be used unless a case is highly problematic. In infants with pains in the back, MRT should be carried out as early as possible as there is nearly always an organic cause. (orig.)

2003-03-01

30

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-07-01

31

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 ...

2008-06-01

32

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

33

Effect of pressure on iodine complexes, 2  

International Nuclear Information System (INIS)

Absorption spectra of the CT bands of I_2 complexes with Et_2O, Et_2S, and Et_2Se in heptane have been measured up to 4400 bar at 25"0C. The equilibrium constants and the volume changes accompanying complex formation, and the molar extinction coefficients and absorption maxima have been estimated. The volume changes were comparable with those estimated by the visible I_2 bands and by the X-ray data of the I_2 complexes in the crystalline state. In the CT bands of Et_2S-I_2 and Et_2Se-I_2 complexes inversion of shift from red to blue has been observed with increasing pressure though the CT band of Et_2O-I_2 complex shifted only through red. This inversion appears to be characteristic of the strong CT complex. Enhancement of the molar extinction coefficient of the CT band has been found with increasing pressure suggesting enhancement of the CT ...

1979-01-01

34

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 ...

1990-01-01

35

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

36

Energy Dispersive X-ray Analysis in the Electron Microscope  

CERN Document Server

Energy Dispersive X-ray Analysis in the Electron Microscope

2003-01-01

37

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 ...

38

An X-ray source population study of the Andromeda galaxy M 31  

CERN Document Server

XMM-Newton EPIC observations reveal the population of X-ray sources of the bright Local Group spiral galaxy M 31, a low-star-formation-rate galaxy like the Milky Way, down to a 0.2-4.5 keV luminosity of 4.4E34 erg/s. With the help of X-ray hardness ratios and optical and radio information different source classes can be distinguished. The survey detected 856 sources in an area of 1.24 square degrees. Sources within M 31 are 44 supernova remnants (SNR) and candidates, 18 super-soft sources (SSS), 16 X-ray binaries (XRBs) and candidates, as well as 37 globular cluster sources (GlC) and candidates, i.e. most likely low mass XRBs within the GlC. 567 hard sources may either be XRBs or Crab-like SNRs in M 31 or background AGN. 22 sources are new SNR candidates in M 31 based on X-ray selection criteria. Time variability information can be used to improve the source classification. Two GlC ...

2005-01-01

39

Optimizing radiotherapy of orbital and paraorbital tumors: intensity-modulated X-ray beams vs. intensity-modulated proton beams  

International Nuclear Information System (INIS)

Purpose: This study presents a dosimetric optimization effort aiming to compare intensity-modulated (IM) X-rays and IM protons in 4 different orbital and paraorbital tumors. These are most challenging targets for standard radiotherapy due to their close relationship with the eyes and related structures. Methods and Materials: A primary orbital lymphoma, an optic nerve meningioma, a sphenoidal ridge meningioma protruding into the orbit, and a pediatric parameningeal paraorbital rhabdomyosarcoma were selected for the purpose of this study. Planning target volumes (PTVs) and organs at risk (OAR) were defined in each patient CT data set for each tumor site. IM X-ray and IM proton three-dimensional treatment plans were implemented. The following total tumor doses were prescribed: 30 Gy for the orbital lymphoma, 54 Gy for both meningiomas, and 50.4 Gy for the rhabdomyosarcoma case. Dose-volume histograms (DVHs) were obtained for ...

2000-07-01

40

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 utilized for the first time in the world ...

2007-09-02

41

Void fraction estimation within rod bundles based on three-fluid model and comparison with X-ray CT void data  

Energy Technology Data Exchange (ETDEWEB)

An interfacial shear stress equation in the dispersed-annular two-phase flow regime has been developed, which is based on a three-fluid model consisting of a liquid film on a rod, vapor and entrained liquid associated with a vapor flow. It is an extension of J.G.M. Andersen's procedure that provides a two-fluid interfacial shear stress equation using the drift flux parameters C{sub 0} and V{sub gj}. This interfacial shear stress equation can take into account a phase and velocity distribution through an equivalence between the drift flux parameters and the interfacial shear stress. Using the three-fluid subchannel analysis code TEMPO with the three-fluid interfacial shear stress model the capability of a three-fluid calculation using the drift flux parameters C{sub 0} and V{sub gj} that reproduce a measured void fraction is demonstrated. A comparison was made with advanced X-ray computed tomography (CT) void fraction data within a 4x4 ...

1990-06-01

42

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

43

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

44

Synthesis and physicochemical properties of iron (2) perrhenates  

Energy Technology Data Exchange (ETDEWEB)

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

1983-01-01

45

PIXE analysis of trace elements in relation to chlorophyll concentration in Plantago ovata Forsk  

Energy Technology Data Exchange (ETDEWEB)

Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations.

2010-03-15

46

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

47

X-ray studies of solid n-H/sub 2/  

Energy Technology Data Exchange (ETDEWEB)

Results of X-ray investigations of solid normal hydrogen are presented. Temperature dependences of the lattice parameteps, molar volumes, linear and volume expansion coefficients in the 2K-Tsub(melt) temperature range are obtaiped. An essential n-H/sub 2/ expansion anisotropy in the premelting temperature region is pointed out. It is shown that the hexagonal lattice parameter ratios over the whole investigated temperature range is considerably higher than for solid parahydrogen. A considerable difference in thermal expansion of normal hydrogen and parahydrogen in the low temperature region is revealed. It is caused by contribuation of a rotational subsystem, increasing with the temperature decrease to crystal expansion. A detailed analysis of solid n-H/sub 2/ thermodynamic properties is conducted. The data testifying to the presence of isomorphous phase transformation in the solid n-H/sub 2/ in the premelting temperature region are discussed.

1983-08-01

48

RXTE observations of Cas A  

International Nuclear Information System (INIS)

Rossi X-ray Timing Explorer (RXTE) observations of the bright supernova remnant Cas A have revealed a hard power law component above 10 keV in addition to two thermal components inferred from ASCA measurements of the many line centroids from low-Z elements. The power law can be shown to be consistent with synchrotron emission from radio to hard x-rays by electrons of up to 4 x 10"1"3 eV. Measurement of the 1157 keV line by CGRO from "4"4Sc in the chain of decay of "4"4Ti predicts that the two "4"4Ti lines at 68 and 78 keV should appear at the CGRO intensity. RXTE has placed upper limits on such lines that are marginally consistent with the CGRO measurement. Implications of these results on sites for cosmic ray acceleration and nucleosynthesis are discussed.

1999-01-01

49

Microradiographic examination with the mammographic device 'TUR' after enossal implantation of glass ceramics (bio-vitroceramics)  

International Nuclear Information System (INIS)

As to all sinter variations the microradiographic analysis showed that about 86 to 90 % of the implant surface were enclosed split-free with newly formed bone 16 weeks post operationem. A silicat salt addition of the test variation Ap_4_0KS_1_5 and Ap_4_0KS_3_0 did not cause a negative influence on bone regeneration. On the surface of all test implants a double layer was revealed radiologically, consisting of a 30 - 40 #mu#m thick bone near X-ray impermeable area and an X-ray permeable area of maximum 120 #mu#m thickness directed to the nucleus of the implant.

50

Microradiographic examination with the mammographic device 'TUR' after enossal implantation of glass ceramics (bio-vitroceramics)  

Energy Technology Data Exchange (ETDEWEB)

As to all sinter variations the microradiographic analysis showed that about 86 to 90 % of the implant surface were enclosed split-free with newly formed bone 16 weeks post operation. A silicate salt addition of the test variation Ap/sub 40/KS/sub 15/ and Ap/sub 40/KS/sub 30/ did not cause a negative influence on bone regeneration. On the surface of all test implants a double layer was revealed radiologically, consisting of a 30 - 40 ..mu..m thick bone near X-ray impermeable area and an X-ray permeable area of maximum 120 ..mu..m thickness directed to the nucleus of the implant.

1984-01-01

51

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

International Nuclear Information System (INIS)

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

52

Electrical properties and x-ray diffraction of wood and wood plastic composite (WPC)  

Energy Technology Data Exchange (ETDEWEB)

Wood plastic composite (WPC) of kadom, simul, mango and debdaro were prepared with two monomers methylmethacrylate (MMA) and butylmethacrylate (BMA) using high energy ionizing radiation. X-ray diffraction and scanning electron microscope (SEM) studies reveal that significant grafting occurred with wood fiber. Electric properties like resistivity and dielectric constant of both wood and WPC were measured under different moisture contents and relative humidities. The resistivities of wood decreased dramatically with increase of moisture content, but those of WPC decreased very slowly with moisture content. The dielectric constant of wood increased significantly with moisture content but no significant difference was observed in the case of WPC within the range of moisture contents studied. The dielectric constants of untreated wood also increased with their densities. (author).

1991-01-01

53

Corrosion of gold bridgewire in electronic components  

Energy Technology Data Exchange (ETDEWEB)

Accelerated aging tests on gold bridgewired detonator assemblies to determine compatibility of the Au and Pd-In-Sn solder with the organic explosive, PENT, have revealed an unusual corrosion process. These tests, conducted at 74/sup 0/C and 54/sup 0/C indicated a preferential attack of the gold. A matrix of corrosion test units was established to study this corrosion problem with accelerating temperatures up to 100/sup 0/C. Scanning electron microscopy (SEM), energy dispersive x-ray (EDX), and x-ray diffraction techniques were used to determine the extent of the corrosion and identify the corrosion products. Results indicate the preferential attack of the gold was due to HCN formed by decomposition of the explosive powder (PETN) at high temperatures. Other associated reactions were also observed including subsequent attack of the solder by the gold corrosion product and degradation of the plastic header.

1986-01-01

54

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

55

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 exposures, and noise ...

2004-12-07

56

The role of computed tomography in complex facial trauma  

Energy Technology Data Exchange (ETDEWEB)

Tridimensional localization of bone and soft tissue injuries in complex facial trauma is fundamental for treatment. The face can be conceptualized as 3 groups of interconnected osseous struts that are oriented in the horizontal, sagittal and coronal planes. Each group of struts is closely related to specific soft tissue structures that are susceptible to injury. Any single CT section in the coronal plane or in the axial plane contains parts of one or more these struts. Facial CT in biplane were performed in 32 patients of facial trauma. The most common site of facial fractures is found in middle part of horizontal struts, geometrically in anteromedial portion of the inferior orbital fissure of the face. The most common soft tissue injury combined with facial fracture is hematoma and/or herniated orbital contents into the maxillary sinus. The serious combined soft tissue injuries were ocular rupture, retroorbital hematoma and optic nerve injury ...

1988-02-15

57

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 ...

1980-10-31

58

X-ray diffraction analysis of corrosion products of Fe-Ni-Cr alloys formed in molten nitrate salts  

Energy Technology Data Exchange (ETDEWEB)

Chemical phase identifications of complex, multilayered corrosion products formed on Fe-Ni-Cr alloys immersed in molten NaNO/sub 3/-KNO/sub 3/ and LiNO/sub 3/-NaNO/sub 3/-KNO/sub 3/ were obtained by X-ray diffraction analysis. Diffraction analyses performed after successive material removal steps provided depth profiles of corrosion products and identified the dominant phases as NaFeO/sub 2/, Fe/sub 3/O/sub 4/, and Cr/sub 2/O/sub 3/ for Alloy 800 and 316SS after immersion in NaNO/sub 3/-KNO/sub 3/. In LiNO/sub 3/-NaNO/sub 3/-KNO/sub 3/, the major corrosion products identified on Alloy 800 were LiFeO/sub 2/, Fe/sub 3/O/sub 4/, and Cr/sub 2/O/sub 3/. X-ray diffraction results were supplemented by electron microprobe analyses that revealed the solid solution nature of several of the oxide phases.

1984-08-01

59

Elastic properties and structural studies on some zinc-borate glasses derived from ultrasonic, FT-IR and X-ray techniques  

International Nuclear Information System (INIS)

Glasses in the system (1 - x) [29Na2O- 4Al2O3- 67B2O3]- xZnO (0 ? x ? 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N4 values (fraction of tetrahedral coordinated boron atoms), and substitution of longer bond lengths of ...

2009-05-05

60

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

61

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

62

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

63

Element distribution in the brain sections of rats measured by synchrotron radiation X-ray fluorescence  

International Nuclear Information System (INIS)

The concentration of trace elements in brain sections was measured by synchrotron radiation X-ray fluorescence. The relative concentration was calculated by means of the normalization of Compton scattering intensity approximately 22 keV, after the normalization for collecting time of X-ray spectrum and the counting of the ion chamber, and subtracting the contribution of the polycarbonate film for supporting sample. Furthermore, the statistical evaluation of the element distribution in various regions of the brain sections of the 20-day-old rats was tested. For investigating the distribution of elements in the brain of iodine deficient rats, Wistar rats were fed with iodine deficient diet and deionized water (ID group). The rats were fed the same iodine deficient diet, but drank KIO_3 solution as control (CT group). The results showed that the contents of calcium (Ca) in thalamus (TH) and copper (Cu) and iron (Fe) in ...

2004-02-27

67

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).

68

X-ray micro-spectroscopy: a tool for micro-scale radionuclide speciation in heterogeneous nuclear waste repository materials  

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Large-scale problems such as nuclear waste disposal are increasingly recognized to be interconnected to small scale-mechanisms. Thus, synchrotron-based high-resolution analytical X-ray probes become important tools for exploring the micro-scale chemical reactivity of heterogeneous barrier materials used in nuclear waste repositories. In this study the layout of the micro-XAS beamline at the Swiss Light Source (SLS) will be presented. The beamline is optimized towards micro beam experiments ({approx}1 x 1 {mu}m{sup 2}) in the hard-X-ray regime (4 - {approx}22 keV) and allows to combine micro X-ray fluorescence (micro-XRF), micro X-ray absorption spectroscopy (micro- XAS), and micro X-ray diffraction (micro-XRD) investigations with radioactive samples. Furthermore, the potential of micro-XRF/XAS/XRD for acquiring spatially resolved molecular level ...

2005-07-01

69

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 sources. Applying a uniform background ...

2009-05-01

70

Diagnostic value of immediate CT after chemoembolization in patients with hepatocellular carcinoma: comparison with 2-3 week delayed CT  

Energy Technology Data Exchange (ETDEWEB)

Lipiodol CT is a important modality for the diagnosis of hepatocellular carcinoma and compared is usually performed at 2-3 week after Lipiodol injection. Therefore, we assessed and the diagnostic value and merits of immediate CT after chemoembolization from there of 2-3 week delayed Lipiodol CT. Thirty three cases of chemoembolization which were performed both immediate CT after chemoembolization and 2-3 week delayed Lipiodol CT were reviewed retrospectively. They were divided into four grades according to pattern of lipiodol uptake by three radiologists. The diagnostic value of immediate Lipiodol CT was compared to delayed Lipiodol CT. Grade 0 was two cases(3.0%) and Grade 1 was seven cases(21.2%). In the cases of Grade 2(23/33, 69.7%), tumor uptake could be dishing wished from parenchymal uptake of Lipiodol by its density and pattern, ...

1995-08-15

71

Use of the parmbsc0 force field and trajectory analysis to study the binding of netropsin to the DNA fragment (5'CCAATTGG)2 in the presence of excess NaCl salt in aqueous solution  

British Library Electronic Table of Contents (United Kingdom)

The parmbsc0 force field was applied to study in detail the binding of netropsin, at a salt concentration of 0.28M Na^+, to the minor groove of an 8-mer (5'CCAATTGG)2 DNA duplex forming a netropsin.DNA complex which previously has been characterized by X-ray crystallography, albeit with the use of closely related DNA duplexes. The X-ray structure revealed that the terminal guanidinium and amidinium groups of netropsin interact with the extreme ends of the palindromic AATT sequence of the receptor DNA. The parmbsc0 parameters of B-DNA and AMBER v9 parameters of netropsin generated a stable 6ns molecular dynamics (MD) trajectory for a 1:1 class I binding motif of this complex. Trajectory analysis for the salt and hydration effects on the binding of netropsin to the 8-mer DNA duplex revealed ...

2011-01-01

72

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

International Nuclear Information System (INIS)

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

2006-01-01

73

Surface modification of 17-4PH stainless steel by DC plasma nitriding and titanium nitride film duplex treatment  

Energy Technology Data Exchange (ETDEWEB)

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

2007-04-15

74

Surface modification of 17-4PH stainless steel by DC plasma nitriding and titanium nitride film duplex treatment  

International Nuclear Information System (INIS)

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

2007-04-01

75

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

76

Nanocrystallization of the amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloys studied by the Moessbauer spectroscopy  

International Nuclear Information System (INIS)

Formation of the soft magnetic nanostructure in amorphous Fe_1_4Ni_4_0Zr_7B_1_2 alloy due to heat treatment is studied by the Moessbauer, differential scanning calorimetry, and X-ray diffraction techniques. Annealing at temperatures 520-580 "oC leads to the formation of extremely soft nanocrystalline alloy as revealed by the rf-Moessbauer measurements. The superparamagnetic behaviour was observed for the alloy annealed at 620-640 "oC. At higher annealing temperatures good soft magnetic properties deteriorate. (author)

2001-09-23

77

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

78

Role of Computed Tomography in postoperative diskitis  

International Nuclear Information System (INIS)

Six patients with diskitis following lumbar disk surgery were investigated by Computed Tomography (CT). Four patients underwent CT in a rather early phase of the disease (5-37 days after the onset of the symptoms): a posterior paravertebral fluid collection was always recognized, while the plain film was normal. Later on (2-4 months), the classical signs of diskitis were evident, with both CT and the plain film. The collection was always present at CT. A reintervention, performed on 3 patients, revealed the purulent content of the collections. It seems reasonable to suggest a relationship between the collection and the subsequent diskitis; the collection is probably an early sign of the disease. Its detection is of grat value, because it could allow an immediate and adequate therapy. The authors stress the usefulness of performing CT in an early phase on this ...

1988-01-01

79

Local Structures and Interface Morphology of InGaAsN Thin Films Grown on GaAs  

Energy Technology Data Exchange (ETDEWEB)

The compound semiconductor system InGaAsN exhibits many intriguing properties which are particularly useful for the development of innovative high efficiency thin film solar cells and long wavelength lasers. The bandgap in these semiconductors can be varied by controlling the content of N and In and the thin films can yet be lattice-matched to GaAs. In the present work, x-ray absorption fine structure (XAFS) and grazing incidence x-ray scattering (GIXS) techniques have been employed to probe the local environment surrounding both N and In atoms as well as the interface morphology of InGaAsN thin films epitaxially grown on GaAs. The soft x-ray XAFS results around nitrogen K-edge reveal that N is in the sp{sup 3} hybridized bonding configuration in InGaAsN and GaAsN, suggesting that N impurities most likely substitute for As sites in these two compounds. The results of In K-edge XAFS suggest a possible ...

1999-02-23

80

Element selective X-ray magnetic circular and linear dichroisms in ferrimagnetic yttrium iron garnet films  

Energy Technology Data Exchange (ETDEWEB)

X-ray magnetic circular dichroism (XMCD) was used to probe the existence of induced magnetic moments in yttrium iron garnet (YIG) films in which yttrium is partly substituted with lanthanum, lutetium or bismuth. Spin polarization of the 4d states of yttrium and of the 5d states of lanthanum or lutetium was clearly demonstrated. Angular momentum resolved d-DOS of yttrium and lanthanun was shown to be split by the crystal field, the two resolved substructures having opposite magnetic polarization. The existence of a weak orbital moment involving the 6p states of bismuth was definitely established with the detection of a small XMCD signal at the Bi M{sub 1}-edge. Difference spectra also enhanced the visibility of subtle changes in the Fe K-edge XMCD spectra of YIG and {l_brace}Y, Bi{r_brace}IG films. Weak natural X-ray linear dichroism signatures were systematically observed with all iron garnet films and with a bulk YIG single crystal cut ...

2009-12-15

81

Electronic structure of KTiOAsO_4: A comparative study by the full potential linearized augmented plane wave method, X-ray emission spectroscopy and X-ray photoelectron spectroscopy  

International Nuclear Information System (INIS)

First-principles self-consistent band-structure calculations of potassium titanyl arsenate, KTiOAsO_4 (KTA), have been made using the full potential linearized augmented plane wave (FP-LAPW) method. Total and partial densities of states of the constituent atoms of KTA have been derived. The results obtained show that the valence band of KTA is dominated by contributions of the O 2p-like states, while the Ti 3d-like states are the main contributors into the conduction band of the compound. Additionally, the FP-LAPW calculations have revealed that potassium atoms are highly ionized in KTA. In the present work, the X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy (XPS) methods were also employed to investigate experimentally the electronic structure of potassium titanyl arsenate. For the mentioned compound, the XES K Ll, Ti L#alpha#, As K#beta#_2 and O K#alpha# bands reflecting the valence K s-, Ti s,d-, ...

2009-05-27

82

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

83

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

84

Microstructural aspects of the corrosion of Alloy 800  

International Nuclear Information System (INIS)

Transmission electron microscopy studies on solution-annealed Alloy 800 revealed small (100-200 nm), spherical-shaped titanium carbide (face centered cubic structure) and large (200 nm-5 #mu#m), faceted titanium nitride (hexagonal structure) particles randomly distributed in the austenite matrix. The volume fraction of former particles was found to be greater than that of the latter. Corrosion studies of the alloy in acidic, chlorides and acidic chloride environments at room temperature indicated that the passivity of Alloy 800 was adversely affected by the addition Cl"- ions. X-ray photoelectron spectroscopy revealed that the surface film formed on the alloy at the onset of passivity consisted of Cr"3"+ (as Cr_2O_3), without any Fe"3"+/Fe"2"+ or Ni"2"+. Scanning electron microscopy studies indicated initiation of pitting at large, faceted particles, not at small, spherical-shaped ones.

2004-12-01

85

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 ...

2008-08-15

86

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

87

X-ray and IR analysis of Cu-Si ferrite  

Science.gov (United States)

Polycrystalline soft ferrite, Cu1+xSixFe2?2xO4 (x=0.0, 0.05, 0.1, 0.15, 0.2 and 0.3) were prepared by standard ceramic technique. The X-ray analysis confirmed the single phase formation of the samples up to x=0.1 beside a second phase for x?0.15. The lattice parameter was found to decrease with composition(x), which is attributed to ionic size difference of cations involved. The bulk density measurements shows two different behavior for x0.15. The IR spectra of Cu Si ferrite system have been analyzed in the frequency range 200 1200 cm?1. It revealed two prominent bands ?1 and ?2 which are assigned to tetrahedral and octahedral metal complexes, respectively. The position of the highest frequency band is around 575 cm?1 while the lower frequency band is around 400 cm?1.

2006-08-01

88

Processing and characterization of polyethylene/Brazilian clay nanocomposites  

Energy Technology Data Exchange (ETDEWEB)

Nanocomposites containing polyethylene (PE) and montmorillonite clay organically modified (OMMT) with quaternary ammonium salts were obtained via direct melt intercalation. A montmorillonite sample from the Brazilian state of Paraiba was treated with four different types of quaternary ammonium salts. After the treatment, the powder was characterized by X-ray diffraction and scanning electron microscopy. The dispersion and morphologies of OMMT within PE were investigated by X-ray diffraction and transmission electron microscopy. The results revealed the formation of intercalated montmorillonite layers in the PE matrix. The thermal stability and flammability of the PE/montmorillonite clay nanocomposites were measured by thermogravimetry and horizontal burning tests for HB classification, Underwrites Laboratories (UL 94), respectively. It was shown that the samples do not degrade at the processing temperature. By adding only 3 ...

2007-02-15

89

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 revealed. These include processes such as the initiation of ...

2009-12-01

90

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 revealed. These include processes such as the initiation of ...

2009-12-01

91

Local structure of Ca dopant in BaTiO_3 by Ca K-edge X-ray absorption near-edge structure and first-principles calculations  

International Nuclear Information System (INIS)

The local environment of Ca dopants in barium titanate, BaTiO_3, is investigated by Ca K-edge X-ray absorption near-edge structure (XANES) spectroscopy. In conjunction with experiments, first-principles calculations by two methods are systematically made. The projector-augmented wave (PAW) method is used to optimize the local structure and obtain the formation energy. The augmented plane wave plus local orbitals method is adopted to obtain theoretical XANES spectra. A comparison between experimental and theoretical XANES spectra shows that Ca dopants are located at the Ba"2"+ sites forming Ca"2"+. Formation energy calculations of Ca doped BaTiO_3 by the PAW method also give the same results. The Ca atom in BaTiO_3 is off-centering in comparison with the Ba site in BaTiO_3. The off-centering of Ca atom is newly revealed by the combination of XANES spectroscopy and first-principles DFT calculations.

2010-06-01

92

Cross-sectional Specimen Preparation and Observation of a Plasma Sprayed Coating Using a Focused Ion Beam/Transmission Electron Microscopy System.  

Science.gov (United States)

A focused ion beam (FIB) technique was applied to cross-sectional specimen preparation to observe an interface between a plasma sprayed coating and an aluminum (Al) substrate by transmission electron microscopy (TEM). The surface of the sprayed coating film has a roughness of several tens of microns. Sputter rates for the coating film and the substrate are greatly different. The rough surface and the difference in sputter rate cause problems in making TEM specimens with smooth side walls. The top surface of the coating film was planerized by the FIB before fabricating the TEM specimen. The interfaces were investigated by TEM and energy-dispersive X-ray (EDX) analysis. The TEM observation revealed that there is a 10 nm thick amorphous layer at the interface between the coating film and substrate. The coating film consists of two kinds of sublayers with bright and dark contrast. The bright contrast sublayers were amorphous layers with thickness ...

2000-05-01

93

Multidetector-row helical CT: analysis of time management and workflow  

International Nuclear Information System (INIS)

The purpose of this study was to evaluate time management and workflow for multidetector-row helical CT (MDCT). Time for patient and data handling of at total of 580 patients were evaluated at two different time periods (December 1999, August 2000), each for the following baseline measurements: (a) change of clothes/instruction; (b) patient placement on the CT table/i.v. catheter; (c) CT planning and programming; (d) CT data acquisition; (e) CT data reconstruction; (f) CT data storage/printing. All imaging was performed on a Somatom Volume Zoom (Siemens, Erlangen, Germany). Time measurements summarized for different CT protocols revealed the following: (a) 5:01 min (#+-#2.06 min); (b) 4:36 min (#+-#2.43 min); (c) 4:11 min (#+-#2.55 min); (d) 0:43 min (#+-#0.15 min); (e) 6:59 min (#+-#2.39 min); (f) 09:51 min (#+-#3.51 ...

2002-03-01

94

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

95

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.

96

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

97

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

98

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

99

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

100

Passivity behavior of melt-spun Mg-Y Alloys  

Energy Technology Data Exchange (ETDEWEB)

Several Mg-Y binary ribbons with Y content up to {approx}17.9 at.% were fabricated by melt-spinning. X-ray diffraction (XRD) revealed that the phase structure changes with increasing Y content from extended solid solution to partially amorphous, and then fully intermetallic Mg{sub 24}Y{sub 5}. Anodic potentiodynamic polarization performed in 0.01 M NaCl electrolyte (pH=12) revealed improved anodic passivity behavior compared to pure Mg for all the Mg-Y alloys. X-ray photoelectron spectroscopy (XPS) revealed that the improved passivity of Mg-Y was more related to the elemental oxidation state rather than the concentration of the surface components. To study the effect of Cl{sup -} ion on the passivity behavior, anodic potentiodynamic and potentiostatic polarization were performed on Mg-17.9 at.% Y in alkaline (pH=12) NaCl electrolytes containing Cl{sup -} ion in the concentration ...

2003-12-15

101

Passivity behavior of melt-spun Mg-Y Alloys  

International Nuclear Information System (INIS)

Several Mg-Y binary ribbons with Y content up to #approx#17.9 at.% were fabricated by melt-spinning. X-ray diffraction (XRD) revealed that the phase structure changes with increasing Y content from extended solid solution to partially amorphous, and then fully intermetallic Mg_2_4Y_5. Anodic potentiodynamic polarization performed in 0.01 M NaCl electrolyte (pH=12) revealed improved anodic passivity behavior compared to pure Mg for all the Mg-Y alloys. X-ray photoelectron spectroscopy (XPS) revealed that the improved passivity of Mg-Y was more related to the elemental oxidation state rather than the concentration of the surface components. To study the effect of Cl"- ion on the passivity behavior, anodic potentiodynamic and potentiostatic polarization were performed on Mg-17.9 at.% Y in alkaline (pH=12) NaCl electrolytes containing Cl"- ion in the concentration range from 0.00 to ...

2003-12-15

102

Atomic substitution reveals the structural basis for substrate adenine recognition and removal by adenine DNA glycosylase  

Science.gov (United States)

Adenine DNA glycosylase catalyzes the glycolytic removal of adenine from the promutagenic A {center_dot} oxoG base pair in DNA. The general features of DNA recognition by an adenine DNA glycosylase, Bacillus stearothermophilus MutY, have previously been revealed via the X-ray structure of a catalytically inactive mutant protein bound to an A:oxoG-containing DNA duplex. Although the structure revealed the substrate adenine to be, as expected, extruded from the DNA helix and inserted into an extrahelical active site pocket on the enzyme, the substrate adenine engaged in no direct contacts with active site residues. This feature was paradoxical, because other glycosylases have been observed to engage their substrates primarily through direct contacts. The lack of direct contacts in the case of MutY suggested that either MutY uses a distinctive logic for substrate recognition or that the X-ray structure had ...

2010-01-14

103

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 ...

105

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.

106

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

107

Study of osteoporosis using dual energy X-ray absorptiometry  

Energy Technology Data Exchange (ETDEWEB)

Dual energy X-ray absorptiometry (Hologic QDR-1000) was used to quantitatively analyze the diagnosis and prevention of osteoporosis. The peak bone mineral density (BMD) of the spine appeared in normal men in their twenties and in normal women in their thirties. There was acceleration of bone loss in the 50 to 60 year age bracket (premenopause and postmenopause) in normal women. On the contrary, the peak BMD of the femoral neck in normal men and women appeared in their twenties after which it decreased slightly with age. Comparison showed that the femoral neck BMD of normal women was lower than that of men throughout all ages. The fracture threshold, 0.756 g/cm[sup 2] for the spine, was obtained by scanning 73 females with spinal fractures, the mean BMDs for L2-L4 at the 90th percentile level were used as the fracture threshold. The fracture threshold of femoral neck fracture was the femoral proximal BMD of the 9th decile. Classification by the Public Welfare Silver ...

1992-04-01

108

Elastic properties and structural studies on some zinc-borate glasses derived from ultrasonic, FT-IR and X-ray techniques  

Energy Technology Data Exchange (ETDEWEB)

Glasses in the system (1 - x) [29Na{sub 2}O- 4Al{sub 2}O{sub 3}- 67B{sub 2}O{sub 3}]- xZnO (0 {<=} x {<=} 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N{sub 4} values (fraction of tetrahedral coordinated ...

2009-05-05

109

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 X-ray waveguide as an excellent tool ...

2001-09-23

110

Electronic structure of face-centred cubic MoO_2: A comparative study by the full potential linearized augmented plane wave method, X-ray emission spectroscopy and X-ray photoelectron spectroscopy  

International Nuclear Information System (INIS)

X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy (XPS) methods were employed in the present paper to investigate the electronic structure of face-centred cubic (fcc) molybdenum dioxide, fcc-MoO_2. For the mentioned compound, the XES O K#alpha# and Mo L#beta#_2_,_1_5 bands reflecting the valence O p- and Mo s,d-like states, respectively, were derived and compared on a common energy scale with the XPS valence-band spectrum. For comparison, the similar experimental studies of the electronic structure were made for a usual orthorhombic form of molybdenum trioxide, MoO_3. Band-structure calculations of fcc-MoO_2 were made using the full potential linearized augmented plane wave (FP-LAPW) method. A rather good agreement of the experimental XES and XPS results and the theoretical FP-LAPW data for the electronic properties of fcc-MoO_2 has been achieved in the present paper. A new near-Fermi sub-band was detected on both the XES ...

2008-07-14

111

Computerized tomography and head growth curve infantile macrocephaly with normal psychomotor development  

Energy Technology Data Exchange (ETDEWEB)

Macrocephaly was defined as a head measuring larger than 98th percentile. We have evaluated CT findings and head growth curves in 25 infants with large heads. Ten (40%) of 25 infants with large heads were normal developmentally and neurologically. Five (20%) of those were mentally retarded. The other 10 infants (40%) included hydrocephalus (4 cases), malformation syndrome (3 cases), brain tumor (1 case), metabolic disorder (1 case) and degenerative disorder (1 case). Their head growth curves were typed as (I), (II) and (III): Type (I) (excessive head growth curve to 2 SDs above normal); Type (II) (head growth curve gradually approached to 2 SDs above normal); Type (III) (head growth curve parallel to 2 SDs above normal). Ten of macrocephaly with normal psychomotor development were studied clinically and radiologically in details. They were all male. CT pictures of those showed normal or various abnormal findings: ventricular dilatations, wide ...

1982-01-01

112

Radiological diagnosis of lesions of intervertebral discs; Radiologische Diagnostik von Bandscheibenlaesionen  

Energy Technology Data Exchange (ETDEWEB)

During their life, intervertebral discs undergo degenerative changes which need not necessarily become lesions. Conventional X-rays do not provide information on the condition of the intervertebral discs, so MRT or CT are recommended as primary techniques as they are non-invasive. Invasive methods like myelography and especially discography should not be used unless a case is highly problematic. In infants with pains in the back, MRT should be carried out as early as possible as there is nearly always an organic cause. (orig.) [German] Die Bandscheibe ist im Laufe des Lebens degenerativen Veraenderungen unterworfen, die klinisch zu Beschwerden fuehren koennen, aber nicht fuehren muessen. Konventionlle Roentgenaufnahmen lassen zwar die Hoehenminderung des Bandscheibenfachs und begleitende knoecherne Veraenderungen erkennen, nicht aber den Zustand der Bandscheibe selbst. Die Beurteilung der Bandscheibe und des Knochens gelingt mit der ...

2003-03-01

113

Synthesis, crystal structure, spectroscopic properties, antibacterial activity and theoretical studies of a novel difunctional acylhydrazone  

British Library Electronic Table of Contents (United Kingdom)

A novel difunctional acylhydrazone has been synthesized by the reaction of 5-methylisoxazole-4-carboyl hydrazine with benzaldehyde and characterized by X-ray crystallography and spectroscopy. The obtained results demonstrate the crystal belongs to triclinic, space group Formula Not Shown . Moreover, the spectroscopic properties were evaluated through density functional theory (DFT) and time-dependent density functional theory (TD DFT) calculations. The results reveal that UV-Vis absorption peaks at 194, 217.5 and 290.5nm are mainly attributed to (p, p)p*, partly (p, p)p* and partly pp*, and predominantly pp*, respectively, with intraligand charge-transfer transition (ILCT) character. The fluorescence emission peak at 485.96nm should be assigned to ILCT. In addition, the results of antibact...

2011-01-01

114

Synthesis and characterization of myristic acid capped silver nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

Reduction of silver myristate (AgMy) under mild thermal reaction conditions in a dipolar aprotic solvent i.e. N, N-dimethylformamide (DMF) has been carried out. UV-visible absorption measurements of dried and re-dispersible brown flocculants showed broad features of surface plasmon resonance (SPR) due to silver nanoparticles. The freshly isolated particles showed absorption bands at 414 and 485 nm, respectively, due to inter-particle coupling or clustering of silver ions and silver atoms. X-ray diffraction (XRD) pattern of fcc zero-valent silver resulted in crystallite size of about 10 nm. Scanning electron microscopy (SEM) revealed formation of rod shaped silver with increasing reaction temperature. Thermal analysis (TGA) showed about 10% weight loss due to organic capping.

2008-08-15

115

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

116

Stabilizing effect of the electron-beam self-fields on the phase-space trajectory in a self-amplified spontaneous emission free-electron laser operating in ultraviolet and x-ray spectral ranges  

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the FEL interaction grows exponentially.

2004-02-28

117

Simple chemical method for nanoporous network of In2S3 platelets for buffer layer in CIS solar cells  

British Library Electronic Table of Contents (United Kingdom)

Indium sulfide thin films consisting of porous network of nanoplatelets, have been deposited using chemical bath deposition (CBD) method onto the tin-doped indium oxide (ITO) coated glass substrate. Aqueous solutions of indium sulfate and thioacetamide have been used as indium and sulfur precursors. As a complexing agent, acetic acid was used. The chemically deposited indium sulfide thin films were examined for their structural, surface morphological and optical characterizations. The X-ray diffraction analysis revealed the formation of the cubic b-In2S3 onto the substrate. From scanning electron micrograph, it is observed that the surface of substrate is covered by nanoporous platelets type morphology. The optical studies showed a direct band gap of 2.84eV for indium sulfide platelets. Ph...

2008-01-01

118

Radio frequency plasma nitriding of aluminium at higher power levels  

International Nuclear Information System (INIS)

Nitriding of aluminium 2011 using a radio frequency plasma at higher power levels (500 and 700 W) and lower substrate temperature (500 deg. C) resulted in higher AlN/Al_2O_3 ratios than obtained at 100 W and 575 deg. C. AlN/Al_2O_3 ratios derived from X-ray photoelectron spectroscopic analysis (and corroborated by heavy ion elastic recoil time of flight spectrometry) for treatments preformed at 100 (575 deg. C), 500 (500 deg. C) and 700 W (500 deg. C) were 1.0, 1.5 and 3.3, respectively. Scanning electron microscopy revealed that plasma nitrided surfaces obtained at higher power levels exhibited much finer nodular morphology than obtained at 100 W.

2006-12-05

119

Microstructure and mechanical properties of magnesium alloy AZ31B laser beam welds  

International Nuclear Information System (INIS)

Microstructure and properties of a Mg AZ31B laser beam weld without filler are studied using electron microscopy, X-ray diffraction and mechanical tests. The microstructure of the weld is characterized by a narrow heat affected zone, columnar grains and precipitate coarsening in the fusion zone. Texture in the fusion zone is significantly different from the texture of the base material. The residual stress distribution observed is similar at the top and the bottom of the weld, maximum tensile residual stress values are observed in the fusion zone. Tensile tests reveal differences in the mechanical behavior of the fusion zone and the parent material, which can be related to the differences of texture and the resulting deformation mechanisms.

2008-06-25

120

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.

121

Electrochemical deposition of indium sulfide thin films using two-step pulse biasing  

British Library Electronic Table of Contents (United Kingdom)

Indium sulfide thin films were deposited onto indium-tin-oxide coated glass substrate by electrochemical deposition from an aqueous solution containing In2 (SO4) 3 and Na2S2O3. The deposition conditions were optimized on the basis of data obtained by scanning electron microscope, Auger electron spectroscopy and optical transmission measurements. Furthermore, the photosensitivity of the films was observed by means of photoelectrochemical measurements, which confirmed that the indium sulfide showed n-type conduction. The X-ray diffraction and Raman studies revealed that the as-grown films were amorphous or nanocrystalline in nature and became polycrystalline In2S3 after annealing.

2008-01-01

122

Effects of manganese doping on properties of sol-gel derived biphasic calcium phosphate ceramics  

British Library Electronic Table of Contents (United Kingdom)

We have investigated the effect of manganese (Mn) doping on properties of nanosized biphasic calcium phosphate powders and their dense bodies. Manganese levels of 0.6, 1.3, 1.9, 4.3, 7.0 and 11.9at.% were successfully incorporated into biphasic calcium phosphate via a sol-gel route. The prepared powders were calcined at temperatures of 500-1200^oC. The X-ray diffraction analysis revealed that a mix phase comprising of hydroxyapatite and @b-tricalcium phosphate were present, however the content of each phases in the structure was affected by the Mn content. The studies found that the largest portion of @b-tricalcium phosphate was detected at 4.3at.% Mn doping. The incorporation of Mn has also greatly increased the crystallinity of the biphasic calcium phosphate powder due to progressive den...

2011-01-01

123

Effects of carbon fiber surface treatment on the tribological properties of 2D woven carbon fabric/polyimide composites  

British Library Electronic Table of Contents (United Kingdom)

Polyacrylonitrile (PAN)-based carbon fabric (CF) was modified with strong HNO3 oxidation and then introduced into polyimide (PI) composites. The friction and wear properties of the carbon fabric reinforced polyimide composites (CFRP), sliding against GCr15 stainless steel rings, were investigated on an M-2000 model ring-on-block test rig under dry sliding. Experimental results revealed that the carbon fiber surface treatment largely reduced the friction and wear of the CFRP. Compared with the untreated ones, the surface-modified CF can enhance the tribological properties of CFRP efficiently due to the improved adhesion between the CF and the PI matrix. Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) study of the carbon fiber surface showed that the fiber surfa...

2009-01-01

124

Effects of carbon fiber surface treatment on the friction and wear behavior of 2D woven carbon fabric/phenolic composites  

British Library Electronic Table of Contents (United Kingdom)

To improve the friction and wear behavior of carbon fabric reinforced polymer composites (CFRP), nano-SiO2 was deposited on the fabric surface. The friction and wear behavior of the resulting composites were investigated on a model ring-on-block test rig. Experimental results revealed that fiber surface treatment contributed to largely improve the tribological properties of the CFRP composites. Scanning electron microscope (SEM) investigation showed that the worn surface of the surface modified CFRP composite was smoother under given load and sliding rate. Field emission scanning electron microscopy (FESEM), FTIR and X-ray photoelectron spectroscopy (XPS) studies of the carbon fiber surface showed that nanostructured Sio2 thin film can be obtained by SiO2 sols deposition, which improved th...

2009-01-01

125

Characterization of (In1−xAlx)2S3 thin films grown by co-evaporation  

British Library Electronic Table of Contents (United Kingdom)

In this paper, it is shown that (In1?xAlx)2S3 thin films can be grown through the co-evaporation of elemental indium, aluminum and sulfur. It is nevertheless observed that the introduction of aluminum within the indium sulfide thin films hinders the crystallites size and even yields almost amorphous films when x is 0.2. The investigations of the optical properties of the films reveal that contrary to what could be expected, the band gap increase is low; the highest values measured do not exceed 2.2eV. However, as suggested by X-ray photoelectron spectroscopy measurements, such widening most probably affects the lower conduction band states.

2010-01-01

126

Characterization and residual stress analysis of wear resistant Mo thermal spray-coated steel gear wheels  

British Library Electronic Table of Contents (United Kingdom)

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

2006-01-01

127

Banana peel extract mediated novel route for the synthesis of palladium nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Bio-inspired palladium nanoparticles were synthesized by using banana peel extract (BPE), a non-toxic eco-friendly material. Boiled, crushed, acetone precipitated, air-dried peel powder was used to reduce palladium chloride. The palladium nanoparticles were characterized by using UV-Visible spectroscopy, scanning electron microscope-energy dispersive spectra (SEM-EDS) and X-ray diffraction (XRD) analysis. Dynamic light scattering (DLS) studies revealed the average size of nanoparticles to be 50nm. Fourier transform infra red spectroscopy (FTIR) implicated the role of carboxyl, amine and hydroxyl groups in the synthetic process. This paper thus describes a novel green method for the synthesis of palladium nanoparticles.

2010-01-01

128

A micro-alloyed ferritic steel strengthened by nanoscale precipitates  

British Library Electronic Table of Contents (United Kingdom)

A ferritic steel with finely dispersed precipitates was investigated to reveal the fundamental strengthening mechanisms. The steel has a yield strength of 760MPa, approximately three times higher than that of conventional Ti-bearing high strength hot-rolled sheet steels, and its ultimate tensile strength reaches 850MPa with an elongation-to-failure value of 18%. Using energy dispersive X-ray spectroscopy (EDXS) and transmission electron microscope (TEM), fine carbides TiC with an average diameter of 10nm were observed in the ferrite matrix of the 0.08%Ti steel, and some cubic M23C6 precipitates were also observed at the grain boundaries and the interior of the grains. The finely dispersed TiC precipitates in the matrix provide matrix strengthening. The estimated magnitude of precipitation ...

2011-01-01

129

Thermal annealing effect on optical properties of electrodeposited ZnO thin films  

Energy Technology Data Exchange (ETDEWEB)

ZnO thin films were electrodeposited in aqueous solution on gilded p-type Si wafer substrates. Thermal treatments were carried out on different films in Ar atmosphere at different temperatures, between 200 and 600 {sup 0}C. Surface morphology studies using scanning electron microscopy and atomic force microscopy show a smooth surface for an annealing temperature of 400 {sup 0}C with a roughness mean square value of about 15 nm and a precipitation of ZnO microcrystals on the deposit surface at 600 {sup 0}C. X-ray diffraction experiments reveal a decrease in the c-parameter value from 5.223 to 5.206 A after treatment at 600 {sup 0}C, due to the removal of hydrogen from the film. Raman spectroscopy analyses show an improvement in the crystal quality of the film and a decrease in the compressive stress inside the deposit. Photoluminescence observations reveal an important change in the UV emission band after annealing at 200 ...

2008-10-07

130

The effect of a metal hip prosthesis on the radiation dose in therapeutic photon beam irradiations  

International Nuclear Information System (INIS)

Prostate and cervical cancer patients are often treated with external X-ray beams of bi-lateral incidence. Such treatment may incur some dose effect that cannot be predicted precisely in commercial treatment planning systems (TPS) for patients having undergone total hip replacement. This study performs a Monte Carlo (MC) simulation and an analytical calculation (convolution superposition algorithm which is implemented in ADAC TPS) of a 6 MV, 5x5 cm"2 X-ray beam incident into water with the existence of hip prosthesis, e.g. Ti6Al4V and CoCrMo alloy. The results indicate that ADAC TPS cannot precisely account for the scatter and backscatter radiation that a metal hip prosthesis causes. For percent depth dose (PDD) curves, the maximum underdosage of ADAC TPS up to 5 mm above the interface between dense material and water is 5%, 20% and 27% for PDD_B_o_n_e, PDD_T_i and PDD_C_o, respectively. The dose re-buildup, which occurs behind the hip region, ...

2002-07-01

131

Rare-earth mixed oxide thin films as 100% lattice match buffer layers for YBa2Cu3O7-x coated conductors  

International Nuclear Information System (INIS)

Buffer layers with 100% lattice match with YBa2Cu3O7 - ? (YBCO) were prepared from mixed rare-earth-oxides applying a simple sol-gel process and dip-coating method. Structural analysis of the sol-gel derived powder by X-ray diffraction revealed that the mixing parameter, which eliminates the lattice mismatch with YBCO, is x = 0.2382, 0.1852, 0.1252, 0.0906, 0.0793 and 0.0395 in (Eu1 - xHox)2O3, (Eu1 - xErx)2O3, (Eu1 - xYbx)2O3, (Gd1 - xHox)2O3, (Gd1 - xYx)2O3 and (Gd1 - xYbx)2O3, respectively. Microstructural investigations were carried out for Gd1.819Ho0.181O3 films epitaxially grown on cube-textured Ni (100) substrates by sol-gel dip-coating process. X-ray diffraction of the buffer showed strong out-of-plane orientation on Ni tape. The (Gd1 - xHox)2O3 (222) pole figure indicated a single cube-on-cube textured structure. The omega and phi scans revealed good out-of-plane and in-plane alne alignments. ...

2010-04-02

132

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 ...

2010-07-01

135

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

136

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).

142

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

143

Radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

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

1973-01-01

144

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

145

NONDESTRUCTIVE DETERMINATION OF AIRBORNE LEAD ...  

Science.gov (United States)

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

147

Ectopic Ureter  

Science.gov (United States)

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

151

Multi-Phase Fracture-Matrix Interactions Under Stress Changes  

Energy Technology Data Exchange (ETDEWEB)

The main objectives of this project are to quantify the changes in fracture porosity and multi-phase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) counter-current fluid transport between the matrix and the fracture, (c) studying the effect of confining stress on the distribution of fracture aperture and two-phase flow, and (d) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several ...

2005-12-07

152

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

153

Mineralogical Data of Shocked Quartz Materials from K/T Boundary and Impact Crater  

Science.gov (United States)

Shocked quartz minerals from the Cretaceous-Tertiary (K/T) boundary and impact craters have been mainly discussed from distribution of optical directions, mean optical refractive index, and X-ray data (1). The purpose of the present study is presentation of the detailed mineralogical data of shocked quartz found in the K/T boundaries and terrestrial impact craters (2,3,4,5). X-ray powder diffraction pattern of shocked quartz aggregate reveals that all Xray peaks are split into major three peaks composed of low-density quartz (LQ), normal quartz (Q), and shocked quartz with high density (SQ). X-ray peaks of (110), (200), (201), (202), and (211) in the hexagonal cell are also split into many peaks. The X-ray intensity among LQ, Q, and SQ phases indicates that the SQ phase shows 36% to 53% in six K/T boundary samples (5). The relative X-ray intensity ratio of ...

1992-07-01

154

Biomechanical properties of the femoral neck relative to osteosynthesis methods and bone mineral content assessed by computed tomography  

International Nuclear Information System (INIS)

Bone mineral content as determined by computerized tomography (CT) and mechanical strength on axial loading were compared in 36 cadaveric femur specimens. Based on the CT measurements of density and area, the mass of a transverse slice of the femur was estimated. Highly significant correlations were demonstrated between strength and cancellous bone density. Even higher correlations were revealed when the bone masses of the proximal and distal femoral areas were calculated. Based on these findings, an equal distribution of the effective mass of the femur was postulated. This hypothesis was confirmed in an experimental rotational model. The CT attenuation values were also correlated to direct measurements of bone mineral content, i.e. calcium. Moreover, the strength of different metal implants, commonly used in femoral neck fractures, were assessed in cadaver specimens. 134 refs., 13 figs., 12 tabs.

155

3-D brain CT image display for planning of craniofacial operation  

International Nuclear Information System (INIS)

The authors have been developing a 3D brain CT image display system for planning of craniofacial operations. This system helps doctors plan craniofacial operations on a graphic display (GD) terminal by rendering 3D images reconstructed from a set of slices. The authors reveal how the system generates 3D shapes of organs from given CT images and how it modifies or transforms the obtained shapes according to the user's request. The system functions now available are extraction and display of the skull and the skin, measurement of the distance between two points on the skull given through the GD terminal, and generating and eliminating a polygonal region arbitrarily given on the skull as an operative region. (Auth.).

156

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 inside the phantom include the lactiferous duct system, the ...

2009-07-21

157

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

158

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

159

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

160

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

161

Lung studies with spiral CT. pitch 1 versus pitch 2; Confronto tra diversi parametri (pitch 1 e 2) nello studio del polmone con Tomografia Computerizzata spirale  

Energy Technology Data Exchange (ETDEWEB)

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. [Italian] Nella Tomografia Computerizzata (TC) spirale il rapporto tra la distanza percorsa dal lettino portapaziente in una rotazione e lo spessore nominale dello strato, entrambi espressi in millimetri, si definische pitch. Se i due valori del rapporto coincidono si avra' pitch uguale a 1, mentre raddoppiando la distanza percorsa dal lettino portapaziente, per il medesimo spessore nominale, conseguentemente raddoppia il pitch (pitch 2). Eseguire gli esami TC spirale utilizzando pitch 2, consente di ridurre la durata ...

1999-03-01

162

Review of progress in quantitative NDE. Abstracts  

Energy Technology Data Exchange (ETDEWEB)

The meeting was arranged into the following sessions: introductory; advanced ceramics and ceramic composites; ceramic and metal matrix composites; electronic materials and devices; acoustoelasticity, stress, and texture; composites-porosity, strength, and UT propagation; process modeling and monitoring; thermal wave physics; material properties, composites, surfaces, and interfaces; acoustic emission; ferromagnetic materials; new sensors; NDE reliability assessment; elastic wave scattering and propagation; image analysis, data storage, and signal processing; UT transducers; weldments and bonded materials; eddy current models; unified life cycle engineering; x rays, CT, and NMR; eddy current probes and instruments; acoustic microscopy imaging, and reconstruction; signal processing, measurement techniques, and systems; NDE applications of artificial intelligence; crack behavior influenced by history; inversion procedures for ...

1986-01-01

163

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 FEL beam. Cancer ...

2003-06-01

164

Metal contacts to n-GaN  

International Nuclear Information System (INIS)

Al, Au, Ti/Al and Ti/Au contacts were prepared on n-GaN and annealed up to 900 deg. C. The structure, phase and morphology were studied by cross-sectional transmission and scanning electron microscopy as well as by X-ray diffraction (XRD), the electrical behaviour by current-voltage measurements. It was obtained that annealing resulted in interdiffusion, lateral diffusion along the surface, alloying and bowling up of the metal layers. The current-voltage characteristics of as-deposited Al and Ti/Al contacts were linear, while the Au and Ti/Au contacts exhibited rectifying behaviour. Except the Ti/Au contact which became linear, the contacts degraded during heat treatment at 900 deg. C. The surface of Au and Ti/Au contacts annealed at 900 deg. C have shown fractal-like structures revealed by scanning electron microscopy. Transmission electron microscopy and XRD investigations of the Ti/Au contact revealed that Au diffused ...

2006-11-15

165

Microstructural aspects of the corrosion of Alloy 800  

Energy Technology Data Exchange (ETDEWEB)

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

2004-12-01

166

Influence of temperature on corrosion behavior of PbCaSnCe alloy in 4.5 M H{sub 2}SO{sub 4} solution  

Energy Technology Data Exchange (ETDEWEB)

The temperature effect on corrosion behaviors of PbCaSnCe alloy in 4.5 M H{sub 2}SO{sub 4} solution was investigated by using potentiodynamic curve, electrochemical impedance spectra (EIS), Mott-Schottky plot and photocurrent response methods. It was found that PbCaSnCe alloy was in passive state in sulfuric acid solution, a passive film can be formed on alloy surface. The compositions of passive films formed at 0.9 V for 2 h under different temperatures were detected by X-ray photoelectron spectroscopy (XPS). The results showed that the film resistance and the transfer resistance decreased with the increment of the solution temperature. Mott-Schottky analysis and the photocurrent response revealed that the passive film exhibited n-type semi-conductive character, the donor density of the passive film decreased with increasing the solution temperature. Photocurrent response revealed that the photocurrent increased with ...

2010-01-15

167

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

168

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

International Nuclear Information System (INIS)

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

2010-04-09

169

A Chandra Observation of Supernova Remnant G350.1-0.3 and Its Central Compact Object  

CERN Document Server

We present a new Chandra observation of supernova remnant (SNR) G350.1-0.3. The high resolution X-ray data reveal previously unresolved filamentary structures and allow us to perform detailed spectroscopy in the diffuse regions of this SNR. Spectral analysis demonstrates that the region of brightest emission is dominated by hot, metal-rich ejecta while the ambient material along the perimeter of the ejecta region and throughout the remnant's western half is mostly low-temperature, shocked interstellar/circumstellar medium (ISM/CSM) with solar-type composition. The data reveal that the emission extends far to the west of the ejecta region and imply a lower limit of 6.6 pc on the diameter of the source (at a distance of 4.5 kpc). We show that G350.1-0.3 is likely in the free expansion (ejecta-dominated) stage and calculate an age of 600-1200 years. The derived relationship between the shock velocity and the electron/proton ...

2011-01-01

170

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) elaboration of ...

1988-01-01

171

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

172

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

173

Primary malignant lymphoma of the brain; Primaere maligne Lymphome des Gehirns  

Energy Technology Data Exchange (ETDEWEB)

Primary malignant lymphoma of the brain is a disease of unknown etiology, which is increasing in incidence and has an unfavorable prognosis. Despite the lack of specific changes on CT or MRI in most cases, these procedures may typically facilitate the diagnosis: A focal-enhancing mass with subependymal spread on CT or MRI and hyperattenuation on nonenhanced CT are the most reliable features in the diagnosis of primary malignant lymphoma of the brain. Peritumoral edema and mass effect are usually not prominent features. On unenhanced CT scans they usually appear homogeneously isodense to mildly hyperdense relative to the gray matter. On MRI these tumors are slightly hypointense on T1-weighted images and slightly hpyerintense on PD- and T2-weighted images relative to the gray matter. On CT and MRI enhancement is usually homogeneous. Contrast-enhanced MRI, with its multiplanar ...

1997-01-01

174

Closed loop obstructions of the small bowel: role of Computed Tomography  

International Nuclear Information System (INIS)

Small bowel obstructions can be distinguished into more simple and closed loop obstructions. The latter is a more severe condition which is often complicated by strangulation with vascular impairment, edema and intramural and mesenteric hemorrhage. Consequent arterial insufficiency rapidly leads to ischemia, infarction and necrosis. The radiologist plays a role in the early recognition of the closed loop obstruction and of any sign of strangulation. The role of CT in the diagnosis and workup of patients with suspected intestinal occlusion has been analyzed in the literature with reported 63% sensitivity, 78% specificity and 66% accuracy. CT is also capable of revealing the causes of occlusion in 73-95% of cases. The above CT signs allow to identify closed loop obstruction and also small bowel strangulation, thus supplying a valuable contribution to diagnosis and accurate preoperative evaluation. The ...

1999-01-01

175

Magnetic resonance imaging in acute intractional tuberculosis  

International Nuclear Information System (INIS)

We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.).

176

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

177

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. ...

178

Partial preservation of the Tentaculites Crotalinus shell from Ponta Grossa Formation (Devonian)  

International Nuclear Information System (INIS)

This paper deals with an analysis of a single specimen of Tentaculites crotalinus SALTER emend. CIGUEL et al. (1984) that present a possible partial preservation of the shell. It comes from an outcrop of the Grossa Formation (Devonian) near Jaguariaiva, State of Parana. The skeletal microstructure of the Tentaculitoidea shell rather poorly Known. Thus, the phylogenetic relationships of these invertebrates still uncertain. Tentaculitids are very common fossils in Devonian Ponta Grossa Formation (Parana Basin) but so far Known only from external and internal moulds. The objective of this study is to demonstrate wheter the layer found in between the internal and external mould is or not a case shell preservation. The chemical composition of this layer and of the external mould was analysed by X rays. X rays difratometry was applied only to the matrix (at the external mould). The structure of the supposed ...

179

Magnetic properties and low temperature X-ray studies of the weak ferromagnetic monoclinic and trigonal chromium tellurides Cr_5Te_8  

International Nuclear Information System (INIS)

Monoclinic and trigonal Cr_5Te_8 show a transition into the ferromagnetic state with a Curie temperature T_c, which sensitively depends on the actual composition. Monoclinic samples exhibit a lower T_c despite their higher Cr content. This observation is explained on the basis of less effective ferromagnetic superexchange in the monoclinic compounds and the larger number of Cr atoms being antiferromagnetically coupled. Magnetization experiments performed at 5 K demonstrate that the compounds saturate already at rather low magnetic fields. In addition, small values are estimated for the coercitive field H_c as well as for the remanence magnetization both being typical for weak ferromagnetic materials. The values for the saturation magnetization amount to about 72% and 65% for monoclinic and trigonal Cr_5Te_8, respectively. These low values can partially be explained on the basis of antiferromagnetically coupled Cr(III) d"3 centers. An additional spin canting is assumed to fully account ...

2004-03-01

180

Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques  

Energy Technology Data Exchange (ETDEWEB)

A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and ...

2005-06-11

181

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 dislocations with ...

1991-12-01

182

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

183

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

184

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

185

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

186

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

187

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

188

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).

189

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

190

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

191

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

192

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

193

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.

194

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

195

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

196

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 image depicting cartilages was ...

2009-07-01

197

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

198

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

199

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 ...

200

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

201

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.).

202

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

203

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

204

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

205

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

208

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

209

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

210
211

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

212

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

213

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

214

Experimental study of X-ray vidicon  

International Nuclear Information System (INIS)

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

216

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

217

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

218

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

219

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

221

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

222

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

223

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

224

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

225

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

226

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

227

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

228

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

229

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

230

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

231

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

232

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

233

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

234

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

235

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

236

WITNESSING THE KEY EARLY PHASE OF QUASAR EVOLUTION: AN OBSCURED ACTIVE GALACTIC NUCLEUS PAIR IN THE INTERACTING GALAXY IRAS 20210+1121  

International Nuclear Information System (INIS)

We report the discovery of an active galactic nucleus (AGN) pair in the interacting galaxy system IRAS 20210+1121 at z = 0.056. An XMM-Newton observation reveals the presence of an obscured (N _H #approx# 5 x 10"2"3 cm"-"2), Seyfert-like (L _2_-_1_0_k_e_V = 4.7 x 10"4"2 erg s"-"1) nucleus in the northern galaxy, which lacks unambiguous optical AGN signatures. Our spectral analysis also provides strong evidence that the IR-luminous southern galaxy hosts a Type 2 quasar embedded in a bright starburst emission. In particular, the X-ray primary continuum from the nucleus appears totally depressed in the XMM-Newton band as expected in the case of a Compton-thick absorber, and only the emission produced by Compton scattering ('reflection') of the continuum from circumnuclear matter is seen. As such, IRAS 20210+1121 seems to provide an excellent opportunity to witness a key, early phase in the quasar evolution predicted by the theoretical models of ...

2010-10-20

237

Synthesis, microstructure and photoluminescence of Eu{sup 3+}/Tb{sup 3+} activated Y{sub 2}SiO{sub 5} nanophosphors by new silicate sources  

Energy Technology Data Exchange (ETDEWEB)

Y{sub 2-x}Tb{sub x}SiO{sub 5} and Y{sub 2-x}Eu{sub x}SiO{sub 5} nanophosphors with seven different kinds of silicate sources were synthesized by sol-gel method. The structures have been investigated to be composed of nanometer-size grains of 30-60 nm through X-ray diffraction (XRD) and scanning electron microscopy (SEM) was used to compare the different morphology of patterns from seven different silicon sources. The photoluminescence of Y{sub 2-x}Tb{sub x}SiO{sub 5} was investigated as a function of silicate sources and the results revealed that these nanometer materials showed the characteristic emission {sup 5}D{sub 4} {yields} {sup 7}F{sub J} (J 6, 5, 4, 3) of Tb ions. The characteristic emission {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 1, 2, 4) of Eu ions was also found in the materials of Y{sub 2-x}Eu{sub x}SiO{sub 5}.

2008-01-15

238

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

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

239

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

240

Surface Topography of 'Hotspot' Regions from a Single Cell SRF Cavity  

Energy Technology Data Exchange (ETDEWEB)

Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitatively low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed the crystal structure surrounding the pits via crystal phase orientation mapping, while 3D profilometry gave information on the depth and size ...

2009-05-01

241

Structure and magnetic properties of the Al1-xGaxFeO3 family of oxides: A combined experimental and theoretical study  

International Nuclear Information System (INIS)

Magnetic properties of the Al1-xGaxFeO3 family of oxides crystallizing in a non-centrosymmetric space group have been investigated in detail along with structural aspects by employing X-ray and neutron diffraction, Moessbauer spectroscopy and other techniques. The study has revealed the occurrence of several interesting features related to unit cell parameters, site disorder and ionic size. Using first-principles density functional theory based calculations, we have attempted to understand how magnetic ordering and related properties in these oxides depend sensitively on disorder at the cation site. The origin and tendency of cations to disorder and the associated properties are traced to the local structure and ionic sizes. -- Graphical abstract: We have studied both experimentally and theoretically the important role of disorder at the cation site on magnetic and related properties of the Al1-xGaxFeO3 family of oxides crystallizing in a ...

2011-03-01

242

Structure and magnetic properties of nanocrystalline Fe-Mo alloys prepared by mechanosynthesis  

International Nuclear Information System (INIS)

Nanocrystalline samples of Fe_8_0Mo_2_0 and Fe_5_0Mo_5_0 alloys were prepared by the mechanical milling method. The structure, lattice parameters, and crystallite size were determined by the X-ray diffraction. The magnetic properties of the milled products were determined by the Moessbauer spectroscopy. It was observed that in the case of the Fe_8_0Mo_2_0 alloy a solid solution of Mo in Fe was formed with the lattice parameters of the Fe increasing from 0.28659 nm to 0.29240 nm and the crystallite size decreasing from 250 nm to 20 nm. In the case of the Fe_5_0Mo_5_0 alloy there were no clear changes in values of the lattice parameters of Fe and Mo during the milling process, but the crystallite size decreased from 200 to 15 nm. Moessbauer spectra revealed different magnetic phases in the machanosynthesized Fe_Mo samples. In the case of the Fe_8_0Mo_2_0 alloy, the spectrum for the milled mixture indicated the formation of solid solution. In ...

2001-09-23

243

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 ...

2010-07-01

244

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 between the gas and ...

2008-01-01

245

Polypropylene surface modification by active screen plasma nitriding  

International Nuclear Information System (INIS)

Here we describe the use of low energy plasma immersion with active screen as a convenient approach for polypropylene (PP) surface modification. Employing a stainless steel cathodic cage coated with carbon in order to prevent the sputtering of iron from the grid and its deposition onto the polymer sample, the physical chemical properties of PP surface could be effectively modified through the plasma-induced incorporation/formation of nitrogen- and oxygen-containing species. The areal densities of these elements depended on the plasma excitation source, as determined by Rutherford backscattering spectrometry (RBS). Newly formed C-O, C-N, and C=O/O=C-O/N-C=O bonds along with C-C linkages from the PP backbone were identified at the near surface region of the specimens by X-ray photoelectron spectroscopy (XPS). The insertion of such polar reactive functionalities was further confirmed by a substantial decrease in the water contact angle upon plasma treatment. Scanning ...

2009-03-01

246

Pa0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine.  

Science.gov (United States)

Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k(cat)/K(m) values that exceed 10(5) M(-1) s(-1). These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted (?/?)(8) barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the ...

2011-07-06

247

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 nuclear materials. ...

2009-12-16

248

NMR study on the formation mechanism of #beta#-SiAlON from zeolite by nitridation using ammonia gas  

International Nuclear Information System (INIS)

#beta#-SiAlON was synthesized from a zeolite by NH_3 gas nitridation and its formation mechanism was investigated using X-ray diffraction and "2"9Si and "2"7Al NMR spectroscopy. It was revealed that most of the Si and Al atoms react to form #beta#-SiAlON via amorphous forms of Si-Al-O-N and O-SiAlON. Nitridation using NH_3 gas is an effective means of preventing mullite formation and promoting the introduction of nitrogen into aluminosilicate materials at lower temperatures than temperatures required by the carbothermal reduction nitridation process. Further, the NMR spectra showed that the siliceous part of the system changed into low z-value of Si_6_-_zAl_zO_zN_8_-_z (#beta#-SiAlON) and the incorporation of Al components into the #beta#-SiAlON was promoted in the later stages of the reaction. (author)

2008-09-01

249

High lithium ion conductive Li7La3Zr2O12 by inclusion of both Al and Si  

British Library Electronic Table of Contents (United Kingdom)

High lithium-ion (Li^+) conductive garnet-structured lanthanum lithium zirconate (LLZ) solid electrolyte is prepared by incorporation of appropriate amounts of silicon (Si) and aluminum (Al). The resultant pelletized LLZ obtains total Li^+ conductivity of 6.8x10^-^4Scm^-^1 at 298K. This improved conductivity is nearly identical with the bulk Li^+ conductivity of the LLZ reported earlier, suggesting that the grain boundary resistance is effectively reduced by the incorporation of Si and Al. Microanalyses by transmission electron microscopy coupled with energy-dispersive X-ray microanalysis and electron energy-loss spectroscopy revealed the presence of amorphous Li-Al-Si-O with nano crystalline LiAlSiO4 at grain boundaries. Fast lithium-ion transport around the amorphous Li-Al-Si-O/LiAlSiO4 ...

2011-01-01

250

Enhancing the corrosion resistance of dentistry drills by plasma immersion nitrogen in implantation of AISI 434-based SS  

Energy Technology Data Exchange (ETDEWEB)

In order to enhance the resistance to the pitting corrosion due to asepsis processes and to avoid structural fractures in dentistry drills, a plasma immersion ion implantation (PIII) treatment using nitrogen has been performed. The selected drill samples, made of AISI 434 based stainless steel with a 0.670 mm diameter, were treated at a -1kV bias between 350 C and 450 C, this temperature being controlled by both a 20-50 {mu}s pulse width and a 200-1000 Hz repetition rate in the bias. The drills were analysed by cyclic potentiodynamic tests showing a good pitting corrosion resistance when treated at around 400 C, as follows from a resulting very low hysteresis loop. Yet, the resistance appears somehow diminished by the presence of sputtering when processed at temperatures near 450 C. It is also found that the PIII nitriding effectiveness appears to be limited by the appearance of uniform corrosion. Finally, X-ray diffraction of the samples has ...

2007-07-01

251

Effect of gamma irradiation on tensile properties of low molecular weight polyethylene samples  

International Nuclear Information System (INIS)

Three high density polyethylene (PE) samples of different origins, with weight average molar masses ranging from 38 to 63 kg mol"-"1 and displaying a semi-ductile behavior with strain at break ?_R values of the order of 100-140%, were gamma irradiated under nitrogen for doses up to 33.3 kGy. Steric exclusion chromatography and rheometry allowed to quantify the crosslink density X. This later reached values ranging from 4.6 to 9.0x10"-"3 mol kg"-"1, i.e. situated below the gelation point. Differential calorimetry, density measurement and small angle X-rays scattering showed the absence of significant changes in the crystalline morphology, especially lamellar dimensions. Tensile testing revealed an unexpected trend towards brittle regime of fracture while yield stress increases significantly at low doses. It appeared that branching disfavors cavitation during yielding, but this effect is not favorable to ductility.

2011-08-01

252

Dielectric properties of fluxed barium titanate ceramics with zirconia additions  

Energy Technology Data Exchange (ETDEWEB)

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

1990-03-01

253

Dielectric properties of fluxed barium titanate ceramics with zirconia additions  

International Nuclear Information System (INIS)

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

254

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

International Nuclear Information System (INIS)

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

2008-04-01

255

Comparative study of phase stability and film morphology in thin-film M/GaAs systems (M = Co, Rh, Ir, Ni, Pd, and Pt)  

Energy Technology Data Exchange (ETDEWEB)

To attain reproducible and stable contacts to compound semiconductor devices, it is necessary to achieve thermodynamically stable phases after the reaction of metals with the compound semiconductor. In this study, the final phases produced by the reactions between GaAs and thin metal films of Co, Rh, Ir, Ni, Pd, and Pt have been investigated. They are identified as MGa for M = Co, Rh, Ni, Pd, and Pt, monoarsenides of Co and Ni, diarsenides of Rh, Ir, Pd, and Pt, and Ir/sub 3/Ga/sub 5/. These phases, if deposited directly onto GaAs, will produce thermally stable contacts. In addition to the identification of these stable phases, analyses of the products of thin-film M/GaAs reactions by transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry reveal the distribution, grain size, and crystallographic texture of these end phases. Trends in these observations across the six metal/GaAs reactions studied are ...

1987-09-01

256

Capacitance behaviour of passive films on ferritic and austenitic stainless steel  

Energy Technology Data Exchange (ETDEWEB)

The electrochemical behaviour of passive films formed on one austenitic stainless steel (AISI 304) and one ferritic stainless steel (AISI 446) in solutions with pH between 0.6 and 8.4 was studied by capacitance measurements and photocurrent spectroscopy. Compositional characterization of the passive films was done by X-ray photoelectron spectroscopy. The capacitance increases with decreasing pH. Doping densities evaluated from Mott-Schottky plots are in the range 2-6 x 10{sup 20} cm{sup -3} and increased with the pH in the neutral/alkaline range while in pH 0.6, values above 10{sup 21} cm{sup -3} were found. The bandgap energy indicates two transitions, at 2.5-2.8 and 3.2 eV. The analytical data reveal that, as the pH increased, the films become enriched in Fe(II) and Fe(III), whereas the Cr(III) gradually decreases. The films formed at very low pH had a behaviour that contrasts with that of the films formed in the neutral/alkaline media. The ...

2005-03-01

257

Capacitance behaviour of passive films on ferritic and austenitic stainless steel  

International Nuclear Information System (INIS)

The electrochemical behaviour of passive films formed on one austenitic stainless steel (AISI 304) and one ferritic stainless steel (AISI 446) in solutions with pH between 0.6 and 8.4 was studied by capacitance measurements and photocurrent spectroscopy. Compositional characterization of the passive films was done by X-ray photoelectron spectroscopy. The capacitance increases with decreasing pH. Doping densities evaluated from Mott-Schottky plots are in the range 2-6 x 10"2"0 cm"-"3 and increased with the pH in the neutral/alkaline range while in pH 0.6, values above 10"2"1 cm"-"3 were found. The bandgap energy indicates two transitions, at 2.5-2.8 and 3.2 eV. The analytical data reveal that, as the pH increased, the films become enriched in Fe(II) and Fe(III), whereas the Cr(III) gradually decreases. The films formed at very low pH had a behaviour that contrasts with that of the films formed in the neutral/alkaline media. The films are ...

2005-03-01

258

Calcium sulfate crystallization along citrus root channels in a Florida soil exhibiting acid sulfate properties  

Energy Technology Data Exchange (ETDEWEB)

The authors observed euhedral crystals in Manatee soil in a citrus grove in St. Lucie County, Florida. The material was identified as gypsum (CaSO/sub 4/ /times/ 2H/sub 2/O) using x-ray diffraction and infrared spectra. Photomicrography and scanning electron microscopy revealed that gypsum accumulated both in old root channels and within citrus root tissue of the Btg horizon. The subsurface horizons had elevated sulfate levels, a low initial pH, a drop (0.5 unit) in pH upon air-drying. Electrical conductivity paralleled the concentration of water-soluble sulfate. High levels of calcium and sulfate occurred for horizons above the water table. This accumulation is attributed to groundwater bearing these ions and subsequently discharging them to the overlying soil. Dead citrus roots appear to act as wicks to aid water transfer from lower to higher horizons. The roots and their empty channels provide spaces in which the gypsum can precipitate if ...

1988-02-01

259

A comparative study of natural, formaldehyde-treated and copolymer-grafted orange peel for Pb(II) adsorption under batch and continuous mode  

Energy Technology Data Exchange (ETDEWEB)

Natural, formaldehyde-treated and copolymer-grafted orange peels were evaluated as adsorbents to remove lead ions from aqueous solutions. The optimum pH for lead adsorption was found to be pH 5. The adsorption process was fast, reaching 99% of sorbent capacity in 10 min for the natural and treated biomasses and 20 min for the grafted material. The treated biomass showed the highest sorption rate and capacity in the batch experiments, with the results fitting well to a pseudo-first order rate equation. In the continuous test with the treated biomass, the capacity at complete exhaustion was 46.61 mg g{sup -1} for an initial concentration of 150 mg L{sup -1}. Scanning electronic microscopy and energy dispersive X-ray spectroscopy indicated that the materials had a rough surface, and that the adsorption of the metal took place on the surface. Fourier transform infrared spectroscopy revealed that the functional groups responsible for metallic ...

2009-01-30

260

A Single-Shot Method for Measuring Femtosecond Bunch Length in Linac-Based Free-Electron Lasers  

International Nuclear Information System (INIS)

There is growing interest in the generation and characterization of femtosecond and subfemtosecond pulses from linac-based free-electron lasers (FELs). In this report, following the method of Ricci and Smith (Phys. Rev. ST Accel. Beams 3, 032801 (2000)), we investigate the measurement of the longitudinal bunch profile of an ultrashort electron bunch produced by these FELs. We show that this method can be applied in a straightforward manner at x-ray FEL facilities such as the Linac Coherent Light Source by slightly adjusting the second bunch compressor followed by running the bunch on an rf zero-crossing phase of the final linac. We find that the linac wakefield strongly perturbs the measurement, and through analysis show that it can be compensated in a simple way. We demonstrate the effectiveness of this method and wakefield compensation through numerical simulations, including effects of coherent synchrotron radiation and longitudinal space charge. When used in ...

2010-08-26

261

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

262

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

263

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.

264

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

265

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

266

Staging of multiple myeloma with MRI: comparison to MSCT and conventional radiography; Staging des multiplen Myeloms mit der MRT: Vergleich zur MSCT und zur konventionellen Roentgendiagnostik  

Energy Technology Data Exchange (ETDEWEB)

The staging of patients with multiple myeloma demands sensitive imaging methods for the assessment of the skeletal system. MRI allows for direct visualization of the bone marrow which exhibits five different infiltration patterns in multiple myeloma: 1. normal appearance of the bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. ''salt and pepper'' pattern with inhomogeneous bone marrow signals due to multiple fat islands. The combination of T1w-SE and STIR sequences is best suited for detecting all infiltration patterns and for the differential diagnoses e. g. hemangiomas. With parallel imaging in MRI, acquisition times can be markedly reduced and whole-body screening of the bone marrow can be achieved within 30 min. MRI is superior to radiography for the detection of focal as well as diffuse infiltration. Multidetector computed tomography and especially 16- and 64-detector row ...

2004-09-01

267

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

268

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

269

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

270

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 ...

271

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 and the X-ray ...

1989-02-14

272

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, when represented by a ...

2010-01-01

273

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

274

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 terms of the linearity, the fractions of the X-ray photons detected by the two detectors, respectively ...

2007-01-01

275

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

276

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 image by single shot. High density record including 1000 images ...

1998-10-01

277

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 determine that the peak ...

2005-01-01

278

Differential diagnosis of rheumatic diseases; Differenzialdiagnose rheumatischer Erkrankungen  

Energy Technology Data Exchange (ETDEWEB)

Which imaging modalities are appropriate for the Differential diagnosis of Rheumatic diseases. MRI has far most the highest sensitivity and is unequaled in its brilliant presentation of Anatomy and Pathology. But it is sometimes forgotten, that this is at least in part the result of carefully selected sequences, dedicated to the expected result. In a method totally independent of any result, this should not be the case. In contrary this method should be highly standardised and regardless what will be the findings. This is true for Plain X-ray. It will be shown, that already the outer silhouette of the soft parts with different features of swelling, and differences in density and even more - defects or appositions of the bony silhouette in the majority of cases at least will allow to classify the patient for a group of diseases and in many cases will lead to a definite diagnosis. Differential diagnoses like Rheumatoid Arthritis versus Psoriatic Arthritis or simply ...

2006-05-15

279

Magnetic resonance imaging in acute intractional tuberculosis; Magnetresonanztomographie bei akuter intrakranieller Tuberkulose  

Energy Technology Data Exchange (ETDEWEB)

We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.) [Deutsch] Die Befunde von drei Patienten mit intrakranieller Tuberkulose (intrakranielle Miliartuberkulose, Meningitis tuberculosa, Neuritis und Tuberkulome) in der Magnetresonanztomographie (MRT) wurden mit der Computertomographie (CT) verglichen. Sowohl die MRT als auch die CT wurden nativ und nach Kontrastmittelgabe durchgefuehrt. Die MRT zeigte sich im Nachweis von Granulomen insbesondere im Bereich des Hirnstamms ueberlegen. Ebenso wurde ...

1994-12-31

280

Massive tumor pulmonary embolism following transcatheter arterial chemoembolization of hepatocellular carcinoma  

Energy Technology Data Exchange (ETDEWEB)

Pulmonary embolism complicated by transcatheter arterial chemoembolization (TACE) in known to be due to the use of large amount of lipiodol as an embolic agent. To our knowledge, massive tumoral pulmonary embolism following TACE and confirmed by surgery has not been described in the literature. In this report, we detail the cas of a 49-year-old man in whom cyanosis and hypotension developed abruptly on the day of TACE.. Chest CT revealed diffuse low-attenuated lesions in both pulmonary arteries. Histopathological specimens after emergent pulmonary arterial embolectomy confirmed the presence of massive tumor emboli of hepatocellular carcinoma.

2002-12-01

281

Computerized tomography of adrenal glands in the investigation of Cushing's syn  

International Nuclear Information System (INIS)

Computerized tomography of the adrenal glands was performed in 10 patients with Cushing's syndrome using a G.E. 8800 CT/T Body Scanner. The tomographic findings of unilateral adrenal masses in 4 patients were confirmed by surgery. In the remaining 6 patients, computerized tomography did not identify any masses, and both glands were well visualized and showed normal shape. In these patients, measurement of the adrenal glands revealed both normal (n=1) and enlarged glands (n=5). The findings of adrenalectomy (n=4) or transphenoidal surgery and follow-up (n=2) established the diagnosis of adrenal phyperplasia in all patients. (Author).

282

Laparoscopic approach of a nonparasitic splenic cyst; Abordagem videolaparoscopica de cisto esplenico nao parasitario  

Energy Technology Data Exchange (ETDEWEB)

A rare case of primary splenic cyst is shown in a young woman who had a left subcostal abdominal pain. Abdominal echography and CT scan revealed a cyst of the anterior aspect of the spleen. A sorologic test for hidatic disease was negative. On the basis of a presumed diagnostic of nonparasitic cyst, the patient was referred to a laparoscopic decapsulation with excision of the cysts wall not covered by splenic tissue. The patient was discharged 24 hours later. Histological report revealed epidermoid cyst. The laparoscopic approach has being recently considered an effective and less invasive alternative in the treatment of splenic diseases. We demonstrated that it should be considered for the treatment of splenic cysts present in a superficial location, with the advantage of organ preservation. (author)

2000-10-01

283

CT findings of intrahepatic cholangiocarcinoma associated with hepatolithiasis  

International Nuclear Information System (INIS)

To assess the CT findings of intrahepatic cholangiocarcinoma associated with hepatolithiasis. The CT features of 26 patients with cholangiocarcinoma and hepatolithiasis were reviewed and compared with those of 23 patients with intrahepatic stones alone, acting as control subjects. CT findings were analyzed for tumor appearance and adjacency to hepatolithiasis. We studied clinical findings, noting the presence or absence of wall thickening or soft tissue attenuation within the bile duct, the luminal diameter of dilated bile duct, and the presence of periductal enhancement, and compared these with the findings for control groups. CT images of the tumor revealed a hepatic low-attenuating mass with peripheral rim enhancement(n = 14,54 %), or periductal thickening, or low-attenuating lesions in segmental dilatation of intrahepataic bile ducts(n = 12, 46 %). Most hepatic tumors were seen ...

1999-09-01

284

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

285

Monitoring of DNA and cytogenetic damage in lymphocytes from persons with skin cancer diseases  

International Nuclear Information System (INIS)

There is a lot of interest in the studies that would help to understand whether there is a casual association between cancer and various types of molecular or cytogenetic damage detected in human cells. One major oncogenesis process is activation of proto-oncogenes by point mutations or chromosomal translocation. There are substantial evidence that indicates that the loss of heterozygosity of certain chromosomes is involved in human cancerogenesis. Our study aimed to elicit the possible association between cancer and DNA and cytogenetic abnormalities induced in lymphocytes of people bearing various categories of skin cancer cells. Fresh blood was collected by venipuncture from 25 individuals (including nine prior to cancer treatment). All patients were nonsmoking males, however 42.3 % of them were former smokers. Blood samples were divided into two parts and in the first part of samples cytogenetic studies were performed immediately, while from the second part lymphocytes were isolated ...

2004-11-01

286

Influence of the micro-addition of Mo on glass forming ability and corrosion resistance of Cu-based bulk metallic glasses  

International Nuclear Information System (INIS)

(Cu_4_7Zr_1_1Ti_3_4Ni_8)_1_0_0_-_xMo _x bulk metallic glasses (BMGs) with x = 0, 1 and 2 at.% and a bulk metallic glass matrix composite with x = 5 at.% were successfully prepared by water-cooled copper mold casting. The effect of the addition of a small amount of Mo on the glass forming ability (GFA), thermal properties of the base alloy (i.e. x = 0) were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and differential thermal analyzer (DTA). It is found that the addition of appropriate amount of Mo can enhance the GFA of the Cu-based BMG, as indicated by the increase in the reduced glass transition temperature T _r_g (=T _g/T _l) and the parameter #gamma# (=T _x/(T _g + T _l)) with the increase of Mo. On the other hand, the corrosion resistance of the Cu-based BMGs with different Mo contents was examined by electrochemical polarization and weight loss measurement in 1 mol/L H_2SO_4 and 1 mol/L NaOH solutions, respectively. It is ...

2006-05-05

287

Development of SiC-AlN and SiC-SiAlON refractory composites  

International Nuclear Information System (INIS)

SiC-AlN and SiC-SiAlON refractory composites were obtained by means of nitridation of the mixtures of silicon carbide (SiC) powder with a broad granulometric distribution and powders of aluminium (Al) and aluminium-silicon (Al-Si) mixtures. The mixtures of the composition Al-25% Si, Al-50% Si and Al-75% Si were previously prepared by means of 'mechanical alloying' technique. Thermodynamic analysis was accomplished in order to evaluate the viability of SiC-SiAlON and SiC-AlN refractories production by the chosen processing method, and the results confirmed viability of such. Investigation of nitridation of Al and Al-Si powder compacts in order to obtain the AlN and #beta#-SiAlON matrix phases of the composite was accomplished by means of differential thermal analysis (DTA) and thermogravimetric analysis (TG). The results of the thermal analysis show that nitridation of the Al-25% Si, Al-50% Si and Al-75% Si resulting in p-SiAlON formation occur at temperatures of 910 deg C, 811 deg C ...

288

The Primary Patency and Fracture Rates of Self-Expandable Nitinol Stents Placed in the Popliteal Arteries, Especially in the P2 and P3 Segments, in Korean Patients  

Energy Technology Data Exchange (ETDEWEB)

We wanted to evaluate the status of self-expandable nitinol stents implanted in the P2 and P3 segments of the popliteal artery in Korean patients. We retrospectively analyzed 189 consecutive patients who underwent endovascular treatment for steno occlusive lesions in the femoropopliteal artery from July 2003 to March 2009, and 18 patients who underwent stent placement in popliteal arterial P2 and P3 segments were finally enrolled. Lesion patency was evaluated by ultrasound or CT angiography, and stent fracture was assessed by plain X-rays at 1, 3, 6 and 12 months and annually thereafter. At the 1-month follow-up, stent fracture (Type 2) was seen in one limb (up to P3, 1 of 18, 6%) and it was identified in seven limbs at the 3-month follow-up (Type 2, Type 3, Type 4) (n = 1: up to P2: n = 6: P3). At the 6-month follow-up, one more fracture (Type 1) (up to P3) was noted. At the 1-year follow-up, there were no additional stent fractures. Just four ...

2011-04-15

289

Magnetic and thermal properties of cubic single-crystal PrCu_4Ag  

International Nuclear Information System (INIS)

We succeeded in synthesizing a new cubic intermetallic compound PrCu_4Ag in a fcc structure. Measurements of X-ray diffraction, magnetic susceptibility, magnetization, specific heat, electrical resistivity, thermal expansion, and elastic constants have been performed on single crystals of PrCu_4Ag. A maximum value of #chi#(T) with a corresponding peak in C(T) suggests that an antiferromagnetic phase transition occurs at T_N=2.4 K, where a sudden decrease in #rho#_4_f(T) and a sharp peak in the thermal expansion coefficient #alpha#(T) were observed. Characteristic Curie-type softening was observed in the temperature dependence of the transverse mode for (C_1_1 - C_1_2)/2 and C_4_4 from 70 K down to T_N, which implies that the crystalline electric field (CEF) ground state is the magnetic triplet #GAMMA#_5. The anisotropic properties in M(T,H) and C(T,H) are studied when the external magnetic field is applied in the <100>, <110>, and ...

2010-11-01

290

Diagnosis of occipital condyle fractures; Diagnostik von Frakturen der Okzipitalkondylen  

Energy Technology Data Exchange (ETDEWEB)

Following the conventional X-ray diagnosis of the skull and upper cervical spine, CT proved to be the primary diagnostic method after a skull and brain injury: For all 4 cases we succeeded in detecting the occipital condyle fracture and in determing its size and location by reconstructions (coronal, sagittal, 3-D). In the case of complex occompanying injuries like soft tissue hematomas (cerebral, in the spinal cord, and the soft tissue of the neck) or for the detection of brain stem contusion, MRT had significant advantages. MRT can offer a higher image quality in soft tissue, especially in the spinal cord and the brain. (orig.) [Deutsch] Im Anschluss an die konventionelle Roentgendiagnostik des Schaedels und der Halswirbelsaeule, erwies sich die Computertomographie als primaer einzusetzendes diagnostisches Verfahren, nach erlittenem Schaedel-Hirn-Trauma. In allen Faellen gelang der exakte Frakturnachweis an den Okzipitalkondylen, die ...

1995-01-01

291

Feature-based rectal contour propagation from planning CT to cone beam CT  

UK PubMed Central (United Kingdom)

The purpose of this work is to develop a novel feature-based registration strategy to automatically map the rectal contours from planning computed tomography (CT) (pCT) to cone beam CT (CBCT). The rectal...Full Text Available

2008-10-01

292

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 X-ray imaging provides nondestructive information about the entire width ...

1993-08-01

293

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

294

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

295

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.

296

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

297

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

298

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

299

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).

300

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

301

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

302

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

303

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.).

304

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

305

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

306

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.

307

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

308

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

309

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

310

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

311

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

312

Investigation of the hydrogen desorption properties of Mg + 10 wt.%X (X V, Y, Zr) submicrocrystalline composites  

International Nuclear Information System (INIS)

The effects of catalytic metal additives on the hydrogen desorption properties of the submicrocrystalline magnesium hydride (#beta#-MgH_2) formed after hydrogenation of the Mg + 10 wt.%X (X = V, Y, Zr) mechanically (ball) milled composites were studied. The composites with catalytic metals were processed by controlled mechanical milling (CMM) in the magneto-mill Uni Ball Mill 5 under protective Ar atmosphere. X-ray diffraction of the milled powders revealed the formation of Mg nanograins (50-60 nm range) interdispersed with the nanograined metal additives within the powder particles. Scanning electron microscopy showed particle size reduction after milling. After activation and hydrogenation in a Sieverts-type apparatus under about 2 MPa pressure of hydrogen, the tetragonal #beta#-MgH_2 hydride co-exists with the small amount of retained unreacted Mg phase and the small amount of MgO in all three composites. The #beta#-MgH_2 phase after ...

2006-04-13

313

Intrinsic magnetism in Fe doped SnO2 nanoparticles  

International Nuclear Information System (INIS)

Iron doped semiconducting nanoparticles Sn1-xFexO2 with x=0, 0.001, 0.002, 0.003, 0.004, 0.01 and 0.03 were prepared by a sol-gel method. The X-ray diffraction, Transmission Electron Microscopy measurements confirm the rutile structure with no impurity phase. The three characteristic lines of electron spin resonance (ESR) are observed in the doped samples for all compositions, which is a clear evidence for rhombic Fe3+ in rutile phase. The line width of ESR increases with increase in Fe concentration due to induced disorder. The spin-pumping effect is observed at temperatures below 250 K for the samples with x=0.01 and 0.03. However, based on the Curie-Weiss susceptibility, iron is in paramagnetic state and is subject to weak antiferromagnetic interaction. Blue shift in the optical band gap is observed with increase in the Fe content. -- Graphical abstract: The ESR spectra reveal that the nature of Fe in Sn1-xFexO2 samples is isolated rhombic ...

2011-01-01

314

Effect of Ho{sup 3+} substitutions on the structural and magnetic properties of BaFe{sub 12}O{sub 19} hexaferrites  

Energy Technology Data Exchange (ETDEWEB)

Holmium doped barium based hexaferrites BaFe{sub 12-2x}Ho{sub 2x}O{sub 19} with (x = 0.0-1.0) were synthesized by solid state reaction method. Structural and magnetic characterization of these ferrites provide significant information about their reactive physical properties. X-ray analysis reveals that in all samples M-type structure exist with few secondary phases. Scanning electron microscope revealed the grain size of the specimen. The results show that grain size decreases with the substitution degree of Holmium. Thus rare earth element Holmium Ho{sup 3+} acts as a grain growth inhibitor. The magnetic hysteresis loops show the variation in the values of magnetic parameters like saturation magnetization (M{sub s}), remanent magnetization (M{sub r}) and coercivity (H{sub c}) were observed by changing Ho{sup 3+} content in BaFe{sub 12-2x}Ho{sub 2x}O{sub 19} ferrites. Coercivity showed a maximum value of 2230 Oe for (x = ...

2010-04-09

315

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

316

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 ...

317

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

319

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

320

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

321

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

323

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

324

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

325

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

326

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

327

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

330

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

331

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

332

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

333

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

334

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. ...

335

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

336

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

337

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

338

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 ...

339

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

340

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

341

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

342

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

343

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

344

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

345

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

346

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 ...

347

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

350

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

351

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

352

Quantitative CT assessment of proximal femoral bone density. An experimental study concerning its correlation to breaking load for femoral neck fractures  

International Nuclear Information System (INIS)

Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm"3 volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater ...

353

Impact of genetic polymorphisms in ABCB1, CYP2B6, OPRM1, ANKK1 and DRD2 genes on methadone therapy in Han Chinese patients  

British Library Electronic Table of Contents (United Kingdom)

Aims: The present study explored the integrative effect of genes encoding methadone pharmacokinetic and pharmacodynamic pathways on methadone maintenance doses in Han Chinese Patients. Materials & methods: Genomic DNA was extracted from 321 opioid-dependent patients and 202 healthy controls, and realtime-PCR and PCR-RFLP were conducted to determine the genotypes. Results: Pair-wise comparisons revealed that carriers of the variants ABCB1 3435C>T or CYP2B6 516G>T alleles were more likely to require a higher methadone dose than noncarriers (both p G or 939C>T allele had a two-fold chance of requiring a lower methadone dose than noncarriers (p = 0.001). Proportional odds regression with adjustment of cofactors demonstrated that ...

2011-01-01

354

Imaging techniques for the injured ankle joint and tarsal bones  

International Nuclear Information System (INIS)

In the case of injuries of the ankle joint, an imaging technique is expected to reveal the state of the bones, ligaments, and articular cartilage. Irrespective of novel imaging techniques, a plain radiography will be made in order to obtain a first picture of the injury. Examples are given, showing that further orientation along the Lauge-Hansen classification scheme of this type of injury helps to completely ascertain the damage to the Articulatio talocruralis. Further examinations applying specific methods such as arthrography will detect possible, isolated syndesmosis ruptures; lesions of the ligaments can also be directly detected by CT or MRT. The articular cartilage and its lesions can be visualized by a combination of CT and arthrography, but are better shown by the completely non-invasive MRT. This latter method also gives insight into pathological processes with the bone. It allows to detect necrotic bone regions ...

355

Clinical evaluation of life size image of Fuji computed radiography for detection of diffuse interstitial lung diseases  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the diagnostic accuracy of Fuji computed radiography (FCR) in the detection of interstitial pulmonary infiltrates, FCR life-size images at a pixel size of 0.1 mm were compared with conventional radiographs taken on the same day. Seventeen radiologists assessed the radiographs and FCR images of 56 cases, including 39 cases of various interstitial lung diseases such as interstitial pneumonia, pulmonary abnormalities associated with collagen disease, sarcoidosis, multiple pulmonary metastases, diffuse panbronchiolitis and pulmonary emphysema, and 17 normal controls. All of the pulmonary abnormalities were confirmed by high resolution CT. Observer performance tests were carried out using receiver operating characteristic analysis. In 21 cases of increased pulmonary density revealed by high resolution CT, FCR was significantly superior to conventional radiographs in the detection of reticular or linear shadows. In 11 ...

1991-11-01

356

Clinical evaluation of life size image of Fuji computed radiography for detection of diffuse interstitial lung diseases  

International Nuclear Information System (INIS)

To evaluate the diagnostic accuracy of Fuji computed radiography (FCR) in the detection of interstitial pulmonary infiltrates, FCR life-size images at a pixel size of 0.1 mm were compared with conventional radiographs taken on the same day. Seventeen radiologists assessed the radiographs and FCR images of 56 cases, including 39 cases of various interstitial lung diseases such as interstitial pneumonia, pulmonary abnormalities associated with collagen disease, sarcoidosis, multiple pulmonary metastases, diffuse panbronchiolitis and pulmonary emphysema, and 17 normal controls. All of the pulmonary abnormalities were confirmed by high resolution CT. Observer performance tests were carried out using receiver operating characteristic analysis. In 21 cases of increased pulmonary density revealed by high resolution CT, FCR was significantly superior to conventional radiographs in the detection of reticular or linear shadows. In 11 ...

1991-01-01

357

Z-dependence of photon induced L_#alpha#/L_l X-ray intensity ratio in some elements 73 #<=# Z #<=# 92  

International Nuclear Information System (INIS)

L_#alpha#/L_l X-ray intensity ratios have been measured in elements Ta, W, Au, Hg, Tl, Pb, Bi, Th and U using L-shell photoionization by 60 keV photons. The present results are found to agree with the calculated values of Scofield within experimental uncertainties. (author).

1983-11-21

358

XRF and PIXE method as trols for the element analysis of metallic glasses  

International Nuclear Information System (INIS)

The radionuclide X-ray fluorescence and particle induced X-ray emission methods were used for rapid and nondestructive analysis of metallic glasses. The methods were compared for accuracy and precision with the atomic absorption method. Some results of the analyses of Fe_xNi_8_0_-_xB_2_0 materials are briefly reviewed. The distribution of elements along the width as well as the length and a qualitative analysis of the composition of material surfaces are considered. (author).

1986-01-01

359

XRF and PIXE analysis of metallic glasses  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence and particle induced X-ray emission methods were used for a rapid and nondestructive analysis of metallic glasses. The methods are compared in accuracy and precision with the atomic absorption method. Some results of analyses of Fe_xNi_8_0_-_xB_2_0 materials are briefly reviewed. The distribution of elements along the width and length, and a qualitative analysis of the composition of material surfaces are considered. (author) 3 refs.

1987-05-01

360

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.

361

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.

362

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

363

X-RAY MICROANALYSIS OF A RADIOACTIVE PARTICLE WITH THE AID OF THE ELECTRON MICROSCOPE  

Science.gov (United States)

A radioactive particle was analyzed to discover the composition of the inactive material of the particle. The method uses the x-ray line spectrum of the K series caused by electron irradiation of the particle in the electron microscope. Iron and aluminum or silicon (the last two could not be distinguished) were found as inactive components in the particle. (D.L.C.)

1962-07-28

364

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

365

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

366

Soft X-ray spectra of amorphous hydrogenated silicon  

Energy Technology Data Exchange (ETDEWEB)

The Si-L X-ray emission spectrum of amorphous hydrogenated silicon (a-Si:H) is presented and discussed. For a qualitative interpretation of the measured spectra cluster calculations of pure Si clusters (SiSi4) and Si clusters with hydrogen (SiSi3H) have been performed using a simplified LCAO-X scheme. In general the level shifts caused by introduction of hydrogen are small compared with the valence band width.

1985-06-01

367

Radionuclide X-ray fluorescence determination of Mn, Fe, Cu, Zn and Pb in wastewaters and sludges from wastewater treatment plants in Bratislava (SR)  

International Nuclear Information System (INIS)

Radiometric X-ray fluorescence analysis was used for the determination of Mn, Fe, Cu, Zn and Pb in wastewater and sludges from three wastewater treatment plants in Bratislava (SR). Metals were determined in wastewaters after preconcentration by 8-hydroxyquinoline and in sludges by drying and pressing to pellets. "2"3"8Pu and "1"0"9Cd was used for excitation of fluorescence radiation. (author).

1997-01-01

368

Radionuclide X-ray fluorescence determination of Cr, Fe, Cu, Zn,and Pb in industrial wastewaters after preconcentration of determined elements  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of Cr, Fe, Cu, Zn and Ph in industrial wastewaters (from surface treatment of metals and glasses) after precipitation of determined elements by 8-hydroxyquinoline. (author).

1997-01-01

369

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

370

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

371

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 ...

372

K_#beta#/K_#alpha# X-Ray Intensity Ratio Studies on the Valence Electronic States of 3d-Transition Metals in some of their Compounds  

International Nuclear Information System (INIS)

Our studies on K#beta#/K#alpha# X-ray intensity ratios of some of the technologically important 3d-transition metal compounds have been reviewed. Comparison of the experimental results with single-configuration Dirac-Fock calculations provided important information on the valence states of the transition metals in various compounds, which can be helpful in understanding the nature of bonding in the compounds. (author)

2000-02-01

373

Is the Ksub(#beta#)/Ksub(#alpha#) X-ray intensity ratio dependent upon the energy of an inducing proton  

International Nuclear Information System (INIS)

Ksub(#beta#)/Ksub(#alpha#) X-ray intensity ratios have been measured for various elements between Z = 29 and Z = 79 for incident proton energies of 23.6, 32.1 and 43.6 MeV. The results yield no evidence for a variation in ratio with particle energy. (orig.).

1980-01-01

374

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

375

Heavy metals in industrial wastewater determined by radionuclide x-ray fluorescence analysis and their effects on Allium cepa root tip cells  

International Nuclear Information System (INIS)

Radionuclide x-ray fluorescence method was used in the determination of Cr, Ni and other heavy metals content in wastewater of an engineering plant taken both before and after chemical treatment. Toxic effects of the wastewaters using Allium cepa root tip cells were tested. (author) 8 refs.; 2 tabs.

1994-05-01

376

Heavy metals and some other elements in medicinal plants. Determined by X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Determination of Mn, Fe, Cu, Zn, Hg, Pb, Br, Se, Rb, Sr and Cd in the medicinal plants by radionuclide X-ray fluorescence analysis (using "2"3"8Pu, "2"4"1Am/Ag and "1"2"5I) is described. (author). 12 refs., 2 tabs.

1995-01-01

377

Heavy element contamination of surface waters in the region Banska Stiavnica (SR) measured by radionuclide X/ray fluorescence analysis  

International Nuclear Information System (INIS)

Heavy metals (Pb, Cd, Mn, Cu, Zn, Fe) were determined in surface waters in the surroundings of the depositories of the mining shrubs in the region of Banska Stiavnica (SR) by radionuclide X-ray fluorescence analysis. Allowed concentrations of the determined metals are exceeded numerously (multiplicity in some cases was 10"3-10"6). (author).

1997-01-01

378

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

379

Evaluation of adhesive plasters by radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

A radiometric method was elaborated for surface density determinations of the adhesive layer of plasters by radionuclide X-ray fluorescence using the 17.47 keV bremsstrahlung of "1"4"7Pm/Mo. The bremsstrahlung line excites the 8.63 keV characteristic K#alpha# line of Zn contained in the adhesive layer of the plaster as a filling material in the form of ZnO. In homogeneous adhesive layers the Zn content is proportional to surface density. (author).

1976-01-01

380

Determination of cesium and selenium in cultivated mushrooms using radionuclide X-ray fluorescence technique  

International Nuclear Information System (INIS)

Cesium and selenium intake of cultivated mushrooms (Agaricus bisporus), with these elements previously added to culture medium, has been examined from the viewpoint of health- and environmental protection. The process of measuring has been carried out by the radionuclide X-ray fluorescence technique. Treatments of the elementary substance with Se salt appears to influence the Se content of the mushrooms to a significant extent. Cs intake is of considerable importance, as this element is accumulated by mushrooms. (author)

2000-09-01

381

Determination of Y, Ba and Cu in superconductor films by x-ray fluorescence analysis  

International Nuclear Information System (INIS)

Radionuclide x-ray fluorescence analysis was used for the determination of Y, Ba and Cu in thin high-temperature superconducting films. Atomic emission ICP spectrometry was used to estimate the precision and accuracy of analytical results. Reasonable agreement between both methods was obtained when a polynomial calibration curve was applied. (author) 4 refs.; 4 tabs.

1994-06-01

382

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

383

Determination of Fe and Zn in healing plants by radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method was used for the determination of Fe and Zn in healing plants (Sage, Peppermint, Stinging, Common Agrimony, Milfoil, Ribwort, Tansy, White Dead-Nettle). "2"3"8Pu exciting source and Si/Li semiconductor detector were used for the determination. (author)

1999-06-01

384

Determination of Fe and Zn in agricultural plants with special cultivation by radionuclide x-ray fluorescence analysis  

International Nuclear Information System (INIS)

Fe and Zn were determined in various parts of maize (Zea mays) in dependence on quantity of organic substrate EKOFERT as organic fertilizer in soil, using radionuclide X-ray fluorescence analysis. The increase of quantity of organic substrate EKOFERT in soil causes a decrease of heavy metal concentrations in certain parts of the plant. (author). 4 refs., 1 tab.

1996-01-01

385

Determination of Cu, Ni, Zn and Pb contents in taraxacum officinale near the highway D-61 Bratislava-Trnava (SR) by radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with Si/Li semiconductor detector and "2"3"8Pu exciting source was used for the determination of Cu, Ni, Zn and Pb in plant samples (Taraxacum officinale) from various localities near the highway D-61 Bratislava-Trnava (SR). (author) 2 refs.; 1 fig.; 1 tab.

1993-12-01

386

Determination of Cu, Ni, Zn and Pb contents in soil near the D-61 Bratislava-Trnava Highway by radionuclide X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with Si/Li semiconductor detector and "2"3"8Pu exciting source was used for the determination of Cu, Ni, Pb, and Zn in soil samples from various localities near the D-61 Bratislava-Trnava highway (CSFR). (author) 1 ref.; 1 tab.

1993-01-01

387

Comments on possible preferential order-disorder in A-15 compounds based upon Nb  

International Nuclear Information System (INIS)

The possible existence of preferential B-site disorder in A-15 compounds recently claimed on the basis of x-ray powder diffraction data but questioned from the viewpoint of known phase diagrams is examined for some Nb-based compounds of this type. It is concluded that x-ray powder data do not allow the determination of both order and compositional variables as suggested, and the latter must therefore be determined by some other method. (author).

388

Chemical sensitivity of the Ksub(. beta. )/Ksub(. cap alpha. ) x-ray intensity ratio for 3d elements  

Energy Technology Data Exchange (ETDEWEB)

Chemical influences on the relative Ksub(..beta..)/Ksub(..cap alpha..) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarizational effects are of importance.

1982-12-28

389

Chemical sensitivity of the Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio for 3d elements  

International Nuclear Information System (INIS)

Chemical influences on the relative Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarisational effects are of importance. (author).

1982-12-01

390

Chemical effects on L_#gamma#_1/L_#beta#_1 x-ray intensity ratio of molybdenum compounds  

International Nuclear Information System (INIS)

Chemical effects on the intensity ratio of LX-ray of molybdenum compounds irradiated by 11-keV electrons and by 3-MeV protons were studied using an x-ray crystal spectrometer. It was found that the intensity ratios of L_#gamma#_1/L_#beta#_1 markedly decrease with the increase of ionicity of molybdenum compounds, except for the case of metallic molybdenum. (author).

1987-06-01

391

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

392

Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies  

Energy Technology Data Exchange (ETDEWEB)

3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.

2010-09-15

393

Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies  

International Nuclear Information System (INIS)

3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.

2010-09-01

394

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

395

Analysis of high-temperature superconducting films by x-ray fluorescence analysis  

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of Cu, Y and Ba in very thin high-temperature superconducting films. The precision of the method is better than 3% for about 1 #mu#m thick films. The atomic emission ICP spectrometry was used to testify results of XRF analysis. An acceptable agreement of both methods was obtained. (author) 4 refs.; 2 tabs.

1991-09-01

396

A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis.  

Science.gov (United States)

We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +/- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +/- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among ...

1986-01-01

397

A radiant temperature numerical method for laser-plasma diagnostic using SXRSC with absorption method  

International Nuclear Information System (INIS)

An numerical method was developed for measuring radiant temperature using a set of absorption-foils coupled to soft x ray streak camera, SXRSC, in laser plasma experiments. An numerical code, SCC, was given. An x-ray intensity ratio vs temperature was calculated for Parylene, C_3H_6, Mylar and Aluminium. A suitable range of the measuring temperature was discussed to some absorber.

1990-01-01

398

7. Overview of radionuclide X-ray fluorescence analysis of components of the environment  

International Nuclear Information System (INIS)

A survey is presented of studies dealing with radionuclide X-ray fluorescence analysis (RXFA) of impurities in the air, water, soil, sediments and biological materials, mainly blood, urine, hair, soft tissues and bones. Tabulated are lists of published works on RXFA of the air, water and biological materials. (ES).

1983-12-01

399

X-ray, Optical, and Radio Observations of SN 1999em and SN 1998S  

CERN Document Server

Observations of the Type II-P (plateau) Supernova (SN) 1999em and Type IIn (narrow emission line) SN 1998S have enabled estimation of the profile of the SN ejecta, the structure of the circumstellar medium (CSM) established by the pre-SN stellar wind, and the nature of the shock interaction. SN 1999em is the first and only Type II-P detected at both X-ray and radio wavelengths. It is the least radio luminous and one of the least X-ray luminous SN ever detected (except for the unusual and very close SN 1987A). The Chandra X-ray data indicate non-radiative interaction of SN ejecta with a power-law density profile (rho \\propto r^{-n} with n ~ 7) with a pre-SN wind with a low mass loss rate of ~2 \\times 10^{-6} Msun/yr for a wind velocity of 10 km/sec, in close agreement with radio mass-loss rate estimates. The Chandra data show an unexpected, temporary rise in the 0.4--2.0 keV X-ray flux at ~100 days ...

2001-01-01

400

X-ray scattering signatures of {beta}-thalassemia  

Energy Technology Data Exchange (ETDEWEB)

X-ray scattering from lyophilized proteins or protein-rich samples is characterized by the presence of two characteristic broad peaks at scattering angles equivalent to momentum transfer values of 0.27 and 0.6 nm{sup -1}, respectively. These peaks arise from the interference of coherently scattered photons. Once the conformation of a protein is changed, these two peaks reflect such change with considerable sensitivity. The present work examines the possibility of characterizing the most common cause of hemolytic anaemia in Egypt and many Mediterranean countries; {beta}-thalassemia, from its X-ray scattering profile. This disease emerges from a genetic defect causing reduced rate in the synthesis of one of the globin chains that make up hemoglobin. As a result, structurally abnormal hemoglobin molecules are formed. In order to detect such molecular disorder, hemoglobin samples of {beta}-thalassemia patients are collected, lyophilized and ...

2009-08-11

401

X-ray and HeI 1.0830 mu emission from protostellar jets  

CERN Document Server

Context. The high energies of protostellar jets, implied by recent observations of X-rays from such flows, came very much as a surprise. Inferred shock velocities are considerably higher than what was previously known, hence putting even larger energy demands on the driving sources of the jets. The statistics of X-ray emitting jets are still poor, yet a few cases exist which seem to imply a correlation between the presence of HeI 1.0830 mu emission and X-ray radiation in a given source. Aims. This tentative correlation needs confirmation and explanation. If the jet regions of HeI 1.0830 mu emission are closely associated with those producing X-rays, high resolution infared spectroscopy can be used to observationally study the velocity fields in the hot plasma regions of the jets. This would provide the necessary evidence to test and further develop theoretical models of intermediately fast (> 500 - ...

2006-01-01

402

The intriguing nature of the high energy gamma ray source XSSJ12270-4859  

CERN Document Server

The nature of the hard X-ray source XSSJ12270-4859 is still unclear though it was claimed to be a magnetic Cataclysmic Variable. We here present a broad-band X-ray and gamma ray study based on a recent XMM-Newton observation and archival INTEGRAL and RXTE data. From the Fermi/LAT 1-year point source catalogue, we tentatively associate XSSJ12270-4859 with 1FGLJ1227.9-4852, a source of high energy gamma rays with emission up to 10GeV. We complement the study with UV photometry from XMM-Newton and ground-based optical and near-IR photometry. The X-ray emission is highly variable showing flares and intensity dips. The X-ray flares consist of flare-dip pairs. Flares are also detected in the UV range but not the dips. Aperiodic dipping behaviour is also observed during X-ray quiescence but not in the UV. The 0.2-100keV spectrum is featureless and described by a power law model with ...

2010-01-01

403

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 distribution. This affects the ...

2005-01-01

404

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. X-ray spectra in an ...

2008-02-01

405

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 epidermoid carcinoma, ...

1981-11-01

406

Measurement of reactor tube cladding thickness by x-ray fluorescence spectrometry  

International Nuclear Information System (INIS)

An x-ray fluorescence spectrometer was designed and fabricated which nondestructively determines the thickness of aluminum cladding at small suspected thin spots in the inner or outer surface of actinide reactor tubes. The analysis method is based on the difference in absorption of actinide L/sub #alpha#/ and L/sub #beta#/ fluorescent x-rays in passing through the cladding. Calibration plots of the logarithm of the L/sub #beta#//L/sub #alpha#/ x-ray intensity ratio versus cladding thickness are linear to at least 40 mils for U-Al, U_3O_8-Al, and PuO_2-Al substrates. Accuracy and precision of the experimentally determined cladding thickness and evaluated for both uranium and plutonium substrates. Experimental thickness data are reported for 618 quality assurance analyses on six Mark 41 PuO_2-Al target tubes. An x-ray fluorescence cladding thickness monitor operated with a computer-controlled fluoroscope ...

1978-01-01

407

He-like ions as practical astrophysical plasma diagnostics: From stellar coronae to active galactic nuclei  

CERN Document Server

We review X-ray plasma diagnostics based on the line ratios of He-like ions. Triplet/singlet line intensities can be used to determine electronic temperature and density, and were first developed for the study of the solar corona. Since the launches of the X-ray satellites Chandra and XMM-Newton, these diagnostics have been extended and used (from CV to Si XIII) for a wide variety of astrophysical plasmas such as stellar coronae, supernova remnants, solar system objects, active galactic nuclei, and X-ray binaries. Moreover, the intensities of He-like ions can be used to determine the ionization process(es) at work, as well as the distance between the X-ray plasma and the UV emission source for example in hot stars. In the near future thanks to the next generation of X-ray satellites (e.g., Astro-H and IXO), higher-Z He-like lines (e.g., iron) will be resolved, allowing plasmas with ...

2011-01-01

408

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 reduction through ...

2004-01-01

409

Dose, exposure time, and resolution in Serial X-ray Crystallography  

CERN Document Server

The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. We evaluate the incident X-ray fluence (energy/area) required to obtain a given resolution from (1) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (2) explicit simulation of diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency cut off of the transfer function following iterative solution of the phase problem, ...

2007-01-01

410

Direct chemical information from special radiotracers as well as from outer X-ray excitation  

Energy Technology Data Exchange (ETDEWEB)

Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub ..cap alpha..//K/sub ..beta../ X-ray intensity ratio was found to ...

1983-09-01

411

Direct chemical information from special radiotracers as well as from outer X-ray excitation  

International Nuclear Information System (INIS)

Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub #alpha#//K/sub #betta#/ X-ray intensity ratio was found to be an ...

1982-10-01

412

Bendable Focusing X-Ray Optics for the ALS and the LCLS/FEL: Design, Metrology, and Performance  

Energy Technology Data Exchange (ETDEWEB)

We review the recent development of bendable x-ray optics used for focusing of beams of soft and hard x-rays at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory and at the Linac Coherent Light Source (LCLS) x-ray free electron laser (FEL) at the Stanford Linear Accelerator Center (SLAC) National Accelerator Laboratory. For simultaneous focusing in the tangential and sagittal directions, two elliptically cylindrical reflecting elements, a Kirkpatrick-Baez (KB) pair, are used. Because fabrication of elliptical surfaces is complicated, the cost of directly fabricated tangential elliptical cylinders is often prohibitive. Moreover, such optics cannot be easily readjusted for use in multiple, different experimental arrangements, e.g. at different focal distances. This is in contrast to flat optics that are simpler to manufacture and easier to measure by conventional interferometry. The tangential figure of ...

2010-06-02

413

Accretion Properties of A Sample of Hard X-ray (<60keV) Selected Seyfert 1 Galaxies  

CERN Document Server

We examine the accretion properties in a sample of 42 hard (3-60keV) X-ray selected nearby broad-line AGNs. The energy range in the sample is harder than that usually used in the similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey (XSS), and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad H$\\beta$ emission line. The tight correlation between the hard X-ray (3-20keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the H$\\beta$ emission line. In addition, all these hard X-ray AGNs are biased toward luminous objects with high Eddington ratio (mostly between 0.01 to 0.1) and low column density ($<10^{22} \\mathrm{cm^{-2}}$), which is most likely due to the selection effect of ...

2008-01-01

414

A radionuclide analyzer of total sulfur in coal  

International Nuclear Information System (INIS)

The devised radionuclide analyzer for the determination of total sulfur in coal includes two radionuclide sources with different energies, which are accommodated in collimators fitted with adjustable diaphramgs. The sample compartment is located between the two sources. Moreover, an X-ray fluorescence standard can be slid into the sample compartment. A proportional detector for X-ray fluorescence and scattered gamma radiation is located off the sample compartment. The input of the proportional detector is interfaced to the output of a high-voltage supply, the output, to the information input of a control-and-evaluation unit. One of the control outputs of the control-and-evaluation unit is connected to the input of the sliding mechanism for the X-ray fluorescence standard. This arrangement enables automatic energy calibration of the analyzer. The analyzer can measure not only total sulfur in coal by radionuclide ...

1987-05-13

415

Utility of CT in the diagnosis of psoitis  

International Nuclear Information System (INIS)

A 65-year-old woman who was diagnosed as having psoitis by CT findings, which disclosed non-symmetrical dilation of the psoas muscle and gaseous image. Pus from the psoas muscle seen at surgery corresponded to CT findings. Preoperative CT examination was useful in the establishment of diagnosis. (Namekawa, K.).

1984-01-01

417

MULTIMODALITY IMAGING: BEYOND PET/CT AND SPECT/CT  

UK PubMed Central (United Kingdom)

Multimodality imaging with PET/CT and SPECT/CT has become commonplace in clinical practice and in preclinical and basic medical research. Do other combinations of imaging modalities have a similar...Full Text Available

2009-09-01

419

Enhanced CT and CT virtual endoscopy in diagnosis of heterotopic pancreas  

UK PubMed Central (United Kingdom)

AIM: To improve the diagnosis of heterotopic pancreas by the use of contrast-enhanced computed tomography (CT) imaging and CT virtual endoscopy (CTVE).METHODS: A total of six patients with heterotopic...Full Text Available

2011-09-07

420

CT evaluation of acetabular fractures  

International Nuclear Information System (INIS)

The paper deals with sixteen cases of acetabular fractures studied with CT. After a short description of the normal CT findings, the different kind of fractures are reported. The usefulness of CT examination in evaluating acetabular fractures and their complications is confirmed both in conservative treatment and surgical approach.

1986-01-01

421

Severe paraquat poisoning: clinical and radiological findings in a survivor  

International Nuclear Information System (INIS)

Paraquat is a nonselective contact herbicide of great toxicological importance, being associated with high mortality rates, mainly due to respiratory failure. We report the case of a 22-year-old male admitted to the emergency room with a sore throat, dysphagia, hemoptysis, and retrosternal pain after the ingestion of 50 mL of a paraquat solution, four days prior to admission. Chest CT scans revealed pulmonary opacities, pneumomediastinum, pneumothorax, and subcutaneous emphysema. The patient was submitted to two cycles of immunosuppressive therapy with cyclophosphamide, methylprednisolone, and dexamethasone. The pulmonary gas exchange parameters gradually improved, and the patient was discharged four weeks later. The clinical and tomographic follow-up evaluations performed at four months after discharge showed that there had been further clinical improvement. We also present a brief review of the literature, as well as a discussion of the ...

422

Severe paraquat poisoning: clinical and radiological findings in a survivor  

Energy Technology Data Exchange (ETDEWEB)

Paraquat is a nonselective contact herbicide of great toxicological importance, being associated with high mortality rates, mainly due to respiratory failure. We report the case of a 22-year-old male admitted to the emergency room with a sore throat, dysphagia, hemoptysis, and retrosternal pain after the ingestion of 50 mL of a paraquat solution, four days prior to admission. Chest CT scans revealed pulmonary opacities, pneumomediastinum, pneumothorax, and subcutaneous emphysema. The patient was submitted to two cycles of immunosuppressive therapy with cyclophosphamide, methylprednisolone, and dexamethasone. The pulmonary gas exchange parameters gradually improved, and the patient was discharged four weeks later. The clinical and tomographic follow-up evaluations performed at four months after discharge showed that there had been further clinical improvement. We also present a brief review of the literature, as well as a discussion of the ...

2010-07-01

423

Long-term survival following radical surgery after chemotherapy for esophagogastric adenocarcinoma with extensive lymph node metastases: Report of a case  

British Library Electronic Table of Contents (United Kingdom)

A 46-year-old man was referred to us after he presented to his local physician complaining of difficulty eating. Upper gastrointestinal endoscopy revealed a tumor at the esophagogastric junction (EGJ), and moderately differentiated adenocarcinoma was diagnosed from the biopsy findings. Computed tomography (CT) showed apparent enlargement of the pretracheal lymph nodes, the lymph nodes around the bilateral recurrent laryngeal nerves, and the lower thoracic paraesophageal lymph nodes, confirming metastasis. Since the disease was far advanced esophagogastric cancer with marked lymph node metastases throughout the mediastinum, curative resection would have been unlikely. Thus, he was commenced on systemic chemotherapy with cisplatin (90 mg/body, day 8) + S-1 (120 mg/body/day, given for 3 weeks...

2011-01-01

424

Wool-waste as organic nutrient source for container-grown plants  

International Nuclear Information System (INIS)

A container experiment was conducted to test the hypothesis that uncomposted wool wastes could be used as nutrient source and growth medium constituent for container-grown plants. The treatments were: (1) rate of wool-waste application (0 or unamended control, 20, 40, 80, and 120 g of wool per 8-in. pot), (2) growth medium constituents [(2.1) wool plus perlite, (2.2) wool plus peat, and (2.3) wool plus peat plus perlite], and (3) plant species (basil and Swiss chard). A single addition of 20, 40, 80, or 120 g of wool-waste to Swiss chard (Beta vulgaris L.) and basil (Ocimum basilicum L.) in pots with growth medium provided four harvests of Swiss chard and five harvests of basil. Total basil yield from the five harvests was 1.6-5 times greater than the total yield from the unamended control, while total Swiss chard yield from the four harvests was 2-5 times greater relative to the respective unamended control. The addition of wool-waste to the growth medium increased Swiss chard and ...

2009-07-01

425

Weakly-bridged dimeric diorganotin(IV) compounds derived from pyruvic acid hydrazone Schiff base ligands: Synthesis, characterization and crystal structures  

British Library Electronic Table of Contents (United Kingdom)

We report the synthesis of four diorganotin(IV) compounds of Schiff base pyruvic acid hydrazone derivatives formulated as [R2SnLY]2, where L1 is 2-SC4H3CON2C(CH3)CO2 with Y = CH3CH2CH2CH2OH, R = n-Bu (1); L2 is C6H5CON2C(CH3)CO2 with Y = CH3CH2OH, R = p-F-Bz (2); L3 is 2-HOC6H4CON2C(CH3)CO2 with YH2O, R = p-CN-Bz (3); and L4 is 4-NO2-C6H4CON2C(CH3)CO2 with YCH3CH2OH, R = Bz (4). The structures of all compounds have been established by a combination of single-crystal X-ray diffraction analysis, 1H and 119Sn NMR spectroscopy, IR spectroscopy, and elemental analysis. Studies reveal that four ligands present the same coordination mode with tin center, which all present tridentate ONO donor Schiff bases and coordinate to the tin center in an enolic form. In compounds 1-4, each tin atom is seven...

2011-01-01

426

The mechanism of metal nanoparticle formation in plants: limits on accumulation  

Energy Technology Data Exchange (ETDEWEB)

Metal nanoparticles have many potential technological applications. Biological routes to the synthesis of these particles have been proposed including production by vascular plants, known as phytoextraction. While many studies have looked at metal uptake by plants, particularly with regard to phytoremediation and hyperaccumulation, few have distinguished between metal deposition and metal salt accumulation. This work describes the uptake of AgNO{sub 3}, Na{sub 3}Ag(S{sub 2}O{sub 3}){sub 2}, and Ag(NH{sub 3}){sub 2}NO{sub 3} solutions by hydroponically grown Brassica juncea and the quantitative measurement of the conversion of these salts to silver metal nanoparticles. Using X-ray absorption near edge spectroscopy (XANES) to determine the metal speciation within the plants, combined with atomic absorption spectroscopy (AAS) for total Ag, the quantity of reduction of Ag{sup I} to Ag{sup 0} is reported. Transmission electron microscopy (TEM) showed Ag particles of ...

2009-08-15

427

Synthesis of colloidal silver iron oxide nanoparticles--study of their optical and magnetic behavior.  

Science.gov (United States)

Silver iron oxide nanoparticles of fairly small size (average diameter approximately 1 nm) with narrow size distribution have been synthesized by the interaction of colloidal beta- Fe2O3 and silver nanoparticles. The surface morphology and size of these particles have been analyzed by using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Their structural analysis has been carried out by employing x-ray diffraction (XRD), selected-area electron diffraction (SAED), optical and infrared (IR) spectroscopic techniques. The ageing of these particles exhibits the formation of self-assembly, possibly involving weak supramolecular interactions between Ag(I)O4 and Fe(III)O4 species. These particles display the onset of absorption in the near-infrared region and have higher absorption coefficient in the visible range compared to that of its precursors. Magnetic measurements ...

2009-07-01

428

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

Science.gov (United States)

A WO(3)/TiO(2) composite, hollow-sphere photocatalyst with average diameter of 320 nm and shell thickness of 50 nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO(3)/TiO(2) hollow spheres were red-shifted compared to the TiO(2) hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO(3) and TiO(2) 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 40.95 m(2)/g and 19 nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO(3)/TiO(2) hollow spheres under visible light within 80 min. Under the same conditions, only 24% MB can be photodegraded by TiO(2). The photocatalytic mineralization of MB, catalyzed by TiO(2) and WO(3)/TiO(2), proceeded at a ...

2011-02-22

429

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

International Nuclear Information System (INIS)

A new iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2 mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P21/n (No. 14), a=6.2614(13) A, b=9.844(2) A, c=14.271(3) A, ?=92.11(1)o, V=879.0(3) A3). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO4) groups to form ten-membered-ring channels along [1 0 0]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO4)3(OH)2F2], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic exchange below TN=17 K, ...

2010-12-01

430

Solid-state NMR and XRD study of #alpha#-SiAlON powders prepared by combustion synthesis  

International Nuclear Information System (INIS)

"2"7Al and "2"9Si solid-state NMR spectra and X-ray diffraction (XRD) patterns were obtained for #alpha#-SiAlON powders prepared by combustion synthesis, according to which the phase transformation and structure evolution of #alpha#-SiAlON were studied. It was found that in #alpha#-SiAlON "2"9Si chemical shift values (-48 < #delta# _S_i < -47) were close to those in #beta#-Si_3N_4 and #alpha#-Si_3N_4, indicating that Si atoms kept SiN_4 coordination to a large extent in #alpha#-SiAlON despite the presence of O atoms. Dissimilarly, "2"7Al chemical shift values in #alpha#-SiAlON deviated clearly from that corresponding to AlN_4 coordination (#delta# _A_l #approx# 112) and occurred in a range from #delta# _A_l 95.5 to 99.9, which should be assigned to tetrahedral AlO _xN_4_-_x (0 #<=# x #<=# 4) coordination. The broadening effect of AlO _xN_4_-_x peaks was noticed, which was suggested to induced by slight dispersion of #alpha#-SiAlON compositions. "2"7Al ...

2007-07-31

431

Saddle field fast atom beam source: A new low pressure plasma nitriding method for a alloy Ti-6Al-4V  

Energy Technology Data Exchange (ETDEWEB)

Ti and its alloys (Ti-6Al-4V) have been used in different engineering applications due to their several outstanding properties. Nevertheless, their use in practical applications is limited in many cases due to their poor tribological property. Researches are ongoing on surface modification of Ti based materials by different plasma and ion based techniques to overcome this problem. However, the conventional plasma nitriding techniques have several problems such as formation of an arc, increased possibility of surface contamination due to a comparatively higher operating pressure, production of a very thin nitrided layer after a long processing time, etc. In this present work, the possibility of a new low-pressure plasma nitriding process using a Plasma Enhanced Chemical Vapor Deposition (PECVD) based saddle field fast atom beam source on a Ti-6Al-4V alloy sample is investigated. Plasma nitriding was carried out at 900 deg. C and at a pressure 0.1 Pa for 8 h by using a beam current 0.5 ...

2006-09-25

432

Saddle field fast atom beam source: A new low pressure plasma nitriding method for a alloy Ti-6Al-4V  

International Nuclear Information System (INIS)

Ti and its alloys (Ti-6Al-4V) have been used in different engineering applications due to their several outstanding properties. Nevertheless, their use in practical applications is limited in many cases due to their poor tribological property. Researches are ongoing on surface modification of Ti based materials by different plasma and ion based techniques to overcome this problem. However, the conventional plasma nitriding techniques have several problems such as formation of an arc, increased possibility of surface contamination due to a comparatively higher operating pressure, production of a very thin nitrided layer after a long processing time, etc. In this present work, the possibility of a new low-pressure plasma nitriding process using a Plasma Enhanced Chemical Vapor Deposition (PECVD) based saddle field fast atom beam source on a Ti-6Al-4V alloy sample is investigated. Plasma nitriding was carried out at 900 deg. C and at a pressure 0.1 Pa for 8 h by using a beam current 0.5 ...

2006-09-25

433

Quality control in medical radiology using T.L.D  

Energy Technology Data Exchange (ETDEWEB)

In this work tests of quality control in beams of X rays have been carried out, at diagnostic level, of two radiological services equipments of Brazilian hospitals (Aracaju, SE). We obtained the air kerma and kerma rate values, the beams efficiency, the coherence between the luminous fields and the referring fields of irradiation and half-value layer to each equipment and set of parameters. The measures of direct form have been obtained using two ionization chambers, one cylindrical and another one with parallel plates. An optional method for accomplishment some of the tests were carried out with CaSO{sub 4}:Dy + Teflon thermoluminescent dosimeters. The values of air kerma were evaluated for three tube voltage, 40, 60 and 81 kV at 1.0 m from the focus of the equipments. For each one of the voltages three distinct current values were chosen besides a fixed value of exposition time. The results showed that the values of air kerma varied between ...

2006-07-01

434

Punica granatum peel extract protects against ionizing radiation-induced enteritis and leukocyte apoptosis in rats  

International Nuclear Information System (INIS)

Radiation-induced enteritis is a well-recognized sequel of therapeutic irradiation. Therefore we examined the radioprotective properties of Punica granatum peel extract (PPE) on the oxidative damage in the ileum. Rats were exposed to a single whole-body X-ray irradiation of 800 cGy. Irradiated rats were pretreated orally with saline or PPE (50 mg/kg/day) for 10 days before irradiation and the following 10 days, while control rats received saline or PPE but no irradiation. Then plasma and ileum samples were obtained. Irradiation caused a decrease in glutathione and total antioxidant capacity, which was accompanied by increases in malondialdehyde levels, myeloperoxidase activity, collagen content of the tissue with a concomitant increase 8-hydroxy-2'-deoxyguanosine (an index of oxidative DNA damage). Similarly, pro-inflammatory cytokines (TNF-?, IL-1? and IL-6) and lactate dehydrogenase were elevated in irradiated groups as compared to control. PPE treatment reversed ...

2009-07-01

435

Properties of dust particles sampled from windboxes of an iron ore sintering plant: Surface structures of unburned carbon  

Energy Technology Data Exchange (ETDEWEB)

Aiming to understand the formation mechanism of dioxins in the iron ore sintering process, dust samples obtained from some windboxes of a commercial iron ore sintering plant have been characterized with a powder X-ray diffraction (XRD), by the transmission electron microscope (TEM) equipped with an electron energy loss spectroscopy (EELS), and by the temperature-programmed desorption (TPD) and temperature-programmed oxidation (TPO) techniques. The elemental and XRD analyses reveal that the content of the Cl present in the samples ranges from 0.075 mass%-dry to 5.1 mass%-dry and tends to be higher at smaller dust particles, and that some of the Cl exists as KCl with the average crystalline size between 40 nm and 50 nm. Dust samples also contain a significant amount of unburned carbon, and the smallest dust particles, < 500 {mu}m, show the highest C contents in many cases and consist partly of C, K, and Cl elements. The TPD and TPO ...

2006-07-01

436

Plasma treatment of the Mg:Ag/tris-(8-hydroxyquinoline) aluminum interface in OLEDs: effects on adhesion and performance  

Energy Technology Data Exchange (ETDEWEB)

The adhesion of a Mg:Ag cathode to the tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) in organic light emitting devices (OLEDs) can be greatly enhanced by a remote plasma treatment of the Alq{sub 3} layer using either air or N{sub 2} prior to metal deposition. The altered surface properties which lead to increased sticking coefficients of Mg and Ag, as well as enhanced adhesion, are attributed to the introduction of new functional groups into the organic layer, as observed by X-ray photoelectron spectroscopy (XPS). The storage life of the plasma treated devices in air without any capping treatment, as judged by a visible deterioration of the cathode, was increased by approximately five to six times compared to untreated OLEDs. Current-voltage characteristics and EL efficiency, however, were shown to deteriorate for devices incorporating either an air or an N{sub 2} plasma treated Alq{sub 3} layer. For OLEDs subjected to short treatment times with an N{sub 2} ...

2004-05-31

437

Performance improvement of pasted nickel electrodes with an addition of ball-milled nickel hydroxide powder  

Energy Technology Data Exchange (ETDEWEB)

Spherical {beta}-Ni(OH){sub 2} was modified by a low-cost method of normal ball milling (NBM), and the physical properties of both ball-milled and un-milled Ni(OH){sub 2} were characterized by transmission electron microscopy, specific surface area, particle size distribution and X-ray diffraction. It was found that NBM could obviously increase the surface area, decrease the particle and crystallite size, and reduce the crystallinity of {beta}-Ni(OH){sub 2}, which were advantageous to the improvement of the electrochemical activity of Ni(OH){sub 2}. NBM also lowered the packing density and flowability of Ni(OH){sub 2}, as revealed by the measurements of tapping density and angle of repose. Electrochemical performances of pasted nickel electrodes with an addition of ball-milled Ni(OH){sub 2} to spherical Ni(OH){sub 2} as the active material were investigated, and were compared with those of the pure spherical Ni(OH){sub 2} electrodes. ...

2006-09-15

438

Lung perfusion scintigraphy in the diagnosis of peripheral pulmonary stenosis in patients after repair of Fallot tetralogy  

International Nuclear Information System (INIS)

The frequency of peripheral pulmonary artery stenosis in patients after surgical repair of tetralogy of Fallot (TOF) ranges from 20 to 40%. This can be either primary or secondary to the surgical intervention. The influence of resulting lung perfusion alterations on the life quality of patients is difficult to predict. The aim of this study was to compare the utility of the diagnostic procedures in this group of patients, with particular focus on lung perfusion scintigraphy. This study comprised 104 patients who underwent repair of TOF at ages from 5 months to 25 years. The patients have been followed up for from 4.2 to 25 years. On the basis of chest X-ray peripheral pulmonary artery stenosis was suspected in 11 patients, in 12 on the basis of echocardiography examination. Lung perfusion scintigraphy has been performed on 87 patients. The disturbances in lung perfusion (mostly in the left lung) were show by means of lung perfusion scintigraphy in 43 (49%) of ...

439

Luminous HC3N line emission in NGC4418 - buried AGN or nascent starburst?  

CERN Document Server

IRAM 30m observations reveal that the deeply obscured IR-luminous galaxy NGC4418 has a rich molecular chemistry - including unusually luminous HC3N line emission. We furthermore detect: ortho-H2CO 2-1, 3-2; CN 1-0, 2-1; HCO+, 1-0. 3-2, HCN 3-2, HNC 1-0, 3-2 (and tentatively OCS 12-11). The HCN, HCO+, H2CO and CN line emission can be fitted to densities of n=5 x 10E4 - 10E5 cm-3 and gas temperatures Tk=80-150 K. Both HNC and HC3N are, however, significantly more excited than the other species which requires higher gas densities - or radiative excitation through e.g. mid-IR pumping. The HCN line intensity is fainter than that of HCO+ and HNC for the 3-2 transition, in contrast to previous findings for the 1-0 lines where the HCN emission is the most luminous. We tentatively suggest that the observed molecular line emission is consistent with a young starburst, where the emission can be understood as emerging from dense, warm gas with an additional PDR component. We ...

2007-01-01

440

Investigation on corrosion and wear behaviors of nanoparticles reinforced Ni-based composite alloying layer  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate the role of amorphous SiO{sub 2} particles in corrosion and wear resistance of Ni-based metal matrix composite alloying layer, the amorphous nano-SiO{sub 2} particles reinforced Ni-based composite alloying layer has been prepared by double glow plasma alloying on AISI 316L stainless steel surface, where Ni/amorphous nano-SiO{sub 2} was firstly predeposited by brush plating. The composition and microstructure of the nano-SiO{sub 2} particles reinforced Ni-based composite alloying layer were analyzed by using SEM, TEM and XRD. The results indicated that the composite alloying layer consisted of {gamma}-phase and amorphous nano-SiO{sub 2} particles, and under alloying temperature (1000 deg. C) condition, the nano-SiO{sub 2} particles were uniformly distributed in the alloying layer and still kept the amorphous structure. The corrosion resistance of composite alloying layer was investigated by an electrochemical method in 3.5%NaCl solution. Compared with single ...

2008-04-30

441

Investigation on corrosion and wear behaviors of nanoparticles reinforced Ni-based composite alloying layer  

International Nuclear Information System (INIS)

In order to investigate the role of amorphous SiO2 particles in corrosion and wear resistance of Ni-based metal matrix composite alloying layer, the amorphous nano-SiO2 particles reinforced Ni-based composite alloying layer has been prepared by double glow plasma alloying on AISI 316L stainless steel surface, where Ni/amorphous nano-SiO2 was firstly predeposited by brush plating. The composition and microstructure of the nano-SiO2 particles reinforced Ni-based composite alloying layer were analyzed by using SEM, TEM and XRD. The results indicated that the composite alloying layer consisted of ?-phase and amorphous nano-SiO2 particles, and under alloying temperature (1000 deg. C) condition, the nano-SiO2 particles were uniformly distributed in the alloying layer and still kept the amorphous structure. The corrosion resistance of composite alloying layer was investigated by an electrochemical method in 3.5%NaCl solution. Compared with single alloying layer, the amorphous nano-SiO2 ...

2008-04-30

442

Investigation of cell parameters, microstructures and electrochemical behaviour of LiMn{sub 2}O{sub 4} normal and nano powders  

Energy Technology Data Exchange (ETDEWEB)

Nano materials are usually difficult to prepare. This work presents a simple way of preparing LiMn{sub 2}O{sub 4} nano powders using the high-energy ball milling method. This method has the advantage of producing pure, single-phase and crystalline nano powders. The milling method is carefully controlled to avoid unwanted chemical reactions that may change the stoichiometry of the material. Nano powders of between 30 and 50 nm are obtained. Structural studies of the nano powders, as well as the more conventional micron-sized LiMn{sub 2}O{sub 4}, are made using X-ray diffraction and neutron diffraction methods. Electrochemical evaluation of the materials is undertaken with a three-probe cyclic voltammetry technique and galvanostatic charge-discharge measurements. Structural studies reveal that not only are the crystallites of the nano powders much reduced in size from the normal powders, but their cell parameters are also smaller. The performance ...

2009-03-01

443

In vitro H2AX phosphorylation and micronuclei induction in human fibroblasts across the Bragg curve of a 577MeV/nucleon Fe incident beam  

Energy Technology Data Exchange (ETDEWEB)

The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the only major protection to astronauts from harmful exposure. Unlike low-linear energy transfer (LET) {gamma} or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure, since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. The Bragg curve does not necessarily represent the biological damage along the particle traversal, and the 'biological Bragg curve' is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. Here we used a unique irradiation geometry to measure the biological response across the Bragg curve in human fibroblasts exposed to 577MeV/nucleon incident Fe ions in vitro. ...

2006-10-15

444

In situ spectroscopic and corrosion studies of ultra-thin gradient plasma polymer layers on zinc  

International Nuclear Information System (INIS)

By means of an audio frequency plasma polymerisation ultra-thin gradient plasma polymer layers were deposited on zinc and zinc-coated iron. The aim was to generate an interfacial polymeric layer which bonds to an oxidised metal as well as to a subsequently applied organic coating and acts as an interfacial barrier layer for ions and water. Surface modifications were done in an in situ plasma cell with infrared reflection absorption spectroscopy (IRRAS). The zinc surface was first activated by an oxygen plasma to provide a freshly oxidised and contamination free oxide surface. The intermediate stages of the surface reactions could be revealed. Carbon dioxide molecules as oxidation products adsorbed on the growing zinc oxide and were desorbed at a later stage. An organosilicon plasma polymer was deposited directly on top of the oxide layer from a hexamethyldisilane (HMDS) plasma. Afterwards a cyclohexene (CHEX)/hexamethyldisilane co-plasma polymer was deposited. The ...

2003-07-15

445

High density of nanodots on atomically flat CeO_2 buffer layers for inducing effective vortex-pinning centers in YBa_2Cu_3O_7_-_#delta# films on sapphire  

International Nuclear Information System (INIS)

Epitaxial CeO_2 buffer layers were fabricated by pulsed laser deposition (PLD) on r-cut sapphire substrates. An atomically flat CeO_2 surface with a high density of nanodots was formed by a self-assembly process. Scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy investigation showed that the nanodots were CeO_2 other than impurities. YBa_2Cu_3O_7_-_#delta# (YBCO) thin films were then grown on the annealed and the as-grown CeO_2-buffered sapphires by PLD. The transport measurement results showed that the nanodots enhanced the effective pinning potential and significantly increased critical current density (J _c). Especially, YBCO films with an annealed CeO_2 buffer layer showed a high J _c peak when the applied field was directed along the c-axis of YBCO. Cross-section transmission electron microscopy investigation revealed that the J _c peaks in YBCO with annealed CeO_2 buffer layer is caused by c-axis ...

2006-12-05

446

Growth of high-density Ru- and RuO_2-composite nanodots on atomic-layer-deposited Al_2O_3 film  

International Nuclear Information System (INIS)

Growth of Ru- and RuO_2-composite (ROC) nanodots on atomic-layer-deposited Al_2O_3 film has been studied for the first time using ion-beam sputtering followed by post-deposition annealing (PDA). X-ray photoelectron spectroscopy analyses reveal that RuO_2 and Ru co-exist before annealing, and around 10% RuO_2 is reduced to metallic Ru after PDA at 900 deg. C for 15 s. Scanning electron microscopy measurements show that well-defined spherical ROC nanodots are not formed till the PDA temperature is raised to 900 deg. C. The mean diameter of the nanodots enlarges with increasing PDA temperature whereas the nanodot density decreases, which is attributed to coalescence process between adjacent nanodots. It is further illustrated that the resulting nanodot size and density are weakly dependent on the annealing time, but are markedly influenced by the decomposition of RuO_2. In this article, the ROC nanodots with a high density of 1.6 x 10"1"1 cm"-"2, ...

2007-02-15

447

Experimental chemo- and radio-therapy on human cholangiocarcinoma transplanted to nude mice  

International Nuclear Information System (INIS)

A human cholangiocarcinoma, Ch-1, serially transplanted to nude mice was used for experimental chemotherapy, radiotherapy, and conbination chemoradiotherapy. In the group of chemotherapy with single drug, Mitomycin C (MMC) revealed greater effectiveness than Adriamycin in terms of tumor regression, histological findings, and minor side effects. MMC and radiotherapy by Linac X-ray showed exponential linear dose response curve against tumor weight. Their effects were equivalent at doses of MMC 1 mg/kg and radiation 1,000 rads/mouse in the changes of tumor weight and of histological findings which were similar to each other. Combination chemoradiotherapy showed the synergistic action when the radiation (500 rads/mouse) was performed before MMC (0.5 mg/kg) administration, whereas only the additive effect was observed when the sequence was reversed. The cell kinetic analysis was performed by the impulse cytophotometry, "3H-thymidine uptake labeling ...

448

Electron-optical microscopic study of incipient dental microdamage from experimental seed and bone crushing  

Energy Technology Data Exchange (ETDEWEB)

No living analogue exists for the hypothetical early hominid hard/tough-seed, coarse-root-eating, and bone-crushing masticatory adaptation. To investigate possible microdamage/microwear to dental enamel caused by such usage, puncture-crushing experiments were carried out on single human teeth, using an Instron compression apparatus on the following six test materials: Makapansgat Limeworks chert (e.g., taphonomy), fresh steer longbone, mongongo nuts, Grewia berries, Carob beans, and wild-onion bulbs. Pairs of extracted unworn third molars were utilized, with one tooth acting as the control. The teeth were mounted, ultrasonically cleaned, and two-stage replicas made with a vinyl polysiloxane elastomer and araldite epoxy resin. After Instron loading and materials failure (1.2-395.0 kg) the test items and the crowns were prepared for comparison with scanning electron microscopy and dispersive x-ray elemental analysis and mapping. The results ...

1982-03-01

449

Electrochemical and surface analytical studies of the interaction of nitrogen with key alloying elements in stainless steels  

Energy Technology Data Exchange (ETDEWEB)

Surface analytical studies of high nitrogen austenitic stainless steels exposed to deaerated 0.1M HCl have revealed that nitrogen alloying additions influence the composition of salt layers and the passive film/alloy interface. In this study the authors employ electrochemical techniques and variable angle X-ray Photoelectron Spectroscopy (XPS) to examine the passive films formed on a series of austenitic stainless steels, Fe18Cr8Ni, Fe18Cr8Ni0.2N, Fe20Cr20Ni, Fe20Cr20Ni6Mo and Fe20Cr20Ni6Mo0.2N, in acidic chloride aqueous solution. In addition, several other model alloys, Fe19Cr, Fe19Cr9Ni, Fe19Cr2.5Mo, and Fe19Cr9Ni2.5Mo, were examined before and after electrochemical surface nitriding, a technique proven to have an effect analogous to N alloying. It was shown that nitrogen, nickel and molybdenum additions independently and in certain combinations stimulate selective dissolution of iron, resulting in a significant enrichment of chromium ...

1995-12-01

450

Electrochemical and surface analytical studies of the interaction of nitrogen with key alloying elements in stainless steels  

International Nuclear Information System (INIS)

Surface analytical studies of high nitrogen austenitic stainless steels exposed to deaerated 0.1M HCl have revealed that nitrogen alloying additions influence the composition of salt layers and the passive film/alloy interface. In this study the authors employ electrochemical techniques and variable angle X-ray Photoelectron Spectroscopy (XPS) to examine the passive films formed on a series of austenitic stainless steels, Fe18Cr8Ni, Fe18Cr8Ni0.2N, Fe20Cr20Ni, Fe20Cr20Ni6Mo and Fe20Cr20Ni6Mo0.2N, in acidic chloride aqueous solution. In addition, several other model alloys, Fe19Cr, Fe19Cr9Ni, Fe19Cr2.5Mo, and Fe19Cr9Ni2.5Mo, were examined before and after electrochemical surface nitriding, a technique proven to have an effect analogous to N alloying. It was shown that nitrogen, nickel and molybdenum additions independently and in certain combinations stimulate selective dissolution of iron, resulting in a significant enrichment of chromium ...

1995-03-26

451

Crystal and solution structures of an odorant-binding protein from the southern house mosquito complexed with an oviposition pheromone  

Energy Technology Data Exchange (ETDEWEB)

Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding ...

2010-11-15

452

A combinatorial library of micro-topographies and chemical compositions for tailored surface wettability  

Energy Technology Data Exchange (ETDEWEB)

Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X = 1 {mu}m and an intermediate inter-pillar gap size of Y = 4 {mu}m with superhydrophobic CAs over 170 . Surface analysis with X-ray photoelectron spectroscopy (XPS) revealed ...

2011-06-15

453

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

454

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

455

Comparison on the growth of oxide films formed in alloy 800 and alloy 600 in an aqueous medium at high temperature  

International Nuclear Information System (INIS)

Alloy 800 and Alloy 600 are well known for their resistance to corrosion in an aqueous medium at high pressure and temperature, for which they have been widely used for more than 3 decades in different structural components of water refrigerated nuclear reactors, especially as material for the steam generator tubes (SG) in these nuclear plants. The SG tubes in the Atucha I and Embalse Nuclear Plants are made with Alloy 800. The speed of corrosion of these materials in a reactor's refrigerant medium, while very small is perfectly measurable and can be described by parabolic or logarithmic type kinetics. In other words this speed is high in the first states of growth during the formation of a protective oxide film but then drops to almost stationary values. One characteristic of these films is the formation of a double layer (or duplex): i) an internal adhering layer, of approximately constant thickness, formed by small microcrystals (#<=#0.05 mm), ii) a less adhering external one, ...

2006-12-01

456

Phase diagram of SrO-InO1.5-CoOx and a new compound Sr3In0.9Co1.1O6  

International Nuclear Information System (INIS)

Sr3In0.9Co1.1O6, isostructural to Ca3Co2O6, is revealed by the study of the phase relations in the system SrO-InO1.5-CoOx (1000 oC). The structure of Sr3In0.9Co1.1O6 is refined by the combination of powder X-ray and neutron diffraction. Sr3In0.9Co1.1O6 crystallizes in a trigonal lattice with the cell parameters a=b=9.59438(3) A, c=11.02172(4) A with the space group R-3c. Its structure possesses 1D (In/Co)O3 chains running along the c-axis constructed by alternating face-sharing CoO6 octahedra and (In0.9Co0.1)O6 trigonal prisms. The co-occupation of In3+ and Co3+ at the trigonal prismatic site is evidenced by elementary analysis and determined by the structure refinement. Sr3In0.9Co1.1O6 is paramagnetic, and the susceptibility is consistent with the occupation of Co3+ at 10% of the trigonal prismatic positions in a high spin state (HS, S=2). The HS Co3+ is well separated by diamagnetic CoO6 octahedra and InO6 trigonal prisms and shows a g factor ...

2011-04-01

457

Field driven ferromagnetic phase evolution originating from the domain boundaries in antiferromagnetically coupled perpendicular anitsotropy films  

Energy Technology Data Exchange (ETDEWEB)

Strong perpendicular anisotropy systems consisting of Co/Pt multilayer stacks that are antiferromagnetically coupled via thin Ru or NiO layers have been used as model systems to study the competition between local interlayer exchange and long-range dipolar interactions [1,2]. Magnetic Force Microscopy (MFM) studies of such systems reveal complex magnetic configurations with a mix of antiferromagnetic (AF) and ferromagnetic (FM) phases. However, MFM allows detecting surface stray fields only and can interact strongly with the magnetic structure of the sample, thus altering the original domain configuration of interest [3,4]. In the current study they combine magnetometry and state-of-the-art soft X-ray transmission microscopy (MXTM) to investigate the external field driven FM phase evolution originating from the domain boundaries in such antiferromagnetically coupled perpendicular anisotropy films. MXTM allows directly imaging the perpendicular ...

2008-05-01

458

A dinuclear Ni(I) system having a diradical Ni2N2 diamond core resting state: synthetic, structural, spectroscopic elucidation, and reductive bond splitting reactions.  

Science.gov (United States)

One-electron reduction of the square-planar nickel precursor (PNP)NiCl ( 1) (PNP (-) = N[2-P(CHMe 2) 2-4-methylphenyl] 2) with KC 8 effects ligand reorganization of the pincer ligand to assemble a Ni(I) dimer, [Ni(mu 2-PNP)] 2 ( 2), containing a Ni 2N 2 core structure, as inferred by its solid-state X-ray structure. Solution magnetization measurements are consistent with a paramagnetic Ni(I) system likely undergoing a monomer dimer equilibrium. The room-temperature and 4 K solid-state X-band electron paramagnetic resonance (EPR) spectra display anisotropic signals. Low-temperature solid-state X-band EPR data at 4 K reveal rhombic values g z = 1.980(4), g x = 2. 380(4), and g y = 2.225(4), as well as a forbidden signal at g = 4.24 for the Delta M S = 2 half field transition, in accord with 2 having two weakly interacting metal centers. Utilizing an S = 1 model, full spin Hamiltonian simulation of the low-temperature EPR spectrum on the solid ...

2008-10-15

459

Stochastic risk estimation from medical x-ray diagnostic examinations, 2  

International Nuclear Information System (INIS)

The risks of genetic, leukemia and malignant diseases from medical X-ray diagnostic examinations were estimated using the frequency of radiographic and fluoroscopic exposures per diagnostic examination, child expectancy, leukemia and malignancy significant factors, and using a weighting factor determined on the basis of data concerning the cancer mortality among atomic bomb survivors in Nagasaki and of a recommendation of International Commission of Radiological Protection. The organ or tissue doses with respect to the stochastic risks were determined with ionization chambers and thermoluminescent dosimeters placed at the positions of the organs or tissues in a RANDO woman phantom which was exposed to diagnostic X-rays according to technical factors of typical radiographic and fluoroscopic examinations obtained from a nationwide survey. The resultant risks by age-group and type of radiographic and fluoroscopic examination are tabulated in terms ...

1981-01-01

460

Radiation exposure of children in pediatric radiology. Pt. 5. Organ doses in chest radiography; Zur Strahlenexposition von Kindern in der paediatrischen Radiologie. T. 5. Organdosen bei der Roentgenuntersuchung des Thorax  

Energy Technology Data Exchange (ETDEWEB)

Purpose: Reconstruction of organ doses of selected organs and tissues from radiographic settings and exposure data collected during chest X-ray examinations of children of various age groups performed in Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007. Materials and Method: The dosimetric data of all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 119 150 chest radiographs of all age groups. Reconstruction of organ doses in 40 organs and tissues in X-ray examinations of the chest was performed based on the conversion factor concept. Results: The radiation exposure of organs in projection radiography is determined by the exact site of the organs relative to the edges of ...

2009-05-15

461

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

462

K/sub. beta. //K/sub. cap alpha. / transition probability ratios from the measurement of fluorescent X-ray intensities of some lanthanide compounds  

Energy Technology Data Exchange (ETDEWEB)

The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios. The measured relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios were compared to the calculated values ...

1987-01-01

463

K/sub #beta#//K/sub #alpha#/ transition probability ratios from the measurement of fluorescent X-ray intensities of some lanthanide compounds  

International Nuclear Information System (INIS)

The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios. The measured relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios were compared to the calculated values predicted by the ...

1987-01-01

464

A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis  

International Nuclear Information System (INIS)

We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among ...

1986-01-01

465

X-ray magnetic form factor of UTe  

Energy Technology Data Exchange (ETDEWEB)

A measurement of the magnetic form factor of a ferromagnetic actinide compound of UTe with circularly polarized X-rays is reported. The present geometrical configuration of the measurement gives a form factor of L(k)+0.3S(k), where L(k) and S(k) are the form factors of the orbital and the spin magnetic moment, respectively. We have combined the X-ray magnetic form factor with the neutron one which gives L(k)+2S(k) (G. Busch et al.: J. Phys. C 12 (1979) 1391), and have deduced L(k) and S(k) separately. The obtained profiles of L(k) and S(k) show that the orbital and the spin magnetic moments are spatially spread out more than those calculated for a free uranium ion. (author).

1995-07-01

466

X-ray magnetic form factor of UTe  

International Nuclear Information System (INIS)

A measurement of the magnetic form factor of a ferromagnetic actinide compound of UTe with circularly polarized X-rays is reported. The present geometrical configuration of the measurement gives a form factor of L(k)+0.3S(k), where L(k) and S(k) are the form factors of the orbital and the spin magnetic moment, respectively. We have combined the X-ray magnetic form factor with the neutron one which gives L(k)+2S(k) (G. Busch et al.: J. Phys. C 12 (1979) 1391), and have deduced L(k) and S(k) separately. The obtained profiles of L(k) and S(k) show that the orbital and the spin magnetic moments are spatially spread out more than those calculated for a free uranium ion. (author).

467

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

468

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

469

Total M shell X-ray production cross sections and average fluorescence yields in 11 elements from Tm to U at photon energy of 5.96 keV  

International Nuclear Information System (INIS)

Total M shell X-ray production cross section for 11 elements with 69 #<=# Z #<=# 92 have been measured using an incident photon energy of 5.96 keV. Measurements have been performed using an "5"5Fe annular source and a Si(Li) detector. Average M shell fluorescence yield at each incident photon energy has been deduced, using the experimental total M X-ray production cross section and theoretical M shell photoionization cross section. Present experimental results are compared with other experimental and theoretical values. Reasonable agreement (to within 0.3-28%) is typically obtained between present and other experimental and theoretical values.

2005-04-01

470

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 the advantages of phase imaging with respect to standard absorption imaging, in the ...

2009-09-01

471

The X-ray Halo of G21.5-0.9  

CERN Document Server

The emission of the plerion G21.5-0.9 appears more extended in X rays than in radio. This is an unexpected result because it would imply that short-lived X-ray electrons may reach distances even larger than radio electrons. Applying an empirical relationship between dust scattering optical depth and photoelectric column density, the measured column density leads to a large optical depth at 1 keV, of about 1. Therefore we investigate the hypothesis that the detected halo be an effect of dust scattering, re-analyzing an Cal/PV XMM-Newton observation of G21.5-0.9 and critically examining it in terms of a dust scattering model. We also present a spectral analysis of a prominent extended feature in the northern sector of the halo.

2003-01-01

472

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

473

Studies of L x-rays from 64 MeV iodine projectiles in collision with gas targets  

International Nuclear Information System (INIS)

We have studied L x-rays from 64 MeV iodine projectile in collision with various gas targets, Z_2 #18, do not arise from selective M subshell vacancy population, has been conclusively established by the observations by Datz et al (1971) and by Saha et al (1996) that the measured intensity ratio of the Ll and L#alpha# lines, which arise because of transitions from different M subshells into the same L, subshell, does not show any periodic behaviour with Z, but stays rather constant. Differences in the measured L#beta#_1/L#alpha# intensity ratio of iodine with 7"+ and 24"+ charge states impinging on Kr target established the minor role of the electrons in the N shell of the projectile in the x-ray production mechanism. (author)

1997-11-17

474

Simulation Studies of the X-Ray Free-Electron Laser Oscillator  

Energy Technology Data Exchange (ETDEWEB)

Simulations of the x-ray free-electron laser (FEL) oscillator are presented that include transverse effects and realistic Bragg crystal properties with the two-dimensional code GINGER. In the present cases considered the radiation divergence is much narrower than the crystal acceptance, and the numerical algorithm can be simplified by ignoring the finite angular bandwidth of the crystal. In this regime GINGER shows that the saturated x-ray pulses have 109 photons and are nearly Fourier-limited with peak powers in excess of 1 MW. Wealso include preliminary results for a four-mirror cavity that can be tuned in wavelength over a few percent, with future plans to incorporate the full transverse response of the Bragg crystals into GINGER to more accurately model this tunable source.

2009-08-14

475

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

476

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

477

Operation of beam line facilities for real-time x-ray studies at Sector 7 of the advanced photon source. Final Report  

Energy Technology Data Exchange (ETDEWEB)

This Final Report documents the research accomplishments achieved in the first phase of operations of a new Advanced Photon Source beam line (7-ID MHATT-CAT) dedicated to real-time x-ray studies. The period covered by this report covers the establishment of a world-class facility for time-dependent x-ray studies of materials. During this period many new and innovative research programs were initiated at Sector 7 with support of this grant, most notably using a combination of ultrafast lasers and pulsed synchrotron radiation. This work initiated a new frontier of materials research: namely, the study of the dynamics of materials under extreme conditions of high intensity impulsive laser irradiation.

2003-09-10

478

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 waste characterization ...

1981-10-01

479

NEXAFS microscopy of polymeric materials: Successes and challenges encountered when characterizing organic devices  

Energy Technology Data Exchange (ETDEWEB)

We summarize recent developments in x-ray microscopy of polymers by focusing on the characterization of organic electronic devices. The quantitative compositions of model polymer blends have been mapped at a resolution of {approx}35 nm. Since it could be inferred that these devices have structures smaller than 35 nm, quantitative compositional mapping at length scales below the present resolution limit of x-ray microscopy is required. Organic devices thus serve to both highlight the success of NEXAFS microscopy to date, but to also outline the very real need for higher spatial resolution. New approaches to create improved optics or different acquisition modalities are required if x-ray microscopy is to make sustained contributions to such an important area of research as organic devices.

2009-09-01

480

Measurements of K-beta/K-alpha X-ray intensity ratios using VEC beams  

International Nuclear Information System (INIS)

An experiment on the K#beta#/K#alpha# characteristic X-ray intensity ratio in silver was performed at VEC Centre, Calcutta using the #alpha#-beams at energies 40 MeV and 50 MeV employing a Si(Li) detector system on-line. The results show that the K#beta#/K#alpha# X-ray intensity ratio at energies 40 and 50 MeV are 0.215 #+-# 0.006 and 0.216 #+-# 0.006, respectively, which indicates no change with beam energy and in accordance with the earlier reports. The present experiment shows the feasibility of studying the K#beta#/K#alpha# ratios as a function of beam energy in different regions of periodic table. Experiments in elements belonging to the 3d shell and their compounds are suggested to look for the chemical effects and their dependence on #alpha#-energy. (author). 7 refs.

1987-02-03

481

Laser Assisted Emittance Exchange: Downsizing the X-ray Free Electron Laser  

Energy Technology Data Exchange (ETDEWEB)

A technique is proposed to generate electron beam with ultralow transverse emittance through laser assisted transverse-to-longitudinal emittance exchange. In the scheme a laser operating in the TEM10 mode is used to interact with the electron beam in a dispersive region and to initiate the emittance exchange. It is shown that with the proposed technique one can significantly downsize an x-ray free electron laser (FEL), which may greatly extend the availability of these light sources. A hard x-ray FEL operating at 1.5 {angstrom} with a saturation length within 30 meters using a 3.8 GeV electron beam is shown to be practically feasible.

2009-12-11

482

K-edge X-ray absorption spectra of argon in sputtered aluminum films  

International Nuclear Information System (INIS)

We have measured K-edge X-ray absorption spectra of argon in sputtered aluminum films at a synchrotron radiation facility (the Photon Factory). We found that the energy and shape of white line change when the film is annealed at 500 C and the spectrum becomes resembling that of argon implanted in silicon. From the analyses of the X-ray absorption spectra and TEM observation we concluded that argon exists as very small atom clusters with a diameter less than 1 nm or exist as isolated atoms in the as-sputtered aluminum film, and that the size of the clusters become as big as 10 nm diameter when the film is heated. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

1999-01-04

483

Influence of alloying effect on X-ray fluorescence parameters of Co and Cu in CoCuAg alloy films  

British Library Electronic Table of Contents (United Kingdom)

In this study, Kb/Ka X-ray intensity ratios, Formula Not Shown , Formula Not Shown production cross-sections and K fluorescence yields of Co and Cu and Lb/La X-ray intensity ratios, Formula Not Shown , Formula Not Shown production cross-sections and Formula Not Shown average fluorescence yields of Ag in pure metals and in different alloy compositions were measured. In this study, alloying effects on the Formula Not Shown production cross-sections of Co and Cu were investigated and changes interpreted according to the rearrangement of valance state electrons and the charge transfer process between the 3d elements (Co and Cu) and Ag.

2009-01-01

484

Extraction methods of phase information for X-ray diffraction enhanced imaging  

Energy Technology Data Exchange (ETDEWEB)

X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of refraction-angle values than existing methods.

2007-08-21

485

Extraction methods of phase information for X-ray diffraction enhanced imaging  

International Nuclear Information System (INIS)

X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of refraction-angle values than existing methods.

2007-08-21

486

Exploring the Physics of Type Ia Supernovae Through the X-ray Spectra of their Remnants  

CERN Document Server

We present the results of an ongoing project to use the X-ray observations of Type Ia Supernova Remnants to constrain the physical processes involved in Type Ia Supernova explosions. We use the Tycho Supernova Remnant (SN 1572) as a benchmark case, comparing its observed spectrum with models for the X-ray emission from the shocked ejecta generated from different kinds of Type Ia explosions. Both the integrated spectrum of Tycho and the spatial distribution of the Fe and Si emission in the remnant are well reproduced by delayed detonation models with stratified ejecta. All the other Type Ia explosion models fail, including well-mixed deflagrations calculated in three dimensions.

2005-01-01

487

Electron beam, ion beam, X-ray optical techniques for fabricating surface-acoustic-wave and thin-film optical devices  

International Nuclear Information System (INIS)

Most surface-acoustic-wave and thin-film optical devices are made by the planar fabrication process. The exposure of the pattern in the polymer film is the first and most crucial step in ensuring desired device geometry, dimensional control, and freedom from pattern distortion. The methods of exposing the polymer film include: optical projection, conventional contact printing, conformable photomask contact printing, holographic recording, scanning electron beam lithography, projection electron lithography, and x-ray lithography. In this paper scanning electron beam lithography, conformable photomask contact printing, holographic recording, and x-ray lithography are discussed. In the last section, ion beam etching of relief structures is discussed.

488

Design considerations for the magnetic system of a prototype x-ray free electron laser  

Energy Technology Data Exchange (ETDEWEB)

A number of difficult technical challenges need to be solved in the fields of accelerator and free-electron laser (FEL) technologies in order to build an X-ray FEL. One of the tasks well suited to the Advanced Photon Source Low Energy Undulator Test Line (LEUTL) is to take the intermediate step of solving some of the problems of single-pass FEL operation in the ultraviolet range. The existing Advanced Photon Source (APS) linac, in addition to its role of supply positrons for the APS storage ring, will also be used to generate the particle beam for the LEUTL. Here, the design of the magnetic system for the high gain soft x-ray free electron laser is described.

1997-04-01

489

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

490

Cluster Geometry & Inclinations from Deprojection Uncertainties  

CERN Document Server

{The determination of cluster masses is a complex problem that would be aided by information about the cluster shape and orientation (along the line-of-sight).} {It is in this context, that we have developed a scheme for identifying the intrinsic morphology and inclination of a cluster, by looking for the signature of the true cluster characteristics in the inter-comparison of the different deprojected emissivity profiles (that all project to the same X-ray brightness distribution) and by using SZe data when available.} {We deproject the cluster X-ray surface brightness profile under the assumptions of four different geometry and inclination configurations for the observed system; these 4 configurations correspond to four extreme geometry+inclination scenarios. The deprojection in question is performed by the non-parametric algorithm DOPING. The formalism is tested with model systems and then is applied to a sample of 24 clusters. While the ...

2008-01-01

491

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

British Library Electronic Table of Contents (United Kingdom)

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

2009-01-01

492

Association of brain cancer with dental x-rays and occupation in Missouri  

International Nuclear Information System (INIS)

This investigation of a brain cancer cluster in Missouri used two approaches to investigate associations with potential risk factors. In a case-control study in a rural town, we interviewed surrogates of cases and controls about potential risk factors. We found a statistically significant positive association of brain cancer with reported exposure to dental x-rays. Occupation was not associated with the cluster in the rural town. In a standardized proportional mortality study for the state of Missouri, we calculated the observed and expected proportion of brain cancers by occupation and industry in Missouri decedents. We found that motor vehicle manufacturers, beauty shop workers, managers and administrators, elementary school teachers, and hairdressers and cosmetologists had significantly elevated proportions of brain cancer. Brain tumors are inconsistently associated with occupation in the literature. Further study of brain cancer etiology with respect to dental ...

1991-01-01

493

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 interest.

1997-04-04

494

A soft x-ray free electron laser (FEL) using a two-beam elliptical pill-box wake-field cavity  

International Nuclear Information System (INIS)

Stimulated bremsstrahlung in an undulating electric field in the lasing beam direction (electric wiggler) was shown to be possible from the quantum- mechanical viewpoint. Herein, this possibility is scrutinized from the viewpoint of classical electrodynamics. It is found that if stimulated bremsstrahlung in a transverse undulating magnetic field (magnetic wiggler) occurs, stimulated bremsstrahlung in the electric wiggler must also occur. We further show that a free electron laser (FEL) using a magnetic wiggler to provide a catalyzer field for stimulated bremsstrahlung cannot serve as a practical FEL operating in the soft x-ray region from both theoretical and experimental viewpoints. On the other hand, the authors demonstrate that the FEL using a traveling wake field in a two-beam elliptical pill-box cavity is well suited as a source of coherent radiation in the soft x-ray region.

1988-01-14

495

[Somatic radiation risk in conventional tomography of the skull and thorax].  

Science.gov (United States)

The somatically significant dose index can be considered as a measure for the somatic radiation risk to which the population is exposed. Figures are stated for conventional tomography of the skull and thorax. These are compared with the corresponding data for other x-ray examinations, especially computerised tomography. PMID:7134769

1982-10-01

496

Structural transformations in heat-resistant protective coatings on nickel alloys  

Energy Technology Data Exchange (ETDEWEB)

In this work a comprehensive metallophysical study was carried out for two aluminosilicide slip coatings of the systems Al-Si and Al-Nb-Si and an electron-beam Co-Cr-Al-Y coating on alloy EP-539 (17...19% Cr, 4...6% Co, 2.5...4% W, 4.5...6.5% Mo, 2...3% Ti, 3...4% Al, 1.4...2% Nb, balance Ni) after high-temperature testing. The protective properties of the coatings were evaluated from the results of laboratory tests for heat resistance at 1000/sup 0/C in the combustion products of diesel fuel with added sulfur at 970, 1000, and 1060/sup 0/C for 100 h and after full-scale tests for 150, 250, 400, and 700 h. Metallographic, hardness, x-ray, and micro x-ray studies of the coating were carried out. Layer-by-layer phase composition and the lattice spacing of the main phases were determined. X-ray analysis was carried out in an a DRON-1 diffractometer in copper K/sub ..-->../-radiation, and x-ray ...

1987-09-01

497

Somatic radiation risk in conventional tomography of the skull and thorax  

Energy Technology Data Exchange (ETDEWEB)

The somatically significant dose index can be considered as a measure for the somatic radiation risk to which the population is exposed. Figures are stated for conventional tomography of the skull and thorax. These are compared with the corresponding data for other X-ray examinations, especially computerised tomography.

1982-10-01

498

Somatic radiation risk in conventional tomography of the skull and thorax  

International Nuclear Information System (INIS)

The somatically significant dose index can be considered as a measure for the somatic radiation risk to which the population is exposed. Figures are stated for conventional tomography of the skull and thorax. These are compared with the corresponding data for other X-ray examinations, especially computerised tomography. (orig.).

1982-01-01