Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

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)

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).

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 ...

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

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.

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 ...

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 ...

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 ...

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.

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 ...

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.

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).

Energy Technology Data Exchange (ETDEWEB)

Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (mu XRF), X-ray absorption spectroscopy (mu EXAFS), and X-ray diffraction (mu XRD) in conjunction with focused ion beam (FIB) sectioning, and highresolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at ...

UK PubMed Central (United Kingdom)

Catheter ablation is a first line treatment for many cardiac arrhythmias and is generally performed under x-ray fluoroscopy guidance. However, current techniques for ablating complex arrhythmias such...Full Text Available

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 ...

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 ...

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.

International Nuclear Information System (INIS)

Despite its great usefulness in the performance of the recording procedures prescribed by the X-Ray Ordinance the dose-area product is much less frequently measured for X-ray exposures than during fluorscopic examinations. The great multitude of measuring units, mainly on account of different scales of the measuring equipments themselves, is a cause of uncertainty in clinical routine and should be eliminated as far as the circumstances would permit. As the determination of the organ dose is relevant only in very few cases and does not necessarily require previous measurements of the dose-area product, these are of limited practical value in the assessment of individual radiation exposures during radiographic examinations. The measurements may, however, be very helpful in determinations of the radiation dose to the total population, if the future retrievability of the values obtained is ensured. In ...

Science.gov (United States)

Examples are used to demonstrate that a shift in the point of emphasis is necessary with regard to radiation hazard in medicinal X-ray diagnosis. The parameters employed in this study to calculate somatic dose (SD) and somatically significant dose (SSD) m...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

The authors give a survey of the somatic radiation ris in X-ray diagnostics. A somatic dose index is calculated for different examination methods containing the organ doses to the red bone marrow, the lung, the female breast, and the thyroid gland and evaluating their somatic significance. If this somatic dose index by which the individual radiation risk is described, is multiplied by the examination frequencies per year in the German Federal Republic, one gets the somatically significant dose index, which is a measure of the collective somatic radiation risk. In this sense, mammography has the highest, and dental radiography the lowest collective radiation risk. (orig.).

International Nuclear Information System (INIS)

Irradiation of the human body in diagnostic X-ray procedures results in different absorbed doses in the various body organs. A somatic dose index in formulated by applying the relative sensitivity of the human to each of the most important somatic effects and utilizing the absorbed dose in the affected organs. This quantity is used to convey a cumulative somatic impact and is computed for common radiographic views in diagnostic radiology as a function of beam quality for a nominal IR entrance exposure. Using typical X-ray beam qualities and exposures, the frequency of the various radiographic views that make up an examination and the frequencies of the various examinations in the national population, illustrative examples of the application of the somatic dose index are presented. (author).

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 ...

CERN Document Server

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

Energy Technology Data Exchange (ETDEWEB)

A mesoscopically ordered lamellar gel phase of a polymer-grafted, lipid-based complex fluid is used as a scaffolding to spatially organize inorganic nanoparticles. The complex fluid provides both a highly anisotropic environment and a segregated aqueous and organic domains in which inorganic nanoparticles can be selectively placed by tailoring their size and surface characteristics. Three types of silver nanoparticles -- underivatized, surfactant-stabilized, and dodecanthiol-derivatized -- were evaluated. Comparison of the surface plasmon resonance of the various silver particles dispersed in conventional solvents to those contained within the complex fluid was used to determine the region of spatial localization in the lamellar gel phase. Silver particles rendered hydrophobic by capping with an alkane thiol insert into the hydrocarbon bilayer region. Surfactant-stabilized and underivatized silver nanoparticles reside in ...

ScienceCinema

...english of ...

International Nuclear Information System (INIS)

In interventional radiology (IVR) of cerebral aneurysms, it is important to understand the form and physical relationships between the cerebral aneurysm and the surrounding vessels. However, because the vessels in the head area are highly complex, it can be difficult to comprehend the structure using conventional angiography. Therefore, three-dimensional rotational angiography (3D-RA) has been used in recent years. This article discusses studies of the spatial resolution of 3D-RA. We reconstructed 3D-RA of an acrylic slit phantom (slit widths: 0.5, 0.75, 1.0, 1.5 mm) and examined spatial resolution by visual evaluation and profile curves. When the slit phantom was arranged to avoid the effect of beam hardening, the spatial resolution of 3D-RA was found to be as high as 0.75 mm. When the slit phantom was placed orthogonal to the rotational axis of the C-arm, the spatial resolution of 3D-RA was decreased because of the cone angle effect of ...

International Nuclear Information System (INIS)

The measurement of K(alpha)/K(beta) X-ray intensity ratio indicates the excitation process and the chemical state of the atom examined. Theoretical considerations on the origin of this property are presented. The difference of these ratios following photoionization and electron capture are calculated by a computer code generating transition matrix elements. The theoretical assumptions involved in the codes are tested by comparing the experimental and calculated data concerning 3d transition element atoms. (D.Gy.).

CERN Document Server

The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after the burst, indicative of a jet break. The timing of the jet break combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 2.5 degrees. We derive an empirical `time-lag' redshift from the BAT data of z_hat = 0.69 +/- 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modelled by a simple power law with index alpha = -1.2. However after 300s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that dominates in the ...

CERN Document Server

Energy Dispersive X-ray Analysis in the Electron Microscope

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

When evaluating the risks of oncogenesis and cancer mortality following exposure to the radiations of the atomic bombs (A-bombs), the medical X-ray doses received by the A-bomb survivors must also be estimated and considered. Using a human phantom, dosimetry was performed to estimate the X-ray doses received by A-bomb survivors during medical examinations at the Radiation Effects Foundation (RERF) as part of the long-term follow-up on the Adult Health Study (AHS). These examinations have been estimated to represent nearly 45% of the survivors' cumulative medical irradiation dose. Doses to the salivary glands, thyroid gland, lung, breast, stomach and colon were measured using thermoluminescent dosemeters. The results, which are reported here, will aid in estimating organ doses received by individual AHS participants. (Author).

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Purpose: Reconstruction of radiation doses for the thoracoabdominal babygram and the abdomen X-ray from radiographic settings and exposure data acquired at Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007; comparison of these dose values with values reported in the literature; recommendation of a reference dose value for the thoracoabdominal babygram. Materials and Methods: The data from all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 1493 thoracoabdominal babygrams and 3632 abdomen X-rays of newborns and young infants. With the computer program PAeDOS, a specific dose reconstruction algorithm was developed. Results: the entrance dose values ...

Energy Technology Data Exchange (ETDEWEB)

Cerium [ital L][sub 3] XANES (x-ray-absorption near-edge-structure) spectra were analyzed to separate Ce moment contributions and mixed valence (MV) in complex magnetic silicides CePd[sub 2[minus][ital x

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 ...

Science.gov (United States)

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

International Nuclear Information System (INIS)

Modern radiometric analytics demands a complex consideration of nuclear and electron shell processes, if more pretentious aims are envisaged. As an example the small variation of decay rates of radionuclides presents possibilities for information on chemical situations of decaying atoms. In principle this phenomenon is well known since many years, but now the situation is such that, e.g. in /sup 99m/Tc internal conversion, a full agreement of the difficult experiments and the respective theory was established. The secondary emission of X-rays as a consequence of high excitation of electron shells in combination with nuclear transitions supplies another example for a methodical progress of radiometry. Investigations on "5"1Cr as an electron capture nuclide have shown that chemically induced variations of the K/sub #alpha#/ to K/sub #beta#/ X-ray intensity ratio is at least qualitatively understood. (author).

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

The radial distribution function (RDF) derived from wide angle X-ray diffraction patterns gives additional information about the spatial distribution of atoms. Their radial distances and relative average coordination numbers can be calculated using appropriate mathematical procedures. 7 refs.

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Metal-organic chemical vapor deposition (MOCVD) made layers of strontium-bismuth-tantalate (SBT) were characterized by spectroscopic ellipsometry (SE) using the Adachi model [S. Adachi, Phys. Rev. B 35 (1987) 7454-7463]. The evaluated optical parameters were correlated with the physical and chemical behavior examined by X-ray diffraction (XRD). As a result, it was possible to fit the measured spectra with the Adachi model in a wide range covering the region of the band gap. The Adachi model provides electronic layer parameters like the transition energy E 0 and broadening ?. Our investigations established a correlation between XRD-determined average grain size and the electronic layer parameters.

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.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

ScienceCinema

...english ...

Energy Technology Data Exchange (ETDEWEB)

Understanding the mechanical properties of biomedical devices is critical in predicting and preventing their failure in the body. Such knowledge is essential, for example, in the design of biomedical stents, which must undergo repeated strain over their ten year lifetimes without breaking. Computational models are used to predict mechanical response of a device, but these models are not complete; there are significant deviations from the predictions, especially when devices are subjected to repeated multi-axial loads. Improving these models requires comparisons with actual measurements of strained nitinol. Local measurements of the full strain tensor can be made using X-ray diffraction techniques, but they are currently limited to materials whose grain size is larger than the X-ray beam size or require several diffraction patterns produced by rotation of the sample. Nitinol stents are nanocrystalline, with grains smaller than any available ...

Energy Technology Data Exchange (ETDEWEB)

Pd/sub 2/Si layers produced by evaporation or sputtering onto silicon substrates were examined by high resolution electron microscopy, microdiffraction, X-ray, energy loss and Auger spectroscopy. The Si-Pd/sub 2/Si interfaces produced by evaporation were in all cases rougher and more polycrystalline than those produced by sputtering. X-ray microanalysis showed the predictable variation in palladium distribution across the interface but quantification did not produce the expected palladium-to-silicon ratios, primarily because of probe broadening and X-ray-induced fluorescence. Energy loss spectra showed plasmon energy shifts and changes in Si L edge shape due to bond formation with palladium. Auger data provided evidence for a small amount of oxygen at the Si-Pd/sub 2/Si interface. Electrical measurements of the ideality factor for Schottky barriers made from the materials produced higher values for the ...

International Nuclear Information System (INIS)

Full text: As you know, thin films which generate anomalous big photovoltage (APhV) , as film photo resistive structures made of the combinations of A_2B_6 respond to X-ray and #gamma#- radiations. In this work the influence of X-ray and #gamma#-radiations on the quantity of APhV in the system APhV-film-photoresistor was investigated. Earlier polycrystal films with anomalous photo voltage properties were received only on the clean and flat surface with high isolation property (R>10"1"4 #OMEGA#). We worked out the technology of receiving APhV films CdTe on the surface of the photosensitive film CdS. The main condition under which this effect may be observed is that the lining must be slant concerning to the direction of the motion of evaporated substance's molecular bunch during the growing of the film, i.e. received film must have a dendritic structure. That is why photosensitive film CdS was received with thermo vacuum slanting ...

International Nuclear Information System (INIS)

The genetically significant dose (GSD), per Caput mean bone marrow dose (CMD), leukemia significant dose (LSD) and malignancy significant dose (MSD) from medical diagnostic X-ray examinations in Japan were estimated based on a 1979 nationwide survey of randomly sampled hospitals and clinics. The population risk estimates were carried out using the resultant values of GSD, LSD and MSD. In the risk estimates, the significant factors, namely, the relative child expectancy, the leukemia significant factor and the malignancy significant factor, for patients were assumed to be same as those of general population. The risk factors used were 185 x 10"-"6 rad"-"1 for genetic risk of all generations, 20 x 10"-"6 rad"-"1 for fatal leukemia and 165 x 10"-"6 rad"-"1 for fatal malignant diseases, respectively. The resultant annual population doses per person were 15 mrad (0.15 mGy) for GSD, 107 mrad (1.07 mGy) for CMD, 86 mrad (0.86 mGy) for LSD and 43 mrad ...

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 ...

British Library Electronic Table of Contents (United Kingdom)

Crystalline bis(O,O'-di-sec-butyldithiophosphato)platinum(II) was prepared and studied by means of 13C, 31P CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. The unit cell of the platinum(II) compound is comprised of one centrosymmetric mononuclear molecule [Pt{S2P(O-sec-C4H9)2}2], in which the dithiophosphate groups display structural equivalence in both 31P NMR and XRD data. A pair of the dithiophosphate ligands exhibit the same S,S'-bidentate chelating structural function and form two planar four-membered chelate rings, [PtS2P], in this molecule. The planar configuration of the [PtS4] chromophore in structure 1 is governed by the dsp2-hybrid state of platinum(II). The structural states of the dithiophosphate groups in two different samples of complex 1 (one crystallised from...

Energy Technology Data Exchange (ETDEWEB)

Copper complexes of the amino acids histidine, arginine and lysine have been introduced into the supercages of zeolite Y and, for the first time, into the large intracrystalline cavities of zeolites EMT and MCM-22. The resulting host/guest compounds are characterized by X-ray powder diffraction, UV/VIS-spectroscopy in the diffuse reflectance mode and by catalytic tests in the liquid-phase oxidation of aromatic alcohols (viz. benzyl alcohol, 2- and 3-methylbenzyl alcohol and 2,5-dimethylbenzyl alcohol) with tertiary-butylhydroperoxide as oxidant. It was observed that intracrystalline copper-amino acid complexes possess remarkable catalytic activity, yielding the corresponding aromatic aldehydes and acids. (orig.)

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

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 ...

Energy Technology Data Exchange (ETDEWEB)

Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for noninvasive determination of iron and zinc in two distinct skin areas, representing predominantly dermal and epidermal tissues, in 56 patients with beta-thalassemia major and intermedia. The mean iron levels in the skin of patients with beta-thalassemia major and intermedia were elevated by greater than 200% and greater than 50%, respectively, compared with control values. The zinc levels of both skin areas examined were within the normal range. The data indicate that the rate and number of blood transfusions, which correlated well with serum ferritin levels (r . 0.8), are not the only factors that determine the amount of iron deposition in the skin (r less than 0.6). Other sources of iron intake contribute to the total iron load in the tissues, particularly in patients who are not given multiple transfusions. The noninvasive ...

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Doses to the salivary glands, thyroid gland, breast, lung, stomach and colon during mass radiological gastric screening, mass radiographic chest screening, upper gastrointestinal series and computed tomography were determined by exposing a female human phantom to simulated radiological X-ray examinations as performed in community hospitals. The doses were measured using thermoluminescent dosemeters, and the results will be used to document organ doses received by participants in the Atomic Bomb Casualty Commission/Radiation Effects Research Foundation Adult Health Study. (Author).

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In the Wajima lung cancer screening program conducted under the auspices of Kanazawa University Hospital, Fuji Computed Radiography (FCR) was utilized in a new chest radiography trial. The results of the screening program are that the necessity of repeat examinations due to poor image quality are less common and the method enables detection of small pulmonary nodular shadows which are possibly candidates for surgery. Oblique chest X-ray with FCR is remarkably effective for the detection and the identification of small lesions. However, the disadvantage of slow processing and high cost must be fully satisfied if FCR is to become a new imaging modality for mass screening.

International Nuclear Information System (INIS)

The influence of microalloying vanadium or titanium on improving the corrosion resistance of mild steel in saturated calcium hydroxide solution was investigated. Potential-time, potentiodynamic polarization, and impedance measurement techniques were employed. The corrosion products have been examined by infrared and X-ray diffraction analysis and by scanning electron microscopy. It has been shown that the grain refining, due to microalloying, plays an important role in enhancing the corrosion resistance of steel. Scales of calcite and iron oxides on top of a protective oxide are formed on the investigated steels.

International Nuclear Information System (INIS)

The formation of astatide-mercury complexes was investigated in aqueous solutions.The obtained complexes were examined by paper electrophoresis. It was found that Hg(OH)At and Hg(OH)I complexes were formed in neutral solution. The stability constants of the obtained complexes were determined by ion-exchange. The preliminary results indicate that the complex of mercury with astatide is much more stable than similar complexes with iodide. (author)

International Nuclear Information System (INIS)

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

Science.gov (United States)

The vigilance reinforcement hypothesis (VRH) asserts that errors in signal detection tasks are partially explained by operant reinforcement and extinction processes. VRH predictions were tested with a computerized baggage screening task. Our experiment evaluated the effects of signal schedule (extinction vs. variable interval 6 min) and visual field complexity (dial vs. baggage x-ray) on search behavior rates. There was a main effect for signal schedule [F (1, 20) = 14.0, p = 0.001, p[subscript rep] = 0.99], but no effects for field complexity or interaction. The VRH suggests that performance errors in visual screening work may be reduced through operant conditioning of search behaviors by intensive management of artificially planted signals. (Contains 1 table and 3 figures.)

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.

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

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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).

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?...

Science.gov (United States)

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

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.

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The effect of adriamycin in combination with radiation on the skin reactions of mouse feet has been examined under a variety of experimental conditions including: (a) hyperthermic treatment of the foot immediately following adriamycin administration, with the former given either just before or just after x irradiation, and (b) fractionated treatments of drug and radiation in a variety of sequences over an 18-day period. In the case of the most severe hyperthermic treatment, no increased radiation reactions were observed in the presence of adriamycin. However, in the case of the less severe hyperthermic treatment a small but significant increase in skin reactions was observed. In the study of fractionated drug and radiation treatments, an enhancement of reaction in those animals receiving combined modality treatment over those receiving radiation alone was seen in those groups where the initiation of drug treatment succeeded the initiation of radiation treatment by ...

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 was derived from our ...

CERN Document Server

Polarization measurements in the X-ray and gamma-ray energy range can provide crucial information on massive compact objects such as black holes and neutron stars. The Polarized Gamma-ray Observer (PoGO) is a new balloon-borne instrument designed to measure polarization from astrophysical objects in the 30-100 keV range, under development by an international collaboration with members from United States, Japan, Sweden and France. To examine PoGO's capability, a beam test of a simplified prototype detector array was conducted at the Argonne National Laboratory Advanced Photon Source. The detector array consisted of seven plastic scintillators, and was irradiated by polarized photon beams at 60, 73, and 83 keV. The data showed a clear polarization signal, with a measured modulation factor of $0.42 \\pm 0.01$. This was successfully reproduced at the 10% level by the computer simulation package Geant4 after modifications to its implementation of ...

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Membranes in Palladium and its alloys, in particular Pd/Ag alloys, are selectively permeable to hydrogen and can therefore be used to purify hydrogen. It is intended to use them as material for electrodes in fuel cells. As the manufacturing process of a substrate Pd/Ag-layer consists of several stages and is still not completely understood, it would be advantageous to be able to characterise separately the layers of noble metals obtained by electro-plating . Attempts are being made in this work to vary the cristallographical structure of the deposited alloy by the choice of test parameters and by sintering when depositing the Pd/Ag. The layers produced are to be examined using an interference microscope and X-ray diffraction. Moreover, the diffusion behaviour of the hydrogen is to be examined with an electro-chemical pulse method specifically developed for this purpose. figs., tabs., 27 refs.

International Nuclear Information System (INIS)

This paper reports on a series of experiments performed to examine the ability of ion beam assisted thermal deposition to produce good adhesion of Au metallization on GaAs left-angle 100 right-angle substrates. A study of the influence of Ar ion-assisted thermal deposition of the Au films as well as in situ pre-sputtering of the GaAs surface with low-energy Ar ions prior to thermal deposition, shows that strong adhesion can be achieved without resorting to chemical cleaning. The substrate temperature and the relative flux of Ar ions to incident Au atoms were varied in order to correlate these parameters with film adhesion. The interfaces of films processed under these various conditions were examined by XTEM, RBS and XPS. Orientation texture was studied by x-ray diffraction (XRD).

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The IR spectra of complexes of uranyl perhalates with antipyrine (AP), hexamethylphosphorus triamide (HMPTA), dimethyl sulfoxide (DMSO), and water with the composition (UO/sub 2/L/eta/)(Ha10/sub 4/)/sub 2/, where Ha10/sub 4/ = C10/sub 4//sup -/, Bro/sub 4//sup -/, 10/sub 4//sup -/ (except for DMSO and H/sub 2/O), L is a neutral ligand, n = 4 for HMPTA and n = 5 for the remaining L, were investigated. X-ray crystallographic analysis established that the investigated perhalate complexes of uranyl with the same neutral ligands are isostructural. It was established that in the complexes studied the Ha10/sub 4//sup -/ anions are outer-sphere anions, and the value of the frequency of the antisymmetrical stretching vibration of the uranyl group does not depend on the nature of the perhalate anion. From the values obtained for ..nu../sub 3/ UO /SUP 2/2/ /sup +/, the values of the multiplicity and energy of the ...

British Library Electronic Table of Contents (United Kingdom)

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

British Library Electronic Table of Contents (United Kingdom)

One salt and two Cu(II) complexes (H2hsm)(ox), 1, [Cu(hsm)(ox)], 2, and [Cu(hsm)(ox)H2O], 3, have been synthesized and X-ray characterized (hsm is histamine and ox2? is the oxalate dianion). Starting from the prochiral tetracoordinated complex 2, pentacoordinated complex 3 crystallizes as a racemic mixture of the enantiomeric ? and ? isomers, in space group P21/c. In all cases, the side chain of the hsm group is gauche, allowing the formation of strong hydrogen bonds in the salt 1, and to chelate the metal center in complexes 2 and 3. The combination hsm/ox seems to favor the formation of 2D supramolecular structures (planes or wavy planes), through efficient networks of N?H???O hydrogen bonds. Cell parameters: 1, P21/c, a?=?6.260 (2) ?, b?=?11.500 (4) ?, c?=?12.525 (4) ?, ??=?104.047 (17)...

International Nuclear Information System (INIS)

M-type hexagonal ferrite composition, Ba(1-x)SrxFe12O19 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), was prepared by a two route ceramic method. Complex permittivity (?'-j?'') and complex permeability (?'-j?'') have been measured using a network analyzer from 8.2 to 12.4 GHz X-ray diffraction confirmed the M-type hexagonal structure and a scanned electron micrograph was used to analyze the grain size distribution of ferrite. Substitution of Sr2+ ions causes an increase in porosity that deteriorates the electromagnetic and microstructural properties in the doped samples. Both dielectric constant and dielectric loss are enhanced in comparison to the permeability and magnetic loss over the entire frequency region. This is due to a resistivity variation and the formation of Fe2+ ions, which increases the hopping mechanism between Fe2+ and Fe3+ ions.

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

Brief item.

International Nuclear Information System (INIS)

Short communication.

Science.gov (United States)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

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

Science.gov (United States)

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

Science.gov (United States)

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

International Nuclear Information System (INIS)

Published in summary form only.

Energy Technology Data Exchange (ETDEWEB)

Sulfur K-edge X-ray absorption spectroscopy is a powerful in situ probe of sulfur biochemistry in intact cells and tissues. Under favorable circumstances the technique can provide quantitative information on the chemical identify of the sulfur species that are present in a sample. Prange et al. have recently reported an X-ray absorption spectroscopic study of bacterial sulfur storage globules. Unfortunately there are substantial problems with the experimental technique employed that, they contend, lead to completely erroneous conclusions. In the more recent of their two papers Prange et al. employed a curve-fitting method similar to that used by us (for more than 10 years). In essence, the method employs simply fitting a linear combination of the spectra of standard compounds to that of the unknown, in this case cultures of bacterial cells. This type of analysis can provide quantitative estimates of the individual sulfur types in the sample, ...

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In this work dosimetric analysis using thermoluminescence technique to study the beams characteristics of x-rays employed in dental radiology has been carried out. The obtained results with CaSO{sub 4}:Dy thermoluminescent dosimeters (TLD) were compared to the doses obtained with parallel-plates ionization chamber. Dosimetric evaluations were also done using radiographic films of large dimensions. The x-rays equipments analyzed were installed in the radiological services of Odontology Department of Sergipe Federal University (U.F.S.). Depending on the anatomical region to be examined the proper exposure time was select, for a fix voltage of 70 kV. The results with TLD and ionization chamber have been determined to female and male individuals. The intraoral regions analysed were the peri apical of the incisors, molar and pre-molar teeth and the occlusive region. These regions were simulated using acrylic plates absorbers ...

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In virtually all forms of life on earth, proteins in each cell are made according to a genetic blueprint, in the form of DNA. The translation of copies of this genetic blueprint (in the form of messenger RNA) into polypeptides is performed on the ribosome, a highly complex molecular machine composed of RNAs and proteins. To this end, special adaptor molecules called transfer RNAs are lined up by the ribosome in the sequence dictated by the genetic code, such that the amino acids carried by these molecules can be linked into a polypeptide. Several cofactors are involved in these processes, some of which require energy freed up by GTP hydrolysis. Although the ribosome was discovered more than 50 years ago, its structure has only been solved recently by X-ray crystallography. Another technique, cryo-electron microscopy, is starting to contribute toward our understanding of the ribosome's function, by portraying its conformational changes ...

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

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

International Nuclear Information System (INIS)

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

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)

International Nuclear Information System (INIS)

One approach in the design of neutral oxotechnetium complexes is based on the simultaneous substitution of a tridentate dianionic ligand and a monodentate monoanionic coligand on a [Tc(V)O]"+"3 precursor. Following this ''mixed ligand'' concept, a novel "9"9"mTc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethylethylenediamine as ligand and 1-octanethiol as coligand is prepared and evaluated as potential brain radiopharmaceutical. Preparation of the complex at tracer level was accomplished by using "9"9"mTc-glucoheptonate as precursor. The substitution was optimized and a coligand/ligand ratio of 5 was selected. Under this conditions the labeling yield was over 80% and a major product (with radiochemical purity > 80%) was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium complex as structural model. ...

British Library Electronic Table of Contents (United Kingdom)

A series of new non-discoid chiral copper(ii)-salen type complexes, [Cu((4-CnH2n+1O)2salen)], n = 14, 16, 18 and salen = N,N'-cyclohexane bis (salicylideneiminato), containing 4-substituted alkoxy tails in the side aromatic rings and a cyclohexane spacer, have been prepared and their mesogenic properties investigated. The compounds were characterised by Fourier transform infra-red spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, UV-vis spectroscopy and fast atom bombardment mass spectrometry. Mesomorphic properties of these compounds were studied by polarising optical microscopy, differential scanning calorimetry and X-ray diffraction (XRD). The ligands are non-mesogenic but the complexes exhibited enantiotropic rectangular columnar mesophases (Colr) with extended temperat...

International Nuclear Information System (INIS)

The radio, optical, x-ray and gamma-ray nebulae that surround many pulsars are thought to arise from synchrotron and inverse Compton emission. The energy powering this emission as well as the magnetic fields and relativistic particles are supplied by a 'wind' driven by the central object. The inner parts of the wind can be described using the equations of MHD, but these break down in the outer parts, when the density of charge carriers drops below a critical value. This paper reviews the wave properties of the inner part (striped wind), and uses a relativistic two-fluid model (cold electrons and positrons) to re-examine the nonlinear electromagnetic modes that propagate in the outer parts. It is shown that in a radial wind, two solutions exist for circularly polarized electromagnetic modes. At large distances one of them turns into a freely expanding flow containing a vacuum wave, whereas the other decelerates, corresponding to a confined flow.

International Nuclear Information System (INIS)

The opportunity of use self-maintained plasma-beam discharge in an extended pulsing plasma diode of low pressure for making powerful sources of the soft X-rays is investigated. Conditions of formation of the self-maintained plasma-beam discharge are determined. The mode of making of dense high-temperature plasma on the basis of stannum ions in the discharge is shown. The stannum ions are used as a working element of a radiation sources at pulsing power of electron beam P?10...100 MW. Results of the examination on formation of the dense (np?1016 cm3), small sizes (le?100 eV in conditions of working material evaporation from the anode are given. The total contribution of energy to the discharge has made W < 20 J.

British Library Electronic Table of Contents (United Kingdom)

Bilayers of pure palladium and gold films were evaporated alternatively on (100) and (111) monocrystalline silicon substrates. After annealing, in a vacuum furnace from 100 to 650degreeC during 30min, the growth sequence of the Pd2Si and PdSi phases that evolved as the result of the diffusion reaction was examined by means of Rutherford backscattering spectrometry (RBS), X-ray diffraction (XRD), whereas the surface morphology was investigated by scanning electron microscopy (SEM) technique. The effect of the intermediate gold layer is investigated in order to test its effectiveness as barrier for Cu and Si atoms interdiffusion and its influence on the morphology of the formed palladium silicides. The effect of substrate orientation on the palladium silicides growth and formation was also e...

British Library Electronic Table of Contents (United Kingdom)

SummaryPermeable pavement functions as a porous infrastructure interface allowing the infiltration and evaporation of rainfall-runoff while functioning as a relatively smooth load-bearing surface for vehicular transport. Hydraulic conductivity (k) of permeable pavement is an important hydraulic property and is a function of the pore structure. This study examines k for a cementitious permeable pavement (CPP) through a series of pore-structure models. Measurements utilized include hydraulic head as well as total porosity, (t), effective porosity (e), tortuosity (Le/L) and pore size distribution (PSD) indices generated through X-ray tomography (XRT). XRT results indicate that the permeable pavement pore matrix is hetero-disperse, with high tortuosity and t!=e. Power law models of k-t and k-e...

Energy Technology Data Exchange (ETDEWEB)

Cold spray was employed as a novel low temperature approach to deposit titanium dioxide (TiO{sub 2}) photocatalytic film. The film microstructure was characterized using X-ray diffraction and scanning electron microscopy. The photocatalytic performance was examined through acetaldehyde degradation under ultraviolet illumination. Results showed that TiO{sub 2} film was successfully deposited on substrate surface through cold spray. The film thickness reached up to 15 {mu}m. The film presented a rough surface and porous structure. Owing to the low temperature of spray powder, no phase and particle size changes occurred to TiO{sub 2} during deposition. It was found that the cold-sprayed TiO{sub 2} film was active for photodegradation of acetaldehyde.

International Nuclear Information System (INIS)

Fe-Cr amorphous films have been formed by both in situ evaporation of multilayered films and ion beam mixing in a target chamber of a 200 keV implanter. The effects of Cr content and ion irradiation on the amorphization of films were examined by transmission electron microscope (TEM). Corrosion of film was investigated by means of a potential dynamic polarization. Corrosion resistance of amorphous film in 0.5 mol H-2SO-4 solution is considerably increased than that of pure iron. Using X ray photoelectron spectroscopy (XPS) corrosion resistance in atmosphere of amorphous Fe-Cr passive films formed by P"+ mixing was studied. Results show that the richness of Cr and P exist at the surface of Fe-Cr film.

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The ball-milling method was used to produce Mg-50 wt.% ZrFe{sub 1.4}Cr{sub 0.6} composite. The thermodynamic, kinetic, and cycling properties, as well as the resistance to oxidation were examined. This composite possesses excellent kinetic properties, even at moderate temperature. Scanning electron microscopy, energy-dispersive spectrum, transmission electron microscopy and X-ray diffraction were used to characterize the composite before and after hydriding. The fine ZrFe{sub 1.4}Cr{sub 0.6} particles covering Mg particles acting as a ''catalytic film'', a significant amount of imperfections and some alloy powder in the Mg matrix introduced by ball milling all contributed to the enhanced absorption/desorption rate. (orig.)

Science.gov (United States)

X-ray diffraction offers a unique combination of advantages for kinetic study which include the non-destructive nature of the measurement, the use of bulk crystals, and the convenience of the experimental arrangements. These attributes and the availability of position-sensitive detectors and high-flux synchrotron radiation sources make this technique most useful for in situ, dynamical investigations. When using diffraction techniques to determine a diffusion coefficient, the principle of analysis entails a scattering theory and a kinetic model. The former allows the kinetic parameter(s) to be extracted from measured intensity, while the latter relates the kinetic parameter(s) to the diffusion coefficient(s). Three examples are demonstrated: (1) Palladium Silicide (Pd{sub 2}Si) Layer Growth on Silicon, (2) Decomposition of an Ni-12.5at%Si Superalloy, and (3) Short-range Ordering in Cu-Au Solid Solutions.

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 findings.

International Nuclear Information System (INIS)

A method for the determination of stereotaxic coordinates in radiography, e.g. angiography, pneumoencephalography or digital vascular radiography, is described. A special localization frame containing radiopaque structures and scales defines a diagnostic coordinate system. This frame is fixed to the X-ray-table prior to the radiographic procedure and two projections are obtained at arbitrary angles to each other. The focus-film distances do not have to be fixed. The target coordinates are then determined either by a simple graphical procedure or with the use of a digitizing x-y-table, by a computer. With the computer method the films are placed on the digitizing table and the target and a few reference points are marked using a cursor. From the relative positions the computer calculates the coordinates. With the special head fixation system, coordinates of structures visualized in radiographic examinations can be transferred to various ...

International Nuclear Information System (INIS)

Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a ...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

In this study nanocrystalline powders of yttria-stabilized zirconia (ZrO_2-8Y_2O_3) have been synthesized through 'polymerized complex method'. Zirconium chloride, yttrium nitrate, citric acid and ethylene glycol were polymerized at 80 "oC to produce a gel-like mass in which metallic ions were uniformly distributed. During the thermal treatment of dried gel, nanocrystalline powder was formed at 450 "oC and 650 "oC for 2 h. Thermal reactions and crystalline phase formation of the dried gel were investigated through thermal analysis and X-ray diffraction analysis, respectively. The results of thermal analysis and XRD showed the formation of nanocrystalline powder at less than 600 "oC. Chemical bonding of the dried gel was investigated by Fourier transform infrared spectroscopy analysis. Morphology of powder calcined at 650 "oC was analyzed by scanning electron microscope. Yttria-stabilized zirconia powders with the mean crystallite size of 6 nm ...

CERN Document Server

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

British Library Electronic Table of Contents (United Kingdom)

A new cis-dioxomolybdenum complex MoO2(DMLA)2 (DMLA=N,N-dimethyllactamide) has been synthesized and characterized by X-ray crystallography, H NMR and IR spectroscopies and electronic structure calculations at DFT/B3LYP level. This compound (chemical formula C10H20MoO6N2) crystallizes in the orthorhombic space group P212121 with Z=4, a=6.9357(2)?, b=11.8761(4)?, c=17.7251(5), V=1460.00(8)?3 and renders a slightly distorted octahedral structure with two long Mo-O bonds (2.253(3)? and 2.257(3)?) trans to each of the MoO groups and with two short Mo-O bonds of 1.942(3)4? cis to them. The MoO bond length are 1.715(3) and 1.704(3)?). Each lactamide ligand is bidentate; they are coordinated in their deprotonated form with the carbonyl oxygen occupy...

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. ...

UK PubMed Central (United Kingdom)

Designer cellulosomes are precision-engineered multienzyme complexes in which the molecular architecture and enzyme content are exquisitely controlled. This system was used to examine enzyme cooperation...Full Text Available

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

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

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).

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 ...

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.

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.

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).

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)

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 ...

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

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Abstract not provided

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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.

International Nuclear Information System (INIS)

Slovak May 1981. p. 30. Czechoslovakia Sandrik, R. Kliment, V.

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

Science.gov (United States)

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

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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.

Science.gov (United States)

Not Available

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.).

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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.

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).

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).

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).

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.

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.

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 captured a noncatalytically competent ...

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 ...

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New platinum(II) complexes with asymmetrically substituted chiral diamine ligands A{sub 2}PtX{sub 2}, (A{sub 2}=NH{sub 2}CH(CH{sub 3})CH{sub 2}NH(c-C{sub 5}H{sub 9}) (apcpa), NH{sub 2}CH(CH{sub 3})CH{sub 2}NH(c-C{sub 6}H{sub 11}) (apcha); X{sub 2}=2Cl, isopropylidenmalonate (IPM), 1,1'-cyclobutandicarboxylate (CBDCA) have been synthesized and characterized by means of elemental analyses, infrared and NMR spectroscopies, and X-ray crystallography. The crystal structures of (S-apcha)Pt[CBDCA]{center_dot}3H{sub 2}O (orthorhombic, P2{sub 1}2{sub 1}2(No. 18), a=6.926(3), b=15.243(3), c=19.319(4) A, V=2039.5(10) A{sup 3}, Z=4, R=0.072) and (S-apcha)Pt[IPM]{center_dot}2.5H{sub 2}O (monoclinic, P2/c(No. 13), a=9.882(1), b=18.502(1), c=22.056(1) A, V=4032.8(5) A{sup 3}, Z=8, R=0.093) exhibit that the platinum atoms achieve a typical square planar arrangement with two nitrogen atoms in cis position and with the chiral center retained. The ...

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 ...

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.

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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.

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Electrodeposited Zn alloys with Fe group metals are known to be more resistant than pure Zn. However, the role of the corrosion products on the corrosion inhibition is not considered up to date. The aim of the present work was to examine the composition of corrosion products, which form on the Zn and Zn alloy surfaces under atmospheric corrosion conditions up to 3 year of exposure, trying to correlate it with the differences in their corrosion resistance. Zn corrosion products have been characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Corrosion film composition was determined to depend on the sample exposure she, as well on the coating type. During the initial exposure stages oxide film was found to be the principal reaction product (XPS data), which in marine station consists from hydroxide phase exceptionally, while in urban one, contain up to 6-12 % of oxide. Succeeding corrosion ...

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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 ...

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.

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 ...

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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 ...

CERN Document Server

Increasing the speed and complexity of semiconductor integrated circuits requires advanced processes that put extreme constraints on the level of metal contamination allowed on the surfaces of silicon wafers. Such contamination degrades the performance of the ultrathin SiO sub 2 gate dielectrics that form the heart of the individual transistors. Ultimately, reliability and yield are reduced to levels that must be improved before new processes can be put into production. It should be noted that much of this metal contamination occurs during the wet chemical etching and rinsing steps required for the manufacture of integrated circuits and industry is actively developing new processes that have already brought the metal contamination to levels beyond the measurement capabilities of conventional analytical techniques. The measurement of these extremely low contamination levels has required the use of synchrotron radiation total reflection X-ray ...

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.

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The paper presents the preparation, X-ray powder diffraction data as well as some magnetic and spectroscopic properties of a new uranium(III) complex bromide of the formula NH{sub 4}UBr{sub 4}.1.5CH{sub 3}CN.6H{sub 2}O. The compound crystallizes in the monoclinic system with a=11.877 A, b=6.385 A, c=6.815 A, {beta}=101.29deg and Z=2. In the 60-240 K range it follows the Curie-Weiss law with {theta}=-37.24 K and {mu}{sub eff}=3.20 B.M. The IR and UV-VIS absorption spectra were recorded in the 80-4000 cm{sup -1} and 4000-26000 cm{sup -1} spectral ranges respectively. Thermal decomposition at a non-static high vacuum enabled the conversion of the compound into pure and anhydrous UBr{sub 3}. (orig.).

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

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 ...

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This work presents a comparative study of low-alloy steel nitriding for different possible techniques. Active screen plasma nitriding (ASPN) is a successful surface modification method that has many advantages over the conventional DC plasma nitriding (CPN). The corrosion behavior of 30CrNiMo8 low-alloy steel has been examined using anodic polarization tests in 3.5% NaCl solution under varying conditions of ASPN and CPN processes. The process variables included active screen setup parameters, treatment temperature (550 and 580 deg. C), gas mixture (25/75 and 75/25 of N{sub 2}/H{sub 2}) and treatment time (5 and 10 h) in 500 Pa pressure. The structure and phases composition of the compound layer was studied by X-ray diffraction (XRD), microhardness tests, optical microscopy and scanning electron microscopy (SEM). It was observed that ASPN treated samples surface enhanced corrosion resistance while the temperature and/or hole size of screen setup ...

Energy Technology Data Exchange (ETDEWEB)

Several types of coatings have previously been visually identified on the surface of 105-K East and 105-K West Basins fuel elements. One type of coating (found only in K West Basin) in particular was found to be a thick translucent material that was often seen to be dislodged from the elements as flakes when the elements were handled during visual examinations (Pitner 1997). Subsequently it was determined (for one element only in a hot cell) that this material, in the dry condition, could easily be removed from the element using a scraping tool. The coating was identified as Al(OH){sub 3} through X-ray diffraction (XRD) analyses and to be approximately 60 {micro}m thick via scanning electron microscopy (SEM). However, brushing under water in the basin using numerous mechanical strokes failed to satisfactorily remove these coatings in their thickest form as judged by appearance. Such brushing was done with only one type of metal brush, a brush ...

Science.gov (United States)

Superconductivity of binary alloys spanning the A-15 compounds V/sub 3/Si, V/sub 3/Ge, V/sub 3/Ga, and V/sub 3/Al and the pseudobinary derivatives of these stoichiometric compounds was surveyed by studying samples prepared by rf-sputtering from alloy cathodes. The possible formation of the hypothetical A-15 binaries ''V/sub 3/P,'' ''V/sub 3/B,'' and ''V/sub 3/C'' and their pseudobinary formation with V/sub 3/Si was also explored. Efforts to form these hypothetical alloys were not successful. The T/sub c/'s were measured resistively and the structure and lattice constants were determined by x-ray analysis. A maximum T/sub c/ of 11.7/sup 0/K was obtained for A-15 V/sub 3/Al, and the importance of a suitable deposition temperature and high sputtering pressures was examined. It is proposed that large variations of T/sub c/ among ...

International Nuclear Information System (INIS)

Hybrid organic-inorganic coatings with phosphonate functionalities have been synthesized and evaluated as prospective surface treatments for magnesium materials. These coatings have been processed via a sol-gel route by hydrolysis and condensation of a mixture of diethylphosphonatoethyltriethoxy-silane and tetraethoxy-silane with variable molar ratios. The coatings morphology and the surface chemistry at the coating/substrate interface have been characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, "3"1P nuclear magnetic resonance spectroscopy, and time-of-flight secondary ion mass spectrometry. The corrosion protection performance of the coatings deposited on magnesium alloy AZ31B has been examined by a group of electrochemical techniques including potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, a scanning Kelvin probe technique has been used to investigate interfacial ...

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

International Nuclear Information System (INIS)

The adsorption capacity of radionuclides onto suspended sediment was experimented on each of the coastal seawater sampled around the Kori and the Wolsung nuclear power plant. During the experiment the quantity and size fraction of suspended sediment were adjusted and the seawater and sediment chemistry is approximated to the expected field condition. Because the sorption capacity depends on the specific minerals, ocean chemistry and radionuclide involved, it is necessary to analyze sediment mineralogy. Clay mineral is dominant in seabed mineral and suspended sediment as the result of x-ray diffraction. Radionuclide sorbed to silty-clay mineral can be rather transported to ocean than scavenged to seabed because of low quantity and fine grained suspended sediment in the coast around the Kori and the Wolsung. The result of adsorption examinations shows that "1"3"9Ce and "5"1Cr and "1"1"0"mAg are strongly sorbed to suspended particle, while ...

International Nuclear Information System (INIS)

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

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Powders with nominal compositions (in atomic percent) Ti-48Al and Ti-48Al-2Nb-2Cr were prepared by the plasma rotating electrode process (PREP) and gas atomization (GA) techniques. As-solidified and heat-treated (1000degC per 3 h) powder samples were examined by metallography, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The microstructures of the powders were characterized as a function of atomization technique, alloy content, powder particle size (solidification rate) and thermal history. All of the as-solidified powders were comprised of disordered [alpha], and ordered [alpha][sub 2]-Ti[sub 3]Al and [gamma]-TiAl. For both alloys, a larger volume fraction of [alpha] and [alpha][sub 2] was observed in the PREP powders relative to GA powders of comparable size. Additionally, for both alloys and both atomization techniques, the volume fraction of [alpha][sub 2] was observed to increase with decreasing ...

International Nuclear Information System (INIS)

The composite of doped lanthanum gallate (La_0_._9Sr_0_._1Ga_0_._8Mg_0_._2O_2_._8_5, LSGM) and doped ceria (Ce_0_._8Sm_0_._2O_1_._9, CSO) was investigated as an electrolyte for solid oxide fuel cell (SOFC). The LSGM-CSO composite was examined by X-ray diffraction (XRD) and impedance spectroscopy. It was found that the sintered LSGM-CSO composite contains mainly fluorite CeO_2 phase and a minority impurity phase, Sm_3Ga_5O_1_2. The LSGM-CSO composite electrolyte shows a small grain boundary response in the impedance spectroscopy as compared to LSGM and CSO pellets. The composite electrolyte exhibits the highest conductivity in the temperature range of 250-600 "oC, compared to LSGM and CSO. The LSGM-CSO composite can be expected to be an attractive intermediate temperature electrolyte material for solid oxide fuel cells.

CERN Document Server

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\\Gamma_{\\rm pe} = 1.2\\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\\cal D}/10^{-4})(n_{\\rm H}/10^{-5} {\\rm cm^{-3}})^{4/3} (J_{\\rm L}/10^{-21} {\\rm erg s^{-1} cm^{-2} Hz^{-1} sr^{-1}})^{2/3} (T/10^4 {\\rm K})^{-1/6}$, where ${\\cal D}$ is the dust-to-gas mass ratio, $n_{\\rm H}$ is the hydrogen number density, $J_{\\rm L}$ is the mean intensity at the hydrogen Lyman limit of the background radiation, and $T$ is the gas temperature, if we assume the new X-ray photoelectric yield model by Weingartner et al. (2006) and the dust size distribution in the Milky Way by Mathis, Rumpl, & Nordsieck (1977). This heating rate dominates the HI and HeII photoionization heating rates when the hydrogen number density is less than $\\sim10^{-6}$ cm$^{-3}$ if ${\\cal D}=10^{-4}$ which is 1% of that ...

CERN Document Server

HD 100453 has an IR spectral energy distribution (SED) which can be fit with a power-law plus a blackbody. Previous analysis of the SED suggests that the system is a young Herbig Ae star with a gas-rich, flared disk. We reexamine the evolutionary state of the HD 100453 system by refining its age (based on a candidate low-mass companion) and by examining limits on the disk extent, mass accretion rate, and gas content of the disk environment. We confirm that HD 100453B is a common proper motion companion to HD 100453A, with a spectral type of M4.0V - M4.5V, and derive an age of 10 +/- 2 Myr. We find no evidence of mass accretion onto the star. Chandra ACIS-S imagery shows that the Herbig Ae star has L_X/L_Bol and an X-ray spectrum similar to non-accreting Beta Pic Moving Group early F stars. Moreover, the disk lacks the conspicuous Fe II emission and excess FUV continuum seen in spectra of actively accreting Herbig Ae stars, and from the FUV ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

Carbon supported catalysts can lose their activity over a period of time due to the sintering of the nanometer-sized catalyst particles. The sintering of metal clusters on carbon supports can occur due to the weak interaction between the metal and the support and also due to the corrosion of carbon, especially in fuel cell electrocatalysts. The sintering may be reduced by increasing the interaction between the metal and the support and also by increasing the corrosion resistance of carbon supports. In an effort to mitigate the growth of the nanoparticles, carbon-substituted boron defects were introduced in the carbon lattice. The interaction between the Pt nanoparticles on the pure and boron-doped carbon supports was examined using X-ray photoelectron spectroscopy (XPS). The results indicate that the interaction between the Pt nanoparticles and the boron-doped carbon support was slightly stronger than the interaction between the Pt ...

International Nuclear Information System (INIS)

The distribution of lead in lactating mice and suckling offspring was studied with whole body autoradiography at 4 and 24 h after a single intravenous injection of "2"0"3Pb (50 mmol Pb/kg) to the dams. In the lactating mice on day 14 of lactation, the highest uptake of radioactivity at 4 h after administration was recorded in renal cortex, skeleton and liver. A high uptake was also evident in the mannary gland. At 24 h after administration, the radioactivity had decreased in most organs except in the skeleton. In the suckling pups, exposed to lead only via dams' milk for 24 h, the highest level of radioactivity was present in the intestinal mucosa and a much lower level of radioactivity was present in the skeleton. The mammary glands from mice given three daily intravenous injections of 240 #mu#mol Pb/kg were examined with X-ray microanalysis. At 4 h after the last injection, lead was found associated with casein micelles both inside the ...

International Nuclear Information System (INIS)

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

Science.gov (United States)

Multiple treatment of engineering surfaces can provide improved surface properties that cannot be obtained by a single surface treatment. Consequently, this study investigates the effects of laser melting on the microstructures of plasma nitrided Ti-6Al-4V alloy. The study consists of two parts. In the first part, governing equations pertinent to the laser melting process are developed, and temperature variation across the melted zone is predicted. In the second, an experiment is conducted to nitride the surface of the alloy through plasma nitriding process and to melt the plasma nitrided and the untreated alloy surfaces with a CO2 laser beam. The resulting metallurgical changes are examined using x-ray diffraction (XRD), bdenergy-dispersive spectrometry (EDS), and scanning electron microscopy (SEM) techniques. It is shown that three distinct nitride layers are formed in the vicinity of the alloy surface prior to the laser melting process, and ...

Energy Technology Data Exchange (ETDEWEB)

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

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...

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.

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.

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.

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.

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.

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.

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.

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.