[en] Using scanning microscopy shape and orientation of pores in ZnNi(Co)Fe₂O₄ were studied

[en] Fracture stress data obtained by tensile testing of circumferentially notched round tensile specimens made of 20MnMoNi55 and SA333 (Grade 6) steels at different subzero temperatures down to −150 °C have been analysed following Weibull statistics. It is observed that between −50 and −100 °C the mean Weibull modulus of 20MnMoNi55 steel obtained by employing linear regression technique over the complete range of data population for every test temperature increases in a perfectly linear manner with lowering of test temperature. A sharp decrease in the modulus value with further decrease of test temperature to −150 °C is observed. The data population for −50 and −70 °C, however, do not agree well with single straight-line relationship of Weibull statistics. In case of SA333 (Grade 6) steel nearly two fold increase in the value of mean Weibull modulus is observed on lowering of test temperature from −100 °C to −150 °C. Scanning electron fractography reveals different failure modes in both the steels depending upon test temperatures

[en] As the uranium foils for Mo-99 irradiation target, which are charged into a reactor, can be conventionally fabricated at laboratory scale, but not yet at a commercialized scale by a hot rolling method due to some problems in foil quality, productivity and economic efficiency, an attention has shifted to the development of new improved technology. Under these circumstances, an alternative fabrication method of U polycrystalline foils has been investigated using a cooling roll casting method, in order to produce a fission isotope ⁹⁹Mo, the parent nuclide of ^99mTc. The fabrication method of wide LEU foils produced by a coolingroll casting was recently developed to improve the quality of the uranium foils and the economic efficiency of the foil fabrication with modifications of the casting apparatus and adjustments of the process parameters. A continuous polycrystalline LEU foil with a thickness range of 100 to 150μm and a width of about 50 mm, exceeding 5m in length for a batch procedure, could be fabricated with a better quality of the uranium foil and a higher yield of the foil fabrication, through improvements of the casting apparatus and variations of the process parameters

No abstract available

[en] A method for aligning an electron-beam with selected portions of the surface of an irradiated element is presented (miniaturized component fabrication). A plurality of reference-members of predetermined shapes capable of emitting X-rays is first formed, then at least one of these reference-members is irradiated with an aligned portion of an electron beam of predetermined cross-section, the X-ray emissions from the irradiated reference-members are detected and the electron beam is moved along the element so as to align said beam with the different reference members sequentially

No abstract available

[en] To follow an heart transplantation, EBCT is more precise than ultrasonography and scintigraphy to calculate a stroke volume. In lung transplantation, it is important before surgery to know the value of right ventricle stroke volume in order to choice the surgical protocol. After lung transplantation SFE helps to follow the patient to look after complications, to drain a collection or to guide a biopsy. SFE contribution is discussed in rejection, infectious diseases, detection of immuno-induced carcinomas, in bronchiolitis obliterans and recurrence of the primitive disease. (authors). 6 refs., 8 figs

[en] The LAMA laboratory of the Grenoble Nuclear Research Center participates in studies carried out by research teams on fuels. Post-irradiation studies are performed on irradiated pins for research and development and safety programs. A scanning electron microscope was acquired for this purpose. This microscope had to fulfill certain criteria: it had to be sufficiently compact for it to be housed in a lead enclosure; it had to be capable of being adapted to operate with remote handling control. The modifications made to this microscope are briefly described together with the ancillary equipment of the cell. In parallel with these operations, an interconnection was realized enabling materials to be transferred between the various sampling and sample preparation cells and the microscope cell with a small transfer cask. After two years operating experience the microscope performance has been assessed satisfactory. The specific radioactivity of the samples themselves cannot be incriminated as the only cause of loss in resolution at magnifications greater than x 10,000

[en] We studied 44 patients with focal benign (n = 13) or malignant (n = 31) liver tumors proved by histology or follow-up. The flow mode was acquired by electron beam CT (EBCT) after injection (35 cc at 6 ml/sec): 20 slices with a 400 ms exposure time. We looked for abnormal vessels and density curves inside the tumor, liver and aorta. We describe arterial vascularization in most cases (type 1) and particularly in all the hepatocarcinomas (n = 15) associated with abnormal vessels, and also in rare tumors (n = 4). For benign lesions like angiomas (n = 9) we showed surrounding the mass arterial vascularization in add to the typical aspect (type 3); for nodular hyperplasia (n = 3) arterial blush was associated with the last part of the tumoral curve at the same level as liver. Most often metastasis (n = 13) had no central vascularization and a slight peripheral density increased (type 2). Flow mode by EBCT allows a good density curves analysis particularly at arterial time. (authors). 20 refs., 12 figs

[en] The principal metallurgical uses of the scanning electron microscope and the microprobe described here employ images obtained on a CRT from an electron signal or X rays. The various electron signals are the back scattered electrons, secondary electrons and absorbed electrons. The differences in the intensity of thee signals with the acceleration tension E₀, the inclination angle β, the atomic number Z of the target and any potential applied to the sample give rise to contrasts: atomic number contrast, given by the sample current or the back scattered electrons; topographical contrast, given by the emission of the secondary electrons Δ that vary with α (the angle between the normal to the surface and the direction of the incident beam)