[en] The purpose of the present report was to assess the high-resolution computed tomography (HRCT) findings in a group of patients diagnosed as having hypersensitivity penumonitis. HRCT was performed in 10 patients (6 women and 4 men) aged 19 to 56 years (mean: 36.5 years) who presented acute-subacute symptoms of hypersensitivity pneumonitis. Thin-section (1.5 mm) HRCT was carried out at the time of diagnosis all 10 patients, and 6 underwent follow-up HRCT studies. Plain chest X-ray was normal in the three cases. The most relevant HRCT findings were the presence of a nodular pattern (n=9) and ground-glass opacity (n=8). Focal areas of decreased density were observed in 4 cases. Mediastinal adenopathy was detected in 4 patients. The HRCT findings characteristic of hypersensitivity pneumonitis are centrilobular nodules and ground-glass opacity. (Author) 10 refs

[en] The study involved inducing mutations in the varieties Icta-Virginia and Precozicta to obtain genotypes that mature early, are resistant or tolerant to Pyricularia oryzae and have a high yield potential. To optimize the radiation dose for each variety, seeds were irradiated with doses of 0, 150, 200, 250, 300 and 400 Gy. Six thousand seeds of each variety were irradiated with the above doses to establish the M₁ generation, in which the physiological effects and somatic mutations were observed. The M₂ generation was sown in progeny groups and as the crop developed, mutants with chlorophyll changes, morphological changes, improved yield, tolerance to Phyricularia oryzae and mutants which matured earlier than the original variety were identified and selected. In the M₃ generation, derived from the Icta-Virginia and Precozicta varieties, the genetic stability of mutants with morphological changes, chlorophyll changes, tolerance to Pyricularia oryzae (classified as 0-1 on the 0 to 9 scale of the standard rice evaluation system) and those which matured earlier (15 to 20 days) than the original variety was confirmed. (author). 7 refs, 3 tabs

[en] The strong strain sensitivity of the critical properties of Nb₃Sn is well established. However, the roles played by both the reversible strain sensitivity and the susceptibility to brittle fracture of Nb₃Sn filaments is still leading to unexpected results and resulting design modifications of conductors. Practical conductors require acceptance of less than perfect superconducting behaviour because such conductors actually operate continuously in a slightly resistive mode. Performance testing of the ITER conductors has provided a unique database of both strand and corresponding conductor performance. The test database includes strand characterization under uniaxial and bending strain, superconducting measurements on full-size conductor samples and microscopic investigations into filament fracture. A simple mechanical and electrical model of the strands and a multistage cable (capable of operation at 12 T and 45 kA) that focuses on predicting the imperfect superconducting behaviour is used to provide insight into the processes governing the observed conductor behaviour. The conclusions show that a short twist pitch at the first cabling stage provides the best operating conditions for the strands, and further that some strand mechanical properties, essentially a high stiffness to bending and a low stiffness to pinching, increase the ability of the strands to tolerate less well optimized cables. (paper)

[en] The differences in thermal contraction of the composite materials in a cable in conduit conductor (CICC) for the International Thermonuclear Experimental Reactor (ITER), in combination with electromagnetic charging, cause axial, transverse contact and bending strains in the Nb₃Sn filaments. These local loads cause distributed strain alterations, reducing the superconducting transport properties. The sensitivity of ITER strands to different strain loads is experimentally explored with dedicated probes. The starting point of the characterization is measurement of the critical current under axial compressive and tensile strain, determining the strain sensitivity and the irreversibility limit corresponding to the initiation of cracks in the Nb₃Sn filaments for axial strain. The influence of spatial periodic bending and contact load is evaluated by using a wavelength of 5 mm. The strand axial tensile stress–strain characteristic is measured for comparison of the axial stiffness of the strands. Cyclic loading is applied for transverse loads following the evolution of the critical current, n-value and deformation. This involves a component representing a permanent (plastic) change and as well as a factor revealing reversible (elastic) behavior as a function of the applied load. The experimental results enable discrimination in performance reduction per specific load type and per strand type, which is in general different for each manufacturer involved. Metallographic filament fracture studies are compared to electromagnetic and mechanical load test results. A detailed multifilament strand model is applied to analyze the quantitative impact of strain sensitivity, intrastrand resistances and filament crack density on the performance reduction of strands and full-size ITER CICCs. Although a full-size conductor test is used for qualification of a strand manufacturer, the results presented here are part of the ITER strand verification program. In this paper, we present an overview of the results and comparisons. (paper)