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The paper presents the current status of Ente per le Nuove tecnologie, ĽEnergia e ĽAmbiente research on the processing of high-irreversibility-field superconductor YBa2Cu3O7-x. (YBCO) tapes, useful for power application. A major part of this review is concerned with buffer layer growth, because this is the most important stage in the YBCO thick-film fabrication on biaxially textured metallic substrates. Several architectures are presented: CeO2/Pd/Ni, CeO2/(Ni-V) and CeO2/NiO/(Ni-V). For all the buffer layer structures the top CeO2 film was deposited by pulsed-laser deposition, while the Pd film was grown by electron-beam evaporation. The observed epitaxial orientation is [001]. The properties of a new non-magnetic Ni-V alloy substrate, as well as the preliminary results on superconducting multilayer structures, are also presented. The YBCO film grown on the CeO2/NiO/(Ni-V) configuration has the critical temperature Tc onset of 90.9 K, zero resistance at 86 K and the critical current density Jc =...

The volume-pressure relationship of the lung was studied in six subjects on changing the gravity vector during parabolic flights and body posture. Lung recoil pressure decreased by ∼2.7 cmH2O going from 1 to 0 vertical acceleration (Gz), whereas it increased by ∼3.5 cmH2O in 30° tilted head-up and supine postures. No substantial change was found going from 1 to 1.8 Gz. Matching the changes in volume-pressure relationships of the lung and chest wall (previous data), results in a decrease in functional respiratory capacity of ∼580 ml at 0 Gz relative to 1 Gz and of ∼1,200 ml going to supine posture. Microgravity causes a decrease in lung and chest wall recoil pressures as it removes most of the distortion of lung parenchyma and thorax induced by changing gravity field and/or posture. Hypergravity does not greatly affect respiratory mechanics, suggesting that mechanical distortion is close to maximum already at 1 Gz. The end-expiratory volume during quiet breathing corresponds to the mechanical functional residual capacity in each condition.

To study pulmonary arteriolar vasomotion in control conditions and in the transition to hydraulic edema, changes in subpleural pulmonary arteriolar diameter and perivascular interstitial volume were evaluated in anesthetized spontaneously breathing rabbits. Images of subpleural pulmonary microvessels were recorded in control conditions and for up to 180 min during a 0.5 ml x kg(-1) x min(-1) intravenous saline infusion through an intact parietal pleural window. Images were digitized and analyzed with a semiautomatic procedure to determine vessel diameter and perivascular interstitial thickness from which interstitial fluid volume was derived. In control vessels, the diameter of approximately 30-, approximately 50-, and approximately 80-microm arterioles and the perivascular interstitial thickness were fairly stable. During infusion, the diameter increased maximally by 20% in approximately 30 microm vessels, was unchanged in approximately 50 microm vessels, and decreased by 25% in approximately 80-microm arterioles; the perivascular interstitial volume increased by 54% only around 30-microm microvessels. In papaverine-treated rabbits, all arterioles dilated and a larger increase in perivascular interstitial thickness was observed. The data suggest that the opposite vasomotor behavior of 30- and 80-microm arterioles during development of mild edema may represent a local specific response of the pulmonary microcirculation to reduce capillary pressure in the face of an increased transendothelial fluid filtration, thus counteracting progression toward severe edema.