This paper presents the synthesis and characterization of BSCCO superconducting fibers synthesized by heattreating poly(vinyl pyrrolidone) (PVP)/BSCCO precursor microfibers produced by the solution blow-spinning technique. Different concentrations (v/v) of the BSCCO precursor were added to the PVP solution to evaluate the influence of solution viscosity on fiber morphology. The production of PVP/BSCCO microfibers and their morphology were strongly influenced by the volatility of the solvent and the concentration of the added BSCCO in the solution. After heat-treatment, fibrous structures were obtained for the BSCCO system. The structural properties of the samples were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD pattern revealed the formation of Bi 2 Sr 2 Ca 1 Cu 2 O x and Bi 1,9 Sr 1,8 CuO 5,5 phases. Finally, electrical measurements (R×T) showed electrical resistance decay at the transition temperature (Tc) that was typical of that observed in superconductor materials.

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In this work we report the preparation of a superconductor thin film of the BSCCO system using a good quality powder with nominal composition Bi 1.8 Pb 0.4 S r 2 CaCu 2 O x which was thermally treated using a domestic microwave oven (2.45 GHz, 800 W). This film was grew on a single crystal of LaAlO 3 (100) substrate and exhibited a crystalline structure with the c-axis perpendicular to the plane of the substrate. An onset superconducting transition temperature was measured at 80 K.

Abstract Know the precision of potential evapotranspiration models in different agronomic and climatic conditions is useful for irrigated agriculture. Therefore, we aimed to compare 18 methods of estimation of ETP with the Penman-Monteith (FAO-56) method, at different time scales for the State of Mato Grosso do Sul. Time series of climatic data were used on a daily scale between 1983 and 2018 from 22 locations in the state of Mato Grosso do Sul. ETP estimation models tested were: Benevidez-Lopez, Blaney-Criddle, Camargo, Hamon, Hargreaves, Hargreaves-Samani, Jensen-Haise, Jobson, Kharrufa, Linacre, Makkink, Penman, Priestley-Taylor, Radiation, Romanenko, Tanner-Pelton, Thornthwaite, and Turc. These models were compared with Penman-Monteith in daily, weekly, and monthly scales. The comparison between the ETP estimation models and the Penman-Monteith model was performed by the statistical indices: accuracy (MAPE) and precision (R2aj). Estimation methods showed differences in efficiency over time scales. The best performances of the models were on the daily scale. For daily scale, methods of Priestley-Taylor, Hargreaves, Hamon, and Makkink present the best values of accuracy and precision for the State of Mato Grosso do Sul. In the weekly scale, the most accurate methods are Hamon and Makkink, while for monthly scale the best methods are Makkink and Priestley-Taylor.