Search

In the tobacco plantations in Cuba, in the last years the blue mold and the black shank have become the most harmful illnesses for the cultivation of tobacco. In the Experimental Station of the Tobacco of Cabaiguán county of Sancti Spiritus, during the tobacco campaigns 2001-2002, 2002-2003 and 2003-2004 were carried out a comparative test with nine varieties obtained in previous works, resistant to the blue mold and the black shank with the objective of selecting an or more varieties for the tobacco production of the central and oriental counties of the country. An experimental design of blocks was used at random, with four repetitions and the characters were measured: total height of the plant with inflorescence, days to blossom, width of green sheet, number of useful leaves, longitude and with of the central leaf, distance between knots, net yield and yield in superior classes and stockings in the selection of the dry tobacco. The studied varieties introduced morphological characteristic superior or similar 1 to the witness. In the value of total yield there was not significant difference. In yield of superior classes the lines 3 and 7 overcame significantly to the variety 'Sancti Spiritus-96'. [ABSTRACT FROM AUTHOR] more...

In the tobacco plantations in Cuba, in the last years the blue mold and the black shank have become the most lowering illnesses for the cultivation of the tobacco. In the Experimental Station of the Tobacco of Cabaiguán county of Sancti Spiritus, during the tobacco campaigns 2001-2002, 2002-2003 and 2003-2004 were carried out a comparative test with nine varieties obtained in previous works, resistant to the blue mold and the black shank with the objective of selecting an or more varieties for the tobacco production of the central and oriental counties of the country. An experimental design of blocks was used at random, with four repetitions and the characters were measured: total height of the plant with inflorescence, days to blossom, width of green sheet, number of useful leaves, longitude and with of the central leaf, distance between knots, net yield and yield in superior classes and stockings in the selection of the dry tobacco. The studied varieties introduced morphological characteristic superior or similar l to the witness. In the value of total yield there was not significant difference. In yield of superior classes the lines 3 and 7 overcame significantly to the variety 'Sancti Spiritus-96' [ABSTRACT FROM AUTHOR] more...

Abstract: The aim of this work has been the systematic study of the influence of partial substitution of Fe by Ni in the Ni x Fe73.5−x Si13.5B9Nb3Cu1 alloy within the range 0⩽ x ⩽10% atom (x =0,2,4,6,8,10) on electrochemical behavior, corrosion rate and the structural changes in amorphous and nanocrystalline alloys. The amorphous nature of the alloys was confirmed by X-ray diffraction and the chemical compositions were determined by ICP. The glass transition and kinetic crystallization of amorphous alloys were studied by DSC. The technique of XPS was used for evaluating the chemical states of elements present in native oxide films. The electrochemical behavior of amorphous and nanocrystalline alloys have been investigated in 0.5M KOH using cyclic voltammetry. The experimental results show that the formation of different nanocrystalline phases is not excessively transformed by the addition of small amount of nickel and the electrochemical behavior is improved as nickel content increased. [Copyright &y& Elsevier] more...

Shot peening is a well-established surface treatment commonly used to improve mechanical properties of material's surfaces. Studies have shown notable enhancement of fatigue strength, wear, scratch and corrosion resistance and fretting properties as a result of an intensive shot peening treatment, the so-called severe shot peening. Nevertheless, this process has some drawbacks including quite high surface roughness and possible embedment of shot residuals at the treated surface, which can have adverse effects depending on the final application. In this paper, electropolishing has been evaluated as a cleaning post-treatment for shot peened surfaces of 316L stainless steel. For this purpose, electropolishing voltage has been varied with the aim of obtaining clean and smoother surfaces without sacrificing the mechanical improvements produced by shot peening. The treated surfaces have been characterized considering surface roughness, morphology, wettability, residual stresses and microhardness evolution after various shot peening treatments combined with electropolishing using different parameter set-ups to identify the most promising combinations. Unlabelled Image • Peened surfaces are rough with embedded residual shots, adverse for some applications. • Electropolishing selectively produces bright, clean and smooth surfaces. • An effective electropolishing cleaning treatment was suggested for peened surfaces. • Mechanical improvement produced by shot peening were maintained after electropolishing. [ABSTRACT FROM AUTHOR] more...

Dear Editor, Erosive pustular dermatosis of the leg (EPDL) is a rare inflammatory cutaneous disease characterized by nonfollicular sterile pustules, erosions and crusts on an erythematous background.[1] EPDL generally affects the middle third of the leg, typically in elderly patients. Indeed, 10 out of 23 patients (43%) in the TC-only group relapsed, whereas four out of 28 patients (14%) treated with both TC and topical zinc oxide relapsed. On the basis of our results, topical zinc oxide may represent a valid, easy and cheap therapeutic strategy for maintenance therapy of EPDL, after TCs have achieved their anti-inflammatory role in the acute phase. [Extracted from the article] more...

Microstructural (crystalline volume fraction and grain size), magnetization (coercive field), and saturation magnetostriction measurements in Fe73.5-xNixSi13.5B9Nb3Cu1 alloy ribbons (x=5, 10, and 20) treated by current annealing and stress-current annealing are presented. Microstructural analysis of the treated ribbons using x-ray diffraction showed a high content of the amorphous phase in the bulk. In addition, substantial changes in the crystalline state such as grain size of the samples annealed at different conditions were observed. The alloy composition also affects greatly the grain size: increase in Ni content leads to higher values of the average grain size. The evolutions of the coercive field with the two kinds of thermal treatment were analyzed, allowing us to conclude that the addition of Ni tends to reduce the magnetic softness of the original material and that the coercivities are higher in the samples treated by stress annealing than in those treated without tensile stress. On the other hand, the saturation magnetostriction decreases with the thermal treatment, which is in agreement with the microstructural behavior (structural relaxation and nanocrystallization process), although some discrepancies are found for samples with x=5. [ABSTRACT FROM AUTHOR] more...

The changes in the magnetic properties (coercive field and saturation magnetostriction) of Ni5Fe68.5Cu1Nb3Si13.5B9 amorphous alloy after thermal treatment are reported. In order to develop a nanocrystalline structure, the thermal annealing was carried out by Joule heating currents of 1.7 and 1.8 A during different annealing times. Additionally, a microstructural characterization of the treated samples was performed by x-ray diffraction, determining the partial volume of the two, crystalline grains and residual amorphous matrix, existing phases. They seem to be correlated to the softening of the nanocrystallized samples in comparison to the as-cast one. [ABSTRACT FROM AUTHOR] more...

Abstract: The effect of Cr replacement for Fe on the kinetics of Cu clustering and on the electrochemical behavior of Fe73.5−X Cu1Nb3Si13.5B9Cr X amorphous alloys has been studied for improving the corrosion resistance of Fe–Si–B–Nb–Cu Finemet type alloys. The corrosion testing of these materials was performed in 0.5M KOH solutions using AC impedance measurements. These experimental results are discussed from the thermodynamical point of view, and the optimized microstructure to achieve a high corrosion resistance has been found. [Copyright &y& Elsevier] more...

Abstract: Different kinds of magnetic anisotropies have been induced during the nanocrystallization process of Co- and Ni-rich amorphous ferromagnetic (Finemet) ribbons using diverse procedures like the application of a constant stress or an axial magnetic field during the annealing process. Magnetization measurements have evidenced the anisotropy of the treated samples. The main goal of this work has been the structural and microstructural analysis of the treated ribbons using X-ray Diffraction (XRD) and Atomic Force Microscopy (AFM), detecting substantial differences in the crystallization state and grain size of the samples depending on the treatment that was carried out. Moreover, AFM measurements revealed in all the treated samples a strong nanocrystallization of the surface without evidences of amorphous matrix, which contrast with XRD measurements that have shown a high content of amorphous phase in the bulk of the ribbons. Magneto-optical Kerr effect measurements have been performed with the aim to elucidate the complex magnetic behavior that is expected for the surface of the ribbons, measuring surface hysteresis loops that show much higher coercive field values than in the bulk. [Copyright &y& Elsevier] more...

Abstract: In this work a study of the variation of the surface magnetic properties with oxidation in the Finemet amorphous alloy in the as-quenched state and after relaxation at 400°C for 30min is presented. The surface magnetization was obtained by the transverse magneto-optic Kerr effect. The results show that the Kerr intensity is higher in the relaxed samples than in the as-quenched ones with the same cycles of oxidation. In addition the surface saturation magnetization in the relaxed samples is reached at low applied that in the as-quenched ones. These facts indicate that structural relaxation of amorphous ribbon favors improvement of the oxidation resistance. [Copyright &y& Elsevier] more...

Abstract: In this paper the result of a study of the influence of the biological conditions on the surface magnetic properties of nanocrystalline ribbons are presented and discussed. After the biological treatment the results show that, in the longitudinal direction, there is a hardening of the magnetic behavior and in the transverse direction the magnetization takes place in two steps. The surface saturation magnetization decreases in the treated samples. These results are explained considering the presence of magnetic oxides and non-conducting oxides on the surface of the treated samples. [Copyright &y& Elsevier] more...

Abstract: Magnetic anisotropy has been induced during the nanocrystallization process of Ni-rich amorphous ferromagnetic (Finemet) ribbons by means of the application of a constant stress during the annealing process. Magnetization measurements have evidenced the anisotropy of the treated samples. The main goal of this work was the analysis of the treated ribbons using X-ray Diffraction (XRD), Transmission Electronic Microscopy (TEM) and Atomic Force Microscopy (AFM). AFM measurements revealed in all the cases a strong nanocrystallisation of the surface without evidences of amorphous matrix, which contrast with XRD and TEM measurements that have shown a high content of amorphous phase in the bulk of the ribbons. Magneto-optical Kerr effect measurements show much higher coercive field values than in the bulk, indicating a complex magnetic behavior for the surface of the ribbons. [Copyright &y& Elsevier] more...