Investigation of grain orientations of melt-textured HTSC with addition of uranium oxide, Y2O3 and Y2BaCuO5

Local grain orientations were studied in melt-textured YBCO samples processed with various amounts of depleted uranuim oxide (DU) and Y 2O3 by means of electron backscatter diffraction (EBSD) analysis. The addition of DU leads to the formation of Ucontaining nanoparticles (Y2Ba4CuUOx) with sizes of around 200 nm, embedded in the superconducting Y-123 matrix. The orientation of the Y 2BaCuO5 (Y-211) particles, which are also present in the YBCO bulk microstructure, is generally random as is the case in other melttextured Y-123 samples. The presence of Y-211 particles, however, also affects the orientation of the Y-123 matrix in these samples

Friction Stir Welding of Metal Matrix Composite Using Coated Tool

AbstractFriction stir welding (FSW) is a solid state joining technique that has expanded rapidly since its development and has found applications in a wide variety of industries. In the present investigation work, friction stir weldabilty of 5% SiC particulate aluminum matrix cast composite using TiAlN coated tool and effect of process parameters such as tool rotation speed, traverse speed, and axial force on ultimate tensile strength were investigated. The result showed that there was no noticeable tool wear, only aluminum particles were deposited on the tool pin. The effect of process parameters were evaluated using Anova and S/N ratio of robust design. It was observed that the axial force exhibits more influence on tensile strength followed by traverse speed and tool rotation speed

Evaluation of a multimode fiber optic low coherence interferometer for path length resolved Doppler measurements of diffuse light \ud

The performance of a graded index multimode fiber optic low coherence Mach-Zehnder interferometer with phase modulation is analyzed. Investigated aspects were its ability to measure path length distributions and to perform path length resolved Doppler measurements of multiple scattered photons in a turbid suspension of particles undergoing Brownian and translational motion. The path length resolution of this instrument is compared with a system using single mode fibers for illumination and detection. The optical path lengths are determined from the zero order moment of the phase modulation peak in the power spectrum. The weighted first moment, which is equal to the average Doppler shift, shows a linear response for different mean flow velocities within the physiological rang

Eliminating the d=5 proton decay operators from SUSY GUTs

A general analysis is made of the question whether the d=5 proton decay operators coming from exchange of colored Higgsinos can be completely eliminated in a natural way in supersymmetric grand unified models. It is shown that they can indeed be in SO(10) while at the same time naturally solving the doublet-triplet splitting problem, having only two light Higgs doublets, and using no more than a single adjoint Higgs field. Accomplishing all of this requires that the vacuum expectation value of the adjoint Higgs field be proportional to the generator I_{3R} rather than to B-L, as is usually assumed. It is shown that such models can give realistic quark and lepton masses. We also point out a new mechanism for solving the \mu problem in the context of SO(10) SUSY GUTs.Comment: 24 pages in LaTeX, with 3 figure

Predicting the Yield Potential of Guinea Grass (\u3cem\u3ePanicum maximum\u3c/em\u3e Jacq.) Genotypes across India through G x E Analysis

A native of Africa, Guinea grass (Panicum maximum Jacq.) was introduced to almost all tropical countries as a source of animal fodder. It is an ideal forage plant being perennial in growth habit, grows well on a wide variety of soils and tolerant of shade and fire, but not to water logging or severe drought. It also responds quickly to fertilizer and watering. Because of these desirable features, guinea grass is well established throughout tropical countries of both hemispheres where it plays an important role in dairy production. Owing to the cultivation of this crop in varied agro-climatic conditions it is very common to get varied relative performances from the same cultivars when they are evaluated in different environments or in different years. The variations that occur in the performance of cultivars are attributed to the effect of the genotype × environment (G × E) interaction (Haldane, 1946; Falconer and Mackay, 1996). The selection of genotypes to maximise yield when genotype rank changes occur across environments is complicated because of the complexity of genotype responses. This type of interaction reduces selection efficiency and the accuracy of cultivar recommendation (Crossa and Cornelius, 1997). Though guinea grass is in cultivation throughout the world and a good variability is available, concerted efforts have not been made adequately to validate and interpret the effects of G x E interaction on green fodder yield. As a result, the genetic improvement in guinea grass for fodder yield and quality has become impasse. Hence an attempt was made to study the interactive effects between genotype and environment on green fodder yield

Enhanced self-field critical current density of nano-composite YBa(2)Cu(3)O(7) thin films grown by pulsed-laser deposition

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ EPLA, 2008.Enhanced self-field critical current density Jc of novel, high-temperature superconducting thin films is reported. Layers are deposited on (001) MgO substrates by laser ablation of YBa2Cu3O7−δ(Y-123) ceramics containing Y2Ba4CuMOx (M-2411, M=Ag, Nb, Ru, Zr) nano-particles. The Jc of films depends on the secondary-phase content of the ceramic targets, which was varied between 0 and 15 mol%. Composite layers (2 mol% of Ag-2411 and Nb-2411) exhibit Jc values at 77 K of up to 5.1 MA/cm2, which is 3 to 4 times higher than those observed in films deposited from phase pure Y-123 ceramics. Nb-2411 grows epitaxially in the composite layers and the estimated crystallite size is ~10 nm.The Austrian Science Fund, the Austrian Federal Ministry of Economics and Labour, the European Science Foundation and the Higher Education Commission of Pakistan

Remark on the vectorlike nature of the electromagnetism and the electric charge quantization

In this work we study the structure of the electromagnetic interactions and the electric charge quantization in gauge theories of electroweak interactions based on semi-simple groups. We show that in the standard model of the electroweak interactions the structure of the electromagnetic interactions is strongly correlated to the quantization pattern of the electric charges. We examine these two questions also in all possible chiral bilepton gauge models of the electroweak interactions. In all they we can explain the vectorlike nature of the electromagnetic interactions and the electric charge quantization together demanding nonvanishing fermion masses and the anomaly cancellations.Comment: 17 pages, latex, no figure