Congenital Y-type urethro-perineal fistula

A case of primary carcinoma of the urinary bladder associated with a primary retroperitoneal leiomyosarcoma is presented. Due to the lack of early symptoms, diagnosis of the retroperitoneal leiomyosarcoma was late and therefore the prognosis was poor. Twelve months after diagnosis the patient died not of the bladder tumor, but of the recurrent leiomyosarcoma.     

Microstructural evolution during the supersolidus liquid phase sintering of nickel-based prealloyed powder mixtures

A novel concept for full-density sintering is described. Two prealloyed powders with slight compositional differences are tailored to separate the solidus temperatures into high-melt and low-melt compositions. A mixture of these two powder compositions allows full-density sintering at a temperature between the two solidus temperatures. For these experiments, the two powders were nickel-based alloys, where the low-melt powder contained boron. The mixed powders were sintered at temperatures above the solidus of the low-melt powder to form a transient liquid that promoted rapid densification of the mixture. Microstructure evolution during sintering was assisted using quenching experiments. Variables in this study included the heating rate, peak temperature, hold time, and powder ratio. Interdiffusion between the two powders controls microstructure evolution, with a dominant role associated with boron diffusion and reaction. The transient liquid phase responsible for densification is linked to boron diffusion and subsequent compound precipitation.     

A conformal cylindrical microstrip array for producing omnidirectional radiation pattern

Radiation patterns of rectangular microstrip patches arranged circumferentially on a circular cylinder have been computed. Both the axial patches and circumferential patches have been used. It has been found that the number of circumferential patches required for a given ripple in gain pattern is considerably less, thus simplifying the feed network. Comparison with experimental measurements shows good agreement.     

The First Example of Saccharin‐Lithium Bromide Catalysis: Direct Synthesis of N‐Tosylimines from Alcohols

The first procedure to access N‐tosylimines directly from alcohols under mild and neutral conditions is reported. The protocol involves saccharin‐lithium bromide‐catalyzed oxidation of alcohols to aldehydes/ketones with chloramine‐T followed by their condensation with the in situ generated oxidation by‐product p‐toluenesulfonamide in the same reaction vessel to afford N‐tosylimines in 40–90% overall yields. The present work opens up a new and efficient synthetic route to N‐tosyimines directly from alcohols in a one‐pot procedure.     

Hydrogenation effect on structural,electrical and optical properties of CdS thin films for solar cell

Adsorption effects would be expected to be of considerable importance with thin films because of the changes in electron location accompanying adsorption. The effects of hydrogenation on structural, optical and electrical properties of the CdS thin films have been reported. GIXRD patterns shows that films have polycrystalline nature with a hexagonal structure. The optical band gap increased after hydrogenation of the film. The variation of conductivity of CdS films have been investigated depending upon the applied voltage at room temperature. The resistivity increased after hydrogenation of the films. Hydrogenated thin films can be used in solar cells because hydrogen plays an important role to modify the physical properties.     

Stochastic post buckling analysis of laminated composite cylindrical shell panel subjected to hygrothermomechanical loading

In this paper, the effect of random system properties on the post buckling load of geometrically nonlinear laminated composite cylindrical shell panel subjected to hygrothermomechanical loading is investigated. System parameters are assumed as independent random variables. The higher order shear deformation theory and von-Karman nonlinear kinematics are used for basic formulation. The elastic and hygrothermal properties of the composite material are considered to be dependent on temperature and moisture concentration using micromechanical approach. A direct iterative based C⁰ nonlinear finite element method in conjunction with first-order perturbation technique proposed by present author for the plate is extended for shell panel subjected to hygrothermomechanical loading to compute the second-order statistics (mean and variances) of laminated composite cylindrical shell panel. The effect of random system properties, plate geometry, stacking sequences, support conditions, fiber volume fractions and temperature and moisture distributions on hygrothermomechanical post-buckling load of the laminated cylindrical shell panel are presented. The performance of outlined stochastic approach has been validated by comparing the present results with those available in the literature and independent Monte Carlo simulation.     

Reply to comments on “Transition from ploughing to cutting during machining with blunt tools”

The low-stress and gouging wear behavior of a series of Ni-Cr white iron (Ni-Hard 4) samples has been characterized. The samples were processed to contain 5–85% retained austenite in their microstructures so that their Rockwell C hardness ranged from 63 to 47. The low-stress abrasion behavior was measured with loose SiO₂ and Al₂O₃ abrasives in a rubber wheel test system. The gouging abrasion behavior was determined in a bonded Al₂O₃ wheel test system. Wear scars were characterized by scanning electron microscopy used in conjunction with energy dispersive X-ray spectroscopy.Both low-stress and gouging wear behavior were strong functions of test condition and microstructure, and weight losses passed through maxima or minima as the volume fraction retained austenite or abrasion condition varied. Carbides controlled wear behavior in the low-stress test against SiO₂, and their attrition occurred by uniform scratching, preferential chipping at leading edges and cracking-spalling. In low-stress and gouging tests against Al₂O₃ carbides and matrix underwent attrition by uniform micromachining. The test results indicated that retained austenite content could be used to optimize wear resistance in a variety of abrasion situations.