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Abstract: The effect of catalyst loading, operation temperature and co-infiltration of the palladium-based catalysts on the performance and stability of La0.8Sr0.2MnO3 (LSM) cathode of solid oxide fuel cells (SOFCs) is investigated. The result shows that adding a small amount of Pd catalyst (0.08mgcm−2) has a remarkable effect on the reduction of overpotential of LSM cathodes and high palladium loading is detrimental to the electrochemical activity of LSM cathodes. The performance and stability of the Pd-impregnated LSM cathodes can be enhanced significantly by co-infiltration of palladium with either 20 mol% of silver or 5 mol% of cobalt. Increased stability of the co-infiltrated catalyst materials is probably related to the enhanced resistance of the co-impregnated Pd0.95Co0.05 and Pd0.8Ag0.2 nanoparticles against agglomeration and sintering at SOFC operation temperatures. The results indicate the co-impregnation is effective not only to enhance the electrochemical activity but also to improve the stability of LSM cathodes for the O2 reduction reaction of SOFCs. [Copyright &y& Elsevier]

Abstract: La0.7Ca0.3Cr0.5Mn0.5O2.6/Gd-doped ceria (LCCM)/GDC composite oxides are developed as anodes for the hydrogen and methane oxidation reactions of solid oxide fuel cells (SOFCs). The composite anodes are sintered in temperatures range from 1150 to 1350°C and the lowest ohmic and polarization resistances of the cells are obtained on the anodes sintered at 1300°C. Electrode polarization resistance or area specific resistance (ASR) of the LCCM/GDC anode is 0.47Ωcm2 for the hydrogen oxidation reaction and ~2.2Ωcm2 for the methane oxidation reaction at 850°C. Addition of the Pd nanoparticles via a wet impregnation to the LCCM/GDC anodes decreases the ASR substantially to 0.15 and 0.23Ω cm2 for the hydrogen and methane oxidation reaction at 850°C, respectively. The reduction of the ASR is more pronounced for the methane oxidation reaction. The results indicate that the addition of Pd nanoparticles mainly affects the electrode process associated with the low frequencies, revealing the significant promotion effect of the impregnated Pd catalyst for the dissociation and diffusion processes of the hydrogen and methane oxidation reactions. The Pd-Impregnated LCCM/GDC composite anodes show a good stability in H2 and CH4 under conditions studied. [ABSTRACT FROM AUTHOR]

Introduction: Loss of the penis can have a devastating effect on the lives of sufferers with significant psychogenic implications. Penile reconstruction or phallus construction poses a difficult challenge and a demanding problem to the urologists and plastic surgeons. Different techniques have been used for construction of a total penis and reconstruction of severely injured penis. The objective of this review was to determine the efficacy, advantages and disadvantages of the most popular penile reconstruction (PR) and phallus construction techniques. Materials and Methods: We searched without language restriction MEDLINE, Pre-MEDLINE EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from January 1960 to January 2009. In addition, we searched the citation lists of relevant articles and book chapters. Studies evaluating the functional and cosmetic results of different techniques of total phallus construction (TPC) and penile reconstruction (PR) were identified. Two authors independently evaluated studies for selection, study quality, and extracted data. The primary outcome was creation of a sensate and cosmetically acceptable phallus. The secondary outcomes were competent neourethra that allows voiding in comfortable position, sexual intercourse, and the rate of complications. Results: One hundred and forty-six studies with a total of 1 622 patients were included in this review. Conclusion: Data from the available studies are insufficient to recommend any technique for TPC or PR. In the absence of evidence to support any method, the review authors recommend the one-stage TPC or PR. Further studies are warranted, preferably multi-centered studies. [ABSTRACT FROM AUTHOR]

In this research, an experimental method for measuring the clamping force as a result of tightening torque in double lap simple bolted and hybrid (bolted-bonded) joints is proposed. Two types of joints, i.e. double lap simple and hybrid (bolted-bonded) joints were prepared for testing. In order to measure the clamping force or pretension resulting from the tightening torque at different applied torques, for both types of joints, a special experimental method was designed using a steel bush that was placed between the nut and the plate. Two strain gauges were stuck to the outer surface of the bush to measure the compressive axial strain and also the stress in the bush using Hooke's law. Finally, the axial force in the bush and subsequently the clamping force were determined. The test was repeated three times for each case to obtain the mean value of compressive strains and to determine the corresponding clamping forces. The relationship between the applied tightening torques and the mean value of compressive strains for both types of joints are shown in graphs. [ABSTRACT FROM AUTHOR]