778 research outputs found

    Advances in Lasers for the Treatment of Stones-a Systematic Review

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    PURPOSE OF REVIEW: Laser lithotripsy is increasingly used worldwide and is a continuously evolving field with new and extensive research being published every year. RECENT FINDINGS: Variable pulse length Ho:YAG lithotripters allow new lithotripsy parameters to be manipulated, and there is an effort to integrate new technologies into lithotripters. Pulsed thulium lasers seem to be a viable alternative to holmium lasers. The performance of similar laser fibers varies from manufacturer to manufacturer. Special laser fibers and "cleaving only" fiber tip preparation can be beneficial for the lithotripsy procedure. Different laser settings and the surgical technique employed can have significant impact on the success of laser lithotripsy. When safely done, complications of laser lithotripsy are rare and concern the endoscopic nature of procedure, not the technology itself, making laser lithotripsy one of the safest tools in urology. Laser lithotripsy has had several new developments and more insight has been gained in recent years with many more advances expected in the future.info:eu-repo/semantics/publishedVersio

    Improving the photovoltaic response of a poly(3-octylthiophene)/n-Si heterojunction by incorporating double-walled carbon nanotubes

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    Poly(3-octylthiophene)/n-Si heterojunction solar cells were studied with and without incorporation of double-walled carbon nanotubes (DWCNs) in the polymer layer. The performance of the device improves significantly by the incorporation of DWCNs. We report a power conversion efficiency, open circuit voltage, short-circuit current density and fill factor of 0.49%, 0.53 V, 5.9 mA cm−2 and 0.15 respectively for an un-optimized cell containing DWCNs. Reference cells without DWCNs show a much lower performance. DWCN incorporation yields better hole transport, easy exciton splitting and suppression of charge recombination, thereby improving photovoltaic action. DWCN seems a promising material for improving hole transport in organic solar cells

    Improving photovoltaic response of poly„3-hexylthiophene…/n-Si heterojunction by incorporating double walled carbon nanotubes

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    Poly(3-hexylthiophene)/n-Si heterojunction solar cells were studied with and without incorporation of double walled carbon nanotubes (DWCNs) in the polymer layer. Performance of the device improves by manyfold by incorporation of DWCN. The authors report power conversion efficiency, open circuit voltage, short-circuit current density, and fill factor of 0.026%, 0.446 V, 0.3398 mA/cm2, and 0.17, respectively, for an unoptimized cell containing DWCN. Reference cells without DWCNs show much lower performance. DWCN incorporation yields better hole transport, easy exciton splitting, and suppression of charge recombination, thereby improving photovoltaic action. DWCN seems promising materials for improving hole transport in organic solar cells

    Field electron emission of double walled carbon nanotube film prepared by drop casting method

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    Thick films of double walled carbon nanotubes (DWCN) were deposited on indium-tin-oxide (ITO) coated glass substrates by drop casting method and were studied for their field electron emission property in a parallel plate configuration using bare ITO coated glass as counter electrode. They show excellent field electron emission property with low turn-on-field of about 0.8 V/lm and threshold field of about 1.8 V/lm. Field enhancement factor calculated from the non-saturated region of the FN plot is about 1715. Field electron emission current was observed to be stable up to 3000 min, indicating thereby that DWCNs are excellent electron emitters with appreciable stable performance

    Volatile organic compounds are ghosts for organic solar cells

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    All our efforts to demonstrate a multifunctional device – photovoltaic gas sensor (i.e. solar cell which show photovoltaic action depending on the gas / volatile organic compounds (VOC) in the surrounding atmosphere) yielded negative results. Photovoltaic performance of the organic solar cells under study degraded – almost permanently by exposing them to volatile organic compounds (VOCs). Although, the proposed multifunctional device could not be demonstrated; Present investigations yielded very important result that organic solar cells have problems not only with oxygen and humidity (known facts) but also with many VOCs and hazardous gases – making lamination / encapsulation step mandatory for their practical utilizatio

    Mixing global and local competition in genetic optimization based design space exploration of analog circuits

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    The knowledge of optimal design space boundaries of component circuits can be extremely useful in making good subsystem-level design decisions which are aware of the parasitics and other second-order circuit-level details. However, direct application of popular Multi-objective genetic optimization algorithms were found to produce Pareto fronts with poor diversity for analog circuits problems. This work proposes a novel approach to control the diversity of solutions by paritioning the solution space, using Local Competition to promote diversity and Global competition for convergence, and by controlling the proportion of these two mechanisms by a Simulated Annealing based formulation. The algorithm was applied to extract numerical results on analog switched capacitor integrator circuits with a wide range of tight specifications. The results were found to be significantly better than traditional GA based uncontrolled optimization methods

    Technical Considerations in Rehabilitation of an Edentulous Total Glossectomy Patient

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    The technician by virtue of his profession plays an important role in fabricating silicone tongue prosthesis for a total glossectomy patient. The technician, with his skills and specialized knowledge in handling material, plays a valuable role as a member of the oncology team. A patient with total glossectomy can be rehabilitated by silicone tongue prosthesis as an aid to improve his speech and swallowing. This paper describes the technical steps involved in fabricating a silicone tongue prosthesis for an edentulous total glossectomy patient

    Double-walled carbon nanotubes-incorporated donor–acceptor-type organic photovoltaic devices using poly(3-octylthiophene) and C60

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    Donor–acceptor-type photovoltaic devices with a heterojunction between regioregular poly(3-octylthiophene) (P3OT) and C60 are fabricated with and without the addition of double-walled carbon nanotubes (DWCNs) in the polymer layer. Incorporation of DWCNs in the polymer layer improves the performance of the device by many folds, which is attributable to improved exciton dissociation and better charge transport leading to the suppression of charge carrier recombination. We report an opencircuit voltage, short-circuit current density, fill factor and conversion efficiency (%) of approximately 0.37 V, 0.014 mA/cm2,0.22 and 0.001%, respectively, for an unoptimized device incorporating DWCNs
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