92 research outputs found

    Computational Study of Savonius Wind Turbine

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    This project involves study of 2-Blade and 3-Blade Savonius vertical wind turbines positioned at different orientations. For a 2-Blade turbine the orientations considered were 0 degree, 45 degree, 90 degree and 135 degree in reference to the direction of the prevailing wind and for the 3-Blade turbine the orientations taken into account were 0 degree, 30 degree, 60 degree and 90 degree in reference to the direction of the prevailing wind. The basic aim of this thesis was to study how the two designs are different from each other and which design produces more power when applied with constant wind velocity of 10mps. Computational Fluid Dynamics (CFD) analyses were conducted for every case to find out the torque and power generated by the turbines for each orientation. To ensure the accuracy of the results, CFD techniques were applied using Gambit 2.2.30 and Fluent 6.2.16. All cases were run using transition-SST flow model and the faces were meshed using \u27Quadrilateral Pave\u27 meshing scheme. The turbine was also tested for varying wind velocities of 5mps, 20mps, and 30mps for a constant orientation of turbine. The results were later compared and graphs were created for easy comparison of power and torque generated by turbines at different velocities. Maximum change in pressure occurs when 2-Blade turbine in perpendicular to direction of wind flow direction i.e. at 90 degree and when 3-Blade turbine is at 60 degree orientation. The 2-Blade Turbine generates higher value of torque (215.28 N) as compared to 3-Blade turbine, generating torque of value 110.92 N for any given constant wind velocity 30mps in this case. This information can help the designer of the system to select the proper wind turbine considering the efficiency and stability along with other factor

    Classifying sybil in MSNs using C4.5

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    © 2016 IEEE. Sybil detection is an important task in cyber security research. Over past years, many data mining algorithms have been adopted to fulfill such task. Using classification and regression for sybil detection is a very challenging task. Despite of existing research made toward modeling classification for sybil detection and prediction, this research has proposed new solution on how sybil activity could be tracked to address this challenging issue. Prediction of sybil behaviour has been demonstrated by analysing the graph-based classification and regression techniques, using decision trees and described dependencies across different methods. Calculated gain and maxGain helped to trace some sybil users in the datasets

    Cluster based Energy-Efficient and Reliable Routing for Mobile Wireless Sensor Networks

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    The main problem of energy efficient reliable routing is that it doesn’t provide any back up mechanism for the failure of the nodes. The work of the paper major depends on the alternate path provided if the link got failure and to provide energy efficient path in between the network.it will reduce the time,cost and increase the efficiency and the data rate of the network. In wireless sensor networks, because of unreliable wireless media, host mobility and lack of infrastructure, providing secure communications is bit difficult in this type of network environment. In present work to ensure the security in unreliable wireless communication the cluster based topology technique is used, to obtain confidentiality and authentication of nodes hash function and MAC (Message Authentication Code) techniques are use

    Manganese 3×3 and √3 × √3-R30º structures and structural phase transition on w-GaN(0001̄) studied by scanning tunneling microscopy and first-principles theory

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    et al.Manganese deposited on the N-polar face of wurtzite gallium nitride [GaN (0001̄)] results in two unique surface reconstructions, depending on the deposition temperature. At lower temperature (less than 105ºC), it is found that a metastable 3×3 structure forms. Mild annealing of this Mn 3×3 structure leads to an irreversible phase transition to a different, much more stable √3×√3-R30º structure which can withstand high-temperature annealing. Scanning tunneling microscopy (STM) and reflection high-energy electron diffraction data are compared with results from first-principles theoretical calculations. Theory finds a lowest-energy model for the 3×3 structure consisting of Mn trimers bonded to the Ga adlayer atoms but not with N atoms. The lowest-energy model for the more stable √3×√3-R30º structure involves Mn atoms substituting for Ga within the Ga adlayer and thus bonding with N atoms. Tersoff-Hamman simulations of the resulting lowest-energy structural models are found to be in very good agreement with the experimental STM images.Research supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award No. DE-FG02-06ER46317 (STM studies of nanoscale spintronic nitride systems) and by the National Science Foundation under Award No. 0730257 (advancing nanospintronics through international collaboration). V.F. and M.A.B. would like to acknowledge support from CONICET (PIP0038) and ANPCyT (PICT1857) as well as the Ohio Supercomputing Center for computer time. P.O. was supported by Spanish MICINN (FIS2009-12721-C04-01, FIS2012-37549-C05-02 and CSD2007-00050).Peer reviewe

    Accumulation of Rhodopsin in Late Endosomes Triggers Photoreceptor Cell Degeneration

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    Progressive retinal degeneration is the underlying feature of many human retinal dystrophies. Previous work using Drosophila as a model system and analysis of specific mutations in human rhodopsin have uncovered a connection between rhodopsin endocytosis and retinal degeneration. In these mutants, rhodopsin and its regulatory protein arrestin form stable complexes, and endocytosis of these complexes causes photoreceptor cell death. In this study we show that the internalized rhodopsin is not degraded in the lysosome but instead accumulates in the late endosomes. Using mutants that are defective in late endosome to lysosome trafficking, we were able to show that rhodopsin accumulates in endosomal compartments in these mutants and leads to light-dependent retinal degeneration. Moreover, we also show that in dying photoreceptors the internalized rhodopsin is not degraded but instead shows characteristics of insoluble proteins. Together these data implicate buildup of rhodopsin in the late endosomal system as a novel trigger of death of photoreceptor neurons

    Long-term and age-dependent restoration of visual function in a mouse model of CNGB3-associated achromatopsia following gene therapy

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    Mutations in the CNGB3 gene account for >50% of all known cases of achromatopsia. Although of early onset, its stationary character and the potential for rapid assessment of restoration of retinal function following therapy renders achromatopsia a very attractive candidate for gene therapy. Here we tested the efficacy of an rAAV2/8 vector containing a human cone arrestin promoter and a human CNGB3 cDNA in CNGB3 deficient mice. Following subretinal delivery of the vector, CNGB3 was detected in both M- and S-cones and resulted in increased levels of CNGA3, increased cone density and survival, improved cone outer segment structure and normal subcellular compartmentalization of cone opsins. Therapy also resulted in long-term improvement of retinal function, with restoration of cone ERG amplitudes of up to 90% of wild-type and a significant improvement in visual acuity. Remarkably, successful restoration of cone function was observed even when treatment was initiated at 6 months of age; however, restoration of normal visual acuity was only possible in younger animals (e.g. 2–4 weeks old). This study represents achievement of the most substantial restoration of visual function reported to date in an animal model of achromatopsia using a human gene construct, which has the potential to be utilized in clinical trials
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