649 research outputs found

    DESIGN AND ANALYSIS OF A BIOFUEL-POWERED MICRO GAS TURBINE COMBUSTION CHAMBER

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    Small combustion turbines known as micro turbines provide power in the 20 kW to 500 kW range. Small jet engines, auxiliary power units (APUs) for aircraft, and turbochargers for cars and trucks are the origin of the Evolution. A relatively recent development in distributed generation, micro turbines are employed in stationary energy generation applications. In most cases, they are combustion turbines, which on a small scale generate heat as well as power. Radial inflow turbine, combustor, and centrifugal compressor are the three main components of a micro (gas) turbine engine. Along with turning the compressor, it also serves as a power output. For distributed electricity and cogeneration (combined heat and power) applications, micro turbines are becoming more and more common. The micro turbine and gas turbine cycles both run continuously. Studying a brief description of SOLIDWORKS modelling is necessary. With the aid of Solid works, several turbine components (includes the housing, connection, exit, rotor, nozzle, storage, inlet, and so on) are designed (software). They were then put together as one unit and attached to a generator to produce electricity. The axial intake and axial output of the turbine indicate its kind

    Analysis of fuzzy logic controller based bi-directional DC-DC converter for battery energy management in hybrid solar/wind micro grid system

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    This paper proposes a fuzzy logic-based battery energy management system in hybrid renewable system. The novel topology consists of solar and wind energy system-based input sources and a battery bank to store the energy when in excess. The PV-Wind source is equipped with unidirectional boost converter whereas, the battery storage system is connected to the system with a bi-directional DC/DC converter. The main novelty of this research is the fuzzy logic-based battery management system which charges and discharges into the DC bus system based on the supply-load demand. The fuzzy logic controller (FLC) based maximum power point tracking (MPPT) is used in the PV and wind energy conversion system (WECS) to track the maximum available power for the different irradiance and wind velocity respectively. The obtained results are compared to conventional P&O MPPT control algorithm to find the effectiveness of the system. A 500 W PV system and a 500 W Permanent magnet synchronous generator (PMSG) based WECS is implemented for its simplicity and high efficiency. The proposed control topology is designed and tested using MATLAB/Simulin

    Regression Models For Prediction Of Water Quality In Krishna River

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    The River Krishna and its tributaries drain three important states of South India. The river water plays a very important role in the overall socioeconomic development of Andhra Pradesh.  In large river basins monitoring non-point sources pollution is rather difficult and expensive and is subjected to analytical errors. Hence, modeling water quality using land use data of the basin is attempted in the present study. The contribution from non-point sources (runoff from the river basin) is quiet considerable as the river drains various type of land uses. In this context, it is necessary to make a detailed study of the water quality of the river, to estimate the level of pollution and also main sources of pollution. Correlation studies explain the relationships, between dissolved solids concentration and land use of the basins. The multiple regression models accounted for significant variation in concentrations for majority of dissolved solids. The predicted concentrations are in good agreement with the observed values. The proposed models can be useful for planning land use controls in integrated water quality management program. As water quality of flowing water is closely linked to the land use in the basin, it is essential to include land use management in future river basin planning. Carefully designed land use studies to identify characterized and quantity of non point sources is essential elements to be emphasized to plan water quality management programme. The results of study indicate relative importance of non point sources pollution in addition to point sources pollution. Keywords: Dissolved solids, Land use planning , Regression models, Water quality

    Current Controller Based Power Management Strategy for Interfacing DG Units to Micro Grid

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    This paper proposes a power management strategy of parallel inveters based system, to enhance the power generation capacity of the existing system with distributed energy sources one has to choose DG source based inverter connected in parallel with the existing system.Two DG sources PV, Fuel cells feeds the DC voltage to two parallel inverters connected to the grid. Fixed band hysteresis current control with Instantaneous p-q power theory is adopted to create an artificial environment. Two parallel inverters are able to deliver the harvested power from PV, FC to grid and able to balance the load Without communication between parallel inverters this controller having the capability of load following, the harmonic components of currents at output of inverter are also very low; this will automatically reduces the circulating currents between parallel inverters. Simulation studies are carried out to investigate the results of PV, FC systems connected to the utility grid

    Optimal 4G OFDMA Dynamic Subcarrier and Power Auction-based Allocation towards H.264 Scalable Video Transmission

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    In this paper, authors presented a price maximization scheme for optimal orthogonal frequency division for multiple access (OFDMA) subcarrier allocation for wireless video unicast/multicast scenarios. They formulate a pricing based video utility function for H.264 based wireless scalable video streaming, thereby achieving a trade-off between price and QoS fairness. These parametric models for scalable video rate and quality characterization arederived from the standard JSVM reference codec for the SVC extension of the H.264/AVC, and hence are directly applicable in practical wireless scenarios. With the aid of these models, they proposed auction based framework for revenue maximization of the transmitted video streams in the unicast and multicast 4G scenario. A closedform expression is derived for the optimal scalable video quantization step-size subject to the constraints of theunicast/multicast users in 4G wireless systems. This yields the optimal OFDMA subcarrier allocation for multi-userscalable video multiplexing. The proposed scheme is cognizant of the user modulation and code rate, and is henceamenable to adaptive modulation and coding (AMC) feature of 4G wireless networks. Further, they also consider aframework for optimal power allocation based on a novel revenue maximization scheme in OFDMA based wireless broadband 4G systems employing auction bidding models. This is formulated as a constrained convex optimization problem towards sum video utility maximization. We observe that as the demand for a video stream increases inbroadcast/multicast scenarios, higher power is allocated to the corresponding video stream leading to a gain in the overall revenue/utility. We simulate a standard WiMAX based 4G video transmission scenario to validate the performance of the proposed optimal 4G scalable video resource allocation schemes. Simulations illustrate that the proposed optimal band width and power allocation schemes result in a significant performance improvement over the suboptimal equal resource allocation schemes for scalable video transmission.Defence Science Journal, 2013, 63(1), pp.15-24, DOI:http://dx.doi.org/10.14429/dsj.63.375

    A NOVEL VESICULAR APPROACH FOR TRANSDERMAL ADMINISTRATION OF ENALAPRIL MALEATE LOADED NANOPRONIOSOMAL GEL: FORMULATION, EX VIVO EVALUATION AND IN VIVO ANTIHYPERTENSIVE STUDY

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    Objective: The objective of the study was to formulate and evaluate the nanoproniosomal gel of Enalapril maleate (EM) for the treatment of hypertension through the transdermal administration and to provide better bioavailability. Methods: The nanoproniosomal gel of the EM was formulated by Lecithin, Cholesterol, Non-ionic surfactants using the Coacervation-phase separation method. The prepared nanoproniosomal gels were evaluated for pH and viscosity, vesicle size analysis, rate of spontaneity, entrapment efficiency, zeta potential, ex vivo skin permeation studies, skin irritation test, stability studies and in vivo antihypertensive studies. Results: Physical characterization was found to be within acceptable limits. The ex vivo skin permeation studies showed the cumulative permeation of 58.75 % to 89.72 % through the albino rat skin in 24 h for all the formulations, which indicate the zero-order drug permeation with diffusion, non-fickian release. Among all formulations, EMNP7 was selected as best formulation because it showed better characteristics than other formulations in several aspects like physicochemical characterization, ex vivo skin permeation studies, permeation kinetics, and other evaluation parameters. The skin irritation study revealed that there was no irritation after topical application and it was found to be safer to use. The In vivo antihypertensive study revealed that the formulation of EMNP7 was successful to regress the rat blood pressure (BP) to normal values in experimental hypertensive rats. Conclusion: The nanoproniosomal gel is an efficient transdermal therapeutic system for the delivery of EM for the treatment of hypertension. It is suitable for once a day controlled release formulation

    DESIGN AND CFD ANALYSIS OF SOLAR FLAT PLATE COLLECTOR BY USING CREO

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    : Flat-plate collectors, developed by Hottel and Whillier in the 1950s, are the most common type. They consist of (1) a dark flat-plate absorber, (2) a transparent cover that reduces heat losses, (3) a heat-transport fluid (air, antifreeze or water) to remove heat from the absorber, and (4) a heat insulating backing. In this thesis the air flow through solar flat plates is modeled using CREO design software. the thesis will focus on thermal and CFD analysis with different fluid air, water and different angles (900,300,450&600) of the solar flat plates. thermal analysis done for the solar flat plates by, aluminum & copper at different heat transfer coefficient values. These values are taken from CFD analysis. In this thesis the CFD analysis to determine the heat transfer coefficient, heat transfer rate, mass flow rate, pressure drop and thermal analysis to determine the temperature distribution, heat flux with different materials. 3D modeled in parametric software CREO and analysis done in ANSYS

    The neural correlates of intertemporal decision‐making: Contributions of subjective value, stimulus type, and trait impulsivity

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    Making choices between payoffs available at different points in time reliably engages a decision‐making brain circuit that includes medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and ventral striatum (VS). Previous neuroimaging studies produced differing accounts of the functions of these regions, including that these regions: (1) are sensitive to the value of rewards discounted by a function of delay ('subjective value'); (2) are differentially sensitive to the availability of an immediate reward; and (3) are implicated in impulsive decision‐making. In this event‐related fMRI study of 20 volunteers, these hypotheses were investigated simultaneously using a delay discounting task in which magnitude of rewards and stimulus type, i.e., the presence or absence of an immediate option, were independently varied, and in which participants' trait impulsivity was assessed with the Barratt Impulsiveness Scale. Results showed that mPFC, PCC, and VS are sensitive to the subjective value of rewards, whereas mPFC and PCC, but not VS, are sensitive to the presence of an immediate reward in the choice option. Moderation by individual differences in trait impulsivity was specific to the mPFC. Conjunction analysis showed significant overlap in mPFC and PCC for the main effects of subjective value and stimulus type, indicating these regions may serve multiple distinct roles during intertemporal decision‐making. These findings significantly advance our understanding of the specificity and overlap of functions subserved by different regions involved in intertemporal decision‐making, and help to reconcile conflicting accounts in the literature. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86833/1/21136_ftp.pd
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