201 research outputs found

    A Novel MPPT Technique based on Hybrid Radial Movement Optimization with Teaching Learning Based Optimization for PV system

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    Because of its pure and plentiful accessibility, solar power is a remarkable resource of energy for the generation of electrical power. The solar photovoltaic mechanism transforms sunlight striking the photovoltaic solar panel or array of photovoltaic panels directly into non-linear DC power. Due to the nonlinear characteristics of solar photovoltaic panels, power must be tracked for their effective usage. When the photovoltaic arrays are shaded, the problem of nonlinearity becomes more pronounced, resulting in large power loss and intensive heating in a few areas of the photovoltaic arrangement. The tracking challenge is made more difficult by the fact that bypass diodes, which are used to completely eradicate the shading effect, generate numerous power peak levels on the power vs. voltage (P-V) curve. Traditional methods for tracing the global peak point are unable to examine the entire P-V curve as they frequently get stuck at the local peak point. Recently, machine learning or optimization algorithms have been used to determine the global peak point. Because these algorithms are random, they search the entire search area, reducing the possibility of being caught in the local maximum value. This article proposes a hybrid of two optimization approaches: radial movement optimization and teaching-learning optimization (HRMOTLBO). The proposed MPPT method was thoroughly investigated and tested in a wide range of photovoltaic partial shading combinations. The recommended HRMOTLBO MPPT approach outperforms and is more reliable than a recent Jaya-based MPPT approach in terms of tracing time and power variation under dynamic and static partial shading conditions. Experimental as well as simulation outcomes demonstrate that the proposed MPPT successfully traces the global peak point in less time and with fewer fluctuations during various partial shading conditions

    Three Phase Active Shunt Power Filter with Simple Control in PSIM Simulation

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    Generally the electrical system used by many consumer and industry usually uses passive filter and capacitor bank to compensate, harmonics and reactive power absorbed by the loads .The passive filter and capacitor bank make harmonic resonance with input impedance so that magnitude of harmonic current increased with harmonic frequency generated by nonlinear load. In this paper a simple active filter with PSIM simulation model used, the reference current generated by simple method of power synchronous detection and gate pulses generated by the use of modulated hysteresis current controller. The proposed model compensates current harmonics, and it  does power factor correction. The active filter designed in PSIM software and control of active filter is done in Simulink environment. PSIM and MATLAB software is linked by Sim coupler. The capacitor voltage is maintained constant by using PI controller. Simulation results with PSIM software shows that the designed active filter is very effective in harmonic elimination and power factor correction Keywords: : Active filter, Modulated Hysteresis current control, power synchronous detection (PSD),current harmonics, Pulse Width Modulation, , PSIM software

    Optimization of Cutting Parameters for Cutting Force in Shoulder Milling of Al7075-T6 Using Response Surface Methodology and Genetic Algorithm

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    AbstractThis paper aims at developing a statistical model to predict cutting force in terms of machining parameters such as cutting speed, cutting feed rate and axial depth of cut. Response surface methodology experimental design was used for conducting experiments. The work piece material was Aluminum (Al 7075-T6) and the tool was a shoulder mill with two carbide insert. The cutting forces were measured using three axis milling tool dynamometer. The second order mathematical model in terms of machining parameters was developed for predicting cutting force. The adequacy of the predictive models was tested by analysis of variance and found to be adequate. The direct and interaction effect was graphically plotted which helps to study the significance of these parameters with cutting force. The optimization of shoulder mill machining parameters to acquire minimum cutting force was done by genetic algorithms (GA). A Matlab genetic algorithm solver was used to do the optimization

    Antibacterial property of neem nanoemulsion against Vibrio anguillarium infection in Asian sea bass (Lates calcarifer)

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    1222-1226Fish vibriosis is among the most common diseases that is caused by a bacteria belonging to the genus Vibrio (Vibrio anguillarium). It causes considerable economic loss in the commercial cultivation of Asian sea bass (Lates calcarifer). The resistance of microorganisms to antibiotics has resulted in a growing need for developing a new antibacterial therapy that is effective in aquaculture. The aim of this study is to develop neem nanoemulsion with antibacterial activity against V. anguillarium to identify a possible alternative to the commonly used antibiotics in aquaculture. Neem nanoemulsion was prepared and the effectiveness was studied both in vitro and in vivo (agar well diffusion assay and artificial infection). Injection and immersion challenge of neem nanoemulsion formulated the fish less susceptible to V. anguillarium infection. The results confirmed the potential use of neem nanoemulsion as a source of antibacterial compounds or as a health-promoting medicine for fish culture

    Estimation of Standby Power Consumption for Typical Appliances

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    In the past days, many consumers could simply unplug their appliances and go on holidays, assuming that their electricitymeter would just stop. Standby power is a power consumed by an appliance when switched off or not performing its primaryfunctions. Standby power consumption provides good opportunity for reducing both energy consumption and green housegas emissions. Through co-operation among governments, industry and consumers and the co-ordination of internationalpolicies, standby modes can be made more efficient, thereby reducing the overall demand for power.In this paper, standby power consumption of various domestic appliances was determined using an energy cost meter. Theexperimental results shows that the standby power of various house hold electrical appliances is consuming more electricityduring standby mod

    Gain control network conditions in early sensory coding

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    Gain control is essential for the proper function of any sensory system. However, the precise mechanisms for achieving effective gain control in the brain are unknown. Based on our understanding of the existence and strength of connections in the insect olfactory system, we analyze the conditions that lead to controlled gain in a randomly connected network of excitatory and inhibitory neurons. We consider two scenarios for the variation of input into the system. In the first case, the intensity of the sensory input controls the input currents to a fixed proportion of neurons of the excitatory and inhibitory populations. In the second case, increasing intensity of the sensory stimulus will both, recruit an increasing number of neurons that receive input and change the input current that they receive. Using a mean field approximation for the network activity we derive relationships between the parameters of the network that ensure that the overall level of activity of the excitatory population remains unchanged for increasing intensity of the external stimulation. We find that, first, the main parameters that regulate network gain are the probabilities of connections from the inhibitory population to the excitatory population and of the connections within the inhibitory population. Second, we show that strict gain control is not achievable in a random network in the second case, when the input recruits an increasing number of neurons. Finally, we confirm that the gain control conditions derived from the mean field approximation are valid in simulations of firing rate models and Hodgkin-Huxley conductance based models

    Extraction and characterization of essential oil of nutmeg (Myristica fragrans) fruit pericarp and utilization as a surface coating material to improve the shelf life of paneer

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    Paneer is a traditional dairy product of India and is similar to unripened soft cheese. It is used as a raw material for the preparation of a variety of culinary dishes and snacks. Paneer is marble white in appearance, with a firm, cohesive and spongy body and a sweetish-acidic-nutty flavor. But it is highly perishable with a limited shelf- life like other indigenous dairy products. Its shelf life was reported to be only six days under refrigeration, though its freshness is lost within three days. The spoilage of paneer occurs mainly due to the growth of microorganisms, which bring about various physico-chemical changes. In the present study, attempts were made to increase the shelf-life of paneer at refrigerated storage by the application ofnutmeg pericarp essential oil surface coating. The essential oil was prepared from fresh nutmeg fruit flesh by steam distillation method. The physico-chemical and bio functional properties of essential oil were determined. The specific gravity and refractive index of the essential oil were found to be 0.903 and 1.477 respectively. The acid value and total polyphenolic value of essential oil were 3.36 and 4.04 mg GAE/g respectively. The essential oil was also found to have good antimicrobial and antioxidant activity. The shelf life of samples coated with essential oil packaged in LDPE pouches had more shelf life than the control paneer, as the coated paneer kept well for 9 days while the control paneer spoiled after the 6th day of refrigerated storage. The paneer with essential oil coating obtained satisfactory sensory score

    Effect of thermization of dahi on post fermentation acidification during refrigerated storage

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    Post fermentation acidification is defined as the development of acidity past the desired level of fermentation or acid development. Effect of thermization at 65oC for different periods (30 sec, 60 sec, 2 min and 5 min) on post fermentation acidification of dahi samples prepared using Lacticaseibacillus rhamnosus 18 or Lacticaseibacillus casei 01 upon refrigerated storage was assessed in this study. Significant changes (p< 0.01) were observed between the two starter cultures in terms of their post acidification potential with L. rhamnosus 18 dahi showing lower pH, higher titratable acidity and lactobacilli count than L. casei 01 during refrigerated storage. On assessing the impact of heat treatment on post acidification, significant decrease (p< 0.05) in pH, increase (p< 0.01) in titratable acidity and lactobacilli count of the heat treated and control samples were observed throughout the storage. Based on this study, it can be inferred that heat treatment at 65oC for even upto 5 min is not having any significant inhibitory effect on post fermentation acidification characteristics of the lactobacilli cultures tested
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