Browse Articles

    Volume 3, Issue 2, June 2017

    Connexions on globally para framed metric manifold
    Savita Patni
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      • Abstract: In this paper M and N-connexion have been defined and various properties have discussed therein. Theorems related to these connexions have also been stated and proved..

    Comparison of linear and non-linear power factor convertors for power factor improvement and reduction of total harmonic distortion
    D. Kumar, S. Godha and R. Mishra
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      • Abstract: The usage electronic equipment is increasing rapidly in daily life to fulfill consumers and industrial needs. All these electronic equipment have power supplies that obtain required energy from utility grid. As a consequence, they are currently in very wide use and recent improvements in power electronics devices, topologies, and controls are extending their range of application. In many of these applications, Ac utility power is converted to dc by means of uncontrolled diode rectifier that is driven by the ac line frequency. These rectifiers can be made controllable by replacing diodes with silicon controlled rectifiers (SCR) to provide a controlled dc output when required. Though simple in design and high in efficiency, these conventional rectifiers produce problem in that they do not draw sinusoidal current from the utility source and inject current harmonics into the supply. This results in poor power factor seen by the utility and loads drawing poor power factor can disrupt other equipment connected to the same source. This is why utility companies today have power factor requirements. Power factor determines how much real power is drawn from the utility line. Which also gives rise to the Total Harmonic Distortion (THD)? There are numbers of international standards to limit the harmonic content, caused due to the line currents of equipment coupled to electricity distribution networks. Accordingly, a reduction in line current harmonics, or Power Factor Correction – PFC is vital. In this paper we present the different types of methods for Power Factor Correction (PFC) and compare those methods and find out which one of them is particularly for system’s needs. The objective is to improve the power factor nearly unity with minimum Total Harmonic Distortion (THD). There are numbers of technique for PFC. Based on the selection electric element to filter out the harmonics and to get nearly unity input power factor, the PFC technique is categorized into “active” and “passive” PFC method. The “passive PFC? circuit uses low-frequency filter components to reduce harmonics. Moreover, in this technique power factor cannot be highly improved and output voltage is not controllable. Active switches are used in association with reactive element for - Active PFC approach? for the improvement of line current shape and to obtain controllable output voltage. For this DC-DC converter is employed and is operated at high frequency to shape the line current waveform as sinusoidal as possible..

    Analysis, implementation and simulation of different CPU scheduling algorithms
    A. Balodiya, A.K. Sharma and A. Balodiya
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      • Abstract: In the Operating System, resources are required to use efficiently and effectively. To fulfill this objective various types of scheduling algorithms exist to decide how and in which order process should be executed. The main objective of this paper is to introduce experimental analysis of CPU Scheduling algorithms. This paper gives an overview of various CPU Scheduling algorithms such as First Come First Serve (FCFS), Shortest Job First (SJF), Priority Scheduling Algorithm (PJF), Round Robin Scheduling Algorithm (RR) followed by comparison of all these algorithms on different parameters. In addition, this paper is mainly focuses on implementation and simulation of all these algorithms on GUI interface software called ‘Inside My Machine’..

    The role of quantum correction and black body radiation on wave propagation in viscous self-gravitating molecular cloud
    A. Kumar, D.L. Sutar and R.K. Pensia
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      • Abstract: The concept of wave propagation is discussed in the framework of viscous, self-gravitating molecular cloud under the influence of quantum correction and black body radiation. The solution has been obtained through the normal mode analysis and the dispersion relation has been derived with the help of linearized perturbation equations. The modified conditions of instability are obtained and we find that the presence of viscosity parameter modify the dispersion relation but do not affect the Jeans criterion of instability. Quantum correction and black body radiation modifies the fundamental Jeans criterion of gravitational instability into a quantum-corrected radiative instability. It is noted here that the role of quantum correction is to stabilize the considered system by decreasing the value of critical Jeans wavelength. .

    Review on Ferrite Polymer Nanocomposites Aspects
    Vishal Mathur, Arvind Samaria, Rana Mukherji and Pramod Arya
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      • Abstract: Hybrid nanomaterials have attained great interest due to the combination of unique properties of organic and inorganic component in one material. In this class, ferrite polymer nanocomposites are of particular interest because of the combination of excellent magnetic properties, stability, and good biocompatibility. Ferrite polymer composites are increasingly replacing conventional ceramic magnetic materials because of their mouldability and reduction in cost. They are also potential material candidates for microwave absorbers, sensors and other aerospace applications. This review article is mainly focused on fabrication of ferrite polymer nanocomposites and their applications. Different types of ferrite nanoparticles, methods of their synthesis, properties, and applications have also been reviewed briefly. As the field is considerably large, an effort has been made to include the original references discussing each particular application on a more detailed manner..