Volume 4 Issue 1
Authors: Sergey Smirnov; Michael Uspensky
Abstract: Approaches to cascade failure modeling and their consequences are considered; requirements to controlled separation of power systems for the major emergency prevention with possible blackout are presented; existing approaches to its realization are shown. The power system restoration method after a major emergency with the separation, based on assembly sequence search of its scheme taking into account generation start-up for time is offered.
Keywords: Power Systems, Cascade Failures, Blackouts, Controlled Separation, Power System Restoration
Authors: M Husain; N V Halegowda; S P Shekhawat
Abstract: With the tremendous growth in science and technology, followed by the industrialization, the global energy demand is steeply increasing. Presently, mankind is largely dependent upon fossil fuel as a source of energy. Yet its overexploitation has lead to severe environmental concerns. Moreover the resource of fossil fuel is at a vanishing point, therefore global energy researchers are exploring alternative energy options. Salt Gradient Solar Pond (SGSP) is one such alternative which has been successfully applied in many parts of the world. India has vast potential for exploiting this technology. The present paper explores the scope of SGSP in India and its future prospects.
Keywords: Energy Scenario, Environmental Degradation, Salt Gradient Solar Pond.
Authors: S. M. Reda
Abstract: Luminescent solar concentrator samples using PMMA / SiO2 composites as the matrix with Erythrosine B are prepared. Three films of PMMA/ silica composition ration (70:30) %, (50:50) % and (30:70) % are prepared. The photostability of Erythrosine B doped PMMA/SiO2 composites is examined through four weeks exposure to sunlight. The obtained results show that the stability of collector increases with the increasing silica content. Moreover, the transition energy for electrons are direct allowed transition for all examined samples and the value of optical gap energy (Eg) increases with the increasing the silica content. However, the tail width of localized states in the band gap (Eu) decreases with the increasing exposure time due to the degradation of the dye. Emission spectra and quantum efficiency are also investigated. Erythrosine B is shown to have a higher fluorescence quantum yield in (30:70) % matrix. Collectively, these results suggest that PMMA/SiO2 composites provide the better system for use in fluorescent solar collector systems.
Keywords: PMMA; PMMA/SiO2 Composites; Erythrosine B; Photostability; Fluorescence Quantum Yield.
Authors: Amer Kh. Massad
Abstract: This paper presents a study of optimization of the geometrical correlations of the linear electrictromagnetic motors (LEMM) to ensure minimum mass and constant mechanical integral output work. The simplified electromagnetic circuit was built, and mathematical models of the system were laid out. To show the optimization process for geometrical correlations between main dimensions of the LEMM and ensuring minimum mass and constant mechanical integral output work, two variable factors are used in this paper: copper winding to magnetic core ratio and height winding to internal radius of motor . Analyzing the above optimizations, it’s seen that LEMM has minimum mass when and , which is reduced by compared with the LEMM without optimization.
Keywords: Linear Electro-Magnetic Motor, Geometrical Correlations, Minimum Mass Motors, Dimensions, Mechanical Integral Output Work.
Authors: K. R. Anderson; S. Hill; C. Selerberg; E. Guiterez
Abstract: In this paper, results are presented for the testing of a flat plate solar thermal collector. A wealth of technical data regarding the SUNEARTH vendor name brand of flat plate solar collectors is presented to provide references for Solar Engineers. The thermal performance curve is used to determine the air-collector heat removal factor of the device, which is then compared with the manufacturer’s data. The diurnal system efficiency characteristics of this device are also presented herein. These results afford a pragmatic baseline for other researchers seeking to benchmark the performance of their solar collectors.
Keywords: Solar Thermal; Flat Plate Solar Collector; Energy Efficiency
Authors: Hongzhi Yan; Xingli Ren; Ying He; Guoqi He
Abstract: Considering meshing gear backlashes, time-varying mesh stiffness, transmission errors, and ignoring influences of twist-oscillecting vibration on face-gear driving system and systematic axial errors, this paper builds the nonlinear dynamic bending-torsional coupling model of the face-gear drive. And nonlinear dynamic theory is used to analyze the vibration characteristic of face-gear driving system. Besides, some analyses are conducted on influences of different parameters such as modulus, pressure angle, tooth difference, rotational speed and torque on the time domain and frequency domain of face-gear displacement, velocity, acceleration, angular velocity and angular acceleration, in an attempt to find out the influence degree of these parameters on the vibration characteristics of face-gear driving system, making preparations for high quality face-gear machining.
Keywords: Face-Gear Driving System, Dynamic Model, Vibration Characteristic, Dynamic Analysis