An Empirical Model for Prediction of Environmental Attenuation of Millimeter Waves

The latest trends in mobile technology have increased the need for higher spectrum bands from every sector of using wireless applications. As the internet is growing rapidly it has increased the need for wireless services, which require radio spectrum and thus becoming more congested. Engineers show that due to high demand for spectrum, government authorities are regularly introducing schemes to regulate the use of spectrum. New researches are enhancing to resolve the crisis. In order to fix the spectrum for future technologies, propagation studies are required. In this paper an empirical model is proposed for prediction of attenuation due to clouds and fog based on the Rayleigh approximation model. In this model a new concept of calculating dielectric constants of water are also introduced. The implementation results of the proposed model are compared with the other cloud attenuation models. The proposed model proved to be better than the ITU-R model.

     

Energy absorbing materials used in solar still for enhancement in distillate output: a review

Solar energy is an abundant and secure source of vitality and thus is described as one of the most promising alternative energy options. Nevertheless, solar energy is intermittent in nature as there is no sun at night. Its total availability value is seasonal and is hooked on the meteorological conditions of locations. Hence, solar energy presents an unsteady energy resource. So, thermal energy storage will be necessary to save the available solar energy at a period of no load or when excessive solar energy is available, and to make up for the shortage of energy when the load is in need of energy. This article reviews the different energy storage materials tried by various researchers to improve the distillate output of solar stills.     

Experimental analysis of single-basin solar still with porous fins

ABSTRACT

The present research paper explains the experimental analysis of the single-basin solar still with attachment of porous fins on the absorber plate. Here, experiments have been conducted on the single-basin sola still with and without attachment of porous fins. Generally, fins are used in the solar still to reduce the preheating time of water and attain positive water and inner glass cover temperature during morning hours for increment in distillate output. Series of experiments were performed in the Government Engineering College Patan during May 2017 during sunshine hours. Various temperatures such as that of water, inner glass cover and solar insolations have been measured by standard instruments. From the experiment, it was found that the distillate output after attachment of fins was 3.8?L and that of the conventional solar still was 2.67?L. Hence, a percentage increment of 42.3% was found by use of porous fins in a solar still.     

Theoretical and experimental performance analysis of sandstones and marble pieces as thermal energy storage materials inside solar stills

The present research paper deals with the theoretical and experimental investigation of solar stills with two different thermal energy storage materials, namely, marble pieces and sandstones. To carry out this research, three solar stills of 1?m square area have been made. All solar stills have been provided with a glass cover and a cooling and dripping arrangement for reducing top heat loss and maintaining a constant level of water. It has been found that the use of sandstones as storage materials and the cooling and dripping arrangement have a remarkable effect on the distillate output of a solar still. The set-up has been used to augment the distillate output throughout the day. Theoretical results have also been compared with the experimental results and have been found to be in good agreement.     

Soft Clustering for Enhancing ITU Rain Model based on Machine Learning Techniques

Wireless Personal Communications - With the many folds increase in demand for capacity in mobile broadband communication technology every year, wireless carriers must be prepared for the tremendous...     

Performance analysis of waste brick magnesia as a storage material in a solar still

In this current study, a single basin solar still (SBSS) was explored in the climatic state of Patan (23.84° N, 72.12° E) India over March 2019. The SBSS was examined with the use of waste brick magnesia (WBM) for the same amount of water (10 L). For experimentation, three same-sized SBSS were taken with 3 and 6 kg WBM and without storage materials. It was found that a daytime yield for SBSS of 2.27 L without storage materials was obtained; and this was reduced for SBSS with 3 and 6 kg WBM to 1.96 and 1.75 L, respectively. It has also been noticed that the yield of SBSS during off-sunshine hours due to the energy storage capacity increased with WBM but the combined (daytime + off-sunshine hours) yield was found reduced with an increment in a mass of the WBM. It was found that the maximum instantaneous thermal efficiency of the SBSS without WBM, 3 and 6 kg WBM was 60.24%, 45.65%, and 54.26%, respectively. Overall thermal efficiency was also determined and obtained to be higher for SBSS without WBM as storage.     

Effects of Fortifier on Glass/Carbon Fiber Reinforced Tetrafunotional Epoxy Resin

Glass fiber reinforced epoxy composites were prepared using tetra-N-glycidyl-p,p′-diaminodiphenyl methane (TGDDM) as a resin matrix with/without fortifier PGEHA/VCDRC (at 20 phr level) using DDM/DDS as curing agent; the composites were evaluated for their various physical, mechanical, chemical, and electrical properties. Carbon fiber (i.e., unidirectional, bidirectional, and chopped) reinforced composites of TGDDM with/without epoxy fortifier PGEHA/VCDRC (at 20 phr level) were also prepared and evaluated for their physical and some mechanical and chemical properties. It is observed that incorporation of fortifier (at 20 phr level) improves these properties significantly.     

Ant Colony Optimized Fuzzy Control Solution for Frequency Oscillation Suppression

This paper presents a novel approach in addressing a critical power system issue, i.e., automatic generation control (AGC) in a smart grid scenario. It proposes the design and implementation of an optimized fuzzy logic controller (FLC) for AGC of interconnected power network. There are three different sources of power generation considered in the two-area interconnected model of power system network. First area is equipped with a single reheat thermal unit and a superconducting magnetic energy storage (SMES) unit, while another area has a hydro-unit with SMES. A multi-stage optimization strategy for the optimal solution of FLC for tie-line and frequency oscillation suppression is proposed in this paper using an ant colony optimization technique. The optimization of FLC is carried out in four different stages. The first stage is the optimization of range of input and output variables; the second stage is the optimization of membership function; the third and fourth stages are the optimization for rule base and rule weight optimization, respectively. The performance of the proposed controller is also compared with another control approaches to stabilize P_tie-line and Δf oscillations; these are the Ziegler–Nichols-tuned proportional–integral–derivative (PID) controller and genetic algorithm optimized PID controller. A comprehensive analysis of the traditional techniques and proposed techniques is presented on the basis of major dynamic performance parameters, i.e., settling time and peak overshoot.