Types Of Atmospheric Conditions Research Articles

Experimental Comparative Study to Achieve the Maximum Power Point Tracking of a PV System

This paper presents a comparison study in different techniques of maximum power point tracking (MPPT), which have been experimented and validated by simulation in the proposed PV system. The main aim of each MPPT technique is to enhance and optimize the output of photovoltaic (PV) array in dynamic weather conditions through an examination algorithm. Nevertheless, an optimized MPPT technique is described in many sides like achievement, software, precision, convergence velocity, and hardware naturalness. The gained experimental results for the MPPT techniques are compared using the Perturbation and Observation (P&O), Incremental Conductance (IncCond), Short Circuit Current (SCC), Open Circuit Voltage (OCV), and Constant Voltage (CV) at weather conditions variations. These methods were analyzed and their performance was estimated through using the Matlab/Simulink under different types of atmospheric conditions. These results show that the IncCond technique gives larger efficiency, at rapidly changing conditions than the other techniques.

Window-Windcatcher for Enhanced Thermal Comfort, Natural Ventilation and Reduced COVID-19 Transmission

We investigate and test the effectiveness of a novel window windcatcher device (WWC), as a means of improving natural ventilation in buildings. Using ANSYS CFX, the performance of the window-windcatcher is compared to a control case (no window-windcatcher), in three different geographic locations (Cardiff, Doha and Amman) which are representative of three different types of atmospheric conditions. The proposed window-windcatcher has been shown to improve both thermal comfort and indoor air quality by increasing the actual-to-required ventilation ratio by up to 9% compared to the control case as per the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards. In addition, the locations with minimum velocities have been identified. Those locations correspond to the regions with a lower infection risk of spreading airborne viruses such as SARS-CoV-2, which is responsible for the COVID-19 pandemic.

Aerosol Lidar Intercomparison in the Framework of SPALINET—The Spanish Lidar Network: Methodology and Results

A group of eight Spanish lidars was formed in order to extend the European Aerosol Research Lidar Network-Advanced Sustainable Observation System (EARLINET-ASOS) project. This study presents intercomparisons at the hardware and software levels. Results of the system intercomparisons are based on range-square-corrected signals in cases where the lidars viewed the same atmospheres. Comparisons were also made for aerosol backscatter coefficients at 1064 nm (2 systems) and 532 nm (all systems), and for extinction coefficients at 532 nm (2 systems). In total, three field campaigns were carried out between 2006 and 2007. Comparisons were limited to the highest layer found before the free troposphere, i.e., either the atmospheric boundary layer or the aerosol layer just above it. Some groups did not pass the quality assurance criterion on the first attempt. Following modification and improvement to these systems, all systems met the quality criterion. The backscatter algorithm intercomparison consisted of processing lidar signal profiles simulated for two types of atmospheric conditions. Three stages with increasing knowledge of the input parameters were considered. The results showed that all algorithms work well when all inputs are known. They also showed the necessity to perform, when possible, additional measurements to attain better estimation of the lidar ratio, which is the most critical unknown in the elastic lidar inversion.

An Analytical Infrared Radiation Model of the Earth

The spectral distribution and total intensity of the earth’s radiation to space is of interest in the design of instrumentation systems for satellites and in the computation of radiant heat transfer to a satellite. In the absence of sufficient experimental data, an analytical model has been derived covering several types of atmospheric conditions. The necessary equations and relationships are derived, and some results (based on a 1959 ARDC model atmosphere) are presented for several different cloud conditions. An estimate of the appearance of the earth’s infrared horizon is also presented.

Metal Spraying in the Radio Industry

IT is today the normal practice to protect all ferrous metal parts used in the manufacture of chassis, decks, cabinets, etc., for commercial radio work, with an applied spraying of non‐ferrous metal. The metals most commonly used are zinc and aluminium, although it is right to say that practically any metal, which can be drawn into a wire, can be sprayed for protection purposes. Zinc is perhaps the most generally used, on account of its relatively low cost. The sprayed metal reacts favourably to cleaning with wire brushes and an attractive matt finish is readily obtained without the trouble attendant on normal polishing. Hand or rotary brushes can be used with flexible shafts for small articles or large areas. The applied coating can be of various thicknesses, dependent upon the type of atmospheric conditions it is expected to encounter, such as industrial pollution, salt‐laden sea air and spray, and tropical or highly humid atmospheres. The thickness is measured by a direct‐reading contact meter and 0.003 to 0.010 in. depth of metal applied is quite adequate protection for 12 to 15 years.