Renewable energy resources have become a promissory alternative to overcome the problems related to atmospheric pollution and limited sources of fossil fuel energy. The technologies in the field of renewable energy are used also to improve the ventilation and cooling in buildings by using the solar chimney and heat exchanger. This study addresses the design, construction and testing of a cooling system by using the above two techniques. The aim was to study the effects of weather conditions on the efficiency of this system which was installed in Baghdad for April and May 2020. The common weather in these months is hot in Baghdad. The test room of the design which has a size of 1 m3 was situated to face the geographical south. The test room is thermally insulated and connected to a solar chimney which generates a convection current to draw the air out of the room through a heat exchanger. The heat exchanger was submerged in a water tank of 2 m length, 1 m width and 1 m height. It was also covered with a layer of soil mixture with a thickness of 10 cm. The experiment simulates the natural conditions of a shallow water surface, connected to the room from the other side. The study results revealed that the air temperature inside the test room was lower than that of the ambient air outside. Pearson correlation coefficient showed that there was a strong direct relationship between solar radiation, temperature and wind speed from one side and the cooling efficiency from the other side. Also, there was a negative correlation between relative humidity and cooling efficiency.
Water is the basis of the existence of all kinds of life, so obtaining it with good quality represents a challenge to human existence and development especially in the desert and remote cities because these areas contain small populations and water purification requires great materials and huge amounts of fossil fuels resulting pollution of the environment. Cheap and environmentally friendly desalination methods have been done by using solar distillations. Passive solar stills have low yields, so in this research, the problem is overcome by connecting four heat pipes which are installed on the parabolic concentrator reflector with passive solar still to increase the temperature of hot water to more than 90°C, as a resul
... Show MoreSome methods recommended abroad to control the oriental hornet, Vespa orientalis L., attacking the honey bee, Apis mellifera L., colonies were tested, with some modifications, for the first time under the Iraqi conditions. One of these methods was carried out by covering the hive entrance with a piece of queen excluder to prevent the hornet from entering the hive. Also, the position of hive stand was reversed to deprive the hornet from using the flight board as a stage for waiting and creeping toward the defending bees. The second method was carried out by fixing a cardboard cone as a bee passage at the hive entrance to hinder the entry of the hornet into the hive. Both of these methods were found to be unsuccessful to
... Show MorePaul Auster's City of Glass is here singled out as representative of the writer's The New
York Trilogy. All throughout his novelistic career, Auster has been working on a pseudothesis
that adheres to a certain aesthetic of disappearance. The study engages this Austerian
aesthetic apropos of certain theoretical stretches such as the Emersonian "Not Me", the
Thoreauvian "interval" or "nowhere", the Deleuzian "nomadic trajectory", the Derridian
"grammè" or "specter", and the Baudrillardian "disappearance". The city of the novel's titling
is here seen as the trope of all that which has already disappeared, and hence it is seen as the
space (mise en scène) where the perfect crime of the murder of the real is to be thoro
Experimental measurements were done for characterizing current-voltage and power-voltage of two types of photovoltaic (PV) solar modules; monocrystalline silicon (mc-Si) and copper indium gallium di-selenide (CIGS). The conversion efficiency depends on many factors, such as irradiation and temperature. The assembling measures as a rule cause contrast in electrical boundaries, even in cells of a similar kind. Additionally, if the misfortunes because of cell associations in a module are considered, it is hard to track down two indistinguishable photovoltaic modules. This way, just the I-V, and P-V bends' trial estimation permit knowing the electrical boundaries of a photovoltaic gadget with accuracy. This measure
... Show MoreIn this research was conducted to provide a product to analyze the performance sensor fiber optic used to measure and feel the intensity of the electric field results showed obtained that use sensor long gives reactive high electric field strength and a high value for allergic sensor, but that is at the expense of reducing the intensity of the electric field that is detected
In this study, the energy charging mechanism is mathematically modeled to determine the impact of design modifications on the thermofluidic behavior of a phase change material (PCM) filled in a triplex tube containment geometry. The surface area of the middle tube, where the PCM is placed, is supported by single or multi-internal frustum tubes in vertical triplex tubes to increase the performance of the heating and cooling of the system. In addition to the ordinary straight triplex tubes, three more scenarios are considered: (1) changing the middle tube to the frustum tube, (2) changing the inner tube to the frustum tube, and (3) changing both the internal and central tubes to the frustum tubes. The impact of adopting the tube desig
... Show MoreThe study aims to know the nature of the expected relationship between market share management strategies and the variation in the performance of the shares of a number of Iraqi industrial companies listed in the Iraqi Stock Exchange. For the period (2005-2018) in the light of both the monthly closing prices and sales volume during the research period, the (Panel Data) method was relied on through a stylistic test (fixed effects model and random effects model), and the results determined the need to adopt the fixed effects model method for sample data and test Assumptions, the results showed the positive impact of market share according to its strategies on the performance of stocks according to its studied indicators (Treynor index
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