Artificial roughness on the absorber plate of a Solar Air Heater (SAH) is a popular technique for increasing its effective efficiency. The study investigated the effect of geometrical parameters of discrete multi-arc ribs (DMAR) installed below the SAH absorber plate on the effective efficiency. The effects of major roughness factors, such as number of gaps (Ng = 1-4), rib pitch (p/e = 4-16), rib height (e/D = 0.018-0.045), gab width (wg/e = 0.5-2), angle of attack ( = 30-75), and Reynolds number (Re= 2000-20000) on the performance of a SAH are studied. The performance of the SAH is evaluated using a top-down iterative technique. The results show that as Re rises, SAH-effective DMAR's efficiency first ascends to a specified value o

Noor oil field is one of smallest fields in Missan province. Twelve well penetrates the Mishrif Formation in Noor field and eight of them were selected for this study. Mishrif formation is one of the most important reservoirs in Noor field and it consists of one anticline dome and bounded by the Khasib formation at the top and the Rumaila formation at the bottom. The reservoir was divided into eight units separated by isolated units according to partition taken by a rounding fields.

In this paper histograms frequency distribution of the porosity, permeability, and water saturation were plotted for MA unit of Mishrif formation in Noor field, and then transformed to the normal distribution by applying the Box-Cox transformation alg

An acidic environment causes surface changes of resin composites. Filler particlesize and filler distribution also have a direct effect on these surface changes. This invitro study evaluated the influence of Pepsi Cola drink on the surface roughness ofComposan LCM and Composan Ceram over time. Sixteen disc shaped specimens(10mm diameter, 2mm thickness) of each resin composite were fabricated, therebyforming two groups (n= 8). Surface roughness (Ra) was analyzed after 24 hrs beforeexposure to beverage. The specimens were submitted to a five minutes immersion inPepsi Cola three times daily interrupted by immersion in deionized distilled water (37C˚). Surface roughness measurements were done at 10, 30, and 60 days intervals. Datawere

Non-thermal plasmas have become popular as plasma technology has advanced in various fields, including waste management, aerospace technology, and medicinal applications. They can be used to replace combustion fuels in stationary hall motors and need little effort to keep running for longer periods of time. To improve overall system performance, non-reactive gases such as )Xe, Ar, and Kr) are utilized in pure or mixed form to generate plasma. Since DC glow discharge is a fundamental topic of importance, these gases have been researched. The paper concentrates on 2-D modeling and simulation. DC glow-discharge tubes are utilized with argon gas to create plasma and learn about its properties. The magnitude of the electron density, increases wi

The effect of adding different volume of coumarin dye (5, 15, 25 and 35) ml on optical properties of Poly (Methyl Meth Acrylate) was studied. Films of pure PMMA and PMMA with different volume of coumarin dye (5, 15, 25 and 35) ml were prepared using the casting technique. Transmission and absorption of the films were measured by using UV-VIS spectrometer technique type (100 Conc), in order to assess the type of transmission which was found an indirect transition. An optical energy gap of pure PMMA is (4.95e v) and after adding coumarin with volume (25, 35) ml, the energy gap for PMMA decrease by (0.05) compere to pure PMMA films and addition energy gap appear equal to (4.1 e v). It was found that the absorption coefficient, extinction coeff

The tax revenues achieved through projects of transition to private sector are regarded as an important source for using in achieving political, economic and social objectives. Since Iraq is heading towards free market economy, new strategies should be adopted to reform the taxation system from by a qualified taxation management office and to activate the taxation policy and to reconsider legislation in relation to the aware of the legible to the importance of disclosure of their taxable real income in order to arrive at contribution of privatization in the taxation revenues for the important role effect on economic activities. In the light of the above, the research is based upon a hypothesis which stipulates that privatization contribu

The main factors that make it possible to get the corrosion of reinforcing steel in concrete are chloride ions and the absorption of carbon dioxide from the environment, and each of them works with a mechanism which destroys the stable immunity of rebar in the concrete. In this work the effect of carbon dioxide content in the artificial concrete solution on the corrosion behavior of carbon steel reinforcing bar (CSRB) was studied, potentiostatically using CO₂ stream gas at 6 level of concentrations;  0.03 to 2.0  weight percent, and the effect of rising electrolyte temperature was also followed  in the range 20 to 50^ᴼ C. Tafel plots and cyclic polarization procedures were obeyed to investigate the c

Aims: This study was done to investigate the effect of low energy laser therapy on bone healing at the extraction site. Materials and methods:(24) male albino rats were exposed to the extraction procedure of the maxillary first molar on the first day of a seven day experiment and these animals were divided into two main groups; the control group and the laser group. The laser experiment involved using (Ga-As infrared diode laser) from optodent by directing the probe over the extraction site. The control group consisted of 4 rats, and the laser group was subdivided into 5 subgroups of 4 rats each. The laser dose was as follows: B1: a single dose of 5 minutes immediately after extraction.,

Accurate description of thermodynamic, structural, and electronic properties for bulk and surfaces of ceria (CeO2) necessitates the inclusion of the Hubbard parameter (U) in the density functional theory (DFT) calculations to precisely account for the strongly correlated 4f electrons. Such treatment is a daunting task when attempting to draw a potential energy surface for CeO2-catalyzed reaction. This is due to the inconsistent change in thermo-kinetics parameters of the reaction in reference to the variation in the U values. As an illustrative example, we investigate herein the discrepancy in activation and reaction energies for steps underlying the partial and full hydrogenation of acetylene over the CeO2(111) surface. Overall, we find th