The aim of this work is to produce samples from Iraqi raw materials like Husyniat Bauxite (raw and burnt) and to study the effect of some additives like white Doekhla kaolin clays and alumina on that material properties were using sodium silica as a binding material. Five mixtures were prepared from Bauxite (raw and burnt) and kaolin clays, with an additive of (40) ml from sodium silica and alumina of (2.5, 5, 7.5,10 wt %) percentage as a binding material. the size grading was through sieving. The formation of all specimens was conducted by a measured gradually semi-dry pressing method under a compression force of (10) Tons and humidity ratio ranging from (5-10) % from mixture weight. Drying all specimens was done and then they were burnt under (1200)°C temperatures according to a burning program which raised the temperature (5)°C per minute and then the soaking interval. Some tests such as the physical, mechanical and thermal test were connected on the testing results for the specimens indicated that the raw materials with fine size range and high temperature gave specimens a thermal phase with higher percent of Mullit in comparison with coarse size. Bulk density values, coefficient of longitudinal and hardness increase with porosity and ratio of water absorption values decrease. Also, results show that Alumina with Bauxite gives it stiffens because of the increase of the mullite phase which is characterized by high mechanical and thermal properties especially thermal conductivity. Results show that the best thermal and mechanical properties are found in the fifth mixture (X5) which contains a ratio of about (10) % of Al2O3 .
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Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared w
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Incorporating the LiDAR sensor in the most recent Apple devices represents a substantial development in 3D mapping technology. Meanwhile, Apple's Lidar is still a new sensor. Therefore, this article reviews the potential uses of the Apple Lidar sensor in various fields, including engineering and construction, focusing on indoor and outdoor as-built 3D mapping and cultural heritage conservation. The affordable cost and shorter observation times compared to traditional surveying and other remote sensing techniques make the Apple Lidar an attractive choice among scholars and professionals. This article highlights the need for continued research on the Apple LiDAR sensor technology while discussing its specifications and limitations. A
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Total quality management considers one of the modern scientific entrances which practiced by productivity service organizations alike to provide appropriate quality required outputs according to the needs and desires of customers manage , enable the organization seeking to continue and grow in light of the increasing competition from the satisfy and provide the appropriate total quality management requirements whenever led to face risks that they may have in a manner in which they can be addressed and find ways to avoid them in the future when repeated. &n
... Show MoreEpstein-Barr Virus (EBV) infection is associated with broad spectrum of clinical manifestationsdepending on the immune status of the host, To analyze their possible role in the complication ofautoimmune hepatitis, we investigated (30) female patients with autoimmune hepatitis type-1 of(10-40)years and 25 healthy female of same ages(control groups). Both groups were carried outto measure the levels of EBV-CA IgM, IgG Ab, EBV-EA IgM, IgG Ab, and EBV-NA IgM, IgGAb using indirect immunoflourescent assay (IFAT).The prevalence of EBV-CA IgM, IgG Ab were(10%,20%) and EBV-EA IgM, IgG Ab were (10% and20%) respectively, while the prevalence ofEBV-NA IgG Ab was( 3.33%) and there are no prevalence of EBV-NA IgM Ab. There weresignificant differences (P
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