In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at these parameters and comparing them with the randomly used once. The experimental and analytical results showed that the Taguchi method was successful in optimizing the parameters that give the highest properties and it can find the most influential parameter regardless of the material used. Also it showed that the volume fraction was the most influential parameter on the tensile and impact strength. The difference between these composites was in the properties values and that the Kevlar composites have higher tensile and impact strength.
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In this paper, fire resistance and residual capacity tests were carried out on encased pultruded glass fiber-reinforced polymer (GFRP) I-beams with high-strength concrete beams. The specimens were loaded concurrently under 25% of the ultimate load and fire exposure (an increase in temperature of 700 °C) for 70 min. Subsequently, the fire-damaged specimens were allowed to cool and then were loaded statically until failure to explore the residual behaviors. The effects of using shear connectors and web stiffeners on the residual behavior were investigated. Finite Element (FE) analysis was developed to simulate the encased pultruded GFRP I-beams under the effect of fire loading. The thermal analyses were performed using the general-pu
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During the last few years, the greener additives prepared from bio-raw materials with low-cost and multifunctional applications have attracted considerable attention in the field of lubricant industry. In the present work, copolymers derived from sunflower and linseed oils with decyl methacrylate were synthesized by a thermal method using benzoyl peroxide (BPO) as a radical initiator. Direct polymerization of fatty acid double bonds in the presence of a free radical initiator results in the development of environmentally friendly copolymeric additives (Co-1 and Co-2). Fourier Transform Infrared (FTIR) and Proton Nuclear Magnetic Resonance (1H-NMR) were used to characterize the resulting copolymers. Thermal decomposition of copolymers was de
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The purpose of this research was to investigate the beneficial effects of phosphatidylcholine in reducing changes in both lipid and protein profiles in addition to atherogenic index in adult rats with fructose-induced metabolic syndrome. Thirty-six mature Wistar Albino female rats (Rattus norvegicus) (aged 12-15 weeks and weighing 200±10 g) were divided randomly into four groups (G1, G2, G3, and G4); then variable treatments were orally administered for 62 days as follows: G1 (Control group), received distilled water; G2, treated with phosphatidylcholine (PC) orally (1 g/kg BW); G3 (Fr), orally dosed with 40% fructose and 25% fructose mixed with drinking water; G4 (Fr+PC), were also intubated with 40% fr
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The large number of failure in electrical power plant leads to the sudden stopping of work. In some cases, the necessary reserve materials are not available for maintenance which leads to interrupt of power generation in the electrical power plant unit. The present study, deals with the determination of availability aspects of generator in unit 5 of Al-Dourra electric power plant. In order to evaluate this generator's availability performance, a wide range of studies have been conducted to gather accurate information at the level of detail considered suitable to achieve the availability analysis aim. The Weibull Distribution is used to perform the reliability analysis via Minitab 17, and Artificial Neural Networks (ANNs) by approaching o
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current research Cares about study patterns of optical and aesthetic values in the halls of occasions (weddings) because of their importance in providing an atmosphere of joy. The problem was through the study of light and its impact on the receiver and found a researcher that interior spaces allocated to the halls inappropriate in terms of functional and aesthetic so necessitated the need to study this phenomenon in order to be addressed through the study of light and its impact on the users of those spaces where research aims to current detection properties patterns optical in the internal spaces of the halls and identify some of the aesthetic values of the lighting for the interior spaces.The search consists of four chapters, the firs
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Abstract
Background: anabolic androgenic steroids (AASs) are becoming increasingly popular between bodybuilders and people who want to enhance their physiques. However, according to the rise of the Internet and laws prohibiting sales of these substances without prescription, the route of obtaining and administration practices have become more and more dangerous.
Objective: Anabolic-androgenic steroids represents a group of synthetic testosterone derivatives its play an important role in clinical treatment. These group of drugs are widely abused among the general public to increase lean body weight and improve athletic performance. It has been reported that AAS use can cause many adverse e
... Show MoreThe current research aims to determine the intellectual security and the psychological resilience of Secondary school students and how these two variables are related to each other. The study also seeks the extent to which psychological resilience contributes to intellectual security
The research sample consisted of (420) students from the Secondary stage in the Directorate of Education of Baghdad / Rusafa III. Two scales were administered to the participants to collect the needed data. As for the analysis of data, Pearson correlation coefficient, T-test, and the Regression analysis were employed, the results revealed:
- The members of the sample have an intellectual Security.
- The members of the sample have