The present work presents design and implementation of an automated two-axis solar tracking system using local materials with minimum cost, light weight and reliable structure. The tracking system consists of two parts, mechanical units (fixed and moving parts) and control units (four LDR sensors and Arduino UNO microcontroller to control two DC servomotors). The tracking system was fitted and assembled together with a parabolic trough solar concentrator (PTSC) system to move it according to information come from the sensors so as to keep the PTSC always perpendicular to sun rays. The experimental tests have been done on the PTSC system to investigate its thermal performance in two cases, with tracking system (case 1) and without tracking system (case 2). The experimental results showed that the average solar radiation falling on the PTSC prototype in the two cases during the same time was 854 and 701 watt/m2, respectively, which means an increase in the solar radiation about 21.8 % when using tracking system. It was found that the average useful heat gain output of solar collector was equal to (376.2, 252.6 watt) for the two cases, respectively, so there was an increase of about 48.9 % when using the tracking system. Also, the average thermal efficiency of the PTSC was found to be (20.7, 26.5 %) for the two cases, respectively, which means an increase in the average efficiency by 28% with use of tracking system compared to the fixed case.
In this study, the possible protective effects of daidzein on ifosfamide-induced neurotoxicity in male rats were examined by the determination of changes in selected oxidant–antioxidant markers of male rats’ brain tissue.
Twenty-eight (28) apparently-healthy Wistar male rats weighing (120-150gm) allocated into 4 groups (n=7) were used in this study. Rats orally-administered 1% tween 20 dissolved in distilled water/Control (Group I); rats were orally-administered daidzein suspension (100mg/kg) for 7 days (Group II); rats intraperitoneally-injected with a single dose of ifosfamide (500 mg/kg) (Group III); rats orally-administered for 7 days with the daidzein (100mg/
... Show MoreThis work investigates generating of pure phase Faujasite-type zeolite Y at the ranges chosen for this study via a static aging step in the absence of seeds synthesis. Nano-sized crystals may result when LUDOX AS-40 is used as a silica source for gel composition of range 6 and the crystallization step may be conducted for a period of 4 to 19 hr at 100 ⁰C. Moreover, large-crystals with high crystallinity pure phase Y zeolite can be obtained at hereinabove conditions but when hydrous sodium metasilicate is used as a silica source. The other selected ranges also offer pure phase Y zeolite at the same controlled conditions.
Background: Hypertension is probably the most important public health problem around the world. People with periodontal disease may be at greater risk of hypertension. The inflammatory effects of periodontal disease help to promote endothelial dysfunction in arteries which may lead to changes in blood pressure. Salivary MMP-8 has been associated with both periodontal disease and prevalent hypertension. Aim of study: This study was conducted to measure salivary matrix metalloproteinase - 8, in relation to periodontal health condition among a group of patients with hypertension in comparison with control group. Materials and methods: Ninety subjects, aged 45-50 years old were included in this study, seeking treatment for chest pain in Ibn-A
... Show More<span lang="EN-US">The fundamental of a downlink massive multiple-input multiple-output (MIMO) energy- issue efficiency strategy is known as minimum mean squared error (MMSE) implementation degrades the performance of a downlink massive MIMO energy-efficiency scheme, so some improvements are adding for this precoding scheme to improve its workthat is called our proposal solution as a proposed improved MMSE precoder (PIMP). The energy efficiency (EE) study has also taken into mind drastically lowering radiated power while maintaining high throughput and minimizing interference issues. We further find the tradeoff between spectral efficiency (SE) and EE although they coincide at the beginning but later their interests become con
... Show MoreThis article uses coupled Eulerian–Lagrangian finite element algorithm to conduct a three-dimensional thermomechanical study to capture the shape and characteristics of defect type generated while achieving the dissimilar friction stir welding of aluminium alloys. The volume-of-fluid method is used to model the Eulerian region and predict the localised formation of process defects. Three different tool shapes are utilised to achieve the dissimilar friction stir welding joining between AA 2024-T3 on the advancing side and AA 6061-T6 on the retreating side. Process parameter effects such as rotational tool speed, traverse tool speed and tool tilt angle are also investigated. The finite element model results are validated by comparing with t
... Show MoreT-joints are common structures encountered in the assemblage of many industrial applications due to their advantages. However, joining these structures when using Friction Stir Welding (FSW) could be prone to defects that cause severe consequences like loss of strength and fracture. The current paper implements an experimental procedure to assess the effect of geometrical tool shape on void formation in friction stir welded AA 6061-T6 T-joint configuration. Taguchi optimization method was put into service to minimize the number of experiments and fulfil the goal of discovering the optimal FSW parameters that allow the manufacturing of such configurations with high mechanical properties. X-ray radiography and micrograph images were u
... Show MoreThis study was undertaken to introduce a fast, accurate, selective, simple and environment-friendly colorimetric method to determine iron (II) concentration in different lipstick brands imported or manufactured locally in Baghdad, Iraq. The samples were collected from 500-Iraqi dinars stores to establish routine tests using the spectrophotometric method and compared with a new microfluidic paper-based analytical device (µPAD) platform as an alternative to cost-effective conventional instrumentation such as Atomic Absorption Spectroscopy (AAS). This method depends on the reaction between iron (II) with iron(II) selective chelator 1, 10-phenanthroline(phen) in the presence of reducing agent hydroxylamine (HOA) and sodium acetate (NaOAc) b
... Show Moreמטרת המחקר הזה היא לבדוק את שלושה סיפורים קצרים מהקובץ הראשון של אהרון אפלפלד , שנחשב ההצהרה הרשמית על היותו סופר השואה הראשון בישראל , המשותף לשלושת הסיפורים הוא הנימה של הגיבורים היוצאים למסע פיזי ונפשי לגלות את אשר אירע להם , מגמתו של המחקר היא לבדוק את הצורה המיוחדת שבה אפיין אפלפלד את גיבוריו שמעידים על כך , כי השואה היא החוויה המרה והקשה בקרב היהודים והשלכותיה נשארה טמונה בקרבם גם אחרי המלחמה ואחרי שנים
... Show MoreThe study aims to provide a Suggested model for the application of Virtual Private Network is a tool that used to protect the transmitted data through the Web-based information system, and the research included using case study methodology in order to collect the data about the research area ( Al-Rasheed Bank) by using Visio to design and draw the diagrams of the suggested models and adopting the data that have been collected by the interviews with the bank's employees, and the research used the modulation of data in order to find solutions for the research's problem.
The importance of the study Lies in dealing with one of the vital topics at the moment, namely, how to make the information transmitted via
... Show MoreModern French novel has gained a distinctive status in the history of French literature during the first half of the twentieth century. This is due to many factors including the new literary descriptive objective style adopted by novelists like Alain Robbe – Grillet that has long been regarded as the outstanding writer of the nouveau roman, as well as its major spokesman, a representative writer and a leading theoretician of the new novel that has broken the classical rules of the one hero and evolved, through questioning the relationship of man and the world and reevaluating the limits of contemporary fiction , into creating a new form of narrative.
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En vue de résu
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