http://dspace-su.server.ly:8080/xmlui/handle/123456789/1810 2026-05-01T12:45:52Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/1844 Effect of Heat Treatment on Grain Size and Mechanical Properties of 316 Austenitic Stainless Steel Abdulkarim K. Abdulkarim; Moftah H. Alkathafi; Imhamed M. Saleh Ali Grain growth is one of the three important stages take place during annealing of cold-worked materials after the process of recovery and recrystallization. This paper presents the experimental analysis of the grain growth kinetics and hardness of 316 austenitic stainless steel having grain size between 6µm and 69µm. The experiments were carried out for three different temperatures and represent microscope images of grain growth during isothermal annealing at (900oС, 1000°С and 1100oС) within 30, 60, 90 and 120 min respectively. The change of grain size as a function of annealing time for various temperatures have been presented in this study the value of the coefficient n for normal grain growth was determined and found to be in the range from 0.29 to 0.37. The investigation also included the determination of the activation energy for grain growth which found to be 104 KJ/mol. The hardness of 316 austenitic stainless steel has been measured at different grain sizes and the results indicated that the hardness decreased with increasing grain size and the data in general confirm the Hall-Petch equation. 2017-01-01T00:00:00Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/1843 CFD Modeling of Elbow and Orifice Meters Abdalsalam M. Muftah Elbow and Orifice meters are two of the common flow measurement systems which are used to determine the pressure difference occurring as a fluid flows change by resistance. This differential pressure exists when a flowing changes direction due to a pipe turn as in the case of Elbow meter. The pressure difference results from the centrifugal force. Since pipe elbows exists in plants and its cost is very low. However, the accuracy is very poor [2]. Due to the fine pressure measurements required for the orifice meter, small changes in the physical geometry leads to large errors in the flow meter calculation. For example, if the fluid flow rate is too large for a given orifice, cavitation can occur, causing wear on the orifice. The same would be true for fast moving fluid with solid particulates included in the flow. For this reason, an additional study was conducted on an orifice plate with a slightly enlarged orifice to determine the sensitivity of flow measurements in regards to the orifice diameter. The purpose of this paper is to run a CFD Model (Computational Fluid Dynamics) at Elbow and Orifice meters using Solidworks Flow Simulation [1] with different pipe sizes, ranging from nominal diameter. The CFD Simulation will be extended to run with using different fluid viscosities, varying as air, steam, oil and water. The goal is to determine the sensitivity of flow measurements in regards to these parameters. The results will be compared to a corresponding theoretical solution to investigate how much the accuracy can be improved by changing the geometry of the pipes and fluid viscosities. 2017-01-01T00:00:00Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/1842 Study of Galvanic Corrosion of Carbon Steel Pipelines Versus Some Types of Stainless Steel Musbah M. Abomadina In petroleum industry under special conditions (NaCl concentration of 70,000 ppm and temperature of 70 C˚ ) a significant galvanic corrosion problems are appeared . The conditions in the petroleum wells in the eastern region in Libya regarding the characteristics of formation water, which has concentration of NaCl ranging between 40,000 to 70,000 ppm and varied temperature degrees between 40 C˚ and 70 C˚ The constructing materials of these wells are connected with piping system made essentially from carbon steel .The piping system contains for special purposes some joints of stainless steel of grades 304 as well as 316 . The connection points between carbon steel and stainless steel considered as focal points for galvanic corrosion due to the potential difference between both materials in the electromotive series . The objective of this work is to study the galvanic corrosion in such case and the evaluation of rates of corrosion (for carbon steel) by laboratory tests . The experimental technique used in this study is the weight loss method. 2017-01-01T00:00:00Z http://dspace-su.server.ly:8080/xmlui/handle/123456789/1841 Multiple Performance Measures and Organisational Performance in an Emerging Market Abdallah M. Amhalhal The performance measurement diversity approach suggests that organisations attain superior performance when they place greater emphasis on a broad set of financial (FPMs) and non- financial performance measures (NFPMs). This study is an empirical investigation of the relationship between multiple performance measures (MPMs) and organizational performance (OP) in a Libyan context. Cross-sectional questionnaire survey data was obtained from 132 Libyan companies (response rate of 61%). The results indicate that MPMs are commonly used by both manufacturing and non-manufacturing Libyan companies. However, these companies still rely heavily on financial performance measures. The relationships between NFPMs and OP, and MPMs and OP are positive and highly significant. The relationship between FPMs and OP is positive but not significant. 2017-02-01T00:00:00Z