This paper presents valuable potential savings from fuel and financial expenses of a steam boiler being studied at Elkhmus power plant, Libya. For this research, a visual basic program was developed and being applied for analyzing the gathered data. Key findings pointed to an acceptable level of savings throughout the entire operations within the studied section of the power plant. The highest level of findings was found to be the increasing of thermal gain along with the total efficiency of the boiler as a result of using the exhaust temperature for heating-up the feed water to the boiler. It was clearly found that the increase of the total efficiency has a direct impact on saving the amount of consumed fuel, and thereby the financial expenses were saved by an average of about 11.6% arabic 16 English 78
Rajab HOKOMA, Nabil M. Muhaisen, Omran Alshogi(1-2014)

Abstract It is found in the literature that correlations and methods used in the determination of the lifting capacity for vertical wells cannot be applied directly for calculating the lifting capacity for horizontal well section without modifications. It is therefore necessary to formulate a new experimental technique from which new lifting capacity correlation is deduced which will be applied for the determination of the lifting capacity for the horizontal well section.The phenomena of cuttings concentration accumulated in the bottom of the horizontal section which is present in horizontal wells, does not exist in the vertical sections of the well. This problem makes it necessary to conduct an experimental work in a horizontal well simulator, to exactly simulate the drilling operation in the horizontal section of the well, from which lifting capacity values are determined for different mud formulations containing different cuttings sizes, concentrations and different mud reheology circulation at different flow rates. The objective of this study is to investigate the behavior of whole cleaning in the horizontal well section and to determine the factors effecting the cleaning capacity of the mud in this section. Also to deduce correlations relating the lifting capacity of the mud in the horizontal section of the well with various drilling parameters and mud circulation conditions. This study is conducted in the laboratory using a horizontal well simulator consists of the circulating mud component similar to that present in actual drilling operations. The experimental work used consists of using four muds formulation systems mixed with different cutting sizes and concentrations. The returned cuttings are extracted from mud return line for selected given time increments and accordingly their weights and sizes are determined. It is concluded that there is an optimum cutting size for maximum lifting capacity for each cutting concentrations used. The lifting capacity observed form the experimental results is not only dependent on mud velocity, but it is also dependent on the cutting concentrations used. It was observed that when cleaning the system after each experiment, accumulation of rock cuttings were present in the bottom of the horizontal section of the model. In this study a lifting capacity correlation relating the lifting capacity with mud flow rate, cutting size, cutting concentration, mud density, and mud viscosity is generated for the horizontal section of the well. Therefore it recommended that cleaning of the horizontal section of the well should be conducted frequently (consecutively) after each drilling time increment, which means that the drilling operation is stopped and the mud circulation rate is set to maximum. A maximum mud circulation rate is needed in order to ensure that the cuttings generated by the bit are removed efficiently in the horizontal section. It is therefore recommended during drilling the horizontal section a sequential drilling and cleaning technique should be applied.
عادل محمد جالوتة (2010)

Abstract Today computers play an integral part in the analysis and design of civil engineering structures. Hand calculation is limited to simple structures, and initial member sizing (either during the preliminary design or prior to computer analysis). The matrix theory of structural analysis first began appearing in the early 1950s. Since that time, the engineers were not familiar with this new concept, hence a relationship between the matrix structural analysis, and the classical methods arise but the structural engineers as designers still follow the classical methods of solution such as, Hardy Cross moment distribution, Kani's method and deflection distribution ,method (D. D method) , etc. Structures that were too complicated to solve by classical calculations can now be handled with comparative ease when using computers. The analysis of complicated systems, such as highly indeterminate structures like space structures, grids-shells, etc. often could be handled by making many simplifying assumptions, to such extent, that in many cases the validity of the results had to be questioned. The use of computer techniques has broadened the scope of what the engineer can now handle in a reasonable time, and at a reasonable cost. Structures such as canopies, floor systems, and bridge deck systems. Are known as Grid structures. The members of a grid structure in general are subject to torsion as well as to shear and bending. Since the external loads are normal to the plane of the structure, the axial deformations are negligible. Consequently, a free joint in a grid is subject to a linear displacement perpendicular to the plane of the structure and to a rotation in the plane of the structure. It must be realized that the; use of so called matrix algebra methods and principles and methods of analysis, systematic matrix techniques have been now developed into recognized methods.
عمر على عودة (2009)