Abstract The static behavior of large deflection of plates is considered. The w-F governing equations for large deflection of plates are derived and Solved using Finite Element with Galerkin approach to calculate the static deflection and for parameter values which span the design space. An Incremental Iterative technique were used. The Galerkin Method was used to derive the element stiffness matrix and load victor. A three node- 18DOF Triangle Element was selected to calculate the nodal field variables. Two boundary conditions were considered, the simply supported and clamped plates. A well prepared program used for plates with small deflection,, Linear Problem,, was modified to handle the changes in the governing equations and apply the solution techniques. A good fit with previous published studies was found.
القاسم محمد كامور (2009)

An efficient way to reduce the energy required for conditioning buildings and therefore to reduce CO2 emission is the use of proper thermal insulation in buildings' external walls. This measure requires data from metrological stations that can be used in the optimization of the thermal insulation. The main objectives of this study are to construct thermal climatic zones for Libya and to specify the optimum insulation thickness for external walls for the different zones. This work is comprehensive as the metrological data from all existing 33 weather stations has been collected and used for identifying thermal zones. For the optimization of the construction of external walls, the most commonly used local wall structures are investigated: hollow concrete block, limestone block and hollow brick. In addition, four thermal insulation materials: extruded polystyrene, expanded polystyrene, rock wool and foamed polyurethane are used with every wall type. Optimum insulation thickness, energy savings, energy cost and payback periods were estimated for the 33 locations using life cycle cost analysis. A map is constructed for the thermal zones based on degree-day values for the entire country. The results show that limestone blocks with expanded polystyrene insulation form the optimum wall construction as it provides the minimum total cost for all locations. Depending on the Degree-day values, the optimum insulation thickness varies between 5.4 and 15.3 cm across the country with energy saving varies between 28 and 178 $/m2. Using the optimum thickness, the average CO2 emissions can potentially be reduced by about 85%. Finally, a contour map represents the optimum thickness of expanded polystyrene is presented in this work. arabic 12 English 80
Samah Khlifa Otman Alghoul, (1-2021)

Abstract The contribution of this thesis is to improve the understanding of acoustic dynamics in the audio duct with HQ (Herschel-Quincke tube) is essentially a hollow side-tube that travels along a main-duct axis and attaches to the main-duct at each of the two ends of the tube. In this project the detailed measurements of acoustic in a duct with HQ induced by a loudspeaker at various frequencies have been carried out experimentally. Two microphones have been used to measure the net acoustic power transmission in the duct downstream of HQ and compared with the net acoustic power transmission in the duct without the HQ. Two types of HQ and three different ducts have been studied. The acoustic wave signals are traveling in the duct as a plane wave these waves are generated by a signal generating system with a known sinusoidal wave (sine wave). One of the microphones is located just before the HQ-duct interface and the other microphone after the HQ in the duct. Labview software is used to analyze the signals with a sampling rate of 44100s/sam and number of samples is 20000. This study makes an exhaustive understanding of power spectrum of two acoustic channels in the duct with and without HQ. The results show that there is a great potential for HQ tube system to attenuate the noise over conical and cylindrical sections. The sound attenuation on conical section with short HQ shows about 70% and that of cylindrical section a meager 47% at higher frequency. Further more the sound attenuation of cylindrical section with long HQ is occurred at low frequencies.
رضوان نجمي الكوني الشريف (2010)