https://repository.sustech.edu/handle/123456789/1294 2026-04-04T13:35:35Z https://repository.sustech.edu/handle/123456789/28272 Title: Enhancement of Heat Transfer Using Perforated Pin Fin Authors: AL-Jumaily, Mohanad Hatem Fezea; Supervisor, -Hassan Abdellatif Osman; Co-Supervisor, -Wadhah Hussein AL Dori Abstract: Today is very important to save our electronics devices by making a new technic to enhance the heat transfer through the pin fin one of the technic is the perforation which mean cut of some material from the body. A base plate of Aluminum thickness of 20mm and (100*100) mm2 as a dimensions and it consider as heat source by putting 3 heaters 80mm length with 10mm diameter 200 watts for each one ,the fins is fixed on the plate like a bolts to ensure open and connect again and the thermocouples are fixed on the fin by small bolts. The model was putted on a duct constructed of aluminum foil with dimensions of (1000*200*200) mm3 and a fan mounted at one operating at speed (0-3m/sec) was used in the tests. To get readings, the working model was fixed within the duct. The number of holes in each test of perforation varies from one to four for each fin and each time readings are tabulated. The results shows that the Nusselt number ,fin efficiency increases with perforation increase, pressure drop and the weight of the device decrease with perforation increase. As a result, thermal boundary thickness was reduced, it will be decreasing the pumping power and the device is protected from damage. The processor found in electronic computers and micro-devices that contain processors for processes and activities that take place in industrial, commercial, and even military organizations is the closest approximation to the field of application of the research. Description: Thesis 2023-01-18T00:00:00Z https://repository.sustech.edu/handle/123456789/28068 Title: A Reconnaissance Study and a Model for Estimating Real Estate Market Value in Inefficient and Unstable Markets: Real Estate Valuation in Sudan Authors: AGEEB, TILAL MOHAMMED AHMED; Supervisor, - AWAD SAAD HASSAN Abstract: Asset valuation is the backbone of the money lending process, it allows banks and financial institutions to inject money into all sectors of the economy, where the proper valuation processes based on professional standards ensure that banks get back their money in the case of a borrower default and re-inject the money back again into the of the economy. Uncertainty is one of the features of the valuation process. Valuation uncertainty is inversely proportional to the market activity: the more active the market, the more credible the conclusion of the valuation. Currently, the market performance in Sudan could be classified as an unstable market. This study sought to identify the sources of uncertainty in the asset valuation process in Sudan and to compare the local professional practice with internationally adopted standards. This comparison was conducted through inspection and examination of a number of local valuation reports against the fundamental requirement of the International Valuation Standards (IVS 2017). I also conducted a survey questionnaire to measure the public trust in valuation professionals in Sudan. The study recommends that local valuation experts should improve their skills in professional reporting, while authorities should constitute a regulatory body to organize the assets valuation profession and to develop national valuation practice standards or adopt any of the international standards. In this study, a mathematical model was developed based on the construction cost approach to estimate the market value of the real estate in Khartoum city in the case of an unstable and inefficient market. This model is a spreadsheet model. The most valuable feature of the model developed in this study is its ability to save time. The model can be used to generate market value for real estate in significantly less time than the classical manual method. It can be used to calculate quantities of construction materials and workmanship for the category of buildings that the model supports. Also, contractors can depend on the model to estimate contract values, especially in lump sum contracts. Description: Thesis 2022-11-01T00:00:00Z https://repository.sustech.edu/handle/123456789/27664 Title: Evaluation of The Optimum Pre-tensioning Forces and Construction Stage Analysis of Cable - Stayed Bridges Authors: Zuber, Tahani Mohammed Amin; Supervisor, Abd Elrahman Elzubair Mohamed Abstract: This research is concerned with the study of the problems of the analysis and design of Cable-stayed bridges which are structural systems effectively composed of cables, main girders and towers. These types of bridge are highly indeterminate structures that require a highly complex degree of technology for analysis and design. Hence they demand sophisticated structural analysis and design techniques when compared with other types of conventional bridges. For cable-stayed bridges the cable forces are an important factor in the design and construction process. The cables being flexible supports require pre-tensioning. Since the response of the bridge is highly non-linear an optimization procedure is required to evaluate the pre-tensioning forces. The optimization method used to determine the cable forces is the unknown load factor method; The techniques and methods of erecting cable –stayed bridges are varied and numerous. The erection method not only affects the stresses in the structure during erection but may also have an effect on the final stresses of the complete structure. The required pretension forces in cable-stays and the corresponding structural configurations of the bridge at different erection stages have been examined and compared in detail. The objective of the construction stage simulation is to identify stresses and deformations of the concrete girder and towers, as well as the cable tension stress, to meet the design requirements. Because of the large deflections that occur in bridge during cantilever construction, construction stage analysis was performed for the cable stayed bridge. The finite element analysis program Midas Civil was used in the nonlinear analysis. In this study, TUTI BAHARI cable stayed bridge, under consideration for construction was evaluated, as a case study, determining the cable tension under the effect of Dead load (Self weight, additional loads), Initial pre- tensioning cable force, and live load (moving load) according to AASHTO 57 LRFD 2010, by considering the boundary conditions. Then, analysis of this bridge at different erection stages during construction was carried out using the backward construction process analysis. The stage by stage construction of the TUTI BAHARI cable stayed bridge was performed using Midas civil Software. The maximum cable forces were found to be within the allowable limits. Also, the stresses and displacements satisfied the requirements. The results obtained show that the method presented indeed leads to optimal structural performance for the cable stayed bridge in particular, and might be a useful reference for the design of other similar bridges. Description: Thesis 2022-01-02T00:00:00Z https://repository.sustech.edu/handle/123456789/27662 Title: A Study of the Behavior of Hybrid Fiber Reinforced Concrete Slabs Exposed to Impact Loading Authors: Hamed, Mai Abdel Raheem Sofyan; Supervisor, Abdelrahman Elzubair Mohamed Abstract: he most accurate and reliable approach to investigating concrete slabs structural behavior under impact loading is to conduct impact experiments. This research has the aim of providing a better understanding of the behavior of Hybrid Fiber Reinforced Concrete (HFRC) slabs under impact loading. Experimental work was conducted to study how to enhance the impact resistance of HFRC slabs which are commonly encountered in modern buildings. The focus is on preventing their collapse by increasing their ductility and energy dissipation by strengthening them with steel and Polypropylene (PP) fibers. In this research a study of the behavior of hybrid fiber reinforced concrete slabs under impact loads was carried out by casting and testing eight hybrid fiber reinforced concrete slabs with dimensions of 1700x1700x100 mm and with two fiber volume ratios of 0.5 % and 1.0 %. The tests were carried out at Structural Laboratory of the University of Putra Malaysia. The free-fall impact tests were conducted with a 200-kilogram hammer and two different drop heights (1m and 2m). The relationships between impact loads, displacements, and strains were established from the recorded tests results. The dynamic responses gained during tests, as well as the failure modes detected, had been thoroughly analyzed. The tests findings show that, when appropriately built, hybrid-fiber reinforcement can greatly improve the overall impact resistance of concrete slabs, stop crack growth, and thereby reduce the size of the damaged area. Under impact force, the slab specimen with a mix of 1% steel fibers and 0.5% PP fibers performed best improvement of integrity after failure and impact resistance with an increase 30.79%. The load tests showed that hybrid fiber reinforcement contributes to increasing load capacity and ductility of the slab. In addition, the dissipated energy of the reference slab was doubled in the hybrid reinforced concrete slab. Also, applying the strengthening technique led to a change in the crack pattern from one opened hair crack to multiple cracks in the tension face. However, hybrid fiber reinforcement results in a considerable reduction (by up to 68%) in compressive strength. Description: Thesis 2022-06-04T00:00:00Z