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Thermo-Economic Analysis of Organic Rankine Power Cycles Using Parabolic Trough Solar Technology
No full textA Master of Science thesis in Mechanical Engineering by Mohammed Fouad Azfar Khan entitled, “Thermo-Economic Analysis of Organic Rankine Power Cycles Using Parabolic Trough Solar Technology”, submitted in December 2018. Thesis advisor is Dr. Mohamed Gadalla. Soft and hard copy available.Diversifying into several renewable energy resources has become the goal for many countries striving for a sustainable future. Solar energy is currently one of the most reliable and abundant renewable resource that can be harnessed especially in the United Arab Emirates (UAE). Concentrated Solar Power (CSP) is currently the foremost solar technology able to convert solar radiation to useful heat energy. An Organic Rankine Cycle (ORC) is a variation to the Conventional Rankine Cycle (CRC), where the working fluid used is an organic fluid, which gives several advantages to the ORC such as a low turbine inlet temperature and the absence of moisture content in inlet fluid flow to the turbine, thus increasing plant life. A Regenerative Organic Rankine Cycle (RORC) is proposed to further improve the overall efficiency of the power block. The Parabolic Trough Solar Collector (PTSC) is one of the techniques used in collecting solar energy by concentrating the heat via highly deflective material to a pipe containing a heat transfer fluid (HTF). Thermal Energy Storage (TES) systems are integrated to store thermal energy, which can then be released when required based on the energy demand. Although TES increases the capital cost, it allows CSP to run during night hours to increase the solar share. This in turn improves the feasibility of the integrated system and further reduces carbon emissions. The Integrated Solar Organic Regenerative Rankine Cycle (ISORRC) with thermal energy storage is analyzed using thermodynamic and economic models. In this thesis, a 1 MWe output from the ORC is powered solely by solar energy from the PTSC, and the integrated system is then analyzed for TES with 0, 5 and 8 hours of operation to meet energy demands in rural areas and communities. The optimum fluid for the ORC cycle was found to be cyclopentane based on thermal efficiency and exergetic efficiency analyses. Hitec salt was found to be the optimum molten salt to be used for the TES system. Therminol VP-1 was found to be the optimum heating fluid for the PTSC system. It was concluded that the ISORRC, with 8 operating hours of TES, provides the best thermo-economic system to be implemented in UAE, providing a Levelized Cost of Electricity (LCOE) of 3.59 ¢/kWh and producing annual energy of 4,183,339 kWh.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Adopting Geophysical Testing Techniques in Geotechnical Investigation and Shallow Foundation Design
No full textA Master of Science thesis in Civil Engineering by Mohammad Amer entitled, “Adopting Geophysical Testing Techniques in Geotechnical Investigation and Shallow Foundation Design”, submitted in Spring 2018. Thesis advisor is Dr. Magdi El-Emam. Soft and hard copy available.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Development of an Optimization Scheme for A Fixed-Wing UAV Long Endurance with PEMFC and Battery
No full textA Master of Science thesis in Mechanical Engineering by Zaid Al Rayes entitled, “Development of an Optimization Scheme for A Fixed-Wing UAV Long Endurance with PEMFC and Battery”, submitted in May 2018. Thesis advisor is Dr. Mohamed Gadalla. Soft and hard copy available.Unmanned aerial vehicles (UAVs) and fuel cell industries are seeking to enhance the capability and performance of UAVs powered by fuel cells as propulsion systems. Tasks such as surveillance and land surveying increased the need to improve UAVs flight characteristics especially its endurance. The design for long endurance UAVs along with its integrated propulsion system components should be carefully designed and optimized. In this thesis, an optimization approach is developed to obtain optimal flight endurance. The proposed approach includes a component-level, a subsystem-level as well as a system-level modeling. For the component level modeling, models of all propulsion system components are developed based on real physical models. In the subsystem level modeling, fuel cell subsystems are integrated in a single model that is verified through experiments to obtain its polarization curve. The hybrid subsystem is then integrated through a developed energy management scheme. For the system level modeling, multi-disciplinary design analysis (MDA) is developed for different case studies that include steady level mission and climb flights. This model is solved using a nonlinear solver function of the MATLAB tool box (fsolve). The optimization scheme for all UAV design variables uses a genetic algorithm on the outer loop of the optimization routine to search for the optimal solution using the developed MDA as a fitness function. The optimization selects wing airfoil, hydrogen tank, battery, motor, gear reduction and propeller from different possible combinations to maximize the endurance of a UAV. The combination of propellers with larger diameters and motors with lower voltage constants resulted in higher overall system performance. The fuel cell model that depends on a simple polarization curve test demonstrated good agreement with experimental results. To reduce the uncertainty in the propeller modeling, the propeller-fuselage interference is considered to produce more accurate results. The contribution of integrating the propeller interference reduces the uncertainty from 30% to less than 4%. The results of this study indicated that using a battery for climb rate mission and a fuel cell for steady level flight mission, along with the proposed energy management scheme, increased the overall UAV flight endurance by 19.4% compared to classical approaches in design methods.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
The Use of Lime to Stabilize Clay Soil against Internal Erosion
No full textA Master of Science thesis in Civil Engineering by Rawan Ibrahim Aqel entitled, “The Use of Lime to Stabilize Clay Soil against Internal Erosion”, submitted in December 2018. Thesis advisor is Dr. Mousa Attom. Soft and hard copy available.Internal erosion failure of soils in hydraulic structures is one of the most catastrophic failures in civil engineering projects. Therefore, it is vital to stabilize the soil against this phenomenon. Different materials and methods have been used to stabilize the soil in general such as cement, lime, fly ash, oil shale ash, burnt sludge and other solid wastes. The main objective of this study is to investigate the potential use of lime as a new stabilizing agent against internal erosion of cohesive soil. To achieve the goal of this research, two types of soils CH (Clay of High Plasticity) and ML (Low plastic silt) were selected and used. The selection of the cohesive soils was based on the physical properties of the soils such as gradation, clay content, silt content and Atterberg’s limits. The two types of soils were mixed with lime at different percentages; by the dry weight of the soils. Specimens were remolded at 95% of maximum dry density and optimum moisture content. Two identical specimens from each soil were prepared at 95% of maximum dry density and optimum water content with 0.0% lime as control specimens. The Hole Erosion Test was employed to test the remolded specimens at three different curing times namely; 1 day, 2 days, and 7 days from the time of preparation. The different erosion parameters of the soil such as the friction factor, critical shear stress, and the coefficient of soil erosion, were evaluated and used to calculate the Erosion Rate Index. It was found that lime is more effective when used with CH type soil than with ML type of soil. The addition of 2.0% of lime by the dry weight of the soil will stabilize the CH type of soil, while more than double this percentage is needed to stabilize the ML type of soil. The Erosion Rate Index increased up to 5.7 (very slow erosion rate) at 2.0% and 5.0% lime for CH and ML type of soil, respectively. Additionally, it was found that the increase in the percentages of lime increased the Critical Shear Stress significantly and an increase in curing time increased the Erosion Rate Index and improved the stabilization of both soils against internal erosion.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Workforce localization in the UAE : recruitment and selection challenges and practices in private and public organizations
No full textWorkforce localization (WL) has become an issue of increasing importance in the Arab Gulf region, a key emerging market, where, in many cases, local citizens are the minority in terms of population, and compete with high numbers of expatriate employees for jobs and positions. The purposes of this paper are to empirically explore recruitment and selection (R&S) challenges and practices related to WL in the UAE, and to compare and contrast these between private and public sector organizations. This paper adopts a qualitative, inductive methodology. Data were collected using semi-structured interviews with HR/ Localization managers in five private (PVO) and six public organizations (PSO) in the UAE, in different industrial sectors. Data were analyzed using NVivo 10 software. First, we found that both PVOs and PSOs face six common challenges related to the R&S of local candidates: 1) the lack of relevant education, skills and experience of Emirati Applicants (EA), 2) their high compensation expectations, 3) their lack of business, industry and career awareness, 4) competition from other employers, 5) some sector- and job-person fit considerations and 6) resistance from expatriates. Second, we found that both PVOs and PSOs have dedicated recruitment methods to attract EAs. Both PVOs and PSOs developed and communicated employee value propositions for EAs, used proactive, targeted, diversified internal and external recruitment methods, and evaluated the effectiveness of their recruitment practices, using established quantitative and qualitative measures. We found some differences between PVOs and PSOs: PSOs tended to reserve specific positions for local employees, used more targeted external recruitment methods and more numerous effectiveness evaluation measures than PVOs. Third, at the selection stage, we found that all organizations reviewed their job descriptions and selection processes to avoid any discriminatory items, most of them organized inclusive, culturally trained staffing committees. Most of the PSOs intensively modified their selection processes (e.g. using modified screening, selection criteria and standards, and selection steps) to facilitate WL, whereas PVOs only modified experience requirements for EAs. Both PVOs and PSOs used similar testing, interviewing processes and effectiveness evaluation measures, although PSOs generally utilized a greater range and number. While our findings on R&S practices showed similarities between PVOs and PSOs, they also highlighted a number of differences. This paper contributes to expanding the scope of understanding of the staffing processes in a non-Western context, adding to the body of empirical literature on localization, R&S, and public sector HRM in the Arab Middle East and Gulf countries. Implications for further research, practitioners and policy makers involved in WL are discussed
A Methodology of Rule Discovery from Large-scale Multi-tier Noisy Educational Data
No full textA Master of Science thesis in Computer Engineering by Tasneem Yousuf entitled, “A Methodology of Rule Discovery from Large-scale Multi-tier Noisy Educational Data”, submitted in May 2018. Thesis advisor is Dr. Imran Ahmed Zualkernan. Soft and hard copy available.Recent availability of very large amounts of educational data in digital format often leads to data overload where it is difficult to determine important trends and patterns beyond those provided by traditional statistical techniques. Therefore, educational data mining (EDM) has emerged. Association mining is a type of EDM technique which is well-known for discovering relationships from data with high scale and velocity, but low variety and veracity. This analysis can be performed at the micro-level (e.g., for teachers), meso-level (e.g., for cohorts of schools), or at macro-levels (e.g., at region, province, or country level). This thesis proposes a methodology for the application of association mining to multi-tier sparse and error-ridden educational data. The methodology uses rule templates and is organized around the four analytical dimensions of people, process, environment, and outcomes. The methodology defines Extract Transform and Load (ETL) processes for this type of data and shows how data from lower levels is aggregated to baskets at higher levels. The proposed methodology was applied to data collected from a large-scale continuous professional development (CPD) process for 2,613 teachers in a developing country. The methodology was used to mine interesting rules which were evaluated using the objective metrics of Support, Confidence, and Lift to determine the quality of rules. The Confidence for each level was set to be at least 0.85. The results are that micro-level analysis (n = 2613 teachers) yielded little or no rules with a very low mean Support of 0.00345 (sd. = 0.00214) and mean Lift 6.98 (sd. = 4.63). The situation remained somewhat the same at the meso-level (n = 1391 schools) with a mean Support of 0.0059 (sd. = 0.00051) and mean Lift of 5.46 (sd. = 3.23). The results were significantly better at the macro level (n = 59 clusters) with a mean Support of 0.089 (sd. = 0.021) and mean Lift of 5.925 (sd. = 2.5). The mined rules discovered several anomalies and fidelity violations in the CPD process at various levels. The methodology was also useful in identifying small groups of teachers (6-8 teachers), schools (8-10 schools), and clusters (4-7 clusters) with common characteristics that can be further administered to help improve the CPD process.College of EngineeringDepartment of Computer Science and EngineeringMaster of Science in Computer Engineering (MSCoE
Development of Evaluation Model for Government Services Performance Using Analytic Hierarchy Process
No full textA Master of Science thesis in Engineering Systems Management by Ahmed Ali Al Ameemi entitled, “Development of Evaluation Model for Government Services Performance Using Analytic Hierarchy Process”, submitted in April 2018. Thesis advisor is Dr. Hazim El-Baz and thesis co-advisor is Dr. Imran Zualkernan. Soft and hard copy available.Performance Management is one of the main concerns for many organizations in the public and the private sectors. Although the definition of performance could be complicated when it comes to the public sector, different approaches were developed to measure and evaluate performance along its pillars, based on efficiency, effectiveness and quality. Many of the current models which are used for measuring and evaluating government services in the public sector are based on quality dimensions through performance indicators. Depending on one aspect of performance only such as efficiency or quality will not represent a proper measurement for the government performance level. The aim of the study is to develop an evaluation model for government services performance, aligned with the general framework of performance management. The evaluation of the level of performance at which government services are administered will be done based on different criteria, using the Analytic Hierarchy Process (AHP) approach. The AHP technique was used to develop the structure of the model and find the priority weights of different criteria and attributes that contribute to the government performance. Furthermore, actual data from government authorities in the UAE was used to apply the developed model in this thesis, and the results are analyzed and studied. The contribution of this research is the development of an evaluation framework for government performance in the public services, as one unified index for the public services performance. This unified index is closely measuring the performance of various government entities, as well as identifying specific areas to enhance government performance based on the evaluation criteria. Based on results of the AHP approach and experts judgments for the selected criteria and attributes, conformance to service standards, customer satisfaction level and overall service quality attributes are representing more than 40% of the importance to the government services performance. Another finding of applying the developed model in this research to the actual data collected from government services, is that the ranking of the high-performing and low-performing entities depends on the consistent level of performance among the selected pillars and criteria for the evaluation of the government performance.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Mobile robots obstacles avoidance using dynamic window approach
No full textA Master of Science thesis in Mechatronics Engineering by Omer Ali Abubakr entitled, “Mobile robots obstacles avoidance using dynamic window approach”, submitted in May 2018. Thesis advisor is Dr. Mohammed Jaradat and thesis co-advisor is Dr. Mamoun Abdel-Hafez. Soft and hard copy available.In recent years autonomous mobile robots have been used widely in research and commercial environments. They can be found in industrial, military and security settings. Some robots require operation in environments that are densely cluttered with static and dynamic obstacles. The main objective of autonomous robots is to find a collision-free trajectory that takes account of any possible motions of obstacles in the local environments. Such a trajectory should be consistent with a global goal or plan of the motion and the robot should move with the highest possible speed, subject to its kinematic constraints. While avoiding static obstacles might be a straightforward problem, avoidance of objects in motion, “dynamic obstacles”, is much more complex. Most of the present work on autonomous navigation in dynamic environments does not take into account the dynamics of the obstacles. One of the methods used in research today for dynamic obstacles avoidance is the Dynamic Window Approach. DWA is a well-known navigation scheme that takes into account the kinematic constraint of the robot and considers only the nearest obstacles to the robot at a specific point in time which makes it suitable for dynamic obstacles. One of the problems facing the DWA today is how to optimize the weights of its objective function to allow the robot to move towards the goal while avoiding collisions in all environments. The main contribution of this thesis is to build an intelligent system that will be able to optimize the objective function weights of the dynamic window to make it more resilient to changes and moves as fast as possible towards the goal. The proposed controller was able to reduce the failure rate of the DWA from 20% to only five per cent in static environments, and achieve more than 60% success rate on average in dynamic environments with up to 25 point obstacles/100 m2, while the basic algorithm was failing to less than 50% success rate for approximately 15 point obstacles/100 m2. In conclusion, this work proves that the use of fuzzy logic controllers can improve the performance of the original DWA algorithm.College of EngineeringMultidisciplinary ProgramsMaster of Science in Mechatronics Engineering (MSMTR
Translation and the Quest for Meaning: Adūnīs and Yūsuf al-Khāl's Translation of T. S. Eliot's The Waste Land
No full textThis article examines some Arabic translations of T.S. Eliot's The Waste Land with special reference to Adunis (͑Ali Ahmad Sa'id) and Yusuf al-Khal's al-Ard al-kharab (1958). Translation requires a close reading of an original text; however, in the case of Adunis's and al-Khal's (1958) al-Ard al-kharab, I found that the translation is the offspring not of one original text, but of an original and a translation, which are Eliot's The Waste Land (1922) and its earliest French translation by Pierre Leyris (1983/1947). The reason for Adunis and al-Khal's (1958) inclusion of and reliance on the French version may be attributed to the fact that, at the time of the translation, Adunis' English was limited - it was, at most, at the intermediate level. The article shall discuss this multiplicity in the recreation of the text viz-a-viz the decisions that Adunis and al-Khal (1958) made to agree or disagree with Leyris' (1983) choices. I shall also use other translations of The Waste Land, such as those by ͑Awad (1968), Lu'lu'ah (1980), and Saqqal (1996) in order: i) to show the other possibilities that Adunis and al-Khal (1958) had in rendering the text into Arabic and, ii) to underscore the point that the choices that they made shed light not only on their activity as translators, but also on the nature of their artistry as poets. Drawing on translation theories and the poetics of translation, the article will have a twofold focus: to trace Adunis and al-Khal's (1958) understanding of a key poem in the development of modern Arabic poetry and their aesthetic principles as they emerge in their decisions, to use Venuti's (1994) terms, to "domesticate" or "foreignize" their translation (p. 20). I will demonstrate how, despite the mistakes that the two poets made, their translation is sound and holds an important place in the history of Arabic literature inasmuch as, on the poetic level, it communicates the essence of the original poem. I conclude that there is ample room for many more translations