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Subsonic Flow over a Thin Airfoil in Ground Effect: a Functional Analytic Approach
No full textA Master of Science thesis in Mathematics by Mohamed Ahmed Serry entitled, "Subsonic Flow over a Thin Airfoil in Ground Effect: a Functional Analytic Approach," submitted in May 2017. Thesis advisor is Dr. Amjad Tuffaha. Soft and hard copy available.In this work, the problem of subsonic compressible flow over a thin airfoil located near the ground is studied. A singular integral equation, also known as the Possio integral equation [29], that relates the pressure jump along the airfoil to its downwash is derived. The derivation of the equation utilizes the Laplace transform, the Fourier transforms, the method of images, and the theory of Mikhlin multipliers. The existence and uniqueness of solutions to the Possio equation is verified for the steady state case through the concepts of the finite Hilbert operator, the Tricomi operator, and contraction mappings. Moreover, an approximate solution to the Possio equation, based on a linear approximation, is obtained. The aerodynamic loads are then calculated based on the approximate solution. Finally, the divergence speed of a continuum wing structure located near the ground is obtained based on the derived expressions of the aerodynamic loads.College of Arts and SciencesDepartment of Mathematics and StatisticsMaster of Science in Mathematics (MSMTH
Android mobile app for real-time bilateral Arabic sign language translation using leap motion controller
No full textThis paper introduces an android mobile App for real-time bilateral Arabic sign language translation. The system is designed to operate on isolated sign language words. The mobile App has four main components; sign language capture for training, sign language capture for translation, voice to sign language translation and a sign language quiz game. Therefore, the Mobile App can be used for bilateral communication with the deaf community. Acquisition of sign language words is performed using a portable Leap Motion Controller that is connected to the USB of the mobile phone through an OTG adapter. We use simple feature extraction approaches based on statistical features such as mean, variance and covariance. We also use simple classification approach based on the minimum distance classifier. Classification results performed using 15 different sign language words revealed that excellent classification results are achieved. In comparison to a similar system that uses data gloves, our system has the advantage of higher accuracy and the advantage of real-time processing using a mobile App
Semi-supervised Clustering of Facial Expressions
No full textA Master of Science thesis in Electrical Engineering by Ahsan Jalal entitled, "Semi-supervised Clustering of Facial Expressions," submitted in November 2017. Thesis advisor is Dr. Usman Tariq. Soft and hard copy available.Automated facial expressions recognition (FER) is an important area in computer vision and machine learning due to its eminent role in human-machine interaction. FER is key in building intelligent user interfaces, particularly in smart cities. It is also used to enable social robots to naturally interact with humans. However, FER is not trivial as it may vary significantly within different genders, age groups and occasions. Limited availability of the labeled dataset for expression recognition task is another challenge. Therefore, semi-supervised learning algorithm using triplet-loss based deep convolutional neural network is proposed with the motivation to cluster known and unknown facial expressions under unconstrained environment. Faces are detected and aligned from the image dataset and are then used to train various supervised and unsupervised dimensionality reduction methods. Transformed faces in the new dimensions are used for clustering using K-means and consensus clustering. Dimensionality reduction methods that are employed include, principal component analysis, linear discriminant analysis and learning embeddings with deep convolutional neural networks (CNN). The motivation behind using supervised CNN is their ability to learn non-linear transformations in a highly complex feature space. The best results could be found using embeddings that are learned using deep convolution neural networks with consensus clustering method. The novelty of the proposed work is to cluster facial expressions, which were not present while learning the supervised dimensionality reduction methods. Experimental results on two constrained datasets, Multi-PIE face and MMI face datasets, show that the proposed algorithm does not only produce best clustering results on discrete expressions compared to other linear embeddings, but also clusters expressions with different intensities. The proposed algorithm is also applied on a complete unconstrained YouTube dataset and the clustering of different facial behaviors shows that the proposed work can be generalized to non-standard expressions and can learn expression classes from the datasets themselves.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Online Fuzzy Logic Base Algorithm for Electricity Price Prediction
No full textThis paper presents a web-based system to predict the electricity prices. The proposed system captures the geographical location, weather forecast, and oil price for one week ahead. The captured parameters are fed to a fuzzy-logic-based algorithm to calculate electric energy prices. Based on predicted electricity prices, consumers can turn ON/OFF or reschedule operations of their home appliances to reduce their electricity bill. The proposed algorithm was developed and hosted in a utility server (U-server). On the consumer side, a home gateway (H-gateway), and a monitoring and control system was designed, built, and tested by using a single chip microcontroller
Ultrasound Triggered Release of Estrone-Targeted Liposomes
No full textA Master of Science thesis in Chemical Engineering by Pierre Kawak entitled, "Ultrasound Triggered Release of Estrone- Targeted Liposomes," submitted in May 2017. Thesis advisor is Dr. Ghaleb Husseini. Soft and hard copy available.The fight against cancer has proven to be a lengthy one. Conventional treatment of cancer usually involves chemotherapy, a therapy known for its detrimental side effects. Doxorubicin, a cytotoxic anthracycline antibiotic, is one example of a chemotherapeutic drug that can cause congestive heart failure and other heart-related problems. Drug Delivery Systems (DDS) solve this problem by guarding healthy cells against the effects of chemotherapeutic drugs, while focusing their effect on the diseased tissue. Breast cancer is known to overexpress estrone receptors. This study deals with one DDS: estrone-targeted liposomes incapsulating doxorubicin and its efficacy when used in conjunction with ultrasound for the treatment of breast cancer. The DDS should protect healthy cells from the drug, transport the drug selectively to the cancer cells and release its contents in response to focused ultrasound (US). Two types of carriers were developed and studied: ES-positive and ES-negative liposomes. These DDS were found to be Large Unilamellar Vesicles, or LUVs, with radii of 97.11 ± 6.46 nm and 77.29 ± 0.43 nm, respectively, with uniform distributions. Release triggered by low frequency US was studied using a 20-kHz frequency probe at three power densities: 0.7, 3.09 and 5.25 mW/cm2. An increase in power density caused an increase in the release rate recorded. Comparing both targeted and non-targeted liposomes, the ES-positive ones were found to be more stable and less sonosensitive. High frequency US was studied as a trigger mechanism and no effect was discerned after an hour and a half of application. Comparisons with previous work showed a lower release rate compared to calcein-incorporating liposomes, as well as to doxorubicin-encapsulating micelles and the implications were discussed. Several drug release models were used to model experimental data and the Higuchi Kinetics model was found to be the best fit indicating diffusion-driven release by US. No statistically significant difference was found between the release rate constants of both liposomes under investigation and the different power densities investigated. The average release rate constant was 0.054 %/s.College of EngineeringDepartment of Chemical EngineeringMaster of Science in Chemical Engineering (MSChE
Transformations for Variants of the Travelling Salesman Problem and Applications
No full textA Master of Science thesis in Engineering Systems Management by Mustafa Jamil Assaf entitled, "Transformations for Variants of the Travelling Salesman Problem and Applications," submitted in April 2017. Thesis advisor is Dr Malick Ndiaye. Soft and hard copy available.The Travelling Salesman Problem (TSP) is a well-known problem in the operations research field. This research focuses on solving variants of the TSP through the use of proper transformations, which allows the use of existing solution approaches and algorithms. In this thesis, a comprehensive review with graphical illustrations is provided for the multiple Travelling Salesmen problem (mTSP) and the Multi Depot multiple Travelling Salesmen Problem (MmTSP) transformations that are available in the literature. Furthermore, several variants were solved for the MmTSP such as the Fixed Destination MmTSP, Non-Fixed Destination MmTSP and the Open Path MmTSP through formulated transformations based on duplicated and dummy depots. Solving mTSP and MmTSP variants through duplicating the depots is very traditional, while the use of dummy nodes is not common. We proved that the proposed transformations yield the same optimal solutions for the different variants. Then, numerical testing was used to validate the transformations. Also, a new variant of the TSP is introduced and the Mixed Integer Linear Programming (MILP) formulation is provided. In this variant, salesmen are allowed to start from any city, unlike the traditional TSP and its variants where salesmen are bind to start from a predetermined node. The proposed solution is done by adding dummy nodes that serve as depots to the regular TSP problem. We refer to this model as the Depot-less Travelling Salesmen Problem (DTSP). For the validation of the work, the model is used to solve an already existing problem from the online TSP library via an optimization software. Later, the proposed model is applied to solve supervisors' allocation problem and a clustering problem. Our results confirm that both the transformed and the original graphs yield the same answer, which is the main purpose of using transformation.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Sequential batch contactors for removal of chromium (VI) from wastewater using sheep's wool
No full textA Master of Science thesis in Chemical Engineering by Priyasha Ray entitled, "Sequential batch contactors for removal of chromium (VI) from wastewater using sheep's wool," submitted in May 2017. Thesis advisor is Dr. Taleb Hassan Ibrahim and thesis co-advisor is Dr. Mustafa Khamis. Soft and hard copy available.The effluent streams of various industries contain heavy metals like chromium. The hexavalent form of it is highly toxic, which needs specific intensive treatment before disposal. Sheep’s wool, as a keratinous adsorbent, has been found to be able to reduce the chromium concentration below the permissible limits thus eliminating the requirement for any further treatment before disposal. In this work, sheep’s wool was used to treat synthetic wastewater containing hexavalent chromium in sequential batch contactors. The optimum parameters of dosage, time, pH, shaking speed and temperature were established by batch studies to be 8 g/L, 25 min, 2, 150 rpm and 25 oC respectively. Sequential batch contactors ensured complete removal of hexavalent chromium. With three sequential batch contactors, the Cr(VI) concentration was reduced from 100 mg/L to 0.06 mg/L, which is less than the permissible discharge limit for Cr(VI) in water bodies. Desorption studies were carried out to determine the optimum parameters for effective desorption using potassium chloride. The optimum parameters in terms of time, concentration and temperature were concluded to be 25 minutes, 1.0 M and 50 oC. The removal efficiency of Cr(VI) after the third cycle was determined to be 82 ± 2 percent which is similar to the removal efficiency of Cr(VI) in the first cycle that is 83 ± 2 percent. The adsorption-desorption cycles dictate that wool can be regenerated several times without any pronounced change in its removal efficiency. The lab scale experiments were performed for 100 mL and then were scaled to 1000 mL of sample laboratory synthesized chromium wastewater. The experimental results obtained from the scale up experiment are comparable to the results obtained from 100 mL of sample laboratory synthesized solution without any significant change in removal efficiency of Cr(VI) and total chromium. Thus, this method has the potential to be scaled up to pilot plant, and eventually, industrial scale utilization for chromium removal from industrial wastewater streams.College of EngineeringDepartment of Chemical EngineeringMaster of Science in Chemical Engineering (MSChE
Flexural Behavior of Reinforced Concrete Beams Strengthened with Externally Bonded Hybrid Systems
No full textA Master of Science thesis in Civil Engineering by Abubakr Ahmed Abdelall Mohammed entitled, “Flexural Behavior of Reinforced Concrete Beams Strengthened with Externally Bonded Hybrid Systems”, submitted in December 2017. Thesis advisor is Dr. Jamal Abdalla and thesis co-advisor is Dr. Rami Hawileh. Soft and hard copy available.The demand for strengthening of aging reinforced concrete (RC) structures are continuously rising. Carbon fiber reinforced polymers (CFRP) are the most widely used externally bonded-reinforcing (EBR) materials for strengthening and retrofitting of RC structural members. The use of high strength galvanized steel mesh (GSM) strengthening material has recently gained some acceptance. However, Both CFRP and GSM have high strength but have low ductility. Recently developed aluminum alloys (AA) have high ductility and some desirable characteristics that may overcome some of the shortcomings of CFRP and GSM. Combining AA with CFRP and GSM will result in a hybrid material with balanced strength and ductility. Therefore, the major aim of this research is to develop a hybrid ductile and strong retrofitting system by combining AA plates with GSM and CFRP laminates to strengthen RC beams in flexure. A comprehensive experimental program was carried out to determine the tensile strength and the bond strength of the hybrid system. Fifteen-coupon specimens were tested for tensile strength, six specimens of concrete prisms for bond strength and 25 T-beam specimens for flexural strength under a four-point loading. Results showed an increase in the flexural capacity of the strengthened specimen ranging from 10% to 77% compared to the control beam and a decline in ductility of 13% to 59% compared to the un-strengthened specimen. Furthermore, analytical models based on ACI 440.2R-08 guidelines were employed to capture the flexural behavior of the tested specimens. Experimental results correlated well with the analytical predictions in a range of 30% of the experimental values. The study concluded that the newly proposed hybrid systems are promising systems for the improvement of the flexural behavior (strength and ductility) of RC beams.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Drivers and challenges for implementing ISO 14001 environmental management systems in an emerging Gulf Arab country
No full textWorldwide, ISO 14001 certification for organizations has become the norm, but the Arab world accounts for an insignificant portion of all the certified organizations. There is a dearth of research on environmental management systems (EMS) in Arab and emerging countries and in public organizations. The objectives of this research are to: (1) examine the key drivers and challenges related to implementation of ISO 14001 certified EMS in the United Arab Emirates, an emerging Arab country and (2) compare and contrast these drivers and challenges between private and public organizations. We adopt an explorative, qualitative methodology, using semi-structured interviews with environmental managers in 11 organizations (6 private and 5 public) from different industrial sectors. Drivers of EMS certification were mostly similar between private and public organizations, with some differences. Compliance with regulations and standards, and increasing environmental performance were the main drivers for ISO 14001 certification in both private and public organizations. Commitment to sustainability was more important for public organizations. Cost reduction, competitors, leadership commitment and customers’ demands were shared drivers, but more stressed by private organizations. Local community and employees’ pressures were reported by private organizations only. The challenges to ISO 14001 implementation were similar for private and public organizations. They were: a lack of qualified human resources, practical challenges associated with implementation, a lack of regulations, a lack of support from management, and high costs. Our findings have implications for managers, academics, consultants, and policy makers in the UAE and other emerging markets
Laboratory simulation of irrigation-induced settlement of collapsible desert soils under constant surcharge
No full textThe heterogeneous nature of soil as a load bearing material, coupled with varying environmental conditions, pose challenges to geotechnical engineers in their quest to characterize and understand ground behavior for safe design of structures. Standard procedures for checking bearing capacity and settlement alone may sometimes be insufficient to achieve an acceptable degree of durability and in-service performance of a structure, particularly under varying environmental conditions, whether natural or man-made. There exists a wide variety of problematic soils that exhibit swelling, shrinkage, dispersion and collapse characteristics occasioned by changes in moisture content. Specific examples are collapsible soils, which occur mainly in arid and semi-arid regions, are generally capable of resisting fairly large loads in the dry condition but suffer instability and significant strength loss when in contact with water. A number of case studies in the United Arab Emirates were examined, where lightly loaded structures such as boundary walls, pavements and footpaths had been built on ground overlying collapsible soil strata. Sustained irrigation of the dry landscapes was found to have caused uneven settlement of the collapsible soils leading to continuous distress to the structures as evident from cracking and deformation. To help address the problem, an opportunity has been taken to develop a laboratory method of simulating the loaded behavior of collapsible soils in varying situations and to measure its deformation at constant surcharge and ground water infiltration rates. Finally, relationships were developed to estimate the time and magnitude of settlement, if thickness of collapsible soil is known