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Statistical analysis of air-gap membrane desalination experimental data: Hypothesis testing
No full textMembrane distillation (MD) is a process in which the driving force for mass transfer is temperature gradient rather than conventional ones based on density, static pressure, chemical nature, affinity, and freezing point gradients. Using a porous hydrophobic membrane, MD comes into four configurations; direct contact, air gap, sweeping gas, and vacuum MD. The current technical literature shows a growing interest in experimental investigation of MD processes. In this work, a complete set of experimental data on air gap membrane distillation is analyzed using statistical methods. The experimental data involves a study of the effects of salt concentration on permeate flux for MgCl2, Na2SO4, and NaCl using three commercial membranes in AGMD unit. Hypothesis testing regarding the mean permeation flux under different salt concentrations is implemented. The objective is to gain an idea about the statistical significance of performance differences among these membranes. Several statistical techniques, i.e., F-test, Fisher's LSD test, Bonferroni and Tukey's test for multiple comparisons are applied. The F-test predicts that all three membranes handle the three salts at their low salt concentration levels in a comparable manner with no significant differences in permeate fluxes but handle the same salts differently at the higher level of salt concentrations
Chip Level Implementation of a Digital Radar System
No full textA Master of Science thesis in Electrical Engineering by Yazan Al-Alem entitled, "Chip Level Implementation of a Digital Radar System," submitted in May 2015. Thesis advisors are Dr. Lutfi Albasha and Dr. Hasan Mir. Soft and hard copy available.In this work, an S-Band radar system based on stretch processing technique is developed at chip level. The novelty in this work lies in providing an integrated, compact and miniaturized radar system chipset. The radar has many characteristics that ensure high performance: a wide bandwidth signal (600 MHz) that provides high resolution to distinguish between close objects, stretch processing technique that dramatically reduces the required sampling rates and relaxes the specifications of analog to digital converters, high dynamic range that allows weak signals to be detected from targets masked by high levels of clutter (such as snow and rain), multiple receiver channels that enable digital antenna beam forming at the receiver to mitigate any strong interferer, and finally operation in the S-Band (2-4 GHz) that provides high immunity against clutter in long range surveillance applications. The architecture study revealed a Super-Hetrodyne receiver and modulator architecture offered the best solution. The high order filters were pushed off chip to reduce silicon area, reduce power consumption and improve filtering results. The circuit level design focused on designing the receiver blocks. The design included a high linearity quad passive mixer, IF cascode and common source amplifiers, and a negative gm voltage controlled oscillator. The total receiver system of the radar chipset was designed and simulated at the circuit level using Cadence Virtuoso 6.0 on IBM 180 nm CMOS technology, a high dynamic range of 58 dB was achieved with a total power consumption of 0.32 W.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Applications of Nanotechnology in Aircrafts
No full textA poster submitted in ENG 207 taught by Dr. David Prescott for the Fall 2014 semester.Aircraft manufacturers constantly attempt to develop and implement new ideas in aircraft design, results of which can be seen over the years. The use of composite materials has increased in the aircraft industry, and have slowly replaced metals and alloys
Dubai Metro and Green Energy
No full textA poster submitted in ENG 207 taught by Dr. David Prescott for the Fall 2014 semester.With almost 149,000 daily riders, the Metro is used more frequently and with the proposed expansion, Metro should be modified to run on green energy that will benefit the city in terms of energy consumption and it’s vision towards a smart cit
Air Purifying Billboard
Get PDFA poster submitted in ENG 207 taught by Dr. David Prescott for the Fall 2014 semester.The aim of the project is to analyze how the use of an air purifying billboard can reduce air pollution
Flexural Performance of Reinforced Concrete Beams Externally Strengthened with Carbon and Basalt FRP Sheets
No full textA Master of Science thesis in Civil Engineering by Sahar Samir Choobbor entitled, "Flexural Performance of Reinforced Concrete Beams Externally Strengthened with Carbon and Basalt FRP Sheets," submitted in May 2015. Thesis advisor is Dr. Rami Hawileh and thesis co-advisor is Dr. Jamal Abdalla. Soft and hard copy available.Different strengthening systems have been widely used for many years to retrofit and repair deficient structural members. Reinforced concrete (RC) slabs and beams are commonly strengthened in flexure by externally bonding Carbon Fiber Reinforced Polymer (CFRP) sheets to the bottom side of the member. The CFRP sheets used in strengthening applications have high strength; however, they are brittle materials with low ductility. Basalt Fiber Reinforced Polymer (BFRP) sheets on the other hand have relatively lower strength compared to CFRP, however they have higher ductility. As a result, there is growing interest among researchers and practitioners in combining different types of FRP sheets to produce an enhanced strengthening system in terms of strength and ductility. This study investigates the flexural behavior of RC beams externally strengthened with CFRP sheets, BFRP sheets, and their hybrid combination (CFRP-BFRP). This hybrid system is designed to enhance the properties of composites, where it combines the high strength of CFRP and high ductility of BFRP sheets, respectively. To investigate the behavior of the different strengthening systems, an experimental program was conducted on ten RC beams that were tested under four-point bending. The load versus mid-span deflection data were recorded and used to compare the performance of the strengthened specimens. The test results indicated that all strengthened specimens yielded higher flexural capacity and lower ductility values compared to the unstrengthened control beam. The increase in the flexural capacity of the strengthened beams ranged from 23% to 68% of the control beam. Moreover, the beams strengthened with BFRP and hybrid CFRP-BFRP sheets achieved higher ductility compared with the beams strengthened with CFRP sheets. Thus, it was concluded that the use of a hybrid combination of CFRP-BFRP sheets could achieve the desired increase in the flexural capacity of RC beams with an improved ductility compared to that with CFRP sheets only. Finite element (FE) models were also developed and were able to capture the behavior of the tested beams with a good level of accuracy. The predicted flexural capacity along with the associated mid-span deflection differed by 1% to 10% from the experimental values.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Innovative inlet air cooling technology for gas turbine power plants using integrated solid desiccant and Maisotsenko cooler
No full textGas turbine thermal efficiency has significant dependency on climatic conditions. Evaporative cooling is commonly utilized as an inlet air cooling technique in hot and dry climates though an increase in atmospheric humidity will considerably diminish its performance. Implementing desiccants to dehumidify air will enhance evaporative inlet cooling effectiveness. Furthermore, a recently commercialized cooler named Maisotsenko cooler can be integrated in gas turbine inlet air cooling to replace conventional evaporative coolers. In this paper, four different inlet air cooling systems employing turbine waste heat are proposed for gas turbine power augmentation in hot and humid climates such as UAE. Detailed sensitivity analysis is performed to investigate the impact of ambient air conditions and regeneration temperature on the inlet air cooling systems' effectiveness. Recommended inlet air cooling techniques are evaluated against more commonly used inlet air cooling systems under UAE climatic conditions. Finally, economic and transient analysis are accomplished to signify the most economical inlet air cooling system that is most suitable for UAE gas turbine power augmentation. Maisotsenko evaporative desiccant inlet air cooling with life savings of 31.882 MUS$ is the most economically justified inlet cooling technique for a 50 MWe gas turbine power plant in UAE with life span of 25 years
Analysis of Maisotsenko open gas turbine bottoming cycle
No full textMaisotsenko gas turbine cycle (MGTC) is a recently proposed humid air turbine cycle. An air saturator is employed for air heating and humidification purposes in MGTC. In this paper, MGTC is integrated as the bottoming cycle to a topping simple gas turbine as Maisotsenko bottoming cycle (MBC). A thermodynamic optimization is performed to illustrate the advantages and disadvantages of MBC as compared with air bottoming cycle (ABC). Furthermore, detailed sensitivity analysis is reported to present the effect of different operating parameters on the proposed configurations' performance. Efficiency enhancement of 3.7% is reported which results in more than 2600 tonne of natural gas fuel savings per year
The Jazeera Al Hamra Digital Heritage Project: A Model for Digitally Preserving the Heritage of the Arabian Peninsula
No full textThe digital environment offers an opportunity to establish a museum model that supports contemporary museum thought in regard to collective memory strategies, inclusivity, and equity of tangible and intangible cultural heritage. Al Jazeera Al Hamra, a former coastal village in Ras Al Khaimah in the United Arab Emirates, was abandoned at the time of the formation of the country in the late 1960s and 1970s. It is considered one of the last traditional fishing and pearl diving villages in the nation. As the buildings are now only remnants of a time past, not only does the architecture need to be documented and mapped, but also the stories and traditions of the people who once lived there need to be recorded. Creating a web-based virtual environment that documents both the tangible and intangible cultural heritage of Al Jazeera Al Hamra can provide a cohesive physical and social record for future generations after the buildings and the people who had inhabited the town are gone. Focusing on Al Jazeera Al Hamra, an at-risk site, this paper presents a model for digitally preserving and re-presenting tangible and intangible cultural heritage of the Arabian Peninsula and beyond
Comparison of Energy Efficiency Strategies for Mosques in the United Arab Emirates
No full textAs public buildings that are typically financed by charities, mosques are commonly designed, built, and operated using very limited resources. Hence, failure to design energy efficient mosques either affects occupants' thermal comfort or re-orients the limited resources from other important activities to achieve that comfort. This paper documents part of an on-going study to determine the best allocation of limited financial resources to reach the most feasible energy saving in mosques in the United Arab Emirates. At this stage of the study, energy modeling is used to compare the impact of using various energy efficiency strategies on the cooling load. The results show the importance of controlling infiltration. They also show the value of insulating the walls and roof. However, a significant reduction in cooling load is achieved by splitting the mosque into two zones of operation. A similar result is demonstrated by using fans along with the air conditioning set at a higher temperature