Engineering Commons^™

Vulnerability Functions For Seismic Loss Assessment Of The Modern Multi-Story Buildings In Dubai, Abdul Rahman Abdul Aziz Ashri Hassan

Theses

The rapid developments in the United Arab Emirates along with the repeated seismic activity confirm the significance of planning for the possible damage that may hit earthquake-prone areas in order to mitigate earthquake losses. The contemporary buildings are the most important when estimating the potential losses from earthquakes since they represent concentrated economic and human assets. This study aims at developing vulnerability functions for a wide range of modern building inventory in a highly-populated and earthquake-prone area in the UAE. Ten reference buildings with varying heights from 2 to 100 stories and three different lateral force resisting systems are selected …

Carbon Black Mediated Conductive Polymer Composite, Mohamed Hussein Faris Ali

Theses

The central goal of this thesis is to produce electrically conductive nanocomposites made out of carbon black obtained from waste tires as filler into a polymeric matrix. Waste tires are discarded in substantial numbers on a daily basis, posing a significant environmental concern. By weight, about 25-35% of a tire is carbon black. Pyrolysis is a convenient and environmental friendly process to produce carbon black from tires. Due to carbon black’s low density, high electrical conductivity and economic feasibility, this thesis investigates the electrical conductivity of nanocomposites that utilizes carbon black particles as fillers. As a result of its modified …

Flexural Strengthening Of One-Way Continuous Reinforced Concrete Slabs With Cutoffs In Sagging And Hogging Regions Jafer Husni, Jafer Husni Alshawa

Theses

Installation of cutouts in existing reinforced concrete (RC) floor slabs to accommodate utility services reduces the slab load capacity and ductility. This research examines the effectiveness of using near-surface-mounted (NSM) carbon fiber-reinforced polymer (CFRP) reinforcement to improve the flexural response of continuous RC slabs with cutouts. The study comprised experimental testing and analytical modeling. A total of eleven two-span RC slab strips, 400 x 125 x 3800 mm each, were tested. Test parameters included the location of the cutout, and amount and distribution of the NSM-CFRP reinforcement between the sagging and hogging regions. Installation of a cutout in the sagging …

Flexural Strengthening Of One-Way Continuous Reinforced Concrete Slabs With Cutoffs In Sagging And Hogging Regions, Jafar Husni Alshawa.

Theses

Installation of cutouts in existing reinforced concrete (CR) floor slabs to accommodate utility services reduces the slab load capacity and ductility. This research examines the effectiveness of using near-surface-mounted (NSM) carbon fiber reinforced polymer (CFRP) reinforcement to improve the flexural response of continuous RC slabs with cutouts. The study comprised experimental testing and analytical modeling. A total of eleven two-span RC slabs strips, 400 x 125 x 3800mm each were tested. Test parameters included the location of the cutouts, and amount and distribution of the NSM-CFRP reinforcement between the sagging and hogging regions.

Installation of a cutout in the sagging …

Narrowband And Wideband Spectrum Sensing For Cognitive Radio Networks In A Log-Normal Shadowing Environment, Nedaa Yousef Mohammad Al Hussien

Theses

The efficiency of cognitive radio networks mainly depends on the spectrum sensing stage, in which spectrum opportunities are exploited. However, one of the challenges facing spectrum sensing is the presence of fading and log-normal shadowing. Moreover, when the spectrum utilization is high and details regarding primary user activity are not available, a need to sense the whole spectrum arises. Hence, developing a wideband spectrum sensing technique is a fundamental concern.

In this thesis a narrowband spectrum sensing in a log-normal shadowing .environment is addressed, a closed-form expression for the probability of detection under shadowing is derived. The accuracy of the …

Extending The Sensing Of Online Social Networks – A Healthcare Perspective, Asma’ Wasfi Fayez Mustafa

Theses

Obesity is a rising health concern in the United Arab Emirates. Obesity leads to health risks such as diabetes, heart disease, and other conditions. It may also lead to eating disorders, depression, and low self-esteem. Regular exercising helps to protect from obesity, diabetes, heart disease, high blood pressure and better manage stress. Despite all the benefits of exercising, people are doing less of it. In this research, an effort is made to encourage people to exercise by extending the prevalent sensing abilities of Online Social Networks (OSNs). Sensors are used to collect and generate data to be processed, clustered and …

Development Of Simulation-Based Fragility Relationships For The Seismic Risk Assessment Of Buildings, Anas Salem (Mohammad Ghaleb) Issa

Theses

A number of driving engines are required for earthquake loss estimation and mitigation, including an inventory of exposed systems, seismic hazards of the study area and fragility relationships. The number of existing buildings in the UAE that may be at risk because of insufficient seismic design provisions cannot be underestimated. A crucial role in the recovery period following an earthquake is also played by emergency facilities. Therefore, a systematic seismic vulnerability assessment of a diverse range of reference structures representing pre-seismic code buildings and emergency facilities, in a highly populated and seismically active area in the UAE, has been conducted …

Preparation And Characterization Of Fast Dissolving Pullulan Films Containing Griseofulvin Nanoparticles For Bioavailability Enhancement, Zhelun Ma

Theses

The aim of this study is to enhance the bioavailability of griseofulvin, a model poorly water-soluble drug, via increasing drug dissolution rate through preparation of drug nanoparticle-laden, pullulan-based strip films. The work entails (i) wet-milling griseofulvin in a stirred media mill using pullulan (polymer) along with sodium dodecyl sulfate (surfactant) as stabilizers, (i i) preparing strip films by casting-drying a precursor suspension consisting of the mixture of the milled drug suspension and a film-forming pul l ul an–xanthan gum-glycerin solution, (iii) characterizing the suspensions and the films, and (iv) exploring the effects of film thickness, drug and xanthan gum loadings, …

The Photophysics Properties Of Lanthanide Luminescent Probes, Ke Li

Theses

A detailed study of the luminescence quantum yield, lifetimes and the number of water molecules coordinated to lanthanide luminescent probes based on biphenylyl-7-amino-4- methyl-2(1H)-quinolinon (Bi-cs124) derivatives have been carried out using a time- resolved fluorescence assay (TRFA). Bi-cs124 was conbined with different chelating agents, specifically diethylene triamine pentaacetic acid (DTPA), ethylene diamine tetraacetic acid (EDTA), ethylene glycol tetraacetic acid (EGTA), and 3,6,9,12-Tetrakis carboxymethyl)-3,6,9,12-tetraazatetradecane-1,14-dioic acid (TTHA). The results indicate that Bi-cs 124-TTHA has a longest lifetime and smallest number of coordinated water molecules because TTHA has larger number of chelating groups. The dependence of the luminescence lifetimes on the probes concentrations …

Gaussian Beam Scattering From A Deterministic Rough Metal Surface, Qi Wang

Theses

A full-wave theory of plane wave scattering from rough surfaces called the Correction Current (CC) method was recently developed for the two-dimensional scatter problem that have a one-dimensional roughness profile. The method involves a primary field and radiation modes that are plane-wave-type fields that satisfy the boundary conditions at the rough surface. These fields do not satisfy Maxwell's source free equations, but they are forced to satisfy Maxwell's equations with distributed sources upon the introduction of fictitious volume currents distributions which correct for the field errors. Additionally, current sheet distributions are introduced which generate a radiation modal field that satisfies …

Retrofitting Of Shear-Deficient Reinforced Concrete T-Girders With Composite-Based Systems, Alaa Ahmad Ata Maali

Theses

This research examines the viability of using different composite-based systems to upgrade the shear resistance of shear-deficient reinforced concrete T-girders. The research comprised experimental testing and analytical investigation. Test parameters included the retrofitting system; externally-bonded carbon fiber-reinforced polymer (EB-CFRP) laminates with or without a mechanical end anchorage (MA) and embedded through depth glass fiber-reinforced (ETD-GFRP) rebars; amount of internal stirrups; no stirrups, limited amount of stirrups with spacing s₁ = 0.6d, higher amount of stirrups with spacing s₂ = 0.375d; and initial shear damage prior to retrofitting; no damage, pre-cracking, and pre-failure.

The shear …

Flexural Behavior Of Reinforced Concrete T-Beams Strengthened With Nsm Composite System Under Accelerated Corrosion., Anes Bouchair

Theses

This research work aims at evaluating the effects of corrosion on flexural response of simply supported reinforced concrete (RC) T-Beams strengthened with near-surface-mounted carbon fiber-reinforced polymer (NSM-CFRP) strips. The research comprised experimental testing and analytical modelling. Test parameters included concrete grade, amount of NSM-CFRP strips, presence of U-wraps along the beam span, and time of corrosion exposure. A total of eighteen reinforced concrete beams with a T-shaped cross section were tested. Fourteen beams were strengthened in flexure and four beams were not strengthened to act as benchmarks. The strengthening regime included installation of either two or four NSM-CFRP strips into …

Treatment Of Industrial Wastewater Using Electrocoagulation, Shereen W. Hasan

Theses

The aim of this thesis was to evaluate the potential use of electrocoagulation in the treatment of carbide slurry, which is wastewater generated during the production of acetylene. Several experiments using an electrochemical batch reactor were carried out at different current densities, ranging between 140-290 A/m². Pure air (EA system) and 10% of carbon dioxide in air (CA system) were supplied to ensure good mixing and solution homogeneity. Aluminum plates were used as electrodes, spaced apart and connected to a DC power supply. After 3 hours, samples from treated effluent and waste slurry were collected and analyzed for …

Development Of A Process For Producing Biodiesel From Microalgae Lipids With Supercritical Carbon Dioxide Extraction And Enzyme-Catalyzed Transesterification, Hanifa Easa Taher Al Belooshi

Theses

Lipids were extracted from microalgae using supercritical carbon dioxide (SC-CO2), and used for enzymatic biodiesel production in SC-CO2. The growth of several fresh water and marine strains was tested under aeration with different CO2 enrichments. The highest growth found was for Chlorella sp. grown at 27 oC, 1 % CO2 enrichment and 460 mM NaCl concentration, at which carbon fixation rate was 1.7 g L-1 d-1. The highest enhancement of lipids content by nitrogen starvation was found with Scenedesmus sp., but with a lower growth rate. Two step cultivation of Scenedesmus sp. was carried out in a 5 L internally-illuminated …

Identification And Quantification Of Phthalates In Polyethylene Terephthalate (Pet) Water Bottles Produced In The Uae, Reem Mohamed Ismail Mohamed Ahmed

Theses

This thesis highlights the criticality of phthalate esters (PEs), widely used in plastic molding and possessing carcinogenetic and toxicological effects. The thesis aims to assess the presence and abundance of these compounds in polyethylene terephthalate (PET) bottled water produced in the UAE.

The thesis tests for 6 types of PEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBP) and Di(2-ethylhexyl) phthalate (DEHP) in widely used bottled water brands produced in the UAE. 126 bottled water samples were extracted by liquid-liquid extraction using petroleum ether, followed by analysis of the target compounds using Gas …

Parameter Identification And Robust Control Applied To A Quadrotor, Ismail Sulaiman Al-Ali

Theses

This research intended to design, analyze, and implement a robust controller for a quad rotor system and compare the designed robust controller with a proportional-integral-derivative (PID) controller. The ArduCopter platform was used as a target system with a 3DR airframe and necessary modifications, a system model, and system identification processes were executed as prerequisite steps to reach the objective.

The work in this thesis includes exploring the existing research on this topic and builds on the results presented in these previous studies to add value to the scope of quad-rotor system control. During this study, system modeling was conducted, where …

Hydrodynamic Cfd Modeling Of A Pharmaceutical Reactor Vessel Provided With A Retreat-Blade Impeller Under Different Baffling Conditions, Christopher G. Foehner

Theses

In the pharmaceutical industry, glass-lined reactors and vessels are often utilized to carry out a variety of different unit operations. Within these systems, both the vessel and impellers are typically glass-lined in order to provide superior corrosion resistance, prevent product contamination, and enhance cleanability. This approach, in turn, often requires the use of different, and sometimes sub-optimal, baffling conditions, which affect the hydrodynamics of the vessels and the reactor performance.

Computational Fluid Dynamics (CFD) is a computational tool that employs numerical methods and algorithms to discretize and numerically solve partial differential equations (PDEs) representing mass, energy, and momentum conservation equations …

Evaluation Of Methods To Account For Release From Nanofiber Scaffolds, Jennifer Moy

Theses

Electrospinning is a common technique utilized to form fibers from the micro- to nanometer range. Nanofibers form through electrospinning can be utilized as scaffolds since the fiber structures are similar to the structures within the extracellular matrix. Researchers use additives, such as growth factors, to help facilitate cell proliferation and function. Also, researchers are attempting to use electrospun fibers for drug delivery and as wound dressings since the electrospun fibers have high surface area to volume ratio. In both situations, the release of either the additive or the drug needs to be controlled so that the fibers would release the …

Assessment Of A Marine Polysaccharide For Use As Excipient In Pharmaceutical Hot-Melt Extrusion, Qing Ye

Theses

Pharmaceutical Hot Melt Extrusion (HME) is currently investigated by both industry and academia as a method for manufacturing solid oral dosages with improved bioavailability of poorly-water soluble active pharmaceutical ingredients (APIs) and control drug release of water-soluble APIs. Although HME is traditionally utilizing synthetic polymers to produce such dosages, biopolymers constantly gain ground by virtue of renewability, biocompatibility and in some cases biodegradability. In this work, the possibility of using Keltone, a marine polysaccharide derived from brown seaweed, as a polymeric excipient for pharmaceutical HME is explored. Keltone is insoluble in acidic pH and soluble in basic pH, therefore making …

Short Term Modification Of Vergence Ramp Eye Movements In The Convergent Direction, Chang Yaramothu

Theses

Prior oculomotor studies have investigated the various effects of short-term modification on vergence, saccadic and smooth pursuit eye movements. Previous vergence studies have concentrated on step modification stimuli. Few have investigated the effects of short-term modification on vergence ramp movements. Thus, this study explores the trends observed within a short-term modification experiment studying smoothly tracking vergence eye movements responses elicited from convergent ramp stimuli. A short-term modification experiment is composed of three phases: baseline, modification and recovery. Baseline and recovery phases contain only test stimuli; whereas, during modification, the subject is presented test and conditioning stimuli in a ratio of …

Experimental Determination Of The Mixing Requirements For Solid Suspension In Pharmaceutical Stirred Tank Reactors, Anqi Zhou

Theses

Glass and glass-lined, stirred-tank reactors are of significant importance in the pharmaceutical and related industries. Because of fabrication issues, a retreat blade impeller (RBI) with a low impeller clearance off the tank bottom is commonly used in glass-lined reactors, typically combined with a single baffle (providing only partial baffling conditions) mounted from the top of the reactor. In addition, these reactors are often provided with a torispherical bottom. Other configurations are also used, including full baffling or no baffles at all, hemispherical bottoms, and different impeller types. Despite their common use, some of the most important mixing characteristics of this …

Dispersion And Dissolution Kinetics Of Api Particles In Pharmaceutical Hot Melt Extrusion, Wang Zhan

Theses

Pharmaceutical Hot Melt Extrusion (HME) is essentially a special case of polymer compounding. The elementary steps involved in traditional plastics melt processing are handling of particulates, melting, dispersive and distributive mixing, devolatilization and stripping, and finally pressurization and pumping. However, for pharmaceutical HME, the dissolution of the API (Active Pharmaceutical Ingredient) is an additional and very important elementary step, along with the melting of the polymeric excipient that precedes it, and mixing which accelerates the dissolution process. A major concern in pharmaceutical HME is the thermal degradation of the API. To avoid overexposure of API to heat while ensuring complete …

Optimizing Alginate-Chitosan Microcapsules Using Co-Axial Air Flow Method As 3d Stem Cell Microenvironment, Noel Alfonso

Theses

Microencapsulation of cells is gaining popular interest in the field of biomedical engineering because it provides a more effective 3D scaffold that can mimic the cell microenvironment. The benefits of using microcapsules are biocompatibility, biodegradability, nontoxicity, and formation under mild gelation conditions. In this study, the ability of the alginate microcapsules to control the proliferation and differentiation of mouse OCT4-GFP embryonic stem cells is investigated. Microcapsules are produced by extrusion of alginate into a calcium chloride gelation bath with the aid of a co-axial air flow. It is shown that the size of the spheres is controlled based on needle …

Approach To Flood Mitigation - A Post Sandy Study In New Jersey Meadowlands Area, Banshari Datta

Theses

In the last decade the continuous change in the climate has resulted in an increased frequency of natural catastrophic events and the magnitude of their impact. The immense damage caused by such events brought to light the vulnerabilities of the impacted communities. Coastal communities are alarmingly vulnerable due to flood and storm surge impacts such as those caused by super storm Sandy in 2012. In order to mitigate this risk, the communities need to look beyond the short term recovery measures, and build a sustainable community by implementing long term mitigation measures. The objective of this thesis is to investigate …

The Effect Of Vergence Vision Training On Binocularly Normal Subjects, Henry Talasan

Theses

Vergence is the disjunctive (inward or outward) movement of the eyes that is stimulated by retinal disparity (difference of where an image is projected to the retina and the fovea). A recent randomized clinical trial showed the efficacy of vision therapy for children with the binocular dysfunction known as convergence insufficiency is 73%. However, it is unknown whether binocularly normal persons will have any significant change to their vergence ocular motor system if they participate in vision training sessions. A total of ten (n = 10) binocularly normal persons participated in this study (18 to 28 years of age). A …

Combustion Of Fine Magnesium Particles, Song Wang

Theses

Recent interest in developing Al-Mg alloys as reactive materials prompted studies of combustion mechanisms for particles of such alloys with different Al/Mg ratios. Reference experiments with pure Al and Mg powders are also desired to better understand and model combustion of the respective alloys. While combustion of pure Al powders has been addressed in many recent studies, combustion of magnesium explored mostly coarse, 50 μm, and larger particles. This effort is focused to characterize and understand combustion dynamics for fine Mg powders. Spherical, micron-sized magnesium particles were introduced in an air-acetylene flame using a custom-made screw feeder. Particles were observed …

Aerobic Biodegradation Of 2, 4 Dichlorophenol In A Spouted Bed Bio-Reactor (Sbbr), Taghreed Tahseen Al-Khalid

Theses

Chlorinated phenolic compounds represent a major class of hazardous pollutants commonly encountered in wastewater generated by the petroleum and petrochemical industries. In this regard, biological treatment, as an economical and green technology, has been shown to be one of the most promising approaches for the removal of many organic water pollutants such as chlorophenols. Under aerobic conditions, bacteria utilize chlorophenols as a source of carbon and energy. This study aimed at developing an integrated system for biodegradation of 2, 4 dichlorophenol (DCP) in a specially designed spouted bed bioreactor (SBBR), characterized by systematic intense mixing, resulting in enhanced biodegradation rates. …

A New Clustering Protocol For Hybrid Sensor Vehicular Networks (Hsvns), Saleha Mubarak Mohammed Al Mheiri

Theses

As the UAE is classified among the highest countries in road accidents; it’s an urgent necessity to derive proper and effective solutions. One of the well-known solutions is to move to the Intelligent Transportation Systems (ITS). ITS is achieved by the implementation of advanced technologies to help the roads to be smarter, safer and more coordinated. There are different studies and researches published in this area. This thesis is mainly conducted to achieve the same goal, which is increasing the safety on our roads.

The aim of this research is to build a new clustering protocol in the Hybrid Sensor …

Evaluation Of Electrocoagulation For The Removal Of Chromium (Vi) From Brackish Groundwater, Shaima S Hamdan

Theses

Electrocoagulation (EC) has been evaluated for the removal of Cr (VI) from brackish groundwater using three different bench-scale EC reactors, namely batch stirred tank reactor (BSTR), continuous stirred tank reactor (CSTR) and a continuous electrocoagulation column (ECC). Batch EC process was experimentally examined at room temperature and the results indicated that Fe-Fe electrode pair was the most efficient arrangement and was able to achieve 100 % Cr removal at an electrocoagulation time of 5 minutes, a current density of 7.94 mA/cm², and pH of 8. A kinetic study of batch EC was then performed using both pseudo-first-order and …

Developing A Labview Based Thermally Stimulated Current (Tsc) Controller To Measure Residual Charge In Electrospinning, Jai Abhishekh Veezhinathan

Theses

Electrospinning is an electrohydrodynamic process for the fabrication of nanofibers which are widely used in therapeutical tissue engineering approaches. It utilizes the potential difference of an electrostatic field to overcome the surface tension of the polymer solution to extrude a fine jet of fluid which deposits on the grounded collector as a nanofiber mat. Using this process, nanofibers with diameters less than a micron can be produced.

Previous studies have shown the presence of residual charge in electrospun nanofibers. The presence and decay of residual charge during cell culture media is still unknown. In an attempt to clarify the presence …