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How we use Collection Manager at the American University of Sharjah
No full textPresentation about how we manage electronic resources using WorldShare Management Services (WMS) Collection Manager. Presented at the OCLC WMS User Group Meeting in Dublin, Ohio on September 28, 2017
Study of the Electromechanical Models for Cardiac Activity
No full textA Master of Science thesis in Mathematics by Rana Itani entitled, "Study of the Electromechanical Models for Cardiac Activity," submitted in May 2017. Thesis advisor is Dr. Youssef Belhamadia. Soft and hard copy available.The mathematical modeling of the complex physical phenomena occurring in the heart is an area of increasing interest, as it facilitates the better understanding of relevant mechanisms driving the behavior of the system in both physiological and pathological contexts. In this work, we are interested in the study of the interaction between the propagation of the electrical potential through the cardiac tissue and the related mechanical response. Two mathematical models for this electromechanical coupling will be presented: the first model is based on an active-stress approach that adds an active contribution to the stress of the material, and the second model is based on an active-strain approach that adopts a multiplicative decomposition of the tensor gradient of deformation. Comparison between these two models and numerical results will be presented illustrating some
important features of the cardiac electromechanical coupling.College of Arts and SciencesDepartment of Mathematics and StatisticsMaster of Science in Mathematics (MSMTH
Removal of benzo (a) anthracene from water using a novel UAE sludge-based activated adsorbent
No full textA new adsorbent material from sewage sludge of relatively high surface area (2,230 m2/g) was prepared by carbonization and chemical activation using steam at controlled semi-static conditions. The pore size distributions of the sludge-based activated adsorbent (SW-A2) and commercial activated carbon were compared and found to be remarkably different with noticeable presence of larger micro-pores and small meso-pores for SW-A2. The newly developed activated adsorbent was then evaluated for the adsorption of a polycyclic aromatic hydrocarbon (PAH); benzo (a) anthracene. The adsorption isotherms of benzo (a) anthracene on the adsorbent materials were fitted to both Lang-muir and Freundlich isotherms. The Langmuir isotherm was found to be the best fit for the adsorption of the benzo (a) anthracene on AC with K and qmax of 0.43L/mg and 70.5 mg/g, respectively. On the other hand, the adsorption isotherm for SW-A2 was found to follow the Freundlich isotherm with Kf and n of 100.8 mg/g (L/mol) –0.763 and 1.31, respectively. The adsorption kinetics for both adsorbents were found to follow pseudo second order kinetics with rate constant of 1.55 × 10–4 g mg–1 min–1 for SW-A2 and 1.44 × 10–4 g mg–1 min–1 for AC. The results of this study indicate the high potential of the newly developed sludge-based adsorbent as an efficient and successful material for the removal of carcinogenic PAHs from water body
CFD Study of Particle Concentration and Stokes Number Effect on Erosion Profile.
No full textA Master of Science thesis in Mechanical Engineering by Wahib Mufid Salim entitled, "CFD Study of Particle Concentration and Stokes Number Effect on Erosion Profile," submitted in April 2017. Thesis advisor is Dr. Basil Darras and thesis co-advisor is Dr. Ammar Abdilghanie. Soft and hard copy available. Embargo expires February 18, 2018.A very common problem that continuously faces industrial applications involving fluid flow is solid particle erosion. This type of erosion is caused when solid particles carried by a fluid flow continuously impact a surface thus removing some of its material. It is especially notable in pipelines, oil and gas industry, and gas turbines leading to a decline in their performance, safety, and other aspects. Consequently, it is very important to be able to predict erosion in order to prevent failure of systems, protect the environment, and reduce costs. However, erosion is controlled by many parameters, which increase the complexity of the problem. Literature tends to provide sufficient information on how these parameters affect total erosion and erosion rate. On the other hand, it does not give enough analysis about the effect on the erosion profile. Therefore, this thesis aims at performing a parametric study on the effect of solid particle concentration and Stokes number on the erosion profile of a direct jet impingement slurry flow over a ductile material. A CFD (Computational Fluid Dynamics) model was developed using ANSYS CFX software to perform the needed analysis. The Stokes number was evaluated by looking at three of its defining parameters: solid particle diameter, nozzle average velocity and fluid viscosity. Additionally, the coupled effect of solid particle concentration and Stokes number was studied. It was found that as concentration increases, the erosion profile magnitude also increases but the change in its shape tends to saturate. However, it was also found that the effect of Stokes number on magnitude and shape of the erosion profile is dependent on the level of particle concentration and which defining parameter is under investigation. At low concentration, the change in profile shape saturates with increase in Stokes number when varying the nozzle average velocity and viscosity parameters; whereas, when evaluating the solid particle diameter,the shape tends to develop into a that of a high Stokes flow. However, at high concentration, the profile shape significantly grows into that of a high Stokes flow as the Stokes number increases when varying any of the three defining parameters.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Effect of Fiber Addition on the Performance of Preloaded CFRP Strengthened Concrete Beams
No full textA Master of Science thesis in Civil Engineering by Kareem Helal Helal entitled, "Effect of Fiber Addition on the Performance of Preloaded CFRP Strengthened Concrete Beams," submitted in December 2017. Thesis advisor is Dr. Sherif Yehia and thesis co-advisors are Dr. Rami Hawileh and Dr. Jamal Abdalla. Soft and hard copy available.The aim of this study is to evaluate the effect of fiber addition on the performance of Reinforced Concrete (RC) beams that have been externally strengthened in flexure using Carbon Fiber Reinforced Polymer (CFRP) sheets. Steel, synthetic and hybrid fibers (mix of steel and synthetic fibers) with a volume fraction of 0.5 % were added to the concrete matrix to prepare 15 beams. The experimental program consisted of three groups; 1) control beams without strengthening, 2) beams strengthened without preloading, and 3) beams preloaded to a stress level corresponding to 0.67 of yield stress (fy) of the steel reinforcement before strengthening with CFRP. A steel reinforcement ratio of 0.55% was used for all beams. Eight beams were tested for groups one and two as control (with and without strengthening) and seven beams were pre-loaded before strengthening to simulate the RC beams behavior and conditions at the repair stage. Test results showed that the addition of fibers improved the flexural capacity, crack initiation and propagation, post cracking behavior and ductility of the beams. All beams strengthened after preloading also showed better performance than that of the control beams. Synthetic fiber was found to improve the ductility of the RC beams by 81% when compared to the control specimen without fibers. Additionally, steel fibers caused a strength increase of up to 64% when compared to the control beams. The hybrid mix of fibers provided a combination of benefits from steel and synthetic fiber contributions. Applicability of ACI 440 equations to predict the capacity of fiber reinforce concrete beams was also investigated. The predicted results were in good agreement with the obtained experimental data.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Dispersion of Volatile Organic Compounds (VOCs) Emissions from a Biofilter at an Electronic Manufacturing Facility
No full textPrinted circuit board (PCB) manufacturing industries, known as PCB facilities, emit odorous and toxic volatile organic compounds (VOCs). Such compounds not only harm the health but also create a nuisance environment for people who live in the neighborhood of PCB facilities. Biofilter technology which is based on the bio‐oxidation of pollutants has been used by many industries to remove odorous VOCs. When the removal efficiency drops due to a design or operational deficiency, odorous VOCs are released from the biofilter and this becomes evident by the increased odor complaints. Poor biofilter performance, geographical location of the facility, and meteorological conditions contribute to increased dispersion of VOCs. This research investigates dispersion of a VOC pollutant known as propylene glycol monomethyl ether acetate (PGMEA) which is released from a commercial biofilter unit installed at a PCB facility in Ontario, Canada. A Gaussian dispersion model and California puff model (CALPUFF) were used to examine the dispersion effects due to changes in wind speed, wind direction, temperature, mixing height, atmospheric stability classes as well as biofilter performance. Simulations were done for the three modeling periods (January, May, September) to account for seasonal effects on PGEMEA dispersion and predictions from both models are compared. The contour hourly wind and concentration plots confirm that the seasonal changes have a direct impact on the PGMEA concentration and plume path. The results presented under variable meteorological conditions show that the average daily concentration of PGMEA is the highest in the month of September. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1100–1107, 201
Rapid separation of very low concentrations of bacteria from blood
No full textA rapid and accurate diagnosis of the species and antibiotic resistance of bacteria in septic blood is vital to increase survival rates of patients with bloodstream infections, particularly those with carbapenem-resistant enterobacteriaceae (CRE) infections. The extremely low levels in blood (1 to 100 CFU/ml) make rapid diagnosis difficult. In this study, very low concentrations of bacteria (6 to 200 CFU/ml) were separated from 7 ml of whole blood using rapid sedimentation in a spinning hollow disk that separated plasma from red and white cells, leaving most of the bacteria suspended in the plasma. Following less than a minute of spinning, the disk was slowed, the plasma was recovered, and the bacteria were isolated by vacuum filtration. The filters were grown on nutrient plates to determine the number of bacteria recovered from the blood. Experiments were done without red blood cell (RBC) lysis and with RBC lysis in the recovered plasma. While there was scatter in the data from blood with low bacterial concentrations, the mean average recovery was 69%. The gender of the blood donor made no statistical difference in bacterial recovery. These results show that this rapid technique recovers a significant amount of bacteria from blood containing clinically relevant low levels of bacteria, producing the bacteria in minutes. These bacteria could subsequently be identified by molecular techniques to quickly identify the infectious organism and its resistance profile, thus greatly reducing the time needed to correctly diagnose and treat a blood infection
The lived experiences of foreign women: Influences on their international working lives
No full textWe explored the lived experiences of foreign-born women to discover influences on their international working lives. Life history narratives were collected in interviews with a sample group of participants (#12) in the United Arab Emirates. A phenomenological framework of content analysis was applied to these data, which resulted in identification of three emergent themes of influences on participants' working lives; becoming a new generation of expatriates; adjustment to socio-cultural change; centrality of womanhood. We discuss the implications of these themes for the human development and professional identity of foreign-born working-women. Insight arises from the study, for business practitioners and policy makers, about the actual and potential contributions of these women to a national workforce. The study contributes a new classification, the Foreign-born Working-Woman, to the body of academic knowledge on expatriate workers. A research direction is proposed for further study about the influences on the economic participation of foreign-born women
Removal of lead ions from wastewater using multi walled carbon nanotubes modified with sodium lauryl sulfate
No full textMulti walled carbon nanotubes (MWCNTs) modified with sodium lauryl sulfate (SLS) were synthe-sized, characterized and successfully used for the removal of Pb2+ from aqueous solutions. Adsorp-tion results revealed that this surface modification increased adsorption capacity from 3.84 to 141 mg/g. Adsorption on raw-MWCNTs followed the Langmuir isotherm with qm = 3.84 mg/g and KL = 0.29 L/mg, whereas adsorption on SLS-MWCNTs followed the Freundlich isotherm with n = 2.50 and KF = 15.40 mg 0.6·L0.4/g. Adsorption kinetics on raw and modified MWCNTs followed a pseudo second order law with rate constants 0.11 and 0.06 g/mg·min, respectively. Thermodynamic studies showed that Pb2+ was physisorbed on both adsorbents, with apparent Gibbs free energy, ∆G °,values of –0.45 and –9.21 kJ/mol at 25°C, respectively. Magnetite derivatives of SLS-MWCNTs were synthesized and used for Pb2+ removal. Batch adsorption studies on the magnetite and non-magnetite SLS-MWCNTs gave similar results. The enhanced density of the magnetite pellets of SLS-MWCNTs allowed for their use in a packed bed column. Column operation modeling results showed that the modified dose response model most adequately describes the column data with parameter values qmdr = 28.4 mg/g and a’ = 3.47 mg–1
Functional fatigue of Ni50.3Ti25Hf24.7 - Heterogeneities and evolution of local transformation strains
No full textShape memory alloys achieve their unique and desirable property of large recoverable strains through phase transformation. The attained magnitudes of transformation strains is strongly affected by the level of deformation heterogeneity during the transformation process and is impacted by plastic deformation and the accumulation of retained martensite/austenite following repeated cycling. This paper is dedicated to study the heterogeneity in the total and transformation strains of the high temperature shape memory alloy Ni50.3Ti25Hf24.7 subjected to fatigue loading and aims to provide further insight to the source of transformation strain instability. Under isobaric loading conditions, full field strain measurements were collected during thermal cycling and utilized to assess the local changes in the deformation field. Transformation strains increased globally in the first few cycles of loading followed by a relatively stable response and eventually started to exhibit drop in their magnitudes with continued loading. No homogenization of the transformation strain field was observed as a result of either stress increase or thermal cycling. The transformation strains were localized and the global evolution in their magnitudes was associated with local changes, either increasing or decreasing local strains, in spatially the same regions. The experimental results are discussed with the aim to provide a deeper understanding of the stability of transformations strains, their evolution under cyclic loading, the heterogeneities developing in the deformation field, and the relation between local and global response due to the accumulation of irrecoverable strains