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Synthesis of Metal-Organic Framework from Iron Nitrate and 2,6-Naphthalenedicarboxylic Acid and Its Application as Drug Carrier
No full textMetal-organic frameworks (MOFs) are highly crystalline porous organic–inorganic materials that are comprised of metal salts and organic linkers. The common synthetic methodologies of MOFs include: solvothermal, microwave-assisted, electrochemical, mechanochemical, and sonochemical routes. The synthesized MOF particles can be characterized using several characterization techniques including: X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and other analytical techniques. Recently, MOFs have garnered increasing attention due to their potential applications in numerous areas including: catalysis, gas storage and separation, drug delivery, and others. In this research paper, a new metal-organic framework was synthesized successfully from iron nitrate and 2,6-naphthalenedicarboxylic acid (1) by means of microwave irradiation (Fe-NDC-M) and (2) solvothermally using a conventional electric oven (Fe-NDC-O). They were characterized using XRD, SEM, FTIR, energy-dispersive X-ray (EDS), and thermogravimetric analysis (TGA). The characterization results showed that the synthesized samples were crystals with a rod-like shape and particle sizes in the nanometer range. As a result, the new Fe-NDC-MOF particles can be used as nanocarriers for drug delivery applications utilizing the enhanced permeability and retention effect
Anticipated Discrimination, Choices, and Performance: Experimental evidence
No full textThis paper studies experimentally anticipated discrimination across gender, hiring patterns, and performance in tasks with different stereotypes in a labor-market setting. Participants are assigned to a seven-people group and randomly allocated a role as a firm or worker. In each group, there are five workers and two firms. The only information firms have about each worker is a self-selected avatar (male, female or neutral) representing a worker's gender. Each firm then decides which worker to hire. Female workers anticipate discrimination when they know the task is math-related, but not otherwise. Men choose similar avatar patterns regardless of the task. Surprisingly, we find no evidence whatsoever of discrimination against females in hiring; in fact female avatars are more likely to be hired. Men do perform at much higher levels in the math-related task, but there is no difference in performance in the emotion-recognition task, where there is a strong female stereotype
Characterization of Fine Particulate Matter in Sharjah, United Arab Emirates Using Complementary Experimental Techniques
No full textAirborne particulate matter (PM) pollutants were sampled from an urban background site in Sharjah, United Arab Emirates. The fine fraction (PM₂̣ ₅) (particulates with aerodynamic diameters of less than 2.5 μm) was collected on 47-mm Teflon filters and analyzed using a combined set of non-destructive techniques in order to provide better understanding of the sources of pollutants and their interaction during transport in the atmosphere. These techniques included gravimetric analysis, equivalent black carbon (EBC), X-ray fluorescence, scanning electron microscopy, and X-ray diffraction. Generally, the PM₂̣ ₅ concentrations are within the limits set by the World Health Organization (WHO) and the United States (US) Environmental Protection Agency. The EBC content is in the range of 10–12% of the total PM concentration (2–4 µg m⁻ᵌ), while S (as ammonium sulfate), Ca (as calcite, gypsum, and calcium carbonate), Si (as quartz), Fe, and Al were the major sources of PM pollution. EBC, ammonium sulfate, Zn, V, and Mn originate from anthropogenic sources such as fossil fuel burning, traffic, and industrial emissions. Natural elements such as Ca, Fe, Al, Si, and Ti are due to natural sources such as crustal materials (enhanced during dust episodes) and sea salts. The average contribution of natural sources in the total PM ₂̣ ₅ mass concentration over the sampling period is about 40%, and the contribution of the secondary inorganic compounds is about 27% (mainly ammonium sulfate in our case). The remaining 22% is assumed to be secondary organic compounds.American University of SharjahUniversity of SharjahIAEA in ViennaCenter for Advanced Materials Researc
Effects of Operating Conditions on Water Absorption Capacity of Superabsorbent Hydrogels
No full textA Master of Science thesis in Chemical Engineering by Noun Abdelwahab entitled, “Effects of Operating Conditions on Water Absorption Capacity of Superabsorbent Hydrogels”, submitted in April 2018. Thesis advisor is Dr. Naif Darwish and thesis co-advisor is Dr. Ahmed Aidan. Soft and hard copy available.Superabsorbent hydrogels are three-dimensional networks of hydrophilic polymers that have an extraordinary ability to absorb and retain water. Therefore, they have been utilized in many applications such as disposal diapers, drug delivery, and water desalination. In this study, the effects of environmental and synthetic parameters on the absorbency of superabsorbent hydrogels are investigated using a two-level factorial design. Commercial hydrogels were used to examine the effects of temperature, swelling time, pH, and hydrogel amount, whereas synthesized poly acrylamide hydrogels were used to study the effects of monomer, cross-linker, and initiator concentrations. Moreover, both commercial and synthesized hydrogels were characterized using Fourier transform infrared (FTIR) spectroscopy. Higher absorbency is obtained for the commercial hydrogels by increasing the swelling time from two to eight hours. A reduction of 2.8 g/g(g water/g hydrogel) was observed by increasing the level of pH from 8.5 to 10. Water absorption capacity of the hydrogel increased by 14.72 g/g upon increasing the temperature by 8.5oC above room temperature. For the synthesized hydrogel, it was found that increasing monomer concentration by 5% reduces absorbency by 2.51g/g, whereas increasing cross-linkers concentrations from 0.5% to 1.75% decreases the absorbency by 3.01g/g. Increasing the concentration of the initiator by 0.2% was found to improve absorbency by 0.98g/g. The results show that time, temperature, and monomers have positive effects on absorbency while pH, cross-linkers and initiators reduce it.College of EngineeringDepartment of Chemical EngineeringMaster of Science in Chemical Engineering (MSChE
Non-Linear Profile Monitoring Using Artificial Neural Network Fault Detection
No full textA Master of Science thesis in Engineering Systems Management by Ahmed Fares Mohamed entitled, “Non-Linear Profile Monitoring Using Artificial Neural Network Fault Detection”, submitted in April 2018. Thesis advisor is Dr. Mahmoud Ismail Awad and thesis co-advisor is Dr. Mohammad AlHamaydeh. Soft and hard copy available.In today’s world, the development of technology and industrial systems is becoming much more complex with the ever-demanding need for higher quality. Anomaly detection is the characterization of a normal behavior of a system or process and the identification of any deviation from such normal behavior. Anomaly detection of critical systems provides an important financial and client competitive advantage since it gives decision-makers lead-time and flexibility to manage the health of the system. Structural systems are critical systems that require continuous monitoring of damage accumulation caused by vibrations and other loads that may cause failures of severe consequences. The current research presents a data-driven methodology for the anomaly detection of structural systems using Multivariate Statistical Process Control (MVSPC). In MVSPC, the quality of a system is assumed to be characterized by explanatory variables where one of these variables can be adequately explained as a function of one or more of the other variables, also referred to as a profile or signature. The proposed method is based on modeling the system outputs (displacements or accelerations) as a function of the input (Ground Shaking) using Artificial Neural Networks (ANN). The Hotelling (T squared) technique is then used to identify any shifts in the ANN weights from the healthy state. The results are tested and validated using simulation data that mimic an actual structural system experiencing ground-shaking. The coefficient of determination R2 values exceed 92% that indicating a good fit of the models. In addition, the results indicate a positive false rate range between 0-19% depending on the complication of the system. Overall, the ANN method was able to detect out-of-control Average Run Length (ARL) shifts much faster than the other methods. The methodology presented in this research is scalable and can be applied to a wide range of systems instead of regular inspection checks in order to anticipate and avoid failures. A successful profile monitoring of structural systems will increase safety and reduce cost.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Effect of Basalt Fibers on The Flexural Behavior of Beams Reinforced With BFRP Bars
No full textA Master of Science thesis in Civil Engineering by Abdul Rahman M.Musif AlHafiz entitled, “Effect of Basalt Fibers on The Flexural Behavior of Beams Reinforced With BFRP Bars”, submitted in May 2018. Thesis advisor is Dr. Farid Abed. Soft and hard copy available.Over the last few decades, construction materials have gone through many developments aimed at improving their structural and operational properties. The implementation of fiber-reinforced polymer (FRP) bars as a replacement for conventional teel reinforcement in reinforced concrete structures has gained significant acceptance in the construction field. Basalt Fiber-Reinforced Polymer (BFRP) bars are a new type of FRP reinforcement material that was recently introduced to the construction industry. The main shortcoming associated with the use of the BFRP bars in concrete beams is related to the brittle behavior of these beams. This research investigates, experimentally and analytically, the effects of using different types of fibers within the concrete mix on the flexural behavior of BFRP-reinforced concrete beams. The experimental program consisted of material evaluation and flexural testing. A total of 12 beams were prepared and cast using plain, basalt fiber, and synthetic fiber-reinforced concrete with a 400MPa target compressive strength. Flexural testing was conducted on each of the BFRP-FRC beams using a four-point loading test. Results showed a noticeable improvement in the flexural capacities of these beams due to the delay in concrete failure strain (beyond 0.003) at the compression zone, which helped the BFRP bars to attain a higher ultimate strength. Results also indicated that introducing fibers to the concrete increased curvature ductility. Furthermore, the flexural capacity of the section increased by 12% for the basalt fibers RC beams compared to 19% for specimen with synthetic fibers. The opening of cracks and their deep propagation was effectively restrained by the bridging effect of the fibers, which keeps the crack widths lower than the allowable limit of 0.7 mm at the service stage. In addition, the applicability of ACI 440-1R-06 recommendations was assessed using the results of plain concrete specimen and extended to cover fiber-reinforced concrete beams. The experimental results showed good agreement with the analytical ones obtained using ACI equations in terms of flexural capacity, crack spacing, crack widths and mid-span deflection.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
A Holistic Intersection Rating System (HIRS)
No full textA Master of Science thesis in Civil Engineering by Wesam Emad Saba entitled, “A Holistic Intersection Rating System (HIRS)”, submitted in November 2018. Thesis advisor is Dr. Salwa Beheiry and thesis co-advisor is Dr. Ghassan Abu-Lebdeh. Soft and hard copy available.Signalized urban intersections are key components of urban transportation networks. They are traditionally viewed and designed as primarily motorized traffic facilities thus their physical and operational designs are aimed at maximizing traffic throughput. However, seen from a holistic viewpoint, they are transport and community facilities with direct and indirect impacts on traffic functionalities, the environment, public health and community wellbeing. Thus this study proposed a new rating system, a Holistic Intersection Rating System (HIRS), that is necessary to analyze the comprehensive operational performance of these intersections from a holistic viewpoint. This performance, in essence, covers traffic functionality, sustainability, and public health and community wellbeing. Additionally, this rating system can be used as a guide to design new intersections or revamp existing ones. HIRS is designed to rate signalized urban intersections based on all technologies, physical design, and operational features that allow those intersections to operate holistically. The proposition behind this study is that incorporating and/or enhancing certain technologies, physical design, and operational features as proposed in HIRS, would lead to a more human-centric and sustainable operational performance of the enhanced intersections. Holistic operational performance can be measured through five quantifiable indicators: enhanced traffic performance, reduced air pollution, reduced noise pollution, enhanced user’s physical and mental health, and better safety performance. HIRS was created via an extensive literature review and validated using a panel of experts in the field of construction, transportation, and public health. HIRS was used to collect field data sample based on twenty intersections within the United Arab Emirates (UAE). The Relative Importance Index (RII) method was used to weigh the HIRS indicators. The analysis results showed noticeable gaps in services provided to pedestrians, cyclists, and nearby households. The tested intersections scored a mean of 32% on “Public health and community wellbeing section”. This section is dedicated to the service provided for those users, (mean of 37% on pedestrians sub-section and 15% on cyclist sub-section). Via HIRS, these services can be improved considerably to combine design and operational features and technologies.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Multi-Mode Resource Constrained Project Scheduling Problem with Material Ordering to Maximize NPV
No full textA Master of Science thesis in Engineering Systems Management by Nour Ahmed Kashwani entitled, “Multi-Mode Resource Constrained Project Scheduling Problem with Material Ordering to Maximize NPV”, submitted in April 2018. Thesis advisor is Dr. Abdulrahim Shamayleh. Soft and hard copy available.Project management is critical for companies to stay competitive; nowadays it is regarded as a very high priority. The project management scheduling process of deciding when an activity starts and how resources will be used will highly impact the project duration and cost. A realistic schedule will minimize the chances of failure. Traditionally, the objective of makespan minimization to plan the overall project has been the concept; however, it is critical to incorporate the financial aspect of the project and schedule the activities in such a way that will maximize the net present value (NPV). In this thesis, a mathematical model for the multi-mode resource-constrained project scheduling problem with material ordering to maximize the net present value (MMRCPSPMO) is developed. The model is subjected to precedence, deadline, renewable and non-renewable resources and capital availability constraints. In addition, penalties are imposed in case of any delays. Project scheduling and material ordering decisions are emphasized to determine the time and quantity of an order because setting the material ordering decisions after the project scheduling phase leads to non-optimal solutions. A sensitivity analysis has been performed on the model to see the effect of varying the ordering costs, holding costs and network sizes and complexities. In addition, the variation of both holding and ordering costs at the same time has been performed. The analysis results showed that once the ordering cost is increased, the objective function is affected and hence, the model tends to minimize the overall material orders placed in order to obtain the maximum desired NPV. On the other hand, when the holding cost increases, the model tends to reduce the inventory stored and order the desired materials when needed to avoid storing inventory with high holding costs and longer durations. Furthermore, sensitivity analysis has been performed on 86 different networks with varied sizes of 7, 10, 12, 14, 16, 18, 20, 22 and 25 with a network complexity of 0.2, 0.4, 0.6 and 0.8. The results generated have shown that once the project’s network reaches 20 activities with a network complexity of 0.8, the model tends to take a long computational time; therefore, a heuristic approach is developed in order to minimize the computational time for large size projectsCollege of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Platform Adoption by Mobile Application Developers: A Multimethodological Approach
No full textThis paper investigates the factors that influence the adoption of IT platforms by software developers and how those factors differ from those that influence IT adoption by end-users. We take a multi-methodological approach, beginning with an interpretive field study where we interview mobile application developers. In the initial interpretive phase, we identify a comprehensive set of influences on IT platform adoption, comparing them with the factors that have been identified in previous studies of end-user adoption, noting key differences. In the second phase, we empirically test the factors identified in our interviews. We find several key differences between end-user adoption and developer adoption of IT platforms. Most notably, we observe the importance of network externality considerations when developers make an adoption decision, a consideration that is largely absent for end-users
Shear Strength of Fiber Reinforced Recycled Aggregate Concrete
No full textA Master of Science thesis in Civil Engineering by Mohamed Ramadan Ghoneim entitled, “Shear Strength of Fiber Reinforced Recycled Aggregate Concrete”, submitted in November 2018. Thesis advisor is Dr. Sherif Yehia. Soft and hard copy available.In this research, the shear strength of fiber reinforced recycled concrete was investigated. A High-strength Self Consolidated Concrete (SCC) matrix with 100% coarse recycled aggregate and different types/configurations of fibers were used in the study. Steel (3D and 5D), synthetic and hybrid fibers (mix of steel 5D and synthetic fibers) with a volume fraction of 0.75 % were added to the concrete matrix to prepare eight beams. In addition, four beams were prepared without fibers as control specimens. The aim of the experimental program is to evaluate the effect of: 1) recycled coarse-aggregate replacement; 2) addition of fibers and 3) the steel fiber configuration on the shear strength of recycled aggregate concrete. The results show that recycled aggregate concrete resulted in an improvement in the average concrete shear strength of about 14.4% compared to that of the normal weight aggregate concrete. In addition, the fiber-reinforced beams showed significant improvement in the average concrete shear capacity in the range of 23.44 – 64.48% when compared to that of the control specimen. The highest improvement was achieved by the 3D steel fiber beams. The addition of the fiber delayed the crack initiation, and improved the post-cracking and ductile behavior of all beams. Moreover, the experimental results were compared to that predicted by codes and proposed equations found in the literature for concrete strength with and without fiber. It was found that the ACI simplified equation predicts the closest results for both types of aggregates; while the fib model code 2010 equation predicted the most conservative results.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE