AUS Repository (American University of Sharjah)
Not a member yet
2669 research outputs found
Sort by
INScription: Department of International Studies (INS) Issue #2 (October 28, 2021, Issue 2)
No full textCollege of Arts and SciencesDepartment of International Studie
Moving from plagiarism police to integrity coaches: assisting novice students in understanding the relationship between research and ownership
No full textMuch of the discourse surrounding plagiarism is one of fear—a fear of being caught and punished, but many plagiarism examples happen unintentionally as students struggle with a new language, new ideas, and new communities in tertiary education. Specifically, many students are challenged with the task of writing a research paper, which involves finding academic sources, reading those sources to answer a research question, and integrating direct quotations and paraphrasing. Because novice writers often struggle with these skills, what is a developmental stage is instead interpreted as plagiarism. Much of the discussion of plagiarism involves implicit and explicit definitions of ownership, but there is little research about how students understand the concept of ownership in relation to ideas and language. In this qualitative study, we present data from 18 international students at an American-style university in the Middle East who write an introductory research paper as part of a composition course. Results show that perceptions of plagiarism changed in relation to owning ideas, owning language, and owning time spent on the research process and that distinguishing these boundaries is often difficult for students even within their own final research papers. We suggest teaching more robust note-taking strategies, discussing ownership in terms of a writer’s choices in guiding readers through the paper, and creating an environment where students can understand the complexities of plagiarism rather than simply fearing being caught
In vitro effects of multi-purpose contact lens disinfecting solutions towards survivability of Acanthamoeba genotype T4 in Malaysia
No full textThe incidence of Acanthamoeba keratitis has been increasing since the previous decades, especially among contact lens users. This infection is majorly caused by the use of ineffective contact lens disinfecting solution. Thus, this study was conducted to evaluate the in vitro effects of multi-purpose disinfecting solutions (MPDS) against Acanthamoeba trophozoites and cysts. Acanthamoeba genotype T4 isolated from contact lens paraphernalia and an environmental strains were propagated for trophozoite or cyst-containing culture and adjusted in final concentration of 1 × 105 cells/ml. Amoebicidal and cysticidal assays were conducted by incubating trophozoites and cysts with OPTI-FREE® Express®, ReNu® Fresh™, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive according to the manufacturer’s minimum recommended disinfectant time (MMRDT) for up to 12 h at 30 ⁰C. Trypan blue hemocytometer-based microscopic counts determined amoebicidal and cysticidal effects. The viability of Acanthamoeba trophozoites and cysts was confirmed by re-inoculated them in the 1.5% non-nutrient agar plates. It was found that none of the MPDS showed amoebicidal and cysticidal effects during the MMRDT. However, OPTI-FREE® Express® demonstrated a significant differences in average cell reduction for both stages within MMRDT. When subjected to 12 h exposure, both OPTI-FREE® Express® and ReNu® Fresh™ led to significant reduction in the number of trophozoite and cyst cells. Notably, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive did appreciably improve the solution effectiveness towards trophozoite cells when incubated for 12 h. All MPDS were largely ineffective, with 100% survival of all isolates at MMRDT, while OPTI-FREE® Express® showed limited amoebicidal activity against the contact lens paraphernalia isolate, however, it was more against the environmental strains after 12 h incubation time. The commercially available MPDS employed in this research offered minimal effectiveness against the protozoa despite the contact time. Improvement or development of new solution should consider the adjustment of the appropriate disinfectant concentration, adequate exposure time or the incorporation of novel chemical elements, which are effective against Acanthamoeba for accelerated disinfecting and more reduction of potential exposure of contact lens users to Acanthamoeba keratitis
Assessing the bond strength in thermoplastic fiber composite fabricated by an open mold process
No full textA Master of Science thesis in Mechanical Engineering by Basit Ali entitled, “Assessing the bond strength in thermoplastic fiber composite fabricated by an open mold process”, submitted in July 2021. Thesis advisor is Dr. Maen Abdelqader Alkhader and thesis co-advisor Dr. Wael Abuzaid. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Fiber reinforced polymer (FRP) composites have become popular in marine, aerospace, and structural applications due to their high specific stiffness and strength as well as their ability to conform to complex shapes without the need to intensive subtractive machining. Until recently, thermoset FRP composites have been considered as superior to their thermoplastic counterparts. However, the advent of new thermoplastics that offer high melting temperatures and reduced temperature sensitivity motivated the industry to adopt thermoplastic composites in their products. Thermoplastic FRP composites are mendable and amendable, do not produce harmful emissions during their consolidation, and can potentially be recycled. Generally, two major hurdles slow thermoplastic fabrication: preparation of freeform and forced consolidation at elevated temperatures and pressures in closed molds. To overcome these hurdles and to automate the fabrication processes of thermoplastic composites, automated tape placement (ATP) coupled with in-situ consolidation is used. During this process, composite tapes are simultaneously heated, layered, and consolidated following a layer-by-layer build-up process that resembles filament deposition type of 3D printing. The layering rate, consolidation pressure, and temperature can affect the bond strength between the composite layers and the overall quality of the produced composite. Therefore, it is instrumental to characterize the coupling between these process parameters and the inter-laminar bond strength of thermoplastic composites used in ATP. In this work, plies of GFPP are stacked to process by utilizing an open mold processing approach that simulates ATP process. The layers are consolidated using different ranges of consolidation pressure, temperature, and time. The quality of the bond in the produced specimens were assessed through measuring their Interlaminar shear strength (ILSS) according to short beam ASTM standard. Microscopy imaging along with digital image correlation (DIC) were used to investigate the failure location in the tested specimens. Results show that consolidation pressures exceeding 10 bar do not improve bond strength, consolidation can occur at temperatures below the melting temperature of the processed thermoplastic, and consolidation times between 7 to 13 minutes can result in acceptable bond strengths that can potentially reach 50% of the bond strength resulting from conventional processing techniques.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Optimization of Apparent Eddy Current Conductivity Measurements for Clad Thickness Estimation
No full textA Master of Science thesis in Mechanical Engineering by Noor Ra’a Ahmed Said entitled, “Optimization of Apparent Eddy Current Conductivity Measurements for Clad Thickness Estimation”, submitted in July 2021. Thesis advisor is Dr. Bassam Abu-Nabah and thesis co-advisor Dr. Maen Alkhader. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Transcriptome analysis of Escherichia coli K1 after therapy with hesperidin conjugated with silver nanoparticles
No full textBackgrounds: Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study. Results: 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P< 0.01) in both E. coli K1 treated with Hesperidin conjugated silver nanoparticles and E. coli K1 treated with silver alone, compared to untreated E. coli K1. Of note, the expression levels of cation efflux genes (cusA and copA) and translocation of ions, across the membrane genes (rsxB) were found to increase 2.6, 3.1, and 3.3- log FC, respectively. Significant regulation was observed for metabolic genes and several genes involved in the coordination of flagella. Conclusions: The antibacterial mechanism of nanoparticles maybe due to disruption of the cell membrane, oxidative stress, and metabolism in E. coli K1. Further studies will lead to a better understanding of the genetic mechanisms underlying treatment with nanoparticles and identification of much needed novel antimicrobial drug candidates.Sunway University, MalaysiaAmerican University of Sharja
Isolating Physical Replacement of Identical IoT Devices Using Machine and Deep Learning Approaches
No full textA Master of Science thesis in Computer Engineering by Areej Osama Mohammad entitled, “Isolating Physical Replacement of Identical IoT Devices Using Machine and Deep Learning Approaches”, submitted in April 2021. Thesis advisor is Dr. Imran Zualkernan and thesis co-advisor is Dr. Fadi Aloul. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Many Internet of Things (IoT) applications deploy identical end devices like sensor nodes or surveillance cameras in an organization. The purpose of this thesis was to determine if a malicious physical substitution of one end device by an identical compromised device could be recognized using deep learning or machine learning techniques. Conventional techniques to address the physical replacement of a node require one to implement specialized hardware like Physical Unclonable Functions (PUF) using expensive encryption techniques. For low-resource devices like an ESP32, the device does not come with an integrated PUF module, and a separate chip is required to execute the cryptographic operations. Moreover, recently deep learning techniques are shown to have compromised the PUF-based technique as well. This thesis explored whether machine and deep learning could be used to identify a single end device from a set of identical devices without requiring a PUF-like mechanism for authentication. Network data from 18 identical ESP32 devices was collected in a typical MQTT-based IoT network. In addition to exploring conventional machine learning methods including Random Forest, Bayesian, SVM, LightGBM, Gradient Boosting, and XG-Boost, a tiny Convolutional Neural Network (CNN) was designed and optimized using the Hyperband algorithm. The CNN was small with 85,058 trainable parameters and only used the packet Inter-Arrival Time (IAT) as input. The results are that the CNN outperformed all other models, with a micro-F1-Score of 0.999 (0.0012). The Random Forest model was the best traditional machine learning models with a micro-F1-Score of 0.9501 (0.0036). The worst was Bayesian with a micro-F1-Score of 0.222 (0.0016). There was a statistically significant difference in the F1-Score (Kruskal-Wallis; chi-square=84.192, p < 0.05) between the various trained model using 10-fold validation.College of EngineeringDepartment of Computer Science and EngineeringMaster of Science in Computer Engineering (MSCoE
Strain rate effect on twip/trip high entropy alloy
No full textA Master of Science thesis in Mechanical Engineering by Omar Mohammad Marwan El Batal entitled, “Strain rate effect on twip/trip high entropy alloy”, submitted in July 2021. Thesis advisor is Dr. Wael Abuzaid and thesis co-advisor Dr. Maen Abdelqabder Alkhader. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).High Entropy Alloys (HEA) present opportunities to develop new materials with outstanding mechanical properties. Through the careful selection of constituent elements along with optimized thermal processing for proper control of structure, grain size, and deformation mechanisms, many of the newly developed HEA systems exhibit superior strength and ductility levels across a wide range of temperatures, in particular at cryogenic deformation temperatures. Such a remarkable response has been attributed to the hardening capacity of HEA that is achieved through the activation of deformation twinning. More recent HEA compositions have considered phase transforming systems which have the potential for enhanced strengthening and therefore high strength and ductility levels. However, the strain rate sensitivity of such transforming HEA is not well understood and requires further investigation. In this study, the dynamic and quasi-static tensile properties of the non-equiatomic V10Cr10Fe45Co30Ni5 HEA were investigated temperatures ranging from 77K (196°C) to 573K (300°C).Depending on the deformation temperature, the considered HEA exhibits plasticity through either crystallographic slip, deformation twinning, or solid-state phase transformation. At 300°C, only slip mediated plasticity was observed for all the considered deformation rates. Deformation twinning was detected in samples deformed at room temperature (RT), while phase transformation, face-centered cubic to body-centered cubic, became more favorable at cryogenic deformation temperatures. At a deformation strain rate of 1.32e-3/sand 77K deformation temperature, the alloy reached an impressive tensile strength of around 1.2 GPa with a ductility exceeding 60%. Plastic deformation was accommodated in this case through phase transformation which consequently enabled superior strength and ductility. Both, the strain rate sensitivity (SRS) and strain hardening rates were shown to differ depending on the dominant deformation mechanism. For example, the SRS parameter m decreased as the deformation temperature dropped from RT (m = 0.05) to 77K (m = 0.017). Increasing the loading temperature to 300°C resulted in higher ductility, however at the expense of strength. Due to the absence of either twinning or transformation as hardening mechanisms, the HEA experienced a drop in strength reaching up to 23% at 300°C.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Cyber Security of Market-Based Congestion Management Methods in Power Distribution Systems
No full textAs the penetration rate of flexible loads and Distributed Energy Resources in the distribution networks increases, congestion management techniques that utilize Demand Side Management (DSM) have been developed. These are indirect methods that rely on information exchange between the Distribution Network Operator, aggregators, and consumers’ meters to encourage customers to change their demand to relieve congestion. Cyber attacks against aggregators can compromise the operation of DSM-based congestion management methods, and hence, affect the security and reliability of electrical networks. In this paper, the vulnerability of indirect congestion management methods to Load Altering Attacks is studied. An optimizationalgorithm is developed to determine the aggregators a cyber attacker would compromise, via minimum alteration of their load profiles, to cause congestion problems. The impact of such attacks on congestion and consumers’ electricity bill is then studied. A mitigation scheme is formulated to determine the most critical aggregators in the network. The security of these aggregators is then reinforced to mitigate such cyber attacks.Khalifa University of Science, Technology and ResearchNSERC Canad
The Effects of cRGD Targeting Liposomes When Paired With Ultrasonic Waves on Drug Delivery
No full textA Master of Science thesis in Biomedical Engineering by Doua Jamal Kosaji entitled, “The Effects of cRGD Targeting Liposomes When Paired With Ultrasonic Waves on Drug Delivery”, submitted in April 2021. Thesis advisor is Dr. Ghaleb Husseini. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Cancer is a leading fatal disease, which has the ability to grow uncontrollably and spread throughout the body of the patient. Several approaches have been used to treat cancer, chemotherapy being the most common treatment method. Accompanying this therapy are several drawbacks that have detrimental effects on the patient both physiologically and psychologically. Those effects include hair loss, infection, anemia, in addition to congestive heart failure. New remedies have been introduced to mitigate the undesired side effects of chemotherapy, such as the Novel Drug Delivery Systems (NDDSs). This relatively new technique is an approach that carries the cytotoxic drugs through the blood to the precise tumor site through vesicular structures. Those structures then accumulate at the tumor site and deliver their chemotherapeutic cargo. To induce further effective drug delivery, a moiety is added to the surface of liposomal nanoparticles, in this thesis, the cyclic-RGD sequence. This tripeptide sequence, in turn, actively targets cRGD receptors overexpressed on the surface of cancer cells. Upon binding to the receptor, these targeted liposomes are taken up by the cells through receptor-mediated endocytosis. Ultrasonic waves are then applied to release the liposomal contents in a timely manner. Using DLS, the radii were measured at 84.98 nm and 99.36 for control and cRGD liposomes, respectively. Protein attachment was validated using quantification protocols, which yielded higher protein ratios of 4.5383. 3.1875, and 2.5545 in cRGD liposomes compared to the control. The LFUS release was studied at 6.2, 9, and 10 mW/cm² power intensity with a frequency of 20kHz for 20 secs ON and 20 secs OFF. It was concluded that higher intensities instigated fewer pulses and achieved the rapid release of calcein, a model drug, from liposomes. The zero-order, Higuchi, Korsmeyer-Pappas, and Weibull models were the best fitting kinetic models for the experimental data. By combining biological targeting (via receptor-moiety binding) and an external stimulus (i.e., ultrasound), this thesis shows the promise of targeted drug delivery platforms.College of EngineeringMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME