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Finger-operated pumping platform for microfluidic preparation of nanoparticles
No full textMicrofluidic preparation of nanoparticles (NPs) offers many advantages over traditional bench-top preparation techniques, including better control over particle size and higher uniformity. Although many studies have reported the use of low-cost microfluidic chips for nanoparticle synthesis, the technology is still expensive due to the high cost of the pumps needed to generate the required flows inside microchannels. Here, we present a low-cost finger-operated constant-pressure pumping platform capable of generating pressures as high as 120 kPa using finger-operated pumping caps that can be attached to any pop bottle. The platform costs around $208 and enables the generation of flow rate ratios (FRR) of up to 47:1 for the continuous flow synthesis of NPs. The pump has a resolution of 500 Pa per stroke and exhibits stable pressures for up to a few hours. To show the functionality of the proposed pump, we used it to prepare pegylated liposomes and poly lacticco-glycolic acid (PLGA) nanoparticles with sizes ranging from 47 nm to 250 nm with an average polydispersity of 20% using commercially available micromixer chips and in-house made hydrodynamic flow focusing devices. We believe this platform will render microfluidic preparation of NPs accessible to any laboratory with minimal capabilities
Reflective Writing in Composition: A Question of Well-Being
No full textA Master of Arts thesis in Teaching English to Speakers of Other Languages (TESOL) by Bushra Khaliq Khan entitled, “Reflective Writing in Composition: A Question of Well-Being”, submitted in May 2024. Thesis advisor is Dr. Ji Young Shim and thesis co-advisor is Dr. Adrian Matthew Zytkoskee. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This study investigates the use of reflective writing for ESL learners in academic writing, with a particular focus on student writers’ well-being and attitudes toward writing. Previous research suggests that reflective practices boost students’ morale and enhance language learning as students are able to reflect on their experiences and challenges in writing, which may remain unaddressed otherwise. Thus, through reflection, learners are encouraged to use their metacognitive skills in relation to both their learning and psychosocial experiences, resulting in individual growth and well-being. This supports the premise that the ability to reflect indicates effective experiential learning, thus facilitating learners' positive emotional well-being while increasing the quality of output. Against this background, the study explored the role of reflective writing in connection with student writer’s well-being and attitudes towards writing in an L2 English academic writing course. Participants were 31 students enrolled in academic writing classes (WRI 102) at American University of Sharjah and received a total of 11 treatments of reflection journals throughout the semester. Their well-being and writing attitudes were evaluated by two surveys conducted at the beginning and at the end of the semester. Results showed that the ESL learners reported significant improvement in their well-being and writing attitudes following reflective writing practicing reflective writing. This suggests that reflective writing can be considered an effective pedagogical tool.College of Arts and SciencesDepartment of EnglishMaster of Arts in Teaching English to Speakers of Other Languages (MA TESOL
Microstructure, Phase Transformation and Mechanical Property of NiMnGa/Sn Composites
No full textThis paper proposes to prepare NiMnGa/Sn composites by compositing NiMnGa particles and Sn powder. The microstructure, martensitic transformation and mechanical properties of the bulk alloy, ball-milled powders and composites were systematically investigated. The results show that the milled NiMnGa particles are mainly flaky in shape, and the alloy transforms from ordered to disordered structure after ball milling. The martensitic transformation of milled NiMnGa particles disappeared and it is recovered by post-annealing. The annealed NiMnGa particles and Sn powder were mixed and sintered to make NiMnGa particles /Sn composites. The composites exhibit a different NiMnGa particle distribution morphology for the axial direction and radial direction of the sample. The interfacial reaction between the NiMnGa particles and Sn matrix is observed. The martensitic transformation of the 30% and 40% composites has been observed, but the transformation temperatures for the composites are higher than that of the annealed NiMnGa particles, which should be related to the interfacial reaction that changes the composition of the NiMnGa particles. Most of the composites are not fractured during compressive test irrespective of the particles distribution and show a large plasticity, the mechanical strength of the composites increases with increasing the NiMnGa particle content
Proceedings of the Eight International Conference on Smart Materials & Nanotechnology in Engineering
No full textThis e-book contains the edited proceedings of SMN2024, the Eighth International Conference on Smart Materials & Nanotechnology in Engineering, held on November 25–28, 2024, at the American University of Sharjah, Sharjah, United Arab Emirates
Flexible PDMS Composite Electrodes with Boronic Acid-Modified Carbon Dots for Surface Electrophysiological Signal Recording
No full textConventional surface electrodes are composed of rigid metals such as Ag/AgCl that are not only harsh to the skin but also irritating if used as wet electrodes. Furthermore, rigid, inflexible surface electrodes can cause patient discomfort when used for long term. To reduce the mechanical mismatch, flexible alternatives to metal electrodes are needed. This study reports the development of highly flexible composite electrodes fabricated from the conductive dopant boronic acid-modified carbon dots embedded in a polydimethylsiloxane matrix. The electrodes were characterized for their structural, electrochemical, and mechanical characteristics and ability to record electrophysiological signals. Furthermore, the composition of these electrodes was varied systematically to obtain the optimal electrochemical and mechanical properties. The best-performing electrode composed of 10% boronic acid-modified carbon dots, 16% glycerol, and 74% polydimethylsiloxane (8:1 elastomer to curing agent) had a smooth surface, a promising conductivity of 9.62×10⁻ᵌ S/cm, an impedance of 964 kΩ at 1 kHz, and a charge storage capacity of 21.4 μC/cm². This electrode had a Young’s modulus (0.0545 MPa), which is compatible with biological tissues’ elasticity. The fabricated electrodes recorded high-quality electrocardiography signals with a promising signal-to-noise ratio (SNR) of 36.75 dB that is comparable to the commercial Ag/AgCl, which had a SNR of 39.98 dB. A similarly good performance was observed with electromyography. Furthermore, the developed flexible surface electrodes maintained their ability to record high quality ECG and EMG over a period of three weeks.American University of SharjahAbu Dhabi National Oil Company (ADNOC)Emirates NBDSharjah Electricity, Water, and Gas Authority (SEWA)Dubai Electricity and Water Authority R&D Cente
Project Management Decision Tool for UAE Residential Construction During Pandemic
No full textA Doctor of Philosophy Dissertation in Engineering Systems Management by Hamad Khalifa Al-Hadari entitled, “Project Management Decision Tool for UAE Residential Construction During Pandemic”, submitted in December 2024. Dissertation advisor is Dr. Vian Ahmed and dissertation co-advisor is Dr. Moncer Hariga. Soft copy is available (Dissertation, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This research explores project management practices in the construction industry, with a particular focus on residential projects during pandemic crises, such as COVID-19. The COVID-19 pandemic significantly disrupted the development of residential construction projects both in the UAE and globally. Effective project management practices are essential for analyzing the impact of such pandemics, and implementing practical solutions will be critical for managing similar crises in the future. There are fifteen challenges associated with construction projects during the COVID-19 pandemic were identified through interviewing seven experts. These challenges were classified into four different categories and ranked using AHP method across each of the four phases of the construction project. The four categories were strategic planning and adaptation, resource and supply chain management, project execution and quality control and stakeholder relations challenges. The construction project phases considered were the initiating phase, planning phase, executing phase and closing phase. To identify the most effective project management practices during pandemics, the interaction between alternative project management practices and associated challenges was modeled using the Fuzzy TOPSIS method. Risk management practices proved to be among the most essential aspects during a pandemic, earning consistently high rankings across all four categories. Similarly, communication management practices were found to be essential in addressing the challenges of a pandemic, achieving equally high rankings across the same categories. The significance of these practices cannot be overstated when addressing crises like the COVID-19 pandemic. Their effectiveness in mitigating risks, ensuring clear and timely communication, and maintaining operational stability underscores their essential role in times of pandemics. To effectively address the identified challenges, a dynamic and interactive dashboard was developed using Power BI software. This state-of-the-art tool was custom-built to assist project managers in applying the proposed project management practices, specifically tailored to overcome the unique difficulties faced during crisis scenarios such as pandemics. By leveraging the capabilities of Power BI, the dashboard provides stakeholders with a clear, data-driven visualization of key insights and actionable strategies. These insights empower decision-makers to evaluate and adopt the most suitable practices for managing construction projects during pandemic conditions, ensuring resilience and efficiency throughout the project lifecycle.College of EngineeringDepartment of Industrial EngineeringPhD in Engineering - Engineering Systems Management (PhD-ESM
Yield and Energy Modeling for Biochar and Bio-Oil Using Pyrolysis Temperature and Biomass Constituents Article link copied!
No full textPyrolysis offers a sustainable and efficient approach to resource utilization and waste management, transforming organic materials into valuable products. The quality and distribution of the pyrolysis products highly depend on the constituents’ properties and set process parameters. This research aims to investigate and model this dependency, offering decision-makers a tool to guide them when designing the process for a particular application. Experimental data on the pyrolysis of various types of feedstocks processed at a wide range of pyrolysis temperatures (350–650 °C) are utilized to develop the prediction models. Four variables are modeled: the yield and energy content for both the biochar and bio-oil as a function of the pyrolysis temperature and feedstock characteristics. The models developed had very good prediction power with the coefficient of determination above 90%. The results highlight the advantages of food waste (leftover) as a suitable feedstock to produce biochar at the pyrolysis temperature within the range of 450–550 °C. Furthermore, the biofuels produced from food waste are found to be of good quality, with the bio-oil exceptionally high in energy content (HHV = 34.6 MJ/kg), which is almost 80% of that of diesel. The developed models provide a tool for predicting the biofuel yield and quality based on the feedstock selection and process temperature.American University of Sharjah research grantAmerican University of Sharjah Open Access Progra
Malicious URL and Intrusion Detection using Machine Learning
No full textCyberattacks are becoming increasingly sophisticated and evolving danger to the Web users. Therefore, addressing the growing threat of cyberattacks and providing automated solutions became a necessity. The purpose of this paper is to use machine learning (ML) techniques for malicious websites detection and classification, and intrusion detection. Different ML algorithms were applied, namely Decision Tree (DT), K-Nearest Neighbors (KNN), Naive Bayes (NB) and Support Vector Machine (SVM). Two datasets were utilized to train the MLmodels. The first dataset contains two classes of websites: “malicious” and “benign”. The second dataset has six classes of different network intrusion cyber-attacks: “normal”, “blackhole”, “TCP-SYN”, “PortScan”, “Diversion”, and “Overflow”. Experimental results demonstrated that the ML algorithms were able to achieve high accuracy in predicting website maliciousness and intrusion detection. Using the first dataset, DT KNN, and SVM classifiers exhibited the best performance for detecting malicious URLs with accuracies over 99%. Using the second dataset, the DT classifier proved most suitable for intrusion detection, achieving an accuracy of 95%. This paper suggests the integration of ML techniques into online security systems to enhance their efficacy in detecting and preventing cyber threats
Electric Vehicle Adoption: A Comprehensive Systematic Review of Technological, Environmental, Organizational and Policy Impacts
No full textThis comprehensive systematic review explores the multifaceted impacts of electric vehicle (EV) adoption across technological, environmental, organizational, and policy dimensions. Drawing from 88 peer-reviewed articles, the study addresses a critical gap in the existing literature, which often isolates the impact of EV adoption without considering holistic effects. Technological advancements include innovations in the battery technology and energy storage systems, enhancing EV performance and mitigating range anxiety. The environmental analysis reveals substantial reductions in greenhouse gas emissions, with lifecycle assessments showing significant reductions for EVs compared to internal combustion engine vehicles, particularly when charged with renewable energy sources. Key comparisons include lifecycle emissions between mid-size battery electric vehicles (BEVs) and internal combustion engine vehicles (ICEVs), and global average lifecycle emissions by powertrain under various policy scenarios. The organizational implications are evident, as businesses adopt new models for fleet management and logistics, leveraging EVs for operational efficiency and sustainability. Policy analysis underscores the crucial role of government incentives, regulatory measures, and infrastructure investments in accelerating EV adoption. The review identifies future research areas such as efficient battery recycling methods, the potential impact of EVs on grid stability, and long-term economic implications. This study offers insights for stakeholders aiming to foster sustainable transportation and achieve global climate goals
Flexural strengthening of reinforced concrete beams with CFRP laminates and spike anchors
No full textCarbon fiber-reinforced polymers (CFRP) are widely used to strengthen reinforced concrete (RC) beams. Its major drawback is the brittle failure mode in the form of debonding of the CFRP laminate. The use of CFRP spike anchors demonstrated positive outcomes in mitigating the debonding failure in small-scale concrete prisms in previous studies. However, the real-life behavior of anchored RC beams was rarely studied . This study aims to investigate the flexural behavior of externally strengthened RC beams with CFRP laminates and anchored at end with CFRP spike anchors. The results of anchored beams was compared with unanchored specimens in terms of load-deflection response, strain in the FRP laminates, and failure modes. Results showed that anchorage of CFRP laminates with CFRP splay anchors positively affected the flexural capacity of the specimens. An average increase in the load-carrying capacity of 19 % was portrayed in the anchored specimens compared to the unanchored specimen. Anchorage of FRP laminates resulted in the mitigation of debonding failure and thus, enhanced strain utilization in laminates. A considerable improvement in strain utilization is exhibited by the specimen anchored with two anchors at each end. Moreover, increasing the anchor's dowel diameter significantly improved the load-carrying capacity but lowered the ultimate strain reached in the laminate. Results indicated that larger diameter anchors provide strengthening effect similar to increasing the number of FRP layers instead of providing anchorage to the FRP sheet. This is primarily due to the increase in the fan length and thickness as the anchor's dowel diameter increases.American University of Sharjah research grantRiad Al-Sadek Endowed Chair in Civil Engineerin