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Use of Ultrasound and Ionic Liquids to Enhance the Extractive Desulfurization of Oils
No full textA Master of Science thesis in Chemical Engineering by Karma Zuraiqi entitled, "Use of Ultrasound and Ionic Liquids to Enhance the Extractive Desulfurization of Oils," submitted in December 2016. Thesis advisor is Dr. Paul Nancarrow and thesis co-advisor Dr. Hussain Ahmed. Soft and hard copy available.Desulfurization of diesel oil has been a widely investigated process, due to the detrimental impact on health and the environment caused by sulfur dioxide emissions resulting from the combustion of diesel oil. This has recently impelled many governments to reduce the maximum sulfur content of diesel to 10 ppm. The current desulfurization technology, hydrodesulfurization (HDS), is energy intensive, uses large quantities of hydrogen, and is ineffective at removing some sulfur compounds. The need for cost effective desulfurization methods to achieve this tighter specification gave rise to the study of replacement methods. In laboratory scale equilibrium studies, the use of ionic liquids (ILs) within the context of liquid-liquid extraction (LLE) has been demonstrated to be a viable, low energy, substitute to HDS. However, mass transfer limitations and scale-up issues have not previously been investigated. Since ILs suffer from high viscosities, which reduces the rate of interphase mass transfer, this would require more separation stages and larger processing equipment. Recently, the effect of ultrasound (US) on mass transfer has been investigated to establish whether it can be used to enhance mass transfer in industrial processes. This work aims to study the process development issues associated with extractive desulfurization of diesel using ILs: interphase mass transfer, phase dispersion and settling behavior, and IL regeneration. The impact of US irradiation on each of these process steps is investigated. The study involved the use of model diesel, in which hexadecane was used along with dibenzothiophene (DBT) as the model sulfur compound. The extraction solvent used was 1-ethyl-3-methylimidazolium acetate ([C2mim][CH3COO]) IL. This study has shown that sonification can greatly enhance the rate of mass transfer of DBT from diesel to the IL, resulting in a 57% sulfur removal for a 75% decrease in extraction time, and leading to a reduction in the number of extraction stages required. Furthermore, the phase settling rate was found to be increased by both sonification and the addition of a surfactant. The IL was easily regenerated by extraction using hexane, ultimately obtaining a regeneration of 93% through multiple extractions. However, sonification was found to have no significant benefit in this step of the process.College of EngineeringDepartment of Chemical EngineeringMaster of Science in Chemical Engineering (MSChE
Energy Conservation-based Thresholding for Effective Wavelet Denoising of Partial Discharge Signals
No full textRecent studies have shown that wavelet transform can effectively be used for noise reduction in the context of partial discharge (PD) signal detection and classification. Several thresholding approaches for wavelet denoising have been reported in the literature. In this study, a novel wavelet threshold estimation method, named energy conservation-based thresholding (ECBT), is introduced. The proposed thresholding function is capable of conserving a significant portion of the original signal energy, while the threshold value is determined based on the relative difference between the original and noisy signal energies. The proposed method is first applied to PD signals contaminated with different levels of simulated noise. Results show that ECBT produces a denoised PD signal with higher signal-to-noise ratio (SNR) and less distortion than PDs produced by the existing wavelet methods. Then, ECBT is modified to address actual PD signals corrupted with real noise, where a robust SNR estimation method is derived to estimate the noise level embedded in the measured PD signals. The denoised PD signals indicate that the proposed method yields higher reduction in noise levels than other methods
Drug Delivery Systems Based on Polymeric Micelles and Ultrasound: A Review
No full textAnti-neoplastic drugs used for cancer treatment often produce damage to healthy cells, leading to severe side effects in patients undergoing chemotherapy. The encapsulation of these agents in nanoparticles reduces the adverse side effects of conventional chemotherapy on healthy tissues. Such nanoparticles, considered as drug delivery vehicles, are diverse and include micelles, liposomes, dendrimers, nanocapsules, nanospheres and others. Polymeric micelles have been widely researched as nanocarriers for hydrophobic drugs. They can be designed to have increased stability and blood circulation time, as well as binding specificity to certain receptors overexpressed on the surface of cancer cells. Once these drug-encapsulating nanoparticles reach the tumor site, an external stimulus, such as ultrasound, can be used to spatially and temporally trigger drug release. Methods: This review paper focuses on the recent advances of cancer drug delivery systems employing polymeric micelles and ultrasound. An extensive literature review was performed mainly using PubMed. The introduction explains how nanocarriers are related to chemotherapy and the several modalities of use for this application. Afterwards, the review focuses on polymeric micelles used for drug delivery, their advantages and disadvantages. Subsequently, the physics of ultrasound is briefly reviewed, as well as the way it interacts with polymeric micelles to trigger the delivery of the drug transported by these nanocarriers. The following section focuses on targeting, discussing the several ways by which the nanoparticles can be directed to the target cells, and there deliver their cargo. Finally, a selection of relevant in vitro and in vivo studies, as well as clinical trials, is presented and discussed. Conclusion: Although there are still several research studies to be performed before the combination of micelles and ultrasound can enter clinical trials, the future of controlled delivery using this drug delivery system is promising as a way to reduce the mortality and morbidity of cancer and the noxious side effects of conventional chemotherapy
Arab Culture in Translation: From Exoticism to Terrorism
No full textA Master of Arts thesis in Translation and Interpreting MATI (English/Arabic/English) by Lamia Gharbi entitled, "Arab Culture in Translation: From Exoticism to Terrorism," submitted in May 2016. Thesis advisor is Dr. Said Faiq. Soft and hard copy available.The 9/11 attacks placed the Arab and Islamic World at the center of a global attention characterized by the negativity of an old inherited conception. While portraying Arabs and Muslims again within a clash of civilizations and associating their culture with violence and terrorism, the world seems to recreate an old scenario of the 'Self' and the 'Other'. Viewing the Arab and Islamic World from a fixed ideology is the first mover behind circulating texts designed to create a particular mental model about them that serves the interests of the producers of such an ideology. From orientalism to terrorism, discourses seem to reintroduce and extend a static view of exoticism, misrepresentation and fear. This is reflected not only in the concepts, but also in the terminology and the intensity of fear mobilization. Translation has played a major role in reinforcing and stimulating established ideologies about the Arabs and Islam alike, often without differentiating between the two. In this context, this thesis investigates these reflections through an examination of The Arabian Nights' translation and the rise of exoticism in representing Arab culture. It further explores an article titled الاعدام حرقا...عقوبة اسلامية written by Yasmin Al Khatib, a young Egyptian writer, as a reaction to the execution of the Jordanian hostage pilot, Muath Al-Kasasbeh, by the terrorist organization known as the Islamic State of Iraq and Syria (ISIS), and its English translation by MEMRI.org as 'Death by Fire is an Islamic Punishment'. Both texts are examined through the frame of Critical Discourse analysis. It is concluded that although Arabs are used to misrepresentations of their culture; they do not expect so from Arab writers who are viewed as instruments of hegemony locally implanted in the Arab World to expand Western discourse. The thesis determines that terrorism is not an entirely new concept; it is a reproduction of orientalism through similar means of distortion of Arab culture.College of Arts and SciencesDepartment of Arabic and Translation StudiesMaster of Arts in English/Arabic/English Translation and Interpreting (MATI
Developing an Integrated Water Management Infrastructure in Homes
No full textA poster submitted in ENG 207 taught by Dr. David Prescott for the Fall 2016 semester.As the world population is predicted to increase (see figure 1), the human consumption to sources of life; such as food and water, will increase. However; the freshwater withdrawals have tripled over the last 50 years and predicted to increase even more in the future due to the increase in its demand
Sustainable Integration of Solar Energy for Desalination
No full textA poster submitted in ENG 207 taught by Dr. David Prescott for the Fall 2016 semester.Water extraction, treatment and distribution accounts for 8% of global energy consumption. Which can be estimated as ∼7MJ/m3. The main factors affecting solar desalination plant feasibility are technology maturity, economics and environmental impact.Solar desalination is applicable in arid regions where, solar resource abundance and saline water availability are observed to coincide. Desalination systems remove salts from saline water using one of the following processes: Phase change processes (MSF) , Pressure-driven membrane processes (RO). Large scale desalination has been undertaken using methods such as MSF and MEB, but since about 2003, RO has become dominant. How can solar desalination using Reverse Osmosis and Multi-Stage Flash Desalination be optimized for production of potable water
Effective Teachers of Academic Writing in an EFL Context: Students and Teachers Beliefs
No full textA Master of Arts thesis in Teaching English to Speakers of Other Languages (TESOL) by Lama Saleem Zakzak entitled, "Effective Teachers of Academic Writing in an EFL Context: Students and Teachers Beliefs," submitted January 2016. Thesis advisor is Dr. Ahmad Al-Issa. Soft and hard copy available.In the field on EFL academic writing, the teacher plays a pivotal role in the success of the learning process. This research aimed at investigating the characteristics that constitute an effective academic writing instructor, as perceived by EFL Arab students and their instructors. Questionnaires and follow-up interviews were used to discover the beliefs of students and instructors regarding the characteristics of effective academic writing instructors at AUS, in the UAE. Although the small number of instructor respondents did not allow for comparing and contrasting the beliefs of the students with their instructors, it was clear from the findings that there are some variations in the way students and their instructors perceive effective teachers of academic writing. Both students and instructors valued characteristics such as teacher friendliness, patience, and helpfulness, but to varying degrees. However, the students and instructors had different beliefs about characteristics related to teaching. Moreover, two-proportion tests revealed that the response selection tendency of the students was affected by two variables: gender and high school curriculum.College of Arts and SciencesDepartment of EnglishMaster of Arts in Teaching English to Speakers of Other Languages (MA TESOL
Recent advances on the anti-cancer properties of Nigella sativa, a widely used food additive
No full textThe use of naturally-occurring agents to regulate tumorigenesis is on the rise. Several herbal extracts, pure plant-derived active constituents, and food additives have been reported to possess potent anti-cancer properties and cancer-ameliorating effects. The wide-range anti-cancer effects of Nigella sativa, also known as black seed or black cumin, have been extensively studied using different in vitro and in vivo models. Here, we provide a comprehensive, analytical review of the reported anti-cancer properties of N. sativa seed extracts. This review focuses on analyzing experimental findings related to the ability of N. sativa to exert anti-proliferative, pro-apoptotic, anti-oxidant, cytotoxic, anti-mutagenic, anti-metastatic, and NK cytotoxic activity enhancing effects against various primary cancer cells and cancer cell lines. Moreover, we underline the molecular mechanisms of action and the signal transduction pathways implicated in the suppression of tumorigenesis by N. sativa. The major signaling pathway utilized by N. sativa to manifest its anti-cancer activity is the iNOS signaling pathway. This review underscores the recent developments that highlight an effective therapeutic potential of N. sativa to suppress tumor development, reduce tumor incidence, and ameliorate carcinogenesis. In sum, experimental findings reported in the last two decades strongly suggest that N. sativa fractions could serve, alone or in combination with known chemotherapeutic drugs, as effective agents to control tumor initiation, growth, and metastasis, and hence, treatment of a wide range of cancers
Optimization of Excess of Loss Reinsurance Structure
No full textA Master of Science thesis in Engineering Systems Management by Mai Muhtaseb entitled, "Optimization of Excess of Loss Reinsurance Structure," submitted in January 2016. Thesis advisor is Dr. Malick Ndiaye and thesis co-advisor is Mr. Shivash Bhagaloo. Soft and hard copy available.In the current practice in the region, before purchasing a reinsurance contract, small to medium insurance companies rarely conduct internal analysis of their data and experiences in order to evaluate and achieve optimal reinsurance arrangements and contracts. Most companies settle their reinsurance agreements through reinsurance intermediary, broker, who acts as the link of communication, negotiation and settlement between both the reinsurers and the ceding insurer. Alternatively, the reinsurance companies or intermediaries evaluate and analyze the insurer's historical losses and offer reinsurance agreement and proposal accordingly. Therefore, the proposed reinsurance structure is not necessarily the insurer's optimal arrangement. In this thesis, excess of loss reinsurance optimization models are developed in order to enable insurers to utilize user-friendly and efficient tools to evaluate the optimal reinsurance arrangement depending on financial requirements, and to gain better value of their reinsurance contracts. The models are developed to define the insurer's optimal reinsurance retention and ceding limits for two objectives; minimizing insurer's retention variance and maximizing insurer's return on capital. The model maximizing the return on capital resulted in more realistic optimization solutions of retention limits. A sensitivity analysis to evaluate the impact of the model's parameters on the return on capital was also conducted, and it was concluded that the impact of the insurer's retention limit on the return on capital was significantly small. Moreover, the defined capital and gross premium safety loading had a major impact on the behavior of the return on capital.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
A Decision Tool for Selecting a Sustainable Learning Technology Intervention
No full textEducation is a basic human right. In pursuit of this right, governments in developing countries and their donors often invest scarce resources in educational initiatives that are sometimes not sustainable. This paper addresses the problem of selecting a sustainable learning technology intervention (LTI) for a typical developing country. By solving this problem, more sustainable LTIs can be selected for implementation; this will in turn improve the efficiency with which limited resources are utilised, thereby allowing greater access to education for all. The paper introduces a unique decision framework for project selection by combining “soft” and “hard” decision analysis techniques. The selection problem is modelled as a multi-criteria decision-making (MCDM) problem and a combination of the Future Search Conference technique and the Analytic Network Process (ANP) is used to develop a decision tool for selecting the most sustainable LTI for a developing country. Our analysis revealed that of the nine LTIs considered, school on wheels was the most sustainable LTI in the collective opinion of all the experts involved in this study