United Arab Emirates University
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GENERATING SYNTHETIC SATELLITE IMAGES OF MARS DUST STORMS BASED ON RADIATIVE TRANSFER MODELS, AS A FOLLOW-ON APPLICATION OF MARSWRF DUST CYCLE SIMULATIONS
Get PDFDust is a fundamental component of the Martian atmosphere; it plays a vital role in the planet\u27s climate system and atmospheric variability. For these reasons, it is considered one of the essential keys to understanding the Martian atmosphere\u27s behavior. The dust events on Mars range from local/regional dust storms that occur every Martian year to global dust storms that have only been observed, on average, once every 3-4 Martian years. The large regional and global dust storms have strong thermal and dynamic effects on the atmosphere. MarsWRF is a Mars version of the terrestrial numerical weather and climate model WRF (Weather Research and Forecasting Model) and part of the PlanetWRF models for planetary atmosphere research. This project aims to convert MarsWRF output data into synthetic satellite images of Mars dust storms of different sizes by using the radiative transfer model DISORT. The imagery is generated by passing selected variables from the MarsWRF output through the DISORT model, which is used to compute the top-of-the-atmosphere reflectance for a given band. The main results are synthetic satellite images plotted in 670 nm with a grid resolution of 2°× 2° of different dust events during one year of the MarsWRF model run. The obtained results of this project are consistent with the real cases of satellite images of Mars dust storms
ELECTROCHEMICAL INVESTIGATION OF COPPERZIRCONIUM BASED METALLIC GLASS Cu₅₁Zr₃₀Hf₁₄Ag₅
Get PDFThis thesis is concerned with the electrochemical investigation of the copper-zirconium
based metallic glass Cu51Zr30Hf14Ag5. Studying the corrosion behavior of the novel melt-spun metallic glass ribbons contributes to further research on the possibility of building future bio-implants. The objectives of this thesis are to synthesize the metallic glass ribbons which are free from cytotoxic elements using melt spinning technique, verify their amorphous nature using X-ray diffraction method, study the corrosion behavior using Potentiodynamic polarization and Electrochemical Impedance Spectroscopy in different acidic, neutral and basic solutions, and finally examine the surface morphology of the tested samples using scanning electron microscopy that is coupled with energy dispersive spectroscopy. The results of the experiments done in this thesis show that the addition of Ag and Hf in the novel Cu51Zr30Hf14Ag5 metallic glass generally results in a better corrosion resistance than the previously studied Cu46Zr40Ti8.5Al5.5in the tested solutions, where the novel metallic glass shows a corrosion resistance in the different solutions with the order neutral \u3e alkaline \u3e acidic. The results will contribute to further studies concerned about the potential applications of the novel metallic glass, in addition to its potential use in bio-implants. Furthermore, the study will contribute to introducing more metallic glasses with new compositions tailored for specific potential applications. The Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy results were supported by the scanning electron microscopy and the spectral mapping done using the energy dispersive spectroscopy
THE ASSOCIATION BETWEEM TOTAL AND TYPES OF DIETARY PROTEIN INTAKE AND PREVELENCE OF IMPAIRED FASTING GLUCOSE AND TYPE 2 DIABETES
Get PDFIntroduction: People with impaired fasting glues (IFG) and type type 2 diabetes (T2DM) need to modify their dietary composition. This could assist in the management and prevention of the disease. However, the role played by the composition of specific dietary macronutrients on the risk of IFG &T2D remains uncertain. This study sought to examine the association between total and type of dietary protein consumption with prevalence of type 2 diabetes mellitus (T2D) and impaired fasting glucose (IFG). Examining the dietary assessment in nutritional epidemiology provided the data needed to assess the relationship between the variables. Aims: To investigate the association between total intake and types (animal vs protein) of dietary protein intake and prevalence of IFG & T2D in adults. Method: Data from the Hellenic National Nutrition (HNNHS), a representative nutrition and health survey in Greece was used for this study. Data on all adults enrolled in this study (n=3773) was used to assess the association of T2D prevalence, while a subsample of this population (n=990), to which measurements were performed, was used to assess measured fasting blood glucose levels, in relation to dietary intake. Sociodemographic and lifestyle data were collected using Computer Assisted Personal Interview (CAPI). Information from a validated food propensity Questionnaire (FPQ) and two interviewer-administered 24hr recalls (24hr) was used to assess total, plant and protein intake in relation to IFG & T2D prevalence. Multiple logistic regression models were used to examine probability of disease by type of protein and sensitivity measures were applied.Results: The male odds ratio of having high blood glucose levels was 0.43 times higher compared to females (P\u3c0.001). The results showed that the adjusted odds ratio of having high blood glucose level was 1.8 times higher in individuals who had BMI equal to or more than 25 kg/m2 compared with those below 25 kg/m2 (p\u3c0.001). Moreover, the adjusted odds ratio of elevated blood glucose levels increased by 5.8% (p\u3c0.001) among individuals as their age increased by 1 year. Vegetable protein intake increased per kcal, increased the likelihood of having high blood glucose levels increased by 10% (p=0.02). Following a Mediterranean diet was linked to a lower risk of having impaired fasting glucose levels by 22%(p=0.03). Conclusions: There was no significant difference in total protein intake between the three groups. In light of this, the study shows that total protein consumption may not be a distinguishing factor in terms of glucose status. Therefore, other factors should be examined in the future
INVESTIGATING BIM APPLICATIONS IN REDUCING CO2 EMISSIONS IN THE BUILT ENVIRONMENT
Get PDFLarge amounts of CO2 are released into the atmosphere throughout the life cycle of a building starting from the production of materials and products, in the construction phase of the building itself, in the site setting, the renovations, the later rehabilitation, and up to the final demolition. Hence, this thesis aims to investigate the potential of using Building Information Modeling (BIM) in making informed decisions that can help in reducing CO2 emissions in the life cycle of built environment projects. This study has used a mixed method approach that include literature review, a case study and semistructured interviews. The literature investigates the related various applications of BIM, its barriers, challenges, and underlying benefits, as well as its ability to reduce CO2 emissions through smart design decisions. Also, a case study is used to validate BIM’s ability to calculate a building’s CO2 emissions. Additionally, semi-structured interviews were conducted with construction professionals to capture their viewpoints on the possible contributions of BIM to CO2 emission reduction in the construction sector. The research outcomes are presented through data analysis from the BIM model, supported by insights obtained by interviews. This integrated approach combines theoretical insights from the literature with practical applications and specialist feedback to provide a thorough understanding of BIM\u27s essential contribution in tackling the need of CO2 emission reduction in the construction sector. This research is anticipated to act as a catalyst for sustainable decision-making in the construction sector
THERMO-KINETIC PARAMETERS GOVERNING DECOMPOSITION OF AMINO ACIDS: A COMPUTATIONAL STUDY
Get PDFAmino acid model compounds are important nitrogenated species that in various categories of biomass. These compounds exhibit unique fragmentation pathways because of their adjacent amino and hydroxyl groups. Comprehending the decomposition chemistry of amino acids is essential to reduce harmful nitrogen emissions during biomass thermal treatment. This research reports the kinetic and thermodynamic properties of amino acids, and sulfur-containing amino acid, based on accurate density functional theory calculations coupled with kinetic modelling. The first part of the thesis provides comprehensive thermochemical parameters for the complete set of amino acids in the gas phase. The optimized geometries of amino acid compounds display both similarities and notable variations, which are contingent upon the individual amino acid and its surrounding atomic environment. Across most amino acids, the backbone, which includes the amino group (-NH2), the carboxyl group (-COOH), and the α-carbon, generally maintains a consistent geometry. Isodesmic reactions were utilized to compute standard enthalpies of formation of amino acids in the gas phase; ΔfHo 298. Bond dissociation enthalpies (BDHs) for all plausible H-X (X = C, O, N, and S) bond fissions were computed for the complete set of amino acids. It is found that the fission of α C-H bonds in these compounds systematically entails lower BDH value in reference to other bonds. Internal rotations in these compounds were treated as hindered rotors in computations of standard entropies and heat capacities. Comparison of ΔfHo 298 values with limited available literature values disclose a reasonable agreement. The second part of the thesis ensues to provide a comprehensive data set of kinetic parameters for H abstraction by important radicals from all plausible abstractable sites in the complete set of amino acids. Considered radicals include H, CH3, NH2, OH, HO2, and HS; the most prevailing radicals under pyrolytic and oxidative conditions. Computed Arrhenius parameters and plotted branching ratios portray a similar trend in regard to preference for abstraction from the α C-H sites by the six radicals. For this reason, we have computed kinetic parameters for H subtraction from the α C-H in the other amino acids (glycine, leucine, proline, phenylalanine, tryptophan, tyrosine, serine, threonine and asparagine). The study also examines the individual effects of different substituents (COOH, NH2, HS, and CH2) and uncovers significant insights. Notably, the presence of the COOH group introduces polar effects that counterintuitively deactivate the thermodynamically favoured α-abstraction pathway. The last part of the thesis explores in detail governing decomposition mechanisms of the Serine (Ser) amino Thermo-kinetic parameters are computed for a large set of reactions and involved species in both gas and condensed media. Initial decomposition of Ser is solely controlled by a dehydration channel that leads to the formation of a dehydroalanine molecule. Decarboxylation and deamination routes are likely to be of a negligible importance. The Fall-off window of the dehydration channel extends till the atmospheric pressure. Bimolecular reactions between two Ser compounds simulate the widely discussed cross-linking reactions that prevail in the condensed medium. It is demonstrated that formation of the key experimentally observed products (NH3, CO2, and CO) may originate from direct bond fissions in the melted phase of Ser prior to evaporation. A constructed kinetic model (with 24 reactions) accounts for the primary steps in the degradation of Ser molecule in the gas phase. Overall, Outcomes presented herein shall provide an atomic-based insight into the very complex nitrogen transformation chemistry pertinent to amino acids in strategic applications pertinent to thermal as well as biological domains
MODULATION OF CHRONIC ALLERGIC CONTACT DERMATITIS THROUGH B CELLS REPROGRAMMING
Get PDFAllergic contact dermatitis (ACD) is a common inflammatory disease caused by contact with an allergen and is a T-cell mediated type IV hypersensitivity reaction. Short chain fatty acids (SCFAs) showed the ability to modulate immune cells in case of inflammation. Pentanoate is one of the abundant SCFA that showed therapeutic ability by inducing IL-10 secretion in lymphocytes. IL-10 producing regulatory B cells have shown to decrease different inflammatory responses; however, overall role of B cells in ACD is not well studied. This project aims to explore the role of B cells during chronic ACD and their modulation with the SCFA pentanoate. A chronic CHS mouse model was established in vivo by the hapten TNCB and studied for allergic inflammatory responses by measuring ear swelling, cellular analysis and histology. The B and T cell subsets were analyzed by flow cytometry. The data showed a significance increase in tissue resident memory-like T cell subsets along with the central memory T cell subset and the total CD4+ T cells. Simultaneously, a significant decrease in regulatory T cell subsets, regulatory B cells and naïve T cells was observed. In vitro stimulation of B cells with pentanoate showed a significant increase in IL-10 and STAT3 gene expression which confirmed the modulation of B cells into IL-10 producing regulatory B cells. After the adoptive transfer of these stimulated B cells followed by ACD induction showed a significant decrease in the inflammatory response of the acute CHS response and a mild effect on chronic CHS response. Our data showed that CHS responses can be modulated through pentanoate. Our research highlights the role of B cells in ACD and the therapeutic potential of the pentanoate
MEASURING JUPITER’S WIND FROM CASSINI SPACECRAFT OBSERVATIONS
Get PDFThe Jupiter’s atmosphere has remarkable features like Great Red Spot, and strong dynamic events takes place on its atmosphere for hundreds of years. We have a set 280 images of Cassini spacecraft December 2000 of southern and northern hemisphere of Jupiter planet which were taken by four distinct filters with a wide range of wavelengths extending from 455 nm to 889 nm to study the Great Red Spot dynamics and measure the velocity fields using Correlation Imaging Velocimetry technique. To understand the mechanism of energy transfer between eddies and jets which governs the Jupiter’s atmosphere for a long time, it requires to analyze the interplay between zonal winds and eddies of its atmosphere. This study uses to plot latitudinal profiles versus ̅̅`̅̅̅` and d̅/dy to find a positive correlation which implies that the energy mechanism takes place from eddies to zonal flow
EXPERIMENTAL STUDY OF CENTRAL AND SIDE JET WITH AND WITHOUT CHEVRON NOZZLE EXIT ON GAS TURBINE LEADING EDGE JET IMPINGEMENT COOLING
Get PDFThis thesis presents a comprehensive investigation into the application of jet impingement cooling on turbines blade leading edge. Gas turbines are extensively utilized in power generation and aerospace industries, where efficient cooling techniques are crucial to enhance the performance and lifespan of turbine blades. The leading edge of a turbine blade is particularly vulnerable to high-temperature exposure and thermal stresses, making it an essential area for effective cooling strategies. Jet impingement cooling is one of the most effective cooling techniques mostly used in the leading edge of rotating and stationary blades. This study aims to explore the performance of jet impingement cooling by examining how various parameters affect its efficiency. The effects of Reynolds numbers and Rotation number on the overall heat transfer performance are studied. The experimental study is performed on central and side jets targeting a cylindrical surface. Reynolds number ranges from 5000 to 11000, and rotating speed is between 0 and 200 rotation per minute (rpm). Two jet designs (chevron/normal) are considered. A high-speed camera with liquid crystal sheets are used for temperature mapping and analysis. Results show that side jets cases have a higher average Nusselt number compared to central jets. side non-chevron configuration provided the best overall heat transfer performance. Chevron jets produced a higher Average Nusselt number for central jets. However, for side jets non-chevron design produced better results. For central jets, Increasing the rpm slightly has increased the average Nusselt number. For side jets, Increasing the rpm significantly has increased the average Nusselt number. At low rpm, the average Nusselt number has dramatically increased by increasing Reynolds numbers. For high rpm, the average Nusselt number has a slight increase for central jets configuration. Yet, for side jet configurations the average Nusselt number decreases slightly by increasing Reynolds number. At low rpm, all configurations produced similar Average Nusselt number for the same Reynolds number. Experimental results help us understand the effects of different parameters and configurations on jet impingement cooling. The aim is to optimize the heat removal process to obtain the best thermal efficiency of the gas turbine. Results are used to understand how combining chevron designed jets with side and central configurations affect the overall heat transfer performance and the overall average Nusselt number
DESIGN AND FEM MODELLING OF MEMS CAPACITIVE ACCELEROMETER AND GYROSCOPE FOR QUADCOPTER/UAV APPLICATIONS
Get PDFThis study presents the design, simulation, and analysis of Micro Electromechanical Systems (MEMS) sensors, constituting the principal components of MEMS-based Inertial Measurement Units (IMUs). The main objective of the study is to design, simulate and analyze 3-axis capacitive accelerometer and 3-axis gyroscope. The MEMS-based capacitive accelerometers and gyroscope are analyzed using Ansys Workbench. Modal, Static Structural and harmonic analysis are used to obtain resonant frequencies, deformation/stress and profile of amplitude over a wide range of frequencies. Mechanical sensitivity analysis of the designed accelerometer and gyroscope is performed using the Finite Element Method (FEM). Analytical Equations are developed to calculate mechanical sensitivity and capacitance sensitivity and a comparison is performed between the FEM analysis and the analytical calculations. A simulation study is performed in MATLAB/Simulink for the designed MEMS accelerometer and gyroscope to analyze the performance of the designed accelerometer and gyroscope sensors. Kalman filter is employed in the Simulink model to investigate the effects of measurement noise. The main findings of the study demonstrated that under typical loads of 10 g accelerations and 34.9 rad/s angular rate, the structures of the two sensors can withstand such loading and exhibit little deformations. The IMU sensor can be used in various applications in unmanned aerial vehicles (UAVs) and drones
THE ROLE OF SCHOOL–COMMUNITY COLLABORATION IN THE INCLUSIVE EDUCATION PRACTICES CONCERNING STUDENTS WITH SPECIAL EDUCATIONAL NEEDS IN PUBLIC AND PRIVATE SCHOOLS IN ABU DHABI
Get PDFStrong school-community partnership has been found to play a critical role in the implementation of inclusive education. This dissertation investigates the multifaceted role of school–community collaboration in inclusive education (IE) practices for students with special educational needs (SENs) in Abu Dhabi’s public and private schools in the United Arab Emirates (UAE). Over the past two decades, the UAE government has intensified its efforts to enhance the realm of special education, aiming to improve Students with SEN’s social, cognitive, and academic outcomes. National attention to these practices aligns with the broader aspiration to establish an inclusive and equitable society. In UAE, there is a dearth of research regarding teachers\u27 perceptions of school-community collaboration for students with SEN in inclusive settings. To address the research gap, this study sought to explore the intricacies of school–community collaboration in fostering inclusive education practices. In addition, this study aims to identify the factors that enable or hinder such collaboration. Employing a sequential explanatory mixed-methods design, this study was comprised of filling out online survey questionnaires based on the globally acknowledged SEND Reflection Framework, which is a prominent tool originating from the UK. It offers an inclusive perspective in catering to the educational needs of students with special educational needs and disabilities, as highlighted by Whole School SEND (2016). In the quantitative phase of this study, a stratified random sampling method was employed to select schools. Accordingly, a total of 161 teachers participated, with 72 from public schools and 89 from private schools, Total number of schools involved was 20 schools, 10 public schools, and 10 private schools. For the qualitative phase, purposive sampling was used to select participants for the focus group discussions and one-on-one interviews. Participants were chosen based on their responses to the SEND reflection framework, categorizing them into high-score responses and low-score responses. As a result, 24 participants participated in the focus group discussions, while 4 school leaders participated in one-on-one interviews. This methodological choice allowed for a more in-depth exploration of the perspectives of those most actively engaged with SEND practices.The analysis of collected data revealed three pivotal findings: (1) the significance of “systems and processes” in facilitating effective family communication, (2) the critical role of a supportive environment for effective professional collaboration, and (3) the importance of professional development (PD), substantiated by a p-value of 0.002, in creating an environment conducive to effective learning.These findings not only contribute to the extant literature on IE and special education but also offer insights into the distinct frameworks of school–community collaboration in Abu Dhabi’s public and private educational systems. The study provides actionable recommendations while highlighting the challenges and opportunities in establishing effective school-community collaboration. This study fills an existing gap by offering an in-depth understanding of teachers\u27 and school leaders\u27 practices of the SEND framework and how it affects the inclusion and school-community collaboration concerning students with SENs in public and private schools of Abu Dhabi. The complexities of fostering collaborative partnerships, thereby contributing to the growing body of knowledge on effective strategies for inclusive education in the region