United Arab Emirates University
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ASSESSING SELF-ESTEEM IN UAE STUDENTS WITH AND WITHOUT SPECIAL NEEDS: PILOT STUDY USING ADAPTED ROSENBERG SCALE
Get PDFSelf-esteem is known to be the way that a person values and perceives him/herself. It is affected by many factors and impacts on the person’s life. The main objective of this study was to investigate possible differences on self-esteem between typical students and those who have been diagnosed with special educational needs. In addition, the study explores teachers’ awareness on the importance of self-esteem on children’s life and their recommendations for improving their students’ self-esteem in UAE schools. The study used a mixed methods design and was conducted in two phases. During the first phase a sample of 40 students was divided into 2 groups, one with typical students (N=20) and another with students with an official diagnosis (N=20) and Rosenberg self-esteem rating scale (Rosenberg, 1965) was used to evaluate the self-esteem levels of the participants. In the second phase, semi-structured interviews with two teachers were conducted. An Independent T-test was performed to assess differences on scores between the two groups and findings from this study indicated that there was a statistically significant difference on self-esteem scores between students with and without special education needs, t = 7.03, p = 0.05. In addition, analyzing the data from teachers’ interviews the study provides important recommendations on improving the self-esteem of students with determination in UAE schools which may result to significant improvement in students’ behavior and academic performance
A PARAMETRIC NUMERICAL ANALYSIS INVESTIGATION TO OPTIMIZE THE PERFORMANCE OF THE RANQUE-HILSCH VORTEX TUBE
Get PDFA vortex tube is a device that separates compressed air into two streams: one with a higher temperature (hot stream) and the other with a lower temperature (cold stream). It is a popular cooling option because it is small, safe, and affordable. The main objective of this thesis is to examine the energy separation performance of RHVT by varying the internal tapering angles of convergent angles (2°, 1.75°, 1.5°, 1.25°, 1°, 0.75°, and 0.5°), straight angles (0°), and divergent angles (0.5°, 1°, 2°, 4°, and 6°), While the cold mass fraction is constant (0.317). Length-to-diameter ratio (Lt/Dt), inlet pressure, and the cold mass fraction were investigated to achieve the highest energy separation of RHVT. This thesis conducts a numerical study on the flow structure in a vortex tube using the shear stress transport k-ω turbulence model with viscous heating. The optimal energy separation occurred at a 1.75° convergent angle, Lt/Dt ratio of 3, the inlet pressure of 600 kPa, and a cold mass fraction of 0.56. The internal flow structure of the vortex tube consists of a forced vortex, transition, and free vortex regions, as shown by the static temperature radial distribution This distribution provides an understanding of the energy separation mechanism of the vortex tube by correlating it with the density gradient along the radial direction. We developed a short tube length-to-diameter ratio of RHVT with higher energy separation rather than the standard RHVT. The simulation results were validated by experimental data obtained from the literature for the same vortex tube parameters
ANALYSIS OF CYCLE 2 SCIENCE TEXTBOOKS FOR REPRESENTATION OF ELEMENTS CONTRIBUTING TO QUALITY SCIENCE TEXTBOOKS AS LEARNING RESOURCES
Get PDFScience textbooks are a valuable resource for both students and teachers. They hold a significant role in students\u27 learning of science. Most science teachers in the United Arab Emirates rely on science textbooks as the foundation for their teaching. However, until now, limited research has been conducted to assess the appropriateness of science textbooks prescribed by the Ministry of Education in the UAE. Therefore, this study aims to evaluate the representation of elements contributing to the suitability of cycle 2 (grades 5 to 8) science textbooks as learning resources as prescribed by the Ministry of Education of the UAE. In this study, a quantitative descriptive content analysis design was employed. These textbooks were analyzed using the Science Textbook Evaluation Framework (STEF). The findings revealed that these textbooks appear to differ in their representation of the various elements of the framework. Based on the framework used in this study, these textbooks may be regarded as inappropriate for the students of UAE. This study presents several implications and offers recommendations for future research
SELECTION OF NATURAL SURFACTANTS FOR POSSIBLE USE IN IMPROVING OIL RECOVERY OF CARBONATE OIL RESERVOIRS
Get PDFMiddle East petroleum industry is currently searching for the most suitable enhanced oil technique to improve the oil recovery from local oil reservoirs. The biggest challenge for the application of enhanced oil recovery (EOR) in the Middle East is the harsh environment (high salinity and temperature). Surfactant (synthetic or natural) is one of the enhanced oil recovery (EOR) major players considered for application in the Middle East. However, synthetic surfactants have several drawbacks, such as being economically unattractive and their high levels of toxicity. This study investigated the possible use of natural surfactant extracted from the leaves of three types of plants, namely Aloe Vera, Tetraena qatarensis, and Soapnut in a harsh carbonate reservoir environment. The efficiency of the extracted surfactants was assessed through various laboratory experiments, including interfacial tension (IFT) measurement, contact angle measurement, emulsion tests, and core flooding experiments. The present study follows the static and dynamic experimental work of the combination of the selected three natural surfactants at different concentrations with formation brine (232,000 ppm), seawater (50,000 ppm), and low salinity water (5000 ppm). Interfacial tension and contact angle measurements were measured to assess the effect of water salinity on interfacial activity and system wettability. Core flooding experiments of the optimum systems with lowest IFT and salinity of 232,000 ppm at high pressure (1100 psia) and temperature above 90°C were also performed to evaluate the selected natural surfactant oil recovery under dynamic conditions. Experimental results show that the Soapnut surfactant solution (18%) and Aloe Vera (10%) made with formation brine reduced the IFT from 25 dyne/cm to 0.9 dyne/cm and 0.5 dyne/cm, respectively. The oil recovery factor by of formation water, Aloe Vera surfactant-FW, and Soapnut surfactant-FW flooding was 15, 93, and 94.1%, respectively. It indicates that the Soapnut natural surfactant at a relatively low concentration is capable of working effectively in a harsh environment and was able to remove almost all the oil in place
THE PUBLIC PROSECUTIONS ROLE IN CLOSING CRIMINAL CASES WITHOUT LITIGATION A STUDY OF THE FEDERAL CRIMINAL PROCEDURES LAW AND SPECIAL CRIMINAL LAWS
Get PDFThe thesis highlights the role of the public prosecution in solving criminal lawsuits without a judicial ruling, by the procedures it takes either by dismissal of action at the evidence collection stage or by issuing a criminal case dismissal order at the initial investigation stage. This can also be done through a penal order in some crimes. Though this latter option gives the public prosecution the jurisdiction to adjudicate on some criminal cases, though this jurisdiction belongs to the bench courts, the justification is that it is limited to some simple felonies to expedite the litigation process and save time, effort, and money. This way the bench courts have more time for grave crimes. Moreover, this saves the defendant’s right to object to the penal order, which prevents it from having the power to close the criminal case. The public prosecution has a role also in solving penal cases through settlement and reconciliation in certain crimes where the legislator deems it fit to close them without a ruling. In the case of settlement, the law has in fact allowed it even after the issuance of a final ruling in penal cases. This entails the suspension of the punishment, and in this case the public prosecution handles this, being the legally competent body that oversees the enforcement of criminal penalties. In terms of settlement, the new Federal Code of Criminal Procedures has introduced the power of the public prosecution to offer settlement, proceed in penal mediation, and endorse the document of the settlement achieved through penal mediation. The legislator has also introduced the way for penal mediation, which is a system that allows the public prosecution to opt to close the penal case without litigation when the defendant accepts the procedure or arrangement presented to them and to their lawyer and the judge or trial court approve the settlement. The thesis has reached some conclusions and recommendations in line with the issue of the study, i.e. defining the scope and limits of the public prosecution powers in closing criminal cases before they reach the competent criminal court, be it through traditional ways or through the new ways introduced in Federal Code of Criminal Procedures
CONSTRUING CHILDREN’S PERCEPTIONS OF IDEAL LEARNING SPACES: HOME VS. SCHOOL
Get PDFLearning is an intrinsic aspect of human experience, predominantly shaped by interactions within the socio-physical environment, including engagements with educators, peers, and the built surroundings. The design and character of these learning spaces influence children\u27s cognitive, perceptual, and motor development while also embodying different pedagogical philosophies. Therefore, designing these spaces to align with educational shifts and enhance learning experiences requires a deep understanding of learner’s needs and perceptions. With the COVID-19 pandemic necessitating a shift to home-learning, there arose a unique opportunity to explore children’s perception of ideal learning spaces as they experienced both home and school settings. [Aims:] This research aimed to identify the physical attributes of ideal learning spaces from children\u27s perceptions and place them within the context of existing learning theories. Using the principles of the personal construct theory and the repertory grid technique, a detailed qualitative approach was adopted. Thirty children aged 8 to 10 were engaged in semi-structured interviews to identify the design-related attributes they associate with ideal learning spaces. The newly developed Integrated Learning Space Framework (ILSF) was then utilised to align these attributes with the spatial implications of various learning theories. The study identified 51 key design-related attributes of an ideal learning space. Key findings highlighted children’s preferences for spacious and versatile environments, with themes of personalization, aesthetic consistency, and functional design emerging prominently. Additionally, there was a strong resonance with humanistic principles in their conceptualizations.Beyond emphasising the impact of the pandemic on children\u27s educational expectations, this research introduces the ILSF, a tool that aligns children\u27s spatial preferences with five learning theories. By linking children’s perceptions with learning theories through the ILSF, this research provides insights for the architectural design of future educational spaces that align with both theoretical foundations and learners\u27 preferences
ELECTRICAL, OPTICAL, AND THERMAL PROPERTIES OF SnSe-BASED MATERIALS WITH HIGH THERMOELECTRIC PERFORMANCES
Get PDFThis thesis conducts a thorough exploration of the characteristics and prospective applications of Tin Selenide (SnSe), a pivotal semiconductor for advancing contemporary electronics and optoelectronics. The investigation mainly focuses on comprehending the alterations in SnSe\u27s properties when doped with elements such as Hafnium, Zinc, Bismuth, Germanium, Sodium, Iodine, and Silicon. 2D-SnSe allotropes, when doped with Hafnium, have exhibited remarkable optical characteristics, especially in the δ-SnSe allotrope, rendering it adaptable for varied optical uses like solar cells and LEDs. Additionally, evaluations of elasticity show improved resilience and augmented in-plane stiffness owing to Hf doping, occasionally reducing ductility. The work uniquely emphasizes the properties of Zinc-doped α-SnSe, revealing semiconductor traits conducive for deep ultraviolet applications and capacitors, primarily due to a reduction in the dielectric constant in monolayer structures. The exploration further delves into the impacts of Silicon-doping on α-SnSe, identifying both diminished thermal conductivity and amplified electronic conductivity. The exploration of this thesis broadens to include the co-doping of SnSe, incorporating combinations like Bismuth and Zinc, Germanium and Zinc, and Sodium and Iodine. Introducing both Bismuth and Zinc to SnSe led to enhancements in electrical conductivity and exhibited elevated mechanical durability, underlining its potent thermoelectric capabilities. In contrast, structures co-doped with Germanium and Zinc showcased stability and heightened thermoelectric efficiency due to their p-type semiconductor properties. SnSe, when amalgamated with Sodium and Iodine, manifested a modified triclinic auxetic formation with a minimized bandgap, showing a high probability for uses in capacitors and solar cells owing to its elevated static dielectric constant and stability. Moreover, the attributes of π-SnSe have been scrutinized, highlighting its capabilities in various photovoltaic and thermoelectric applications due to its distinctive lattice constant and optical bandgap
Effects of Adropin on Metabolic Parameters, Oxidative Stress, and Cell Proliferation in Animal Model of Diabetes Mellitus
Get PDFDiabetes mellitus (DM) is a major health issue that has reached alarming levels, affecting around 537 million of the global adult population. DM is a group of metabolic diseases characterized by hyperglycemia with disturbance in carbohydrate, fat, and protein metabolism. The proposed therapeutic options for DM are different according to their mechanism of action, and peptide therapy is one of these options. Adropin, a peptide hormone involved in energy homeostasis, has shown promising results in the treatment of diabetes by lowering fasting blood glucose, reducing insulin resistance, and minimizing fat storage. Moreover, it has been demonstrated that adropin is engaged in other biological activities such as reducing oxidative stress and inflammation. However, little is known about the ability of adropin to modulate pancreatic peptide secretion in DM. So, the aim of this study was to investigate the role of adropin in controlling glucose levels by enhancing pancreatic peptide secretion in streptozotocin-induced diabetic rats. To achieve our aim, normal and diabetic Wistar rats were treated with adropin (2.1 μg/kg/day) for a period of 10 days. Fasting blood glucose and body weight were measured. Pancreatic tissue samples were collected for histomorphological analysis and blood was collected for oxidative stress assay and peptide analysis. We reported enhancement in glucose utilization, decrease in -cells number as well as reduction in glucagon release in adropin-treated diabetic rats. Furthermore, adropin significantly augmented the secretion of certain endocrine pancreatic hormones including C-peptide, amylin, and Glucagon Like peptide-1 (GLP-1) in rats with DM. Interestingly, adropin significantly increased glutathione reductase expression in the pancreas tissue, in addition to serum total glutathione in the diabetic treated rats compare to diabetic untreated. We found that diabetes induction stimulated cell proliferation in both exocrine and endocrine pancreas, and adropin dramatically attenuated this effect in pancreatic exocrine, but not in the islet of Langerhans. This work will add value to the field of diabetes by providing better understanding of how adropin is involved in maintaining glucose homeostasis and glucagon secretion
SELECTIVE PRODUCTION OF LEVOGLUCOSAN (LG) FROM PYROLYSIS OF DATE PITS AND ITS CATALYTIC TRANSFORMATION INTO TRANSPORTATION FUELS
Get PDFLevoglucosan (LG) or (1,6-anhydro-β-D-glucopyranose) signifies an important sugar derivative that is produced in appreciable quantities from thermochemical and biochemical degradation of biomass. It is often regarded as an important platform chemical for the synthesis of value-added products, most notably styrene and furans. The work in this thesis entails two broad aims; to produce LG from pyrolysis of date pits; and then convert the LG into transportation fuels through a hydrodeoxygenation (HDO) reaction. The particular choice of date pits stems from its local relative abundance as a waste biomass. Aiming to further improve the yield of levoglucosan yields from pyrolysis of date pits, pretreatment methods were carried out via washing the biomass with different concentrations of selected acids (sulfuric acid: 1 M /3M, nitric acid:1M / 3M), also well as with hot water. Chemical and elemental compositions of the five considered samples were thoroughly analyzed and characterized by a wide array of techniques such as Neutral Detergent Fiber (NDF %), ASH content and organic Matter (%) and Mineral Nutrients Profile (ppm). By utilizing Py-GC/MS system, the products distribution from pyrolysis of raw and treated date pits were obtained at a range of temperatures between 300-500 °C . Compared to the raw date pits, pyrolysis of treated date pits by 1 M H2SO4 acid exhibited a dramatic increase in the concentration of levoglucosan due to the profound removal of the various categories of minerals in date pits and increasing the NDF % . Results show that the highest yield of (~ 72%) was attained after pre-treatment with 1 M H2SO4 solution at a temperature 300 °C. A positive correlation prevails between the removal efficiency of alkali/alkaline earth metals (AAEMs) and the yield of LG. The former catalyzes ring opening reaction that results in the destruction of sugar derivatives. On the Other hand, the water pretreatment increases the yield of LG compared to the raw date pits. Outcomes demonstrated herein convey a practical method to enhance the production of commodity chemicals from waste biomass. The second part of the thesis presents a viable gaseous hydrodeoxygenation (HDO) route for Levoglucosan (LG) that leads to the formation of non-oxygenated hydrocarbon cuts that make commercial transportation fuels, namely gasoline, diesel, and jet fuels. The outlined process encompasses HDO of an evaporated stream of dissolved LG over 5% Ni-CeO2 catalysts between 100°C– 500°C. It is found that the load of the aliphatic compounds attains values between 68.1% and 75.3% across the investigated temperature window. Similarly, fractions of aromatic compounds remain within 8.1%–13.9%. Major observed aliphatic compounds include tetradecane, dodecane, octane, and decane. Alkylated benzenes appear in appreciable quantities. Governing HDO’s mechanisms were mapped out by density functional theory (DFT) calculations. Utilizing a 10% load of Ni has slightly reduced the relative area of aliphatic compounds. The combined area of the oxygenated compounds remains less than 10% at all temperatures. This finding entails a profound HDO’s capacity of the deployed catalyst and opens a direct venue for the effective utilization of LG in fuel production. Overall, this research underscores the utilization of lignocellulosic biomass, specifically date pits, as a valuable carbon source in the biorefinery concept
CHEATING DETECTION IN ONLINE EXAMS BASED ON CAPTURED VIDEO USING DEEP LEARNING
Get PDFToday, e-learning has become a reality and a global trend imposed and accelerated by the COVID-19 pandemic. However, there are many risks and challenges related to the credibility of online exams which are of widespread concern to educational institutions around the world. Online exam system continues to gain popularity, particularly during the pandemic, due to the rapid expansion of digitalization and globalization. To protect the integrity of the examination and provide objective and fair results, cheating detection and prevention in examination systems is a must. Therefore, the main objective of this thesis is to develop an effective way of detection of cheating in online exams. In this work, a system to track and prevent attempts to cheat on online exams is developed using artificial intelligence techniques. The suggested solution uses the webcam that is already connected to the computer to record videos of the examinee in real time and afterwards analyze them using different deep learning methods to find best combinations of models for face detection and classification if cheating/not cheating occurred. To evaluate the system, we use a benchmark dataset of exam videos from 24 participants who represented examinees in online exam. An object detection technique is used to detect face appeared in the image and crop the face portion, and then a deep learning based classification model is trained from the images to classify a face as cheating or not cheating. We have proposed an effective combination of data preprocessing, object detection, and classification models to obtain high detection accuracy. We believe that the suggested invigilation methodology can be used in colleges, institutions, and schools to look for and keep an eye on suspicious student behavior. Hopefully, by putting the proposed invigilation method into place, we can aid in eliminating and reducing cheating incidences as it undermines the integrity and fairness of the educational system