454 research outputs found

    A case study of an intervention program for students with dyslexia in a primary school in the UAE

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    The study aims to investigate the impact of an iPad programme on the performance of students with dyslexia on reading, writing and spelling skills in two classes of a public primary school in Al -Ain, UAE. The study follows a mixed method approach (questionnaire; face-to-face interviews; pre-posttests). Twenty (20) 3rd graders male students with dyslexia, attending English as a Foreign Language (EFL) classes were the participants of the study. Students’ performance on spelling, reading and writing skills were tested after instructed through an iPad intervention programme with multisensory applications. The experimental group’s performance (10 students with dyslexia) was compared to the control group’s (10 students with dyslexia) instructed through traditional, non-computer-based, methods. A pre-assessment test was conducted for evaluating the reading, spelling and writing skills of both groups of students prior to the intervention. After eight (8) weeks, both groups were involved in post-tests for evaluating their performance on reading, spelling and writing skills. The study found that the students’ with dyslexia skills were improved after the iPad intervention programme as opposed to the students instructed through mainstream methods. Interviews with the parents and the teachers corroborated the results of the post-tests but also validated the usefulness and effectiveness of the intervention programme for the students’ academic improvement

    Graphene-Supported Metal Nanoparticles For Applications in Heterogeneous Catalysis

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    Due to its unique properties and high surface area, Graphene has become a good candidate as an effective solid support for metal catalysts. The Nobel Prize in Physics for 2010 was awarded to Andre Geim and Konstantin Novoselov for groundbreaking experiments regarding the two-dimensional material graphene . Microwave-assisted synthesis of various metallic nanostructured materials was investigated for CO oxidation applications. These metallic nanostructured materials were used to convert CO to CO2 as an effective approach for carbon monoxide elimination due to its harmful effect on health and environment. In particular, this dissertation is focusing on palladium as a transition metal that has a unique ability to activate various organic compounds to form new bonds. The prepared graphene-supported metallic nanostructured materials were successfully used to investigate Suzuki cross-coupling reaction as an important reaction in the field of pharmaceutical applications. In this research, nanostructured materials were used as solid support catalysts which showed remarkable improvements in the aspects of size, surface structure, catalytic selectivity, shape and recyclability. The nano porous structure and superparamagnetic behavior of (Fe3O4) nano particles that were used as an effective ingredient in graphene-supported palladium catalyst improved the catalytic activity and the catalyst recyclability simply by using an external magnetic field. This research has been divided into two main categories; the first category is to investigate other metal oxides as a solid support for palladium to be used in CO oxidation catalysis. The second category will focus on improving of solid support systems of palladium – magnetite catalyst to increase recyclability. The final stage of this investigation will study the use of these solid supported metal catalysts in continuous heterogeneous processes under flow reaction conditions. The structural, morphological and physical properties of graphene-based nanocomposites described herein were studied using standard characterization tools such as TEM, SEM, X-ray diffraction, XPS and Raman spectroscopy

    The Catalytic Activity Of Copper Oxide Nanoparticles Towards Carbon Monoxide Oxidation Catalysis: Microwave – Assisted Synthesis Approach

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    In this research, we report a simple, versatile, and reproducible method for the synthesis of copper oxide nanoparticles via microwave assisted synthesis approach. The important advantage of this catalyst is due to its important role not only in the low temperature oxidation of CO but also in potential applications in pharmaceutical and fine chemical synthesis. The results reveal that the copper oxide catalyst has particularly a remarkable high activity for CO oxidation catalysis as it was found that copper oxide (CuO) catalyst has 100% conversion of carbon monoxide into carbon dioxide at 175 oC. This also could be attributed to the high degree of dispersion of the copper oxide nanoparticles with a particle size of 25-35 nm. Those nanoparticles were characterized by various spectroscopic techniques including; X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM)

    Laser Vaporization And Controlled Condensation (LVCC) Of Graphene Supported Pd/Fe3O4 Nanoparticles As An Efficient Magnetic Catalysts For Suzuki Cross – Coupling

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    Herein, a reproducible, reliable, and efficient method was reported for the synthesis of palladium nanoparticles dispersed on a composite of Fe3O4 and graphene (Pd-Fe3O4/G) as a highly efficient active catalyst for being used in Suzuki cross–coupling reactions. Graphene supported Pd/Fe3O4 nanoparticles (Pd-Fe3O4/G) exhibit a remarkable catalytic performance towards Suzuki coupling reactions. Moreover, the prepared catalyst could be recycled for up to three times with high catalytic activity. The catalyst was prepared using LVCC synthesis; the prepared catalyst is highly magnetic which provides a platform to facilitate the separation process of the catalyst through applying an external magnetic field using a magnet. This adopted approach has several advantages including recyclability, mild reaction conditions, and reproducibility. The high catalytic activity is due to the catalyst-support strong interaction. Moreover, the defect sites found on reduced GO nanosheets act as nucleation centers providing a platform to anchor Pd and Fe3O4 nanoparticles and hence avoid the potential agglomeration and subsequently the anticipated decrease in the catalyst catalytic activity as a direct impact for this unfavorable agglomeration

    Electrohydrodynamic Stability of Self-gravitating Fluid Cylinder

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    Electrohydrodynamic Stability consists of a fluid cylinder with self-gravitation A self-gravitating tenuous medium surrounds it. that is permeated by a transversely variable electric field while being affected by self-gravitating forces, Capillary, and Electrical Forces is covered across all axisymmetric and (non)axisymmetric perturbation types. The problem is solved and all individual solutions are excluded. The model stabilizes as a result of continuous Electric field stability in all perturbation modes. In a narrow area of the axisymmetric perturbation. It has been established that self-gravitating and capillary forces have a destabilizing effect. However, the present model instability is improved and modified by self-gravitating and capillary forces stabilizing effects in all large axisymmetric fields and (non)axisymmetric domains

    Polyvinylpyrrolidone - Reduced Graphene Oxide - Pd Nanoparticles as an Efficient Nanocomposite for Catalysis Applications in Cross-Coupling Reactions

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    This paper reported a scientific approach adopting microwave-assisted synthesis as a synthetic route for preparing highly active palladium nanoparticles stabilized by polyvinylpyrrolidone (Pd/PVP) and supported on reduced Graphene oxide (rGO) as a highly active catalyst used for Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (6500) and turnover frequency of 78000 h-1. Pd/PVP nanoparticles supported on reduced Graphene oxide nanosheets (Pd-PVP/rGO) showed an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction of palladium and in the presence of Gaphene oxide (GO) nanosheets using ethylene glycol as a solvent and also as a strong reducing agent. The highly active and recyclable catalyst has so many advantages including the use of mild reaction conditions, short reaction times in an environmentally benign solvent system. Moreover, the prepared catalyst could be recycled for up to five times with nearly the same high catalytic activity. Furthermore, the high catalytic activity and recyclability of the prepared catalyst are due to the strong catalyst-support interaction. The defect sites in the reduced Graphene oxide (rGO) act as nucleation centers that enable anchoring of both Pd/PVP nanoparticles and hence, minimize the possibility of agglomeration which leads to a severe decrease in the catalytic activity.

    Optimization Of The Catalytic Performance Of Pd/Fe 3 O 4 Nanoparticles Prepared Via Microwave-assisted Synthesis For Pharmaceutical And Catalysis Applications

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    Microwave assisted synthesis technique was used to prepare palladium supported on iron oxide nanoparticles. The advantage of using microwave irradiation as a synthetic tool is due to its unique features as a one step, simple, versatile, and rapid process. The reactants are added simply at room temperature without using high-temperature injection. Hydrazine hydrate was added by the following ratios (0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1, 1.6, and 3) ml to the different prepared samples at room temperature in order to investigate its effect on the catalytic performance of the prepared catalysts. The prepared catalyst could be used as an ideal candidate not only for pharmaceutical industry through cross-coupling reactions but also for low temperature oxidation catalysis of carbon monoxide and pharmaceutical applications as well. The experimental results showed that Pd/Fe3O4 catalyst has a remarkable catalytic activity for carbon monoxide oxidation catalysis due to the strong interaction between palladium and iron oxide nanoparticles. This may be due to the small particle size (7-14 nm) and concentration ratio of the Pd nanoparticles dispersed on the surface of magnetite (Fe3O4). Those nanoparticles were characterized by various spectroscopic techniques including; X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Vibrating Sample Magnetometer (VSM) and transmission electron microscopy (TEM)

    A Comprehensive Review on Hybridization in Sustainable Desalination Systems

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    The contemporary era underscores the paramount significance of the water sector, largely due to dwindling resources and the exponential growth of the global population. Consequently, there is a pressing need to emphasis the vital role of desalination processes in addressing these challenges. In recent times, nations worldwide have shifted their focus towards optimizing treatment facilities. This optimization is pursued through the enhancement of plant efficiency and the amalgamation of diverse desalination technologies. The latter strategy has demonstrated its efficacy in augmenting on-ground productivity. Within this context, we embark on an exploration of the world\u27s foremost desalination facilities, delving into their production capacities and their hybridization status. Furthermore, we delve into the pivotal dimension of integrating renewable energy sources into these processes, acknowledging the substantial energy demands that desalination inherently entails. It is evident that countries in the Middle East have showcased a noteworthy inclination towards hybridization endeavors, which have yielded substantial improvements in station productivity. Notably, the RO-MSF hybrid system has emerged as a highly reliable choice among the various hybridization schemes employed in operational plants. The Middle East, in particular, has substantially bolstered its presence in the global landscape of operational hybrid plants, amassing a staggering total production capacity exceeding 17 million cubic meters per day. This attests to the region\u27s remarkable commitment to securing sustainable water resources through innovative desalination approaches

    Green Synthesis Of Copper Oxide Nanoparticles In Aqueous Medium As A Potential Efficient Catalyst For Catalysis Applications

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    In this research, we have developed a reliable green method for the synthesis of copper oxide nanoparticles as a potential efficient catalyst for several catalysis applications. In our experimental approach, microwave-assisted synthesis technique was used in order to perform chemical reduction of copper salt using hydrazine hydrate as a strong reducing agent. The prepared catalyst was characterized using various techniques showing the formation of well dispersed copper oxide nanoparticles. The synthesized Copper oxide catalyst shows many advantages including the use of environmentally benign solvent systems, green synthetic approach, and mild reaction conditions

    Gravitational Stability of Compressible Thermal Fluid Layer Under Magnetic Viscosity

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