Synthesis of Two Monomers for Proton Exchange Membrane Fuel Cells (PEMFCs)

The overall goal of this research is to synthesize two different monomers for proton exchange membrane (PEM) Fuel Cells. Such monomers are proposed to be polymerized to improve the efficiency and compatibility of electrodes and electrolytes in PEM fuel cells. The first target is to synthesize 4-diazonium-3-fluoro PFSI zwitterionic monomer. Three steps were carried out in the lab. First one was the ammonolysis of 3-fluoro-4-nitrobenzenesulfonyl chloride. Second reaction was the bromination of Nafion monomer. The next coupling reaction, between brominated Nafion monomer and the 3-fluoro-4-nitrobenzenesulfonamide, was failed. The obstacles involve the harsh reaction condition and troublesome purification procedure. The second target is to synthesize 5-nitro-1, 3-benzenedisulfonamide. According to the literature, this synthesis was also designed as three steps: 1)nitration of sodium 1, 3-benzenedisulfonate salt; 2)chlorination of sodium 5-nitro-1, 3-benzenedisulfonate salt; and 3)ammonolysis of 5- nitro-1, 3- benzenedisulfonyl chloride. This monomer is expected to be copolymerized for membrane electrolyte in PEM fuel cells

Design Enhancement of Forced Circulation Solar Water Heater for Residential Buildings in Saudi Arabia

This study presents a proposed configuration of an innovative residential Solar Water Heater (SWH) system that will meet the hot water requirement and achieve a lower payback period in Saudi Arabia. Different SWH configurations were evaluated in terms of collector type, circulation method, heat exchanging mechanism and hot water storage. Also; the effect of SWH variable parameters on its thermal performance were determined. The variable parameters included collector tilt and orientation angles, albedo ratio, circulation flow rate, tank size, heat exchanger effectiveness and customer hot water supply temperature. The study covered five different cities, which represent different climate conditions. Proper optimization of SWH system configuration resulted in 30% reduction in the system payback period, which is about 4.3 years. Better economic figures can be expected for the installation of SWH systems in commercial and industrial sectors. Keywords: Solar water heating, System Advisor Model, SAM, Saudi Arab DOI: 10.7176/JETP/11-4-02 Publication date:July 31st 202

Electrohydrodynamic Driven Airflows for Microelectronics Thermal Management

The increasing demand for effective and compact thermal solutions for the next generation of thin and high-power density consumer electronics is challenging the capability of miniature mechanical systems to meet the required cooling performance. Due to their attractive and unique advantages with no moving parts, design flexibility, small-scale structure, low height profile, silent operation, and effective flow generation, electrohydrodynamic (EHD) air movers are well positioned to become a key emerging cooling technology as alternative to conventional rotary fans. In its general objective, this thesis aims to investigate the benefits and highlight the features of EHD air movers as a thermal management cooling solution in advanced and small-scale microelectronics, supporting all previous efforts in this direction. Due to the strong influence of the geometric parameters of EHD devices on the corona discharge process and the resulting EHD flow, numerical modelling represents a powerful tool to design and optimize EHD devices, especially of complex and small-scale structures, where the capability of experimental investigations is limited or challenging. This study presents an accurate and validated numerical method to solve the coupled equations of electrostatics, charge transport and fluid flow for the two-dimensional (2D) modelling of EHD airflow induced through a wire-to-plane/grid channel configuration, and is the first to develop a three-dimensional model (3D) that couples the EHD flows with conjugate heat transfer modelling. Based on thermal management requirements and from a design perspective, a comprehensive investigation and analysis into the influence of geometric parameters on the efficiency of EHD wire-to-grid blowers is performed and optimal configurations are proposed for a range of heights from 9 to 15 mm. Results reveal that using fine emitter wires is more efficient than thicker ones, and the grounded electrode locations affect significantly the electric field distribution and the blower efficiency. It is also found that using the grid as a further collector increases the blower performance, with higher flow production, lower operating voltage and reduced blower size. Further numerical developments are devoted to optimize the configuration of miniature wire-to-plane EHD blowers for heights up to 10 mm, which is the most preferred geometry for integration in the cooling systems of thin electronic applications. For ranges of fixed operating power and voltage, the efficient optimized electrode gaps are predicted and defined by simple expressions. The influence of channel sidewall on the EHD flow rate and velocity profile are investigated and the results show that the 2D modelling is valid to effectively predict flow rates produced by wide and short EHD blowers compared to that obtained by 3D simulations. A combined EHD air blower that enables a reduction in the level of applied voltage and a control of flow production is developed. Performance comparisons against commercial rotary blowers demonstrate that the optimized miniature EHD blowers are more competitive for cooling miniaturized and extended heated surfaces based on blower size, flow rate with uniform velocity profile, and power consumption. A novel design of an EHD system integrated with compact heat sinks is presented as a thermal management cooling solution for advanced and thin consumer applications. Results of a parametric study demonstrate that the EHD system offers flexible structure design with the ability to reduce the height and increase the width as required, providing a unique feature to be installed in low-profile laptops. Moreover, compared to traditional cooling systems used in the current standard low power laptops, the proposed EHD system offers promising cooling performance with higher thermal design power (TDP), reduced thermal solution volume and lower height profile

A multi-stages multi-objective assignment for facilities layout design

Al-Ma'amun factory of the General Company for Food Products suffers from inefficient facilities layout of its production departments and warehouses of both types (warehouses of raw materials and warehouses of finished products), which causes a lot of waste of time, resources and effort in the process of transporting raw materials or even individuals, which is leads to an increase in the costs of handling materials and not providing the service in time. Therefore, this study came to solve the problem by constructing a mathematical model based on the method of multi-stage assignment to find the optimal assignment, since the management of the factory has many goals, it was necessary to use an efficient mathematical method which is goal programming. Therefore, a multi-stage multi-objectives assignment method is applied in two stages, the first of which includes the process of transporting raw materials from raw material warehouses to the production departments to carry out the manufacturing process within them, the second stage includes the transfer of finished products from the production department to the final production warehouses. After comparing the results of the proposed layout with the results of the current layout of the factory is achieved an optimum layout of the factory because of it reduced the total traveled distance by (%25) per day, it also reduced the overall time spent by (25.5%) and reduced the total volume of spent fuel by (30.7%) per day for the new layout

Challenges Hindering a Supportive Culture of Dialogue in Saudi Arabia

This study identified challenges hindering high school administration to establish a supportive culture of dialogue within the school. A questionnaire was subsequently designed, and its validity and reliability were verified. The questionnaire was then applied to a randomly selected sample of high school principals (N=39) and teachers (N=115) in Riyadh, Saudi Arabia. The researchers used various statistical methods appropriate for analyzing the collected data. Among the key findings of the study include: (1) administration of Riyadh high schools support building a supportive organizational culture of dialogue; and (2) the main challenges for them in establishing a supportive culture of dialogue were related to Organizational, Physical and Human difficulties. The study, therefore, recommended providing guidelines and assistance for creating a supportive culture of dialogue, including the provision of necessary training for the administration and teachers to enhance their abilities to build an appropriate culture of dialogue. Keywords: Culture of dialogue, dialogic pedagogy, high schools, organizational culture, Saudi Arabia

Combining depth and intensity images to produce enhanced object detection for use in a robotic colony

Robotic colonies that can communicate with each other and interact with their ambient environments can be utilized for a wide range of research and industrial applications. However amongst the problems that these colonies face is that of the isolating objects within an environment. Robotic colonies that can isolate objects within the environment can not only map that environment in de-tail, but interact with that ambient space. Many object recognition techniques ex-ist, however these are often complex and computationally expensive, leading to overly complex implementations. In this paper a simple model is proposed to isolate objects, these can then be recognize and tagged. The model will be using 2D and 3D perspectives of the perceptual data to produce a probability map of the outline of an object, therefore addressing the defects that exist with 2D and 3D image techniques. Some of the defects that will be addressed are; low level illumination and objects at similar depths. These issues may not be completely solved, however, the model provided will provide results confident enough for use in a robotic colony

HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC DETERMINATION OF GLIMEPIRIDE AND TIMOLOL IN PHARMACEUTICAL FORMULATIONS USING BRITTON -ROBINSON BUFFER IN MOBILE PHASES

Actually, Glimepiride (GLI) and Timolol (TIM) are analysed by several analytical techniques such as HPLC, Uv Vis and electrochemical methods, but in this study these compounds were determined by use Britton-Robinson (B-R) buffer pH3 in mobile phases as a new work. B-R pH3 : Acetonitrile : Water : Methanol (10 : 30 : 10 : 50 % v/v/v/v) and B-R pH3 : Acetonitrile : Methanol (30 : 15 : 55 % v/v/v), were used as mobile phases for chromatographic studies of GLI and TIM respectively. 1´10-3 mol L-1 of GLI and TIM were prepared  by dissolving the suitable weight of analyte in methanol and distilled water respectively, in 50 ml volumetric flask. GLI and TIM were HPLC separated from interferences and analytical determined using C-18 (5µm) with UV detector at 254 nm and 1.00 mL min-1 flow rate by 10 µL injection volume. The calibration curves for GLI and TIM  were studied over the range 1×10-4 to 1×10-3 mol L-1 (correlation coefficient = 0.994, n=6) for GLI and (correlation coefficient = 0.996, n=6) for TIM. The HPLC reproducibility and stability were evaluated for 5×10-4 mol L-1 of GLI and TIM , yielded good results for ten HPLC measurements with relative standard deviations RSD% were 0.43 and 1.1%, and good stability observed. The developed HPLC was applied to determine of GLI and TIM in pharmaceutical formulations with mean recoveries 103% ±0.71 and 99% ±1.0, respectively.  

Influence of poultry composted manure on soil organic carbon and selected soil properties under Tomato cultivation

Soil quality improvements provide an environment for plant nutrient uptake that impacts the development and yield of the crop. Thus, this study evaluated the effect of applied poultry composted organic manure (PCOM) on selected soil physical attributes and soil organic carbon content (SOC) under two tomatoes (UC82B and BESKE) varieties planted in succession. Three rates 0, 10 and 20 t ha-1 of compost were applied to two tomato varieties. The treatments were arranged in a randomized complete block design (split-plot layout). The soil physical parameters considered are - bulk density, aggregate stability, total porosity and SOC. It was observed that application of PCOM increased SOC, total porosity, aggregate stability and decreased the bulk density in the cropped tomato area. The SOC was highest in 10 t ha-1 of PCOM. Application of 10 t ha-1 compost is adequate to improve carbon content and soil physical properties for a fragile soil

XFix: An Automated Tool for the Repair of Layout Cross Browser Issues

Differences in the rendering of a website across different browsers can cause inconsistencies in its appearance and usability, resulting in Layout Cross Browser Issues (XBIs). Such XBIs can negatively impact the functionality of a website as well as users’ impressions of its trustworthiness and reliability. Existing techniques can only detect XBIs, and therefore require developers to manually perform the labor intensive task of repair. In this demo paper we introduce our tool, XFix, that automatically repairs layout XBIs in web applications. To the best of our knowledge, XFix is the first automated technique for generating XBI repairs