A new microcontroller-based MPPT algorithm for photovoltaic applications

In this work, a new and improved microcontroller-based maximum power point tacking (MPPT) algorithm for photovoltaic (PV) applications is proposed and implemented. The algorithm incorporates new ideas for overcoming the challenges associated with rapidly changing insolation levels and the effect of partial shading. It is simple with ( i.e. no complex computations) and can be implemented on commercial micro-controllers. The proposed algorithm enhances the steady-state and dynamic responses by introducing an improved adaptive step-size for updating the PV module's reference variable ( i.e. voltage, current or duty cycle). This new adaptive step-size approach exploits the first derivative of power as a function of duty cycle ( dP/dD ) and the sign of the second derivative for dividing the panel's operating range into four different regions. Consequently, the PV module's operating point can be tracked more precisely, thereby leading to more accurate step-size update compared to traditional step-size update. The instability issue, under rapidly changing insolation levels, is addressed by incorporating a current measurement I null at the end of each sampling period. The measured I null is used to estimate power dP 2 caused by the insolation change during the sampling period, which is compared to power change dP 1 caused by MPPT update. The algorithm also considers the issue of partial shading, where multiple peaks appear in the power function of the PV modules. The proposed algorithm exploits the relation between the maximum power current I MP and the global maximum power P m ( i.e. P m = Ü I mp ) to estimate the global maximum. Based on this relation, periodic interrupt routines are invoked to estimate the expected global maximum power P m of the present operating current I pv using ( P m = Ü I pv ). This power P m is then compared with the actual output power P o to ensure that the module is operating at the global maximum. The proposed MPPT system is modeled in SIMULINK with the theoretical models of a PV module and a buck converter. Simulation results are presented to validate the algorithm performance under different irradiation schemes, and are then compared to the results of several conventional algorithms ( e.g. P&O, adaptive ICM). In addition, a hardware prototype is implemented where the experimental results are presented and compared to a conventional algorithm

Suggesting a Legal Framework to Construct the Arab Economic Union Post “Arab Uprising”

PhD thesisThroughout the past decade, major non-GCC countries in the Middle East and North Africa Region (MENA), also referred to as the “Arab Region” have undergone major structural changes and reforms in their political, legal, economic, military and social regimes. However, seven years ago, the trend of change took a serious and unprecedented diversion known as the “Arab Spring” and which has brought damaging security, economic and social repercussions and aftermaths on the Arab World in general. As a result, the long-awaited dream of Arab unity has been jeopardised more than ever. Nevertheless, history has proven that times of transition are times for change, and thus the current turbulent Arab situation could be utilised as the golden gate and one-time opportunity to achieve the desired transformation towards Arab economic integration and unification, which, if successful, could place the Arab World in pole positions along with global economic giants and gurus. This research represents a new regulatory approach to regional economic integration. The purpose of this research is to suggest legal, constitutional and structural frameworks for the creation of an Arab Economic Union. This research incorporates the findings of available and existing work on the various attempts of Arab economic integration, and it explores the development, failures and accomplishments in this sphere. In addition, the research fills into the gap of the existing work through exploring former experiences and suggesting a new innovative and speculative constitutional structure of the desired AEU. The research also displays the historic and current economic models and discusses the outcomes of main integration attempts. More importantly it suggests a comprehensive institutional structure for the desired AEU in a detailed manner, and observes economic operational liberty through the performance of currently existence trading blocs. Moreover, and in an unprecedented manner, this research discusses the role of Arab migrant workers’ remittances to enhance the development of the desired AEU. Over and above, the research demonstrates the New Arab Model through proposing the innovative “Shamgate Treaty” and argues that times of commotion, security instability and economic disorder pose the best time for change through economic unity based on common interests between member states, based on economic functionalism

Introducing CFD Numerical Analysis in Fluid Dynamics to Junior Engineering Students

Western Illinois University engineering faculty introduce ANSYS workbench during Fluid Dynamics, a junior level core-engineering course in many engineering programs. Traditionally, advanced analytical software is not introduced until the senior year or in graduate courses. However, since the methods of teaching engineering have evolved dramatically toward using advanced technological tools and software, the use of ANSYS workbench software in the junior year is now quite natural. Using advanced numerical software provides students with better understanding and visualization of a flow field. The current generation of students is accustomed to watching videos and animations to grasp a concept or an idea. The animations, contours and figures generated using a CFD numerical analysis program provide X university\u27s engineering students with a greater understanding of flow behavior in all but the simplest dynamic fluid problems. As in most programs, physical laboratory experiments are conducted in the fluid dynamics class. Then the students model the experiments using CFD simulations. Consequently, both the experimental and numerical results are able to be compared and validated. The decision to use advanced CFD software in the fluid dynamics class has produced a positive impact on the student\u27s overall knowledge of fluid mechanics. The students are excited to use state of the art analysis techniques and demonstrate greater enthusiasm in class

Evaluations of Interactive Learning Tools Among Engineering Students: Effects of Grit and Gender

This study explores what determines engineering students’ evaluations of interactive learning tools (ILTs). Engineering students (n = 323) from large U.S. universities who had used McGraw-Hill’s SmartBook and Connect participated in the study. This study confirms that grit and gender are important factors in opinions and attitudes toward such tools. Specifically, among males, those with higher grit found ILTs as more useful and usable. Moreover, higher levels of grit were related to favorable attitudes toward ILTs. Interesting to note was that females reported more favorable evaluations on ILTs overall. These findings suggest strategies for the use of interactive learning tools for engineering students to succeed. Implications and recommendations for future research will also discussed

Unveiling the Therapeutic Potential of Sarcopoterium spinosum Fruits: A Comprehensive Exploration from Chemical Characterization to Cellular Models of Health Challenges

The search for new bioactive compounds is of increasing interest, and it seems that despite new technical and scientific progress, most of the active ingredients have been known for centuries. Indeed, plants are an inexhaustible source of bioactive compounds that have been used since ancient times in both folk medicines and as preservatives of food. Medicinal plants have always been of interest for many kinds of industries because of their multiple applications for their antioxidant, antibacterial and cytoprotective properties. Plants, and plant-derived secondary metabolites may be applied in the management of a broad spectrum of metabolic dysfunction including obesity, fatty liver, cardiovascular disease. Metabolic diseases encompass a broad category of disorders characterized by disruptions of the body's metabolic homeostasis. These conditions impact on many metabolic pathways, such as glucose and lipid metabolism, with severe consequences for human health. Many phytochemicals being found in plants may exhibit diverse properties that can modulate metabolic pathways, enhance insulin sensitivity, and regulate lipid metabolism. Among them, Sarcopoterium spinosum has emerged as a noteworthy medicinal plant with the potential to address metabolic diseases. Indigenous to the Mediterranean region and the Middle East, this botanical species boasts a rich history in traditional medicine. Recent research has spotlighted its anti-diabetic properties, particularly in the context of its root extracts exhibiting the capacity to regulate blood glucose levels and enhance insulin sensitivity. A flourishing interest has emerged regarding its role as a natural remedy for metabolic disorders, contributing to the expanding array of medicinal plants with the potential to promote metabolic equilibrium and overall well-being. Notably, ongoing investigations have predominantly focused on the roots rather than the fruits of S. spinosum. In the context of this exploration, my PhD thesis aims to study different extracts derived from S. spinosum fruits, examining their bioactive compounds and their promising potential in ameliorating health and metabolic diseases. Three extracts were prepared from S. spinosum fruits, employing water, boiling water, and ethanol as extraction solvents. The ethanol extract, being distinguished by its superior radical scavenging potential, was selected for a detailed examination of the polyphenolic profile and the investigation of the potential beneficial effects. Two relevant cellular models were employed in this study: the rat hepatoma cell line (FaO) to mimic a cell model of hepatic steatosis, and the human endothelial cell line (HECV) to mimic a dysfunctional endothelium. The findings unveiled a rich profile of bioactive compounds for the ethanol extract, highlighting its abundance in ellagitannins, flavonoids, and terpenoids. Notably, this comprehensive chemical composition corresponded with the extract's demonstrated lipid-lowering, antioxidant, anti-inflammatory, and cytoprotective properties. In the final step of our investigation, our focus shifted to the design and develop a cellular model of insulin resistance utilizing the human hepatoma cell line HepG2. Employing hyperinsulinemia and fat accumulation as inducers, we successfully elicited the insulin resistance in vitro and this model will be tested using the S. spinosum extracts. In conclusion, the outcome of this PhD thesis shows that S. spinosum fruits could be a source of many bioactive compounds and the extracts represent a promising candidate to develop nutraceuticals or dietary supplements to treat/prevent obesity-related metabolic diseases

Transport and dispersion of fire extinguishing agents downstream from clutter elements of aircraft engine nacelles

The combination of highly turbulent airflow, flammable fluids, and numerous ignition sources makes aircraft engine nacelles a difficult fire zone to protect. Better understanding of nacelle air flow and how it influences the spread of fires and fire extinguishing agents is needed to improve the efficiency of fire suppression. The first objective was to establish a CFD model for a flow field test section to analyze the transport and dispersion of fire extinguishing agents in the presence of various clutter elements. To validate the use of the CFD model, the simulation results of the CFD model were compared to the experimental data and they show an agreement with the experimental data. The second objective was to present parametric studies to show the effects of the coflow speed, turbulence intensity and agent droplet size on the transport and dispersion of the agent particles downstream from the clutter elements

Oblique strategies

Four of Architecture’s prevailing mythologies. One ghost town.Applied Science, Faculty ofArchitecture and Landscape Architecture (SALA), School ofUnreviewedGraduat

The Anti-Inflammatory Potential of an Ethanolic Extract from Sarcopoterium spinosum Fruits for Protection and/or Counteraction against Oxidative Stress in Dysfunctional Endothelial Cells

Plants and plant extracts are a relevant source of bioactive compounds widely employed as functional foods. In the Mediterranean area, the shrub Sarcopoterium spinosum is traditionally used as an herbal medicine for weight loss and a diabetes treatment. Inflammation is a protective mechanism involved in the development of many pathological conditions, including cardiovascular diseases. The present study aimed to investigate in vitro the antioxidant and cytoprotective properties of an ethanolic extract from S. spinosum fruits (SEE) in a cellular model of endothelium dysfunction. Corilagin and quercetin are two polyphenols abundant in SEE and were tested for comparison. The exposure of HECV cells for 24 h to 30 mu M hydrogen peroxide (H2O2) lead to an oxidative stress condition. When HECV cells were treated with 10 mu g/mL of SEE or single compounds after or before the oxidative insult, the results showed their ability to (i) decrease the reactive oxygen species (ROS) production quantified using fluorometric analysis and the lipid peroxidation measured with a spectrophotometric assay; (ii) rescue both the glutathione reduced to oxidized (GSH/GSSG) ratio and nitric oxide impair and the protein denaturation; and (iii) accelerate the wound repair measured using a T-scratch assay. Taken together, our findings indicate that the ethanolic extract from S. spinosum fruits could be a potential candidate for nutraceutical application

The Potential of Lamiaceae Herbs for Mitigation of Overweight, Obesity, and Fatty Liver: Studies and Perspectives

Numerous plants, plant extracts, and plant-derived compounds are being explored for their beneficial effects against overweight and liver diseases. Obesity is associated with the increased prevalence of non-alcoholic fatty liver disease (NAFLD), becoming the most common liver disease in Western countries. Obesity and NAFLD are closely associated with many other metabolic alternations such as insulin resistance, diabetes mellitus, and cardiovascular diseases. Many herbs of the Lamiaceae family are widely employed as food and spices in the Mediterranean area, but also in folk medicine, and their use for the management of metabolic disorders is well documented. Hereby, we summarized the scientific results of the medicinal and nutraceutical potential of plants from the Lamiaceae family for prevention and mitigation of overweight and fatty liver. The evidence indicates that Lamiaceae plants may be a cost-effective source of nutraceuticals and/or phytochemicals to be used in the management of metabolic-related conditions such as obesity and NAFLD. PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets