Performance of Gradient-Based Optimizer for Optimum Wind Cube Design

Renewable energy is a safe and limitless energy source that can be utilized for heating, cooling, and other purposes. Wind energy is one of the most important renewable energy sources. Power fluctuation of wind turbines occurs due to variation of wind velocity. A wind cube is used to decrease power fluctuation and increase the wind turbine’s power. The optimum design for a wind cube is the main contribution of this work. The decisive design parameters used to optimize the wind cube are its inner and outer radius, the roughness factor, and the height of the wind turbine hub. A Gradient-Based Optimizer (GBO) is used as a new metaheuristic algorithm in this problem. The objective function of this research includes two parts: the first part is to minimize the probability of generated energy loss, and the second is to minimize the cost of the wind turbine and wind cube. The Gradient-Based Optimizer (GBO) is applied to optimize the variables of two wind turbine types and the design of the wind cube. The metrological data of the Red Sea governorate of Egypt is used as a case study for this analysis. Based on the results, the optimum design of a wind cube is achieved, and an improvement in energy produced from the wind turbine with a wind cube will be compared with energy generated without a wind cube. The energy generated from a wind turbine with the optimized cube is more than 20 times that of a wind turbine without a wind cube for all cases studied.     

Correction to: Automatic COVID-19 detection mechanisms and approaches from medical images: a systematic review

Multimedia Tools and Applications -     

An Enhanced Cooperative Communication Scheme for Physical Uplink Shared Channel in NB-IoT

Wireless Personal Communications - Smart Home is one of the most established applications of the Internet of Things. Almost every equipment we use in our daily life—appliances, electric...     

Photocatalytic degradation of agricultural N-heterocyclic organic pollutants using immobilized nanoparticles of titania

Degradation and mineralization of two agricultural organic pollutants (Diazinon and Imidacloprid as N-heterocyclic aromatics) in aqueous solution by nanophotocatalysis using immobilized titania nanoparticles were investigated. Insecticides, Diazinon and Imidacloprid, are persistent pollutants in agricultural soil and watercourses. A simple and effective method was developed to immobilization of titania nanoparticles. UV-vis, ion chromatography (IC) and chemical oxygen demand (COD) analyses were employed. The effects of operational parameters such as H(2)O(2) and inorganic anions (NO(3)(-), Cl(-) and SO(4)(2-)) were investigated. The mineralization of Diazinon and Imidacloprid was evaluated by monitoring of the formed inorganic anions. The selected pollutants are effectively degraded following first order kinetics model. Results show that the nanophotocatalysis using immobilized titania nanoparticle is an effective method for treatment Diazinon and Imidacloprid from contaminated water.     

Radiation-induced Grafting of Acrylic Acid and Vinyl Acetate Monomers onto Heavy-duty Poly(ethylene–vinyl acetate) Films

The preparation of graft films was carried out by direct radiation-induced graft polymerization of acrylic acid and vinyl acetate comonomer onto heavy-duty poly(ethylene–vinyl acetate) films. The effect of various comonomer compositions on the degree of grafting was investigated. The characterization and some selected properties of the graft copolymers prepared were studied. Thermal stability, mechanical and electrical properties of the films showed great promise for some practical applications. © of SCI.     

Changes in membrane fatty acids and murein composition of Bacillus cereus and Salmonella Typhi induced by gamma irradiation treatment

This present study was carried out to evaluate the effects of gamma irradiation on the fatty acids (FA) and mureins composition of two different radiotolerant bacteria. Bacillus cereus LSPQ 2872 and Salmonella Typhi ATCC 19430 were used for this study. The bacterial strains were treated with a sublethal radiation dose of 1 kGy to cause a cellular damage. Gas chromatography (GC) and high performance liquid chromatography (HPLC) analysis were performed to demonstrate respectively the modification of the FA composition and the changes in muropeptide profile. Results obtained show, for both bacteria, that this treatment had a significant effect (P ≤ 0.05) on the FA content with an increase of unsaturated FA percentage. Substantial changes were also noticed for the relative percentage and the number of the muropeptides. This study represents one of the few to demonstrate the modifications on bacterial membrane as a cellular response to survive the ionising radiation stress.     

Image structure preserving denoising using generalized fractional time integrals

A generalization of the linear fractional integral equation u(t)=u₀+∂^−αAu(t), 1<α<2, which is written as a Volterra matrix-valued equation when applied as a pixel-by-pixel technique is proposed in this paper for image denoising (restoration, smoothing, etc.). Since the fractional integral equation interpolates a linear parabolic equation and a hyperbolic equation, the solution enjoys intermediate properties. The Volterra equation we propose is well-posed for all t>0, and allows us to handle the diffusion by means of a viscosity parameter instead of introducing nonlinearities in the equation as in the Perona-Malik and alike approaches. Several experiments showing the improvements achieved by our approach are provided.     

Fair content dissemination in participatory DTNs

Thanks to advances in the computing capabilities and added functionalities of modern mobile devices, creating and consuming digital media on the move has never been so easy and popular. Most of the DTN routing protocols proposed in the literature to enable content sharing have been exploiting users’ mobility patterns, in order to maximise the delivery probability, while minimising the overall network overhead (e.g., number of message replicas in the system, messages’ path length). Common to all these protocols has been the assumption that devices are willing to participate in the content distribution network; however, because of battery constraints, participation cannot be taken for granted, especially if the very same subset of devices are continuously selected as content carriers, simply because of their mobility properties. Indeed, we demonstrate that state-of-the-art DTN routing protocols distribute load in a highly unfair manner, with detrimental effects on delivery once the assumption of unconditional participation is lifted. To overcome this limitation, we propose a load-balancing mechanism whereby nodes maintain local estimates of network workload, and use them to direct traffic towards the least loaded portion of the network. We implement the mechanism on top of a source-based DTN routing protocol, and demonstrate, by means of simulation using a variety of real mobility traces, that high delivery is now achieved without compromising fairness.