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A study on the feasibility of producing polylactic acid from cotton and coffee waste in Egypt

The amount of solid waste is growing In Egypt. It is estimated to be 20 million tons annually according to the Ministry of environment forecasts. The typical competence of collection in urban areas signifies 40 – 80%, although the middling proficiency of assortment processes and transport in rustic areas signifies 40 % which is considered hazardous for communal health and environment deprived of

Energy and Water

Numerical simulation of Oldroyd-B fluid with application to hemodynamics

Oldroyd-B viscoelastic fluid is numerically simulated using the stabilized Galerkin least squares finite element method. The instabilities due to the connective nature of the Oldroyd-B model is treated using the discrete viscous elastic split stress method. The model is used to study the behavior of the flow of blood through an abdominal aortic segment. The results show that the viscoelastic

Energy and Water

Communication—convolution-based estimation of supercapacitor parameters under periodic voltage excitations

Supercapacitors are typically used in applications requiring frequent and continuous charging/discharging cycles, but most of the models available in the literature are designed to predict their behavior for a single sequence. In this letter, we show first that the electrical response and metrics of supercapacitors under periodic voltage excitations can generally be obtained using Fourier series

Energy and Water
Circuit Theory and Applications

Realization of fractional-order capacitor based on passive symmetric network

In this paper, a new realization of the fractional capacitor (FC) using passive symmetric networks is proposed. A general analysis of the symmetric network that is independent of the internal impedance composition is introduced. Three different internal impedances are utilized in the network to realize the required response of the FC. These three cases are based on either a series RC circuit

Circuit Theory and Applications

Anonymous routing protocols in MANETs, a security comparative analysis

A Mobile Ad Hoc Network (MANET) is considered a type of network which is wireless and has no fixed infrastructure composed of a set if nodes in self organized fashion which are randomly, frequently and unpredictably mobile. MANETs can be applied in both military and civil environments ones because of its numerous applications. This is due to their special characteristics and self-configuration

Circuit Theory and Applications
Software and Communications

EPS inclusion to reduce vertical stresses on shallow tunnels

Expanded polystyrene (EPS) has long been used to reduce stresses acting on buried structures. In this study, the efficiency of utilising EPS in reducing vertical stresses acting on cut-and-cover tunnels was investigated. To gauge this, short- and long-term shear strength parameters of EPS with densities of 25, 30, and 35 kg/m3 were determined. Interface friction of EPS with various materials was

Energy and Water
Mechanical Design

Comprehensive comparison based on meta-heuristic algorithms for approximation of the fractional-order Laplacian s α as a weighted sum of first-order high-pass filters

To implement an approximation of the fractional order Laplacian operator s α as a weighted sum of high pass filter sections, it is essential to extract the cutoff frequencies and filter gains of each section in order to achieve the lowest error possible. Therefore, in this work, five meta-heuristic optimization algorithms are tested in this problem based on a weighted sum objective function. The

Circuit Theory and Applications

Interfacial modification of perovskite solar cell using zno electron injection layer with pdms as antireflective coating

Recently, perovskite solar cells (PSCs) exhibits tremendous power conversion efficiency and has shown enhanced figures of merit being secured regarding cell stability. In this paper, perovskite solar cell with Zno electron injection layer is presented. The humidity degradation of the perovskite active layer and the efficiency of the cell is observed under several conditions. Using ZnO as a planner

Energy and Water
Circuit Theory and Applications

Multiple Pinch-Off Points in Memristive Equations: Analysis and Experiments

Pinched hysteresis behavior is considered evidence of the existence of the memristive element. Recently, the multi-lobes (more than two) behavior has been discovered in some memristive devices. In this paper, a fractional-order flux/voltage-controlled memristive model is introduced that is able to develop multiple symmetric and asymmetric pinch-off points. Generalized closed-form expressions for

Circuit Theory and Applications
Innovation, Entrepreneurship and Competitiveness

The effect of the geometric and thermal parameters on the thermal stresses during the passive cooling of printed circuit boards

The effect of components' thermal properties in addition to their geometric configuration on the developed thermal stress in a model printed circuit board (PCB) is investigated. This effect is quantified through three parameters, the average normalized temperature gradient, maximum normalized temperature gradient and the uniformity factor. It is found that the effect of the geometric configuration

Energy and Water
Mechanical Design