Dual Band PIFA MIMO Antenna Design with High Isolation for Mobile and Wireless Applications by Using the Genetics Algorithms and Non-uniform Overlapping Method

Wireless Personal Communications - Due to the development and growth of Internet platforms and web services as communication resources, the competition for the network and its limited resources is...     

Parameter identification and computational simulation of polyurethane foaming process by finite pointset method

Numerical simulation of the polyurethane foaming process is a valuable method to analyze the molding process at an early stage of product development to shorten time-to-market cycles and cut costs by using fewer prototypes. However, this process involves highly coupled thermo-chemo-rheological modeling and needs adequate model parameters’ identification. A theoretical model including chemical reactions and thermo-rheological coupling of conservation equations was developed. Based on the theoretical model, three-dimensional numerical simulation for mold filling of the polyurethane foam was carried out by using Finite Pointset Method (FPM) to predict flow field, flow front advancement, temperature and density distributions during mold filling. A FOAMAT system was used to monitor foam height rise and reaction temperature on a cylindrical test tube and foam viscosity was measured by using a dynamic rotational rheometer with parallel-plate system. The parameters of the model were identified by an inverse analysis method which consists in determining the parameters by comparing the computed quantities to those measured experimentally. The overall modeling was validated by using short shot foams obtained with a panel mold cavity. Mold filling of an automotive underlay carpet cavity was investigated numerically. Flow front results were successfully compared to short shot foams obtained with the industrial mold cavity.     

Effect of the Inclination of Baffles on the Power Consumption and Fluid Flows in a Vessel Stirred by a Rushton Turbine

The role of baffles in mechanically stirred tanks is to promote the stability of power drawn by the impeller and to avoid the fluid swirling, thus enhancing mixing. The present paper numerically investigates the baffles effects in a vessel stirred by a Rushton turbine. The geometric factor of interest is the baffle inclination which is varying between 25°, 32.5°, 45°, 70° and 90° at different impeller rotational speeds. The impeller rotational direction has also been varied. The vortex size and power consumption were evaluated for each geometrical configuration. It was found that the best configuration is the baffle inclination by α = 70° at a negative angular velocity.     

Production of bio‐energy from organic waste: effect of temperature and substrate composition

This article presents the influence of temperature and influent substrate composition on the produced biogas volume in an anaerobic co‐digestion process. Four cases of anaerobic digestion were considered. Digestion of waste sludge only and anaerobic co‐digestion of sludge mixed with solid waste in mesophilic (T = 35 °C) and thermophilic (T = 55 °C) phases. The obtained results show that thermophilic co‐digestion gives the best results; although the temperature has an effect on biogas production, it remains however quite relative compared to the effect of solid waste. They confirm, surely, that the combined effect of temperature and solid waste improves considerably the biogas production rate (GPR). Changing conditions from mesophilic to thermophilic ones for waste sludge alone and for waste sludge mixed with solid waste results in an increase of the GPR from 0.18 to 0.39 m³/m³.d and from 0.29 to 0.96 m³/m³.d, respectively. Copyright © 2013 John Wiley & Sons, Ltd.     

Design of a Symmetric CPW-Fed Patch Antenna for WLAN/WIMAX Applications Using ANN

The upper bound capacity based on the SINR model is a very important parameter when evaluating the performance of the multi-hop wireless ad hoc networks. In this paper, a new upper bound capacity algorithm is proposed. Firstly, we analyzed the classical physics SINR model over the Rayleigh fading channels to establish the relationship between density of nodes and path outage probability. Then, we developed the closed-form expression of the upper bound transmission capacity based on the Weber model for the random networks. Finally, we evaluated effects of parameters in the communication range, density, SINR threshold and fading factors, and consequently transmission capacity of the network by sensitivity analysis. The numerical simulation showed that the optimum density of nodes was existed to obtain the upper bound transmission capacity. The capacity increased firstly and then decreased over the density of nodes increasing. It affected by channel fading factor and communication range sensitively.

     

Novel design of a triple band PIFA antenna by using a binary genetic algorithm

Journal of Computational Electronics - In this study, we propose a miniature triple band PIFA antenna (planar inverted-F antenna) composed of uniform semi-patches for LTE2600/WLAN/WIMAX/HIPERLAN-2...     

Recycling of used motor oil as an alternative method for production feedstock for the conversion processes

Abstract

Used lubricating motor oil is a high pollutant material that requires responsible management. It may cause damage to the environment when dumped into the ground or into water streams including sewers. This may result in groundwater and soil contamination. Recycling of such contaminated materials will be beneficial in reducing lubricating motor oil costs. In addition, it will have a significant positive impact on the environment.

Used oil can be refined to yield base oils that are blended into lubricating products, thus reducing the consumption of virgin oils and it can be used as a feedstock for hydro conversion for production fuels and fuel oil.

This work investigates refining of used lubricating motor oil using solvent extraction method. The laboratory experiment was based on a full factorial design and two categorical factors with two levels were nominated which were solvent to used oil ratio and solvent type (2-Propanol and n-Butanol, MEK and blended the solvents with gazoline).

The type of solvent used and the mixing ratio applied for different runs has shown significant effects on the yield of recovered oil. The yield with bisolvent type MEK+gasoline was higher than the other solvents. The yield of treated oil with butanol mixed with gasoline is 87.5% and it is so close to the yield when we used the butanol alone which is 88.6%.     

Autonomous agents for edge detection and continuity perception on otolith images

An automatic method for edge detection on biological images (otolith images) using a multi-agent system is presented. One of the major problems encountered during an automatic contour detection is the lack of structure continuity perception. In this paper we present a new approach to perceive continuity based on a 2D reconstruction of closed contours using a multi-agent system. Each agent is provided with sensors on the image, which allow it to follow local intensity extremes. The purpose is to detect alternative light and dark concentric structures in an image. To improve the detection of these reactive agents, we have added high-level information about the shape of the contour. An application to fish otolith growth ring detection is presented in this paper.     

Chemical Synthesis of Organo-siloxene 2D Materials from Calcium Di-Silicide: Characterization,Dielectric and Electrochemical Studies

Silicon - Silicon is one of the most used materials in semiconductors and electronic devices. Its miniaturization in two-dimensional (2D) scale is now a great challenge to improve and/or extend its...     

A Pentagonal Shaped Microstrip Planar Antenna with Defected Ground Structure for Ultrawideband Applications

A new compact pentagonal microstrip patch antenna with slotted ground plane structure, developed for use in ultrawideband applications, is studied in this article. The proposed antenna is mainly constituted by a pentagonal shaped patch antenna, a defected ground plane structure, two stubs, and four slots to improve the bandwidth. The designed antenna has an overall dimension of 30?×?17.59?×?1.6 mm³, for WIMAX/WLAN/WiFi/HIPERLAN-2 /Bluetooth/LTE/5G applications with a very large bandwidth starting from 2.66 to 10.82 GHz (S₁₁?<???6 dB). A parametric study of the ground plane structure was carried out to find the final and the optimal UWB antenna, and to confirm that the antenna has good performance and broader bandwidth. The proposed antenna prototype has been fabricated. The measured results indicate that the antenna has a good impedance matching. The antenna has an electrically small dimension with a good gain, a notable efficiency, and a wide impedance bandwidth, which makes this antenna an excellent candidate for ultrawideband wireless communication, microwave imaging, radar applications, and the major part of the mobile phone frequencies as well.