204 research outputs found

    A training monitoring system for cyclist based on wireless sensor networks

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    This paper presents a training monitoring system for cyclist that is based on the technology of wireless sensor networks (WSNs). A stable and reliable wireless cyclist monitoring system is vital to establish a smart and efficient sports management program. A training monitoring system has been developed and tested in a real cyclist training environment in a velodrome. The system is designed is such a way that the packet loss rate is minimum. Using TelG mote as the basis, customized sensor nodes that function as a forwarder node and the relay nodes are developed to form the WSN. This WSN is linked to the cloud network on the Internet. The cloud network is then established and end users application for data accessing is designed. Several experiments have been conducted in a real scenario in a velodrome to measure the reliability of the system architecture. It is shown from the experiments that the proposed system is reliable even when the cyclist is moving at a high speed. The packet loss is less than 2% which does not give a huge impact to the data transmission

    Reconfigurable metamaterial structure for 5G beam tilting antenna applications

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    In this paper, we propose a metamaterial (MTM) structure with a reconfigurable property designed to operate at the millimetre-wave (mm-wave) spectrum. Four switches are used to achieve the reconfigurable property of the MTM with two configurations. These two configurations exhibit different refractive indices, which used to guide the radiation beam of the antenna to the desired direction. The proposed planar dipole antenna operates at the 5th generation (5G) band of 28 GHz. The electromagnetic (EM) rays of the proposed antenna pass through different MTM configurations with different phases, subsequently results in the tilting of the radiation beam toward MTM configuration of high refractive index. Simulated and measured results of the proposed antenna loaded by MTM demonstrate that the radiation beam is tilted by angles of +34° and −31° in the E-plane depending on the arrangement of two MTM configurations onto the antenna substrate. Furthermore, the gain is improved by 1.7 and 1.5 dB for positive and negative tilting angles, respectively. The reflection coefficients of the antenna with MTM are kept below −10 dB at 28 GHz

    Substrate integrated waveguide cavity backed frequency reconfigurable antenna for cognitive radio applies to internet of things applications

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    In this article, a new multiband frequency reconfigurable substrate integrated waveguide cavity slot antenna was designed using Computer Simulation Technology software tool for addressing the specific design challenges posed by the internet of things (IoT) based cognitive radio networks. Reconfiguration of frequency bands is achieved using PIN diodes. The antenna resonated at 2.624, 2.664, 2.720, 2.752, 4.304, 4.532, 4.556, 5.236, 5.304, 5.368, 5.332, and 5.392 GHz. The resonant frequency capability and radiation performance are demonstrated by both simulations and measurements. The simulated and measured results were in agreement. The higher efficiency, gain and average bandwidth obtained are 90%, 8.2 dBi and 65 MHz, respectively. The compactness, integrity, reliability, and performance at various operating frequencies make the proposed antenna a good candidate for IoT applications

    Histopathological Changes of the Flaxseed Extract on Skin Wound Healing in Diabetic Rabbits

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    BACKGROUND: Wound healing includes phases such as cell migration, extracellular matrix deposition, remodeling, and angiogenesis. There are growing medicines that accelerate wound healing, significantly herbal medications that mainly safe and reliable. AIM: The aim of the study is to examine the histological changes induced by flaxseed oil during wound healing in diabetic animal model. METHODS: Forty-five male white New Zealand rabbits divided into two main groups diabetic and non-diabetic each group is divided into three groups (n = 9).Diabetic animal group include: (1) Study group (adding Flaxseed), (2) positive control group (adding fucidin 2% cream), and (3) negative control group (no treatment) same distribution of non-diabetic animals groups. Four linearshape,full-thickness wounds were made in both sides of the backbone skin in each animal. Tissue samples were obtained at days 4th, 7th, and 14th post wounding for microscopical analysis, histopathological parameters included inflammation, re-epithelialization, neovascularization, and surface closure rates. RESULTS: The study groups (using flax seed) in both diabetic and non-diabetic groups show significant reduction in inflammatory cells infiltration at day 14 (0.67 ± 0.753) (1.67 ± 0.516), and noticeable increase in wound closure rate (4.00+-0.000). Both diabetic and non-diabetic animal groups show high re-epithelialization potential at day 4 and day 7, respectively (2.00 ± 1.549; 4.00 ± 0.00). Diabetic animal study group using flaxseed shows high neovascularization rate at the day 14 (2.17 ± 0.753) compared with positive control diabetic animal group (2.00 ± 0.000). CONCLUSION: Topical application of flaxseed promoted healing process particularly in diabetic animal model by shortening inflammation phase, elevating surface closure rate, promoting re-epithelialization process, and enhancing neovascularization, flaxseed is suggested as a potential effective herbal base medication for facilitating wound healing

    The Performance Comparison Of Printed Dipole Antenna With Two Different Structures Of Amc Ground Plane

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    The performances of the triple-band meandered dipole antenna backed by two different Artificial Magnetic Conductor (AMC) structures are discussed in this paper. Two kinds of AMC structures are presented namely rectangular-patch with rectangular slot and rectangular-patch with slotted rectangular and I-shaped slot. The AMCs are designed to operate at 0.92GHz and 2.45GHz. The performances of the antenna with and without the dual-band AMC ground plane are investigated in terms of return loss, realized gain and power received. It clearly shows that the printed dipole antenna has a lower gain compared to the printed dipole antenna with high-impedance structure ground plane (GP). Furthermore, the received power of the dipole antenna backed by the 2x2 rectangular-patch with slotted rectangular and I-slot AMC receives a slightly higher power compared to the dipole antenna backed by the 2x2 rectangular-patch with rectangular slot AMC

    Effect of nanofiller calcination on breakdown performance of zirconia based polyethylene nanocomposites

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    Dielectrics are widely used in electrical and high voltage systems. Studies on new dielectric materials, especially polymer nanocomposites, have been extensively carried out in order to investigate the potential improvements of the materials in high voltage insulation. Significantly, the interface between the base material (polymer) and the nanofiller is a vital factor that influences the dielectric performance of the materials. This paper reports on an investigation into the AC and DC breakdown performance of unfilled and polyethylene nanocomposites containing zirconium oxide (ZrO2) nanofillers at different amounts; 1 wt%, 4 wt%, and 8wt%. The chemical structures of the materials were characterized using Fourier transform infrared (FTIR) spectroscopy. Dielectric spectroscopy was used to measure the dielectric permittivity of the samples. Breakdown testing showed that there were no significant changes on the AC breakdown behaviors of nanocomposites containing both uncalcined and calcined nanofillers. Meanwhile, substantial changes were observed on the materials' DC breakdown strength, even by introducing a small amount of nanofiller (1 wt%); the DC breakdown strength of the nanocomposites enhanced for those containing calcined nanofillers compared to uncalcined nanofillers. The observation is associated with the calcination process of the nanofillers

    Effect of nanofiller calcination on breakdown performance of zirconia based polyethylene nanocomposites

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    Dielectrics are widely used in electrical and high voltage systems. Studies on new dielectric materials, especially polymer nanocomposites, have been extensively carried out in order to investigate the potential improvements of the materials in high voltage insulation. Significantly, the interface between the base material (polymer) and the nanofiller is a vital factor that influences the dielectric performance of the materials. This paper reports on an investigation into the AC and DC breakdown performance of unfilled and polyethylene nanocomposites containing zirconium oxide (ZrO2) nanofillers at different amounts; 1 wt%, 4 wt%, and 8wt%. The chemical structures of the materials were characterized using Fourier transform infrared (FTIR) spectroscopy. Dielectric spectroscopy was used to measure the dielectric permittivity of the samples. Breakdown testing showed that there were no significant changes on the AC breakdown behaviors of nanocomposites containing both uncalcined and calcined nanofillers. Meanwhile, substantial changes were observed on the materials' DC breakdown strength, even by introducing a small amount of nanofiller (1 wt%); the DC breakdown strength of the nanocomposites enhanced for those containing calcined nanofillers compared to uncalcined nanofillers. The observation is associated with the calcination process of the nanofillers

    Suitability of pressmud as an adsorption material in wastewater treatment and as a booster in soil fertility and productivity

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    Press mud is one of the most abundant wastes produced by the sugarcane industry. However, it has received far too little attention as a reactive material for pollutant removal, although its beneficial effect on soil fertility and crop productivity is well established. This paper investigates the potential of press mud to minimize heavy metal migration while boosting soil fertility and productivity. Firstly, the adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Field-Emission Scanning Electron Microscopy (FESEM) analyses, which showed the presence of functional groups such as carbonyl, hydroxyl, and silica capable of adsorbing metal ions. The cation exchange capacity (CEC) of press mud is very high, ranging between 44.9 and 45.2 meq/100 g. Along with removal efficiency testing and evaluating breakthrough curves, characterization, and adsorption analyses (batch equilibrium and column test) were carried out. The press mud reveals promising adsorption characteristics, including a high organic content (17.62%) and the presence of carbon, which significantly affects its excellent removal effectiveness. Based on the removal efficiency test, press mud successfully removes metal ions at the highest value, such as zinc (Zn), at 99.7%. Meanwhile, its breakthrough curve reveals that it efficiently retained all heavy metals, as these metals do not reach 1 to 10 pore volumes (p.v.), indicating that press mud is a good material for heavy metal adsorption and soil productivity. This possible use establishes a new cyclical flow for the material and contributes to its minimization and reuse, adhering to circular economy ideas. However, press mud must be disposed of properly to avoid adverse effects on humans and the environment

    Review on frequency reconfigurable antenna using substrate-integrated waveguide for cognitive radio application

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    Cognitive radio (CR) exploits the spectrum efficiently and minimizes the interference between different devices. Meanwhile, multiband frequency-reconfigurable antennas (FRA) are desirable for CR where it is beneficial to dynamically reconfigure a single antenna to be transmitted and/or received on multiple frequency bands. As stated by the literature review, there is a dearth of work into multiband FRA that is directly applied in CR applications with substrate-integrated waveguide (SIW) technology. Frequency-reconfigurable SIW (FRSIW) is seen as promising for the development of microwave and millimeter waveband antennas. This study’s key objective is for the technical operational advances of SIW antennas to be summarized and compared. The design structure of FRSIW elements using different techniques is discussed in detail. The findings supported the effectiveness of FRSIW for managing radio spectrum to work in most efficient way
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