A Miniature Implanted Inverted-F Antenna for GPS Application

A miniature implanted Hilbert inverted-F antenna design at the 1.575 GHz; global positioning system (GPS) frequency is proposed, which can be used to track the location of its user, e.g., the elderly with declining mental capacity (alzheimer\u27s disease). A detailed parametric study of the antenna design is performed by considering it to be implanted within a human muscle model. The effects of the substrate, superstrate, and the nearby muscle tissue on antenna performance are carefully investigated. A laboratory prototype of the antenna was built and tested within a muscle equivalent fluid indicating good VSWR performance. Finally the said antenna when placed within the tissue equivalent fluid was also tested to track GPS satellites with the help of a low noise amplifier (LNa). Such field measurements demonstrate that the antenna can easily lock into six or more satellites which are more than enough to determine the location of a person

Wideband Smaller Unit-Cell Planar EBG Structures and Their Application

A new low-cost smaller unit-cell planar electromagnetic bandgap (ERG) structure operating at the lower GHz frequencies (below 6 GHz) is proposed. ERG structures based on this new geometry are designed on a number of commonly available substrates. Characteristics of such structures, such as bandgap and reflection phase profile are analyzed. a simple empirical model is proposed to predict the surface wave stopband frequency of the proposed ERG structure. Finally, a low-profile dipole antenna is designed and tested for operation on the ERG structure

The elicitation of key performance indicators of e-government providers: A bottom-up approach

Copyright @ 2013 EMCIS.Delivering an adequate e-Government service (e-service) is becoming more of a necessity in today's digital world. In order to improve e-services and increase the engagement of both users' and providers' side, studies on the performance evaluation of such provided e-services are taking places. However a clear identification of the key performance indicators from the e-Government providers’ side is not well explored. This shortcoming hampers the conduct of a holistic evaluation of an e-service provision from the perspective of its stakeholders in order to improve e-services as well as to increase e-services take-ups. In this paper, a systematic process to identify indicators is implemented based on a bottom-up approach. The process used three focus-group meetings with providers, users, and academics in Qatar, Lebanon and UK to collect, identify and validate key indicators from the perspective of e-services’ providers. The approach resulted in the identification of five factors levels (service, technology, employees, policy and management and social responsibilities) with fifteen sub-categories of SMART variables. Hence, leading to the development of a new model, STEPS, that can fully explain and predict e-government success from the providers’ point of view. It will work as a strategic management tool to align various stakeholders on common goal and values based on evidence based evaluation of e-services using smart measurable indicators for the improvement of an e-service at the engagement level in the field of e-government. In addition, other fields can benefit from the outcome of this work, such as logistics service providers, who make their services available across new and existing relationships between the Internet commerce firms, their customers, and their vendors

Esophageal polypoidal mass: presentation of an uncommon pleomorphic carcinoma

Pleomorphic carcinomas are primary malignant tumours that are known to arise in the lungs, pancreas, gall bladder and intestine. A patient with polypoid tumour of the esophagus is described in this report. The patient presented with dysphagia. Diagnostic and therapeutic intervention required endoscopic evaluation and treatment. Benign esophageal tumours are rarely seen and originate from the upper third of esophagus. We observed an esophageal tumour which was interpreted as spindle cell carcinoma of the esophagus that caused obstruction. We present the clinical picture and histopathological findings of the tumour. To our knowledge this is the first local report of spindle cell carcinoma occurring in the esophagus and describes its endoscopic and histopathological features with distinctive biphasic morphology

Effect of different feeds on growth, survival and production of African catfish (Clarias gariepinus Burchell)

An experiment was conducted to study the effect of different feeds on growth survival and production of African catfish (C. gariepinus) in six cemented tanks (3m² each) over a period of 120 days. Three different feeds namely Feed A (Saudi-Bangla fish feed, 33.43% protein), Feed B (formulated feed, 40.12% protein) and Feed C (chicken raw intestine, 59.58% protein) were applied to treatments I, II and III respectively. Each of the tanks was stocked with 24 fry with mean initial body weight of 2.56±0.06 g. Feeds were supplied to the fish ad-libitum daily in two instalments. Significantly highest weight gain was obtained in treatment III, however, survival rate was low compared to other treatments. The feed conversion ratio (FCR) values ranged from 2.52-6.4. Survival rate of fish varied between 83 and 96%. Treatment II yielded the highest (5000 kg/ha/120 days) production with the highest survival rate of fish. On the basis of survival rate and production, it is suggested that the formulated feed (Feed B) is suitable for the culture of C. gariepinus in cemented tanks

Isolation and typing of the influenza viruses in the Caspian littoral of Iran

Present study introduces results of common influenza virus strains in the north of Iran. Samples collected from 65 patients with acute respiratory illness by throat washing and swabs, randomly from north of Iran (Mazandaran, Golestan and Guilan provinces). The patients suffered from fever (high), cough, sore throat, general malaise, chill and myalgia. Viruses were isolated by cell culture and confirmed with HA (Hemagglutination) test and then typed by and HI (Hemagglutination Inhibition) test. Out of 65 throat samples, 12 influenza viruses were isolated and typed. Isolated viruses belonged to A (H1N1), A (H3N2) and B influenza viruses. This study showed that Influenza viruses displayed identical pattern to other provinces in Iran and to other countries. To fight against epidemics and pandemics, we should collect enough data about status of influenza each year and data of exact vaccine formulation application for use in different areas of the world. Acquired data has shown that the vaccine for above viruses that confirmed by WHO can result in decreased risks of influenza in at risk cases in provinces of north Iran

Novel Wideband Directional Dipole Antenna on a Mushroom Like EBG Structure

A new method to design thin wideband directional dipole antennas on electromagnetic bandgap (EBG) structure is introduced. At the heart of this method is the idea to understand and properly utilize the complex interactions between the dipole impedance and the EBG reflection phase characteristics. Using the proposed technique a thin wideband printed dipole is designed, fabricated and tested. The antenna can satisfy applications, such as Digital Communication System (DCS, 1.71-1.88 GHz), Global System for Mobile Communication (GSM, 1.85-1.99 GHz), Personal Communication System (PCS, 1.85-2.05 GHz), Universal Mobile Telecommunication System (UMTS, 1.92-2.17 GHz) and Wireless Local area Network (WLAN, 2.4-2.485 GHz) within VSWR <= 2.5:1. Antenna peak gain varies from 5.5 to 8.3 dBi from 1700 to 2500 MHz while the front to back (F/B) ratio is higher than 15 dB for an overall antenna size of 102 mm by 76.4 nun by 5.9 mm

A Miniaturized Hilbert PIFA for Dual-Band Mobile Wireless Applications

A miniaturized planar inverted-F antenna (PIFa) is proposed for dual-band mobile phone application in the 900- and 1900-MHz bands. By employing a Hilbert geometry, an overall size reduction of 50% was achieved compared to a conventional rectangular PIFa. The proposed antenna can be easily printed on the inside surface of the plastic housing of a mobile phone or other wireless device. An experimental prototype of this miniature antenna was fabricated on 0.125 mm thick Duroid 5880 substrate. Measured results demonstrate dual-band characteristics with good radiation patterns

A New Class of Miniature Embedded Inverted-F Antennas (IFAs) for 2.4 GHz WLAN Application

A new class of miniature printed embedded inverted-F antennas are proposed for operation in the 2.4-2.485 GHz wireless local-area network band. One of the proposed antennas on FR4 substrate (dielectric constant = 4.4) measures 9.2 mm by 4.1 mm and has a bandwidth of 3.5%. The peak gain of this antenna is 1.4 dBi. An overall size reduction of 70% is achieved compared to a conventional inverted-F antenna. Effects of dielectric loss tangent and material conductivity on the bandwidth and efficiency of these antennas are also investigated. Finally, two embedded antenna elements are analyzed to demonstrate the feasibility for a decoupled antenna pair consisting of switched and combining diversity schemes

Finite Difference and Finite Element Simulation of a Flexible Manipulator

This paper presents a comparative investigation into the dynamic characterisation of flexible manipulators on the basis of accuracy, computational efficiency and computational requirements using finite difference (FD) and finite element (FE) methods. A constrained planar single-link flexible manipulator is considered. Finite-dimensional simulations of the manipulator are developed using FD and FE methods. The simulation algorithms thus developed are implemented on two computing domains and their performances on the basis of accuracy in characterising the behaviour of the manipulator and computational efficiency are assessed