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Islamabad, Pakistan

Razaq A.,COMSATS Institute of Information Technology | Khan A.A.,COMSATS Institute of Information Technology | Asif M.H.,COMSATS Institute of Information Technology | Iqbal S.,COMSATS Institute of Information Technology | And 3 more authors.
Modern Physics Letters B | Year: 2015

Naturally, existing lignocelluloses fibers showed outstanding potential in paper industry and other conventional applications. On the other hand, lignocellulose fibers are suitable candidate for high-tech applications under the scope of abundance, flexibility, light-weight and environment friendliness. In this study, paper sheets were prepared from lignocelluloses fibers extracted from self-growing plant, typha angustifolia. Lignocelluloses paper sheets were characterized for scanning electron microscopy (SEM), universal testing machine (UTM) and vector network analyzer (VNA). Flexible paper sheets displayed a tensile strength of 9.1 MPa and further used as a substrate in patch antenna to observe dielectric characteristics. The patch antenna is designed at 5.1 GHz which showed return loss less than -10 dB and dielectric constant 3.71. The use of lignocelluloses paper sheet as a substrate in patch antenna will provide the opportunity of miniaturization of size and weight in comparison of a jean substrate based antenna. © 2015 World Scientific Publishing Company.

Razaq A.,COMSATS Institute of Information Technology | Asif M.H.,COMSATS Institute of Information Technology | Kalsoom R.,COMSATS Institute of Information Technology | Khan A.F.,COMSATS Institute of Information Technology | And 3 more authors.
Journal of Applied Polymer Science | Year: 2015

Direct use of lignocelluloses fibers as substrate for fabrication of conductive, electroactive, biodegradable, and low-cost electrode materials are in demand for high-tech applications of ion-exchange and energy storage devices. This article presents the preparation and characterizations of conductive and electroactive lignocelluloses-polyaniline (cellulose/PANI) composite paper. Lignocelluloses fibers were directly collected from the stem of self-growing plant, Typha Angusitfolia, and subsequently coated with the conductive and electroactive layer of PANI through chemical synthesis. Individual PANI-coated lignocelluloses fibers were converted into sheet and further characterized with Scanning Electron Microscopy, Fourier Transform Infrared, Thermogravimetric Analysis, electronic conductivity, and Cyclic Voltammetry. Cellulose/PANI composite paper revealed superior thermal characteristics and used as a working electrode in three different electrolytes for ion-exchange properties. Conductive composite paper (CCP) showed the charge storage capacity of ∼52 C/g at scan rate of 5 mV/s in 2M HCl solution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42293. © 2015 Wiley Periodicals, Inc.

Belhedi A.,CEA Saclay Nuclear Research Center | Belhedi A.,National Engineering School of Tunis | Bourgeois S.,CEA Saclay Nuclear Research Center | Gay-Bellile V.,CEA Saclay Nuclear Research Center | And 3 more authors.
Proceedings - International Conference on Image Processing, ICIP | Year: 2012

Time-of-Flight (TOF) cameras measure, in real-time, the distance between the camera and objects in the scene. This opens new perspectives in different application fields: 3D reconstruction, Augmented Reality, video-surveillance, etc. However, like any sensor, TOF cameras have limitations related to their technology. One of them is distance distortion. In this paper, we present a new depth calibration method (estimation of distance distortion) for TOF cameras. Our approach has several advantages. First, it is based on a non-parametric model, contrary to most of the other methods. Second, it models under the same formalism the distortion variation according to the distance and the pixel position in the image. This improves calibration accuracy even at the image boundaries which are typically more distorted than the image center. A comparison with two state of the art parametric methods is presented. © 2012 IEEE.

Ahmad I.,Bahauddin Zakariya University | Ahmad M.,Bahauddin Zakariya University | Ali I.,Bahauddin Zakariya University | Kanwal M.,Bahauddin Zakariya University | And 3 more authors.
Journal of Electronic Materials | Year: 2015

A series of Gd-substituted Ba-Co-based (M-type) hexaferrites having the chemical compositions of Ba0.5Co0.5GdxFe12−xO19 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by co-precipitation method. The pellets formed by co-precipitated powder were calcined at a temperature of 1200°C for 20 h. Final sintering was done at 1320°C for 4 h. From the x-ray diffraction analysis, it was revealed that all the samples showed M-type hexagonal structure as a major phase. The scanning electron microscope was used to examine the morphology of the sintered ferrites. The average grain size estimated by the line intercept method was found to be in the range of 2.8–1.0 μm. The room temperature DC resistivity increases with increasing Gd-contents to make these ferrites useful for high frequency applications and microwave devices. Lower values of coercivity (Hc) and higher saturation magnetization (Ms) may be suitable to enhance the permeability of these ferrites, which is favorable for impedance matching in microwave absorption. In addition, reflection coefficients for a sample was also measured from a frequency of 1 MHz to 3 GHz and a reflection peak was observed at about 2.2 GHz. © 2015, The Minerals, Metals & Materials Society.

Ramadasan D.,CNRS Pascal Institute | Chevaldonne M.,ISIT | Chateau T.,CNRS Pascal Institute
2015 IEEE Virtual Reality Conference, VR 2015 - Proceedings | Year: 2015

This paper presents a new approach for multi-objects tracking from a video camera moving in an unknown environment. The tracking involves static objects of different known shapes, whose poses and sizes are determined online. For augmented reality applications, objects must be precisely tracked even if they are far from the camera or if they are hidden. Camera poses are computed using simultaneous localization and mapping (SLAM) based on bundle adjustment process to optimize problem parameters. We propose to include in an incremental bundle adjustment the parameters of the observed objects as well as the camera poses and 3D points. We show, through the example of 3D models of basics shapes (planes, parallelepipeds, cylinders and spheres) coarsely initialized online using a manual selection, that the joint optimization of parameters constrains the 3D points to approach the objects, and also constrains the objects to fit the 3D points. Moreover, we developed a generic and optimized library to solve this modified bundle adjustment and demonstrate the high performance of our solution compared to the state of the art alternative. Augmented reality experiments in realtime demonstrate the accuracy and the robustness of our method. © 2015 IEEE.

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