Numerical analysis of lateral torsional buckling of steel i-beams with and without web-openings under fire

Steel structures are being widely used in construction industry owing to their excellent structural flexibility and to their high ductility to withstand lateral forces. However, for the case of solid and cellular steel beams, high temperature effect may result in different fire response for each case due to a great reduction of yield stress and Young’s modulus. Moreover, when the beams are not restrained, lateral torsional bending phenomenon which are bound to take place is made worse in the case of fire. The aim of this study is to analyse the behaviour of steel beams with and without web openings when taking into account the effect of geometry and material imperfections. The results from the finite element models produced lateral and vertical displacements as well as the buckling moments.info:eu-repo/semantics/publishedVersio

Multimodal fusion of the finger vein, fingerprint and the finger-knuckle-print using Kernel Fisher analysis

Unimodal biometric have improved the possibility to establish systems capable of identifying and managing the flow of individuals according to the available intrinsic characteristics that we have. However, a reliable recognition system requires multiple resources. This is the main objective of the multimodal systems that consists of using different resources. Although multimodality improves the accuracy of the systems, it occupies a large memory space and consumes more execution time considering the collected information from different resources. Therefore we have considered the feature selection, that is, the selection of the best attributes that enhances the accuracy and reduce the memory space as a solution. As a result, acceptable recognition performances with less forge and steal can be guaranteed. In this paper we propose an identification system using multimodal fusion of finger-knuckle-print, fingerprint and finger's venous network by adopting several techniques in different levels for multimodal fusion. A feature level fusion and decision level is proposed for the fusion of these three biological traits. An optimization method for this multimodal fusion system by enhancing the feature level fusion is introduced. The optimization consists of the space reduction by using different methods.This work was supported by the Erasmus Mundus program EU-MARE NOSTRUM (EUMN) grant agreement number: 2011-4050/001-001-EMA2.info:eu-repo/semantics/publishedVersio

Wheel attitude cancellation thruster torque of LEO microsatellite during orbital maintenance

A cold gas propulsion system is used for orbital maintenance on board microsatellite. Cold gas thrusters are the simplest way of achieving thrust. A microsatellite could be a part of the constellation and to maintain a daily coverage, it will be equipped with a propulsion system for an orbit control. A constellation of several microsatellites could be launched and put at the allocate position in the orbit. To do this, the satellites need few months to be in their final position. A propulsion system is used, among other things, to maintain the satellite at its nominal position. The wheels (reaction/momentum) will be used to dump the thruster disturbances caused by misalignment. This study describes the wheel attitude damping thruster disturbances of Low Earth Orbit (LEO) microsatellite for orbit maintenance with the following points: 1) Attitude dynamics, 2) External disturbances, 3) Magnetic wheel control, 4) Simulation results will be presented to evaluate the performance and design objectives. © 2006 Asian Network for Scientific Information

The Finger-Knuckle-Print recognition using the kernel principal components analysis and the support vector machines

In the computer networks explosion's time, the need to identify individuals increasingly becomes necessary to perform various operations, such as access control and secure payments. So far, inputting alphanumeric code remains the most used solution. This solution, in spite of having the merit to be very simple, has the disadvantage to certify only the individual who enters the correct code. Another possibility that is open to us is to use biometric identification, by identifying directly the physical traits of the user. Biometric identification is defined as a science allowing the identification of people using their behavioral or physiologic characteristics. It seems like an evident solution to the problem explained previously: the identity of a person is then related to who he/she is and not to what he/she possesses or knows. In this work, we propose a biometric system based on a very recent biometric trait, which consists in the finger-Knuckle-Prints. This recognition is based on a mathematical model.info:eu-repo/semantics/publishedVersio

COMSAT 1.0 software aided design for a low earth orbit microsatellite commissioning phase

In the past several years, a plethora of spacecraft control techniques have been developed that address the challenging attitude tracking, stabilization and disturbance rejection requirements of these missions. One major aspect that has been typically missing in the research area of attitude control development is the experimental validation of the theoretical results. Experimental testing is necessary before control laws can be incorporated in the future generation of spacecraft. Based on this fact, we thought on the implementation of a software design COMSAT 1.0 that has the ability to overcome these difficulties. It includes all the attitude control phases, from the launcher separation i.e., initial attitude acquisition until the accurate nadir attitude pointing. This software uses micro satellites i.e., small satellites as testing models in orbit. We have chosen Alsat-1 the first Algerian micro satellite as a test model. © Medwell Journals, 2007

Hollow micro and nanostructures for therapeutic and imaging applications

Hollow particles have been extensively used in bioanalytical and biomedical applications for almost two decades due to their unique and tunable optoelectronic properties as well as their significantly high loading capacities. These intrinsic properties led them to be used in various bioimaging applications as contrast agents, controlled delivery (i.e. drugs, nucleic acids and other biomolecules) platforms and photon-triggered therapies (e.g. photothermal and photodynamic therapies). Since recent studies showed that imaging-guided targeted therapeutics have higher success rates, multimodal theranostic platforms (combination of one or more therapy and diagnosis modality) have been employed more often and hollow particles (i.e. nanoshells) have been one of the most efficient candidates to be used in multiple-purpose platforms, owing to their intrinsic properties that enable synergistic multimodal performance. In this review, recent advances in the applications of such hollow particles fabricated with various routes (either inorganic or organic based) were summarized to delineate strategies for tuning their properties for more efficient biomedical performance by overcoming common biological barriers. This review will pave the ways for expedited progress in design of next generation of hollow particles for clinical applications. © 2020 Elsevier B.V

Modelling and optimization of the absorption rate of date palm fiber reinforced composite using response surface methodology

The aim of this work to explore the absorption behavior of bio composites reinforced with date palm fibers. RSM and ANOVA were utilized to evaluate the impact and interdependence of input variables (Time: from 24 h to 672 h, Fiber content: 15 %, 20 %, and 25 %, and types of water: seawater, distilled water, and rainwater) on the output variables (Mass of CDPF) during a water absorption process that lasted more than 670 h at 23 °C. The findings revealed that the bio composites with the above-mentioned filler content absorbed more water as the amount of fibers increased, with absorption rates of 14.03 %, 19.39 %, 30.94 % for seawater, 15.42 %, 20.64 %, and 36.08 % for distilled water, and 16.37 %, 21.98 %, and 42.10 % for rainwater, respectively. Additionally, the study measured the diffusion coefficient of bio composites, which had a minimum value of about 2.11 × 10−6mm2/s and a maximum value of about 3.99 × 10−6mm2/s. The results of RSM model analysis showed that this model is accurate and reliable. Where the values of R2 and adjusted R2 coefficients for the Mass of CDPF were 99.63 % and 99.61 %, respectively, indicating an ideal match between experimental and predicted values. These findings provide valuable information for engineers interested in incorporating date palm fiber bio composites during development and implementation