Modeling a Wireless Network for International Space Station

This paper describes the application of wireless local area network (LAN) simulation modeling methods to the hybrid LAN architecture designed for supporting crew-computing tools aboard the International Space Station (ISS). These crew-computing tools, such as wearable computers and portable advisory systems, will provide crew members with real-time vehicle and payload status information and access to digital technical and scientific libraries, significantly enhancing human capabilities in space. A wireless network, therefore, will provide wearable computer and remote instruments with the high performance computational power needed by next-generation 'intelligent' software applications. Wireless network performance in such simulated environments is characterized by the sustainable throughput of data under different traffic conditions. This data will be used to help plan the addition of more access points supporting new modules and more nodes for increased network capacity as the ISS grows

Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+

The purpose of this study was to synthesize polydimethylsiloxanes by heterogeneous catalysis, based on the polymerization of the hexadecamethylcyclooctasiloxane (D8) by an environment-friendly solid catalyst (Maghnite-H+). Maghnite-H+ is a natural Algerian clay of the montmorillonite type, prepared by activation with sulfuric acid, the impact of this activation was observable in the XRD spectrum, by the increase in the interlayer spacing (d001) resulting from the intercalation of hydronium ions between layers. The molecular structure of the obtained polymer was determined by different chemical methods of analysis such as IR, 1H NMR, and 13C NMR. The thermal behavior of the polysiloxane obtained was confirmed by DSC. In order to achieve the best possible yield and at the same time to get a polymer of high molecular mass, the operating conditions have been set at t = 8 h and T = 70 °C after the reaction was repeated several times. The average molecular mass and the polydispersity index were measured by GPC. A reaction mechanism has been suggested to show the action of the Maghnite-H+ during the reaction.

Catalytic Activity of Maghnite-H+ in the Synthesis of Polyphenylmethylsiloxane under Mild and Solvent-free Conditions

In this study, a new and easy strategy was discussed for the purpose of synthesizing of a polymer of phenylmethylcyclosiloxane type (PPMS). The cationic ring opening polymerization of triphenyltrimethylcyclotrisiloxane (D3Ph,Me) was initiated by a solid, efficient and environmentally-friendly catalyst called Maghnite-H+. Maghnite-H+ is a natural clay composed essentially of montmorillonite, it is activated with an acid treatment by replacing the interlayer ions by protons, that results to the increase of the basal space, this may be confirmed by XRD analysis. The reaction was carried out without solvent at different temperatures and for different periods of time, using also several catalyst contents. Subsequently, the operating conditions were opted in order to obtain a maximum yield of the linear polymer and a high average molecular mass as well. The structure of polymers obtained was confirmed by IR analysis. 1H NMR and 13C NMR analyzes were used to follow the crosslinking of polymer chains over time. The thermal behavior was investigated by DSC analysis. The average molecular mass and the polydispersity indices were determined by GPC

Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+

The purpose of this study was to synthesize polydimethylsiloxanes by heterogeneous catalysis, based on the polymerization of the hexadecamethylcyclooctasiloxane (D8) by an environment-friendly solid catalyst (Maghnite-H+). Maghnite-H+ is a natural Algerian clay of the montmorillonite type, prepared by activation with sulfuric acid, the impact of this activation was observable in the XRD spectrum, by the increase in the interlayer spacing (d001) resulting from the intercalation of hydronium ions between layers. The molecular structure of the obtained polymer was determined by different chemical methods of analysis such as IR, 1H NMR, and 13C NMR. The thermal behavior of the polysiloxane obtained was confirmed by DSC. In order to achieve the best possible yield and at the same time to get a polymer of high molecular mass, the operating conditions have been set at t = 8 h and T = 70 °C after the reaction was repeated several times. The average molecular mass and the polydispersity index were measured by GPC. A reaction mechanism has been suggested to show the action of the Maghnite-H+ during the reaction. Copyright © 2018 BCREC Group. All rights reserved Received: 8th March 2017; Revised: 27th July 2017; Accepted: 1st August 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Kherroub, D.E., Belbachir, M., Lamouri, S. (2018). Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 36-46 (doi:10.9767/bcrec.13.1.993.36-46

Nacera Naar, Patrice Bourson, Sidi Ould Saad Hamady, Polyaniline-doped benzene sulfonic acid/epoxy resin composites: structural, morphological, thermal and dielectric behaviors

International audienceno abstrac

<italic>X</italic>-Band Microwave Absorbing Properties of Epoxy Resin Composites Containing Magnetized PANI-Coated Magnetite

International audienc

Cationic Ring Opening polymerization of ε-caprolactam by a Montmorillonite Clay Catalyst

<p>The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H+ was reported. Maghnite-H+ is a montmorillonite silicate sheet clay was prepared through a straight forward proton exchange process. The effect of the amount of catalyst, and temperature was studied. Increasing Maghnite-H+ proportion and temperature produced the increase in ε-caprolactam conversion. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. Mechanism studies showed that monomer inserted into the growing chains with the acyl–oxygen bond scission rather than the break of alkyl–oxygen bond. © 2014 BCREC UNDIP. All rights reserved</p><p><em>Submitted: 3rd October 2013; Revised: 28th February 2014; Accepted: 1st March 2014</em></p><p>[<strong>How to Cit</strong>e: Kherroub, D.E., Belbachir, M., Lamouri, S. (2014). Cationic Ring Opening Polymeriza-tion of ε-caprolactam by a Montmorillonite Clay Catalyst. <em><strong>Bulletin of Chemical Reaction Engineering &amp; Catalysis</strong></em>, 9 (1): 74-79. (doi:10.9767/bcrec.9.1.5555.74-80)]</p><p><br />[<strong>Permalink/DOI</strong>: <a href="http://dx.doi.org/10.9767/bcrec.9.1.5555.74-80">http://dx.doi.org/10.9767/bcrec.9.1.5555.74-80</a>]</p><p><em><br /></em></p

Chemical synthesis and characterization of highly soluble conducting polyaniline in the mixtures of common solvents

This work presents the synthesis and characterization of soluble and conducting polyaniline PANI-PIA according to chemical polymerization route. This polymerization pathway leads to the formation of poly(itaconic acid) doped polyaniline salts, which are highly soluble in a number of mixtures between organic common polar solvents and water, the solubility reaches 4 mg mL-1. The effect of synthesis parameters such as doping level on the conductivity and the study of solubility and other properties of the resulting PANI salts were also undertaken. The maximum of conductivity was found equal to 2.48×10-4 S cm-1 for fully protonated PANI-EB. In addition, various characterizations of the synthesized materials were also done with the help of viscosity measurements, UV-vis spectroscopy, XRD, FTIR and finally TGA for the thermal properties behaviour