scholarly journals Recent Advances in the Processing and Properties of Alumina–CNT/SiC Nanocomposites

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 86 ◽  
Author(s):  
Ibrahim Momohjimoh ◽  
Mohamed Hussein ◽  
Nasser Al-Aqeeli
Keyword(s):  
Fracture Toughness ◽  
Characteristic Size ◽  
Research Trends ◽  
Alumina Matrix ◽  
Related Research ◽  
Conductive Materials ◽  
Mechanical Hardness ◽  
Recent Advances ◽  
Potential Applications ◽  
Thermal And Electrical Properties

An alumina-based nanocomposite is fabricated through the addition of secondary nanophase material to an alumina matrix to alter and tailor the properties of alumina. The addition to alumina of semi-conductive materials, such as silicon carbide (SiC), and high conductive materials, such as carbon nanotubes with a characteristic size in the nanometer range, can alter the mechanical strength, hardness, toughness, and electrical and thermal properties of alumina. This paper discusses recent advances in the synthesis of alumina–SiC and alumina-carbon nanotube (CNT) nanopowders and their consolidation using conventional and non-conventional techniques. Mechanical (hardness, fracture toughness and flexural strength) and functional (thermal and electrical) properties are discussed. The influence of the microstructure on the properties of alumina–SiC and alumina–CNT nanocomposites is discussed. Furthermore, potential applications and current related research trends are described.

scholarly journals Recent Advances in the Chemical Biology of N-Glycans

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1040
Author(s):  
Asuka Shirakawa ◽  
Yoshiyuki Manabe ◽  
Koichi Fukase
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Molecular Basis ◽  
Chemical Biology ◽  
Molecular Level ◽  
Chemoenzymatic Synthesis ◽  
Complex Structures ◽  
Recent Advances ◽  
Protein Functions ◽  
Potential Applications

Asparagine-linked N-glycans on proteins have diverse structures, and their functions vary according to their structures. In recent years, it has become possible to obtain high quantities of N-glycans via isolation and chemical/enzymatic/chemoenzymatic synthesis. This has allowed for progress in the elucidation of N-glycan functions at the molecular level. Interaction analyses with lectins by glycan arrays or nuclear magnetic resonance (NMR) using various N-glycans have revealed the molecular basis for the recognition of complex structures of N-glycans. Preparation of proteins modified with homogeneous N-glycans revealed the influence of N-glycan modifications on protein functions. Furthermore, N-glycans have potential applications in drug development. This review discusses recent advances in the chemical biology of N-glycans.

Comparative Analysis of Fracture Toughness Obtained by Different Techniques in Alumina Matrix - Dispersed TZP Zirconia Composites

2016 ◽  
Vol 869 ◽  
pp. 46-51
Author(s):  
Daniel Alessander Nono ◽  
Eron Fernandes da Silva ◽  
Maria do Carmo de Andrade Nono ◽  
Francisco Piorino Neto ◽  
Sergio Luiz Mineiro
Keyword(s):  
Fracture Toughness ◽  
Tetragonal Zirconia ◽  
Ceramic Composites ◽  
Alumina Matrix ◽  
Single Edge ◽  
Chemical Inertness ◽  
Edge Notch ◽  
Properties Of Materials ◽  
Experimental Values ◽  
Benefit Cost

The fracture toughness is one of the requirements for mechanical properties of materials for use in satellites. The ceramic TZP zirconia (tetragonal zirconia polycrystals) have been investigated for applications in ballistic armor. Due to the chemical inertness and fracture toughness, this material has the potential to act as a screen against impacts of micrometeorites and space debris. The ceramic composites of alumina-zirconia 3Y-TZP (tetragonal zirconia polycrystals doped with 3 mol% ytria ) are the materials with the best benefit / cost for this application. This paper presents and discusses the results obtained from the use of two techniques for determining fracture toughness. The composite alumina - 18.5% of 3Y-TZP zirconia nanoparticles obtained from deflocculated powders have been tested for Vickers and the SEVNB penetration method (Single-Edge-Notch Beam V) to obtain the fracture toughness values (KIC). The KIC values obtained were analyzed due to the lower dispersion of experimental values. The SEVNB method showed better reliability in determining the toughness values in the studied ceramics.

Recent advances in the construction of cyclic grafted polymers and their potential applications

2018 ◽  
Vol 9 (6) ◽  
pp. 677-686 ◽  
Author(s):  
Shuangshuang Zhang ◽  
Yasuyuki Tezuka ◽  
Zhengbiao Zhang ◽  
Na Li ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Grafted Polymers ◽  
Recent Advances ◽  
Potential Applications ◽  
Grafting Through ◽  
Grafting From ◽  
Grafting Onto

Three main strategies used for the construction of cyclic grafted polymers, “grafting through”, “grafting onto”, and “grafting from”, are summarized.

Internet of Things and Cognitive Radio

2021 ◽  
Vol 11 (1) ◽  
pp. 39-52
Author(s):  
Badr Benmammar
Keyword(s):  
Cognitive Radio ◽  
Internet Of Things ◽  
Research Trends ◽  
Iot Applications ◽  
Enabling Technologies ◽  
Potential Applications ◽  
Worldwide Network

Internet of things (IoT) is a worldwide network of interconnected objects. However, the things-oriented, internet-oriented, semantic-oriented, and tactile-oriented versions of IoT are meaningless if the IoT objects are not equipped with intelligence. For this, current research trends are oriented towards cognitive radio. This paper presents IoT, its definition, its potential applications, its challenges, as well as its enabling technologies. Among these technologies, particular importance is given to cognitive radio. The overall objective of this paper is to make a global synthesis on the motivations as well as on the challenges to be raised by the integration of cognitive radio in IoT in order to serve as self-reconfigurable solutions for a certain number of IoT applications.

Sem and Tem Studies of NiAl2O4 Spinel Phase Distribution in Alumina Matrix

2013 ◽  
Vol 58 (2) ◽  
pp. 501-504 ◽  
Author(s):  
K. Konopka ◽  
L. Litynska-Dobrzynska ◽  
J. Dutkiewicz
Keyword(s):  
Fracture Toughness ◽  
Phase Distribution ◽  
Spinel Phase ◽  
Metal Particles ◽  
Alumina Matrix ◽  
Sem And Tem ◽  
Alumina Matrix Composite ◽  
Composite Properties ◽  
Almost Continuous ◽  
Properties Of Composites

Methods of enhancing of mechanical properties of ceramic-metal composites, particularly fracture toughness by introducing dispersed metal particles such as W, Mo, Ni, Al, etc to a ceramic matrix are well known. However, the dependence of the microstructures, especially interfaces, on the properties of composites is not well understood yet. Moreover, the ceramic-metal interfaces play a crucial role in tailoring the composite properties. In this paper we examine the alumina matrix composite with NiAl2O4 spinel phase and present the SEM and TEM studies of spinel distribution, size and crystallographic orientation. The composites were prepared by sintering Al2O3 and Ni powders below the melting point of Ni in argon. During the process of sintering the spinel phase appeared. It was not homogeneously distributed in the alumina matrix. The spinel phase areas were linked together and constituted an almost continuous form. We observed that the distribution and size of spinel influenced the fracture toughness of the composite.

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