Vol 2 , No 2 (Published)





DOI: http://dx.doi.org/10.18063/msacm.v2i2

Table of Contents

Original Research Articles

by Nanzhu Zhao 1, Yongha Kim 1, Joseph H. Koo 1
118 Views, 86 PDF Downloads
High electrical and thermal conductivity associated with high stiffness and strength offer tremendous opportunities to the development of a series of carbon nanotube incorporated composite materials for a variety of applications. In particular, a small amount of carbon fibers or carbon nanotubes in a non-conductive polymer will transform a composite into a conductive material, which reveals superb potential of their future application in electronic devices. The relation between the amount of carbon nanotubes in a polymer and the electrical conductivity of it can be studied experimentally as well as theoretically with various simulation models. A three-dimensional (3D) Monte Carlo simulation model using resistance network formation was developed to study the relation between the electrical conductivity of the polymer nanocomposite and the amount of carbon nanotubes dispersed in it. In this model, carbon nanotubes were modeled as curvy cylindrical nanotubes with various lengths and fixed tube diameter, all of which were randomly distributed in a non-conductive constrained volume, which represents polymer. The model can be used to find the volumetric electrical resistance of a constrained cubic structure by forming a comprehensive resistance network among all of the nanotubes in contact. As more and more nanotubes were added into the volume, the electrical conductivity of the volume increases exponentially. However, once the amount of carbon nanotubes reached about 0.1 % vt (volume percentage), electrical percolation was detected, which was consistent with the experimental results. This model can be used to estimate the electrical conductivity of the composite matrix as well as to acquire the electrical percolation threshold.
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Original Research Articles

by Afreen Usmani 1, Pragyandip P Dash 2, Anuradha Mishra 1
76 Views, 67 PDF Downloads
An important reason for investigation using plants for nanotechnological research is due to their easy availability as well as applications in various ailments. Silver nanoformulation can be synthesized using whole plant extract or bioactive of that particular plant. In addition, plant extracts or bioactive of the plant may act both as reducing agents and stabilizing agents in the synthesis process of nanoformulation. The therapeutic effect of plant extract is hindered because of its instability, poor solubility, and low bioavailability. So, nowadays, researches have been carried out for improving all these properties including sustainability through silver nanotechnological approach. The major advantage of green synthesis using plant extracts is that, organic solvents and other excipients are not used because the plant phytochemicals are involved directly in the reduction of the ions and formation of silver nanoparticles. The present review provides an updated knowledge on mechanism of green synthesis of silver nanoparticle and their mechanism of action as antibacterial and anticancer activities.
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Original Research Articles

by Yan Shi 1, Jie Yang 1, Hua Shen 1, Zhankui Meng 1, Tong Hao 1
123 Views, 59 PDF Downloads
In this paper, a metamaterial-based ferromagnetic absorber has been designed at microwave frequencies. The proposed absorber is composed of a periodic array of stacked circular ferromagnetic patches fabricated on the FR4 substrate. With the ferromagnetic property, the single-layer patch array generates a good resonant absorption mode. By stacking multiple ferromagnetic patches, the designed absorber with the absorption above 90% has a wide absorption bandwidth from 10 to 21 GHz. Due to the symmetric structure, the proposed absorber is polarization insensitive. At oblique incident with the incident angle of 45o, the good absorption more than 80% can be achieved in the whole operation band.
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Original Research Articles

by Assia A. Mahamat 1, Salifu T. Azeko 2
92 Views, 96 PDF Downloads
This paper presents the results of the experimental and theoretical study of the mechanical and structural properties of termite soil as a partial replacement to cement for different applications, especially in the building/construction industry. Different volume fractions of termite soil are mixed with Portland cement and their compressive and flexural strengths as well as fracture toughness values are determined. The mechanical properties of the composites are also elucidated after curing the samples for 7 days, 14 days and 28 days. The study shows that the 28 days Compressive strength decreases with increasing volume percentage of termite soil for volume percentages up to 60%. The 28 day strength was also greater than the requirement of (NIS 87: 2000) for non-bearing load walls (δmin=2.8N/mm²› 2.5 N/mm²). The flexural strength for 20% replacement (at all curing days) was greater than 7 N/mm². The fracture toughness was also observed to decrease with increasing volume percentage of termite soil up to 20 vol. %. This resulted in a maximum fracture toughness of 4.24  for the materials with 20 vol. % of termite soil stabilization. The samples are then characterized via X-ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDX). The implications of the results are discussed for the development of sustainable termite-stabilized building materials.
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