RAJEEV KUMAR

Journal of Polymer Materials, Vol.37, No.3-4, pp. 131-142, 2020, DOI:10.32381/JPM.2020.37.3-4.2

Abstract The optical, electrical and acoustical properties of a polymer solution based on polyvinyl pyrrolidone (PVP) doped with different concentration of cupric sulphate (CuSO₄ ) were studied.UVVIS spectroscopy results reflected that absorption increases in asymmetric manner and the absorption peak showed red shift with increasing Cu ions concentration. The optical band gap (direct and indirect) was found to decrease with increase in Cu ions concentration in the polymer due to increase in the density of localized states in the band-gap.The value of Urbach energy is also evaluated from the transmission spectra and the activation energies are also evaluated from the conductivity… More >

ARUN KUMAR M, JAYAKUMARI LS^*, RAMJI CHANDRAN

Journal of Polymer Materials, Vol.40, No.3-4, pp. 141-156, 2023, DOI:10.32381/JPM.2023.40.3-4.2

Abstract Nanocomposites are very important materials because it imparts superior properties than other composites with low level of filler loading. Styrene butadiene rubber (SBR) is a non-polar rubber which acts as an insulator and has low electrical conductivity. Graphene platelet nano-powder from 0.1 to 1.25 phr level is incorporated into SBR rubber in order to improve the electrical properties. Comparative studies on electrical and mechanical properties of styrene butadiene rubber with graphene platelet nano-powder (GPN) by varying the filler content are made. The incorporation of Graphene platelet nano-powder increases the electrical conductivity in styrene butadiene rubber. It has been observed that… More >

Ahmed M. Zeyada^1,*, Khalid A. Al-Gaadi^1,2, ElKamil Tola², Rangaswamy Madugundu², Ahmed A. Alameen²

Phyton-International Journal of Experimental Botany, Vol.92, No.5, pp. 1603-1620, 2023, DOI:10.32604/phyton.2023.027267

Abstract The estuary tides affect groundwater dynamics; these areas are susceptible to waterlogging and salinity issues. A study was conducted on two fields with a total area of 60 hectares under a center pivot irrigation system that works with solar energy and belong to a commercial farm located in Northern Sudan. To monitor soil salinity and calcium carbonate in the area and stop future degradation of soil resources, easy, non-intrusive, and practical procedures are required. The objective of this study was to use remote sensing-determined Sentinel-2 satellite imagery using various soil indices to develop prediction models for the estimation of soil… More >

Zhi Xu, Yoshio Bando, Lei Liu, Wenlong Wang, Xuedong Bai, Dmitri Golberg

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 41-42, 2011, DOI:10.3970/icces.2011.017.041

Abstract A specially designed suspended graphene oxide (GO) device has been fabricated and investigated in a transmission electron microscope (TEM)-scanning tunneling microscopy (STM) based setup. The detailed study of step-by-step slow reduction of an individual GO sheet under current flow and thereby Joule heating, while in-parallel performing conductivity measurements, atomic structure imaging, chemical composition, and bonding alternations tracing have been performed. As monitored by electron energy core loss spectroscopy, the oxygen content is tuned from that peculiar to a pristine GO, i.e. 23.8 at.%, to oxygen-free pure graphene. Six orders of magnitude conductance rise is achieved during this process with the… More >

A. Delgado-Lima, M. C. Paiva^*, A. V. Machado

Journal of Renewable Materials, Vol.5, No.2, pp. 145-153, 2017, DOI:10.7569/JRM.2017.634104

Abstract Cellulose acetate (CA) is produced from a natural polymer and presents excellent properties, finding applications in a variety of areas. Unlike cellulose, CA is melt processable and may be molded into parts and formed into fibers or films. In this context, the production of conductive CA composites that may be processable and integrated into parts to provide specific functionalities is an area of increasing interest. The present work aims to prepare electrically conductive composites based on CA and carbon nanotubes (CNTs) by melt mixing. The nanocomposites were produced with pure and pyrrolidine-functionalized nanotubes, using a batch mixer and a twin-screw… More >

B.J. Yang¹, K.J. Cho¹, G.M. Kim¹, H.K. Lee^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.103, No.5, pp. 343-365, 2014, DOI:10.3970/cmes.2014.103.343

Abstract The addition of carbon nanotubes (CNTs) to a matrix material is expected to lead to an increase in the effective electrical properties of nanocomposites. However, a CNT entanglement caused by the matrix viscosity and the high aspect ratio of the nanotubes often inhibits the formation of a conductive network. In the present study, the micromechanics-based model is utilized to investigate the effect of CNT agglomeration on the electrical conductivity and percolation threshold of nanocomposites. A series of parametric studies considering various shapes and curviness distributions of CNTs are carried out to examine the effects of entanglement on the electrical performance… More >