A brief review on preparation and application of MWCNT-based polymer nanocomposites

Technological advancementalways seeks new materials with improved functional properties, particularly for smart applications. In this regard, nanotechnology is offering today wide range of novel material designs fabricated by compounding nanofillers into the polymer matrix. Different allotropic forms of carbon can reinforce the properties of polymers for various applications. Reinforcement depends on the dimension, shape, size and compatibility of the nanofiller with the polymer matrix. Chemical modification of filler surfaces and the matrix can selectively localize the filler in the hybrid composites in the desired phase or at the interface by melt mixing or solution casting method, during compounding procedure. In this regard, the conducting nature of the additioin of multiwalled carbon nanotubes (MWCNTs) into a polymer matrix fosters the conductivity into the materials. Such nanocomposites can be used for numerous applications such as conducting materials, super-capacitors, light emitting devices, medical purposes etc,. This review paper focuses on different methods of preparation of MWCNT/polymer nanocomposites, their surface properties, and microbial properties etc,

Influence of Controlled Epoxidation of an Asymmetric Styrene/Butadiene Star Block Copolymer on Structural and Mechanical Properties

The chemical modification (namely the epoxidation) of a star shaped block copolymer (BCP) based on polystyrene (PS) and polybutadiene (PB) and its effect on structural and mechanical properties of the polymer were investigated. Epoxidation degrees of 37 mol%, 58 mol%, and 82 mol% were achieved by the reaction of the copolymer with meta-chloroperoxy benzoic acid (m-CPBA) under controlled conditions. The BCP structure was found to change from lamellae-like to mixed-type morphologies for intermediate epoxidation level while leading to quite ordered cylindrical structures for the higher level of chemical modification. As a consequence, the glass transition temperature (Tg) of the soft PB component of the BCP shifted towards significantly higher temperature. A clear increase in tensile modulus and tensile strength with a moderate decrease in elongation at break was observed. The epoxidized BCPs are suitable as reactive templates for the fabrication of nanostructured thermosetting resins

Traditional, video and extended reality (XR) assisted flipped classroom teaching methods:an approach and comparison

This paper examines the comparative effectiveness of three distinct Flipped Classroom (FC) teaching methods in the context of Power and Electrical (PE) engineering education: Traditional Flipped Classroom (TFC), Video-Assisted Teaching Methods (VAFC), and Virtual Reality Flipped Classroom (VRFC). The study incorporates valuable feedback from students who experienced these methods and provides an evaluation of their perceptions. A cross-over methodology for comparing these FC methods is presented. The VAFC method is perceived to be an effective approach and preferred over TFC and VRFC by students. The paper also provides Teachers' perception in implementing above FC methods, which outlines a process for developing VAFC and VRFC teaching resources. Operational difficulties in implementing such methods are highlighted, especially in the context of fast-paced, privately-catered undergraduate education sector striving for implementing non-conventional teaching methods

Understanding COVID-19 Situation in Nepal and Implications for SARS-CoV-2 Transmission and Management

CC BY-NC 4.0Emerging infectious diseases (EIDs) present one of the greatest challenges to public health in the 21st century. An emerging virus, depending on its potential to spread among humans, may cause individual or sporadic cases, culminating in a localized outbreak requiring public health intervention, or, in the worst-case scenario, a widespread epidemic, or worldwide pandemic.1 The novel Coronavirus Disease 2019 (COVID-19) is a new respiratory disease caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) that is causing worldwide public health and economic challenges and has been recognized as a pandemic by the World Health Organization.2 The virus was first reported in Wuhan, Hubei Province, China, in December 2019.2,3 SARS-CoV-2 is an enveloped and positive single-stranded RNA virus belonging to the ß-coronavirus genus.2-4 SARS-CoV-2 holds high homology with SARS-CoV and targets angiotensin-converting enzyme receptor-2 (ACE2) for the viral attachment.4 A schematic depicting SARS-CoV-2 structure and pathogenesis is presented in Figure 1.5 There are very few studies on the transmission of SARS-CoV-2 through treated or untreated wastewater from advanced countries; however, COVID-19 surveillance of wastewater in developing countries has not been reported adequately.6 There is thus a need to study the presence of SARS-CoV-2 in wastewater in the developing countries like Nepal.OA publication support through Carolina Consortium agreement with Sag

An exercise-based international polymer syllabus

The IUPAC Subcommittee on Polymer Education has been pursuing the development of a compact syllabus covering the essential topics required for a tertiary education in polymer science, with numerical and short answer exercises addressing each topic. The primary goal of the document is to provide a framework for a complete course made freely available worldwide so that any educator can implement a professionally-curated course in polymer science for their students without needing expensive textbooks or reliable internet access. An important secondary goal is to popularize the use of approved IUPAC terminology in polymer science by using it consistently throughout the document and providing references to IUPAC source documents. Professor Melissa Chin Han Chan was an active and enthusiastic participant in the project who played a significant role in its design and implementation. The late Professor Richard ‘Dick’ Jones also had a keen interest in the project and had a great influence on its direction and structure. This brief note is dedicated to these two illustrious polymer scientists

Association of Antibiotic and Heavy Metal Resistant Bacteria Screened from Wastewater

Wastewater treatment plant is a potential reservoir contributing to the evolution and spread of heavy metal and antibiotic resistant bacteria. The pollutants such as biocides, antibiotics, heavy metals are to be feared for as they have been known to evoke resistance in microorganisms in such polluted environment. The aim of this study was to the isolate bacteria from the treated wastewater and assess the resistance pattern of the isolates against antibiotics and heavy metals. Grab sampling was performed from April to June 2017, from the treated effluent from the secondary treatment plant. To assess the resistance pattern for antibiotic(s) and heavy metal(s), antibiotic susceptibility test and minimum inhibitory concentration by cup well method were performed respectively. Staphylococcus aureus, Enterococcus faecalis, Citrobacter freundii, Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, P. vulgaris, Salmonella Typhi, Pseudomonas aeruginosa were isolated. Multi drug and heavy metal resistant isolates were screened. Fisher’s exact test revealed that there is a significant association (p&lt; 0.001) between antibiotic resistance pattern and resistance patterns at dilution of 2500 g/L (25%). Cramer’s V test revealed that the effect size of antibiotic resistance pattern and heavy metal resistance pattern at dilution 2500 g/L is medium. P. aeruginosa was able to resist the metal concentration up to 10000 g/L (100%) dilution of Fe++. Heavy metal resistant bacteria can be safely used to lower chemical concentration in the environment once their harmful genes are edited, knocked etc. so that risks of evoking antibiotic resistance could be minimized. </p

Comparative Study of Polymer Composites with Cellulose Microfibers from Different Plant Resources

Wheat stalk (W), Fosro (F), Nigalo with waxy layer (NW), and Nigalo without waxy layer (NWo) were used to extract microcrystalline cellulose (MCC), the xMCC (where x represents origin such as W, F, NW, and NWo) by thermochemical and mechanical treatments. About 10 wt% of xMCC and commercial MCC (C-MCC) were solution casted with ethylene oxide-epichlorohydrin (EO-EPI) to prepare microcomposites. The xMCC and cryo-fractured composites were observed by scanning electron microscopy, and the mechanical properties of the composites were measured by dynamic mechanical analysis to observe the effect of fillers on viscoelastic properties. The results concluded that the xMCCs are homogeneously dispersed in the EO-EPI polymer matrix, which reinforced the viscoelastic and mechanical properties in EO-EPI composites, and reinforcement is dramatically high with NWoMCC compared to NWMCC, WMCC, FMCC, and C-MCC

Assessment of iridoids and their similar structures as antineoplastic drugs by <i>in silico</i> approach

Iridoids commonly found in plants as secondary metabolites have been reported to possess significant biological activities such as anticancer, antioxidant, hypoglycemic, antimicrobial etc. The strong interactions of iridoids with cyclic-dependent kinase 8 (CDK8) protein could show inhibitory effects that could modulate tumour growth. From the molecular docking calculations, some iridoids interacted effectively with the target CDK8 protein (PDB ID: 5ICP) with better binding affinities of −9.1, −9.0, −9.0, −8.9 kcal/mol, than that observed for the native ligand with −8.7 kcal/mol and for the reference compound gemcitabine with −6.9 kcal/mol. The GI50 values (50 predictions as CDK2 inhibitors were greater than 10 µM with type I non-allosteric binding mode. The stability analysis of protein-ligand complex from 125 ns long molecular dynamics simulations showed moderately smooth trajectories and RSMD value around 5 Å for the docked ligands. The binding free energy changes up to −47.65 ± 5.97 kcal/mol from MMGBSA method and −30.33 ± 5.40 kcal/mol from MMPBSA method hinted at the spontaneous nature of the complex formation. Furthermore, geometrical evaluators like RMSF, Rg, SASA, and hydrogen bond count also corroborated with the structural stability of the complexes and the capacity of hit molecules to inhibit the target, indicating its therapeutic potential against cancer. The toxicity and drug-likeness from ADMET predictions suggested experimental verification and that the proposed candidates could be employed for further trials in the development of safer and more effective anticancer drugs. Communicated by Ramaswamy H. Sarma</p

Synthetic Polymer Composites Reinforced by Bamboo Fibers

International audienc