Tanvir Arfin

Development of PANI/MWCNTs decorated with cobalt oxide nanoparticles towards multiple electrochemical, photocatalytic and biomedical application sites

In the present work, a ternary nanocomposite of Co3O4doped/PANI/MWCNTs (cobalt oxide-doped polyaniline multi-walled carbon nanotubes) was synthesized via the in situ oxidative polymerization of aniline. The composite was fully characterized using instrumental analysis, and further tested for its potential in electrochemical, photocatalytic and biomedical applications. The Co oxide nanoparticles were first synthesized using the sol–gel approach in the presence of starch as a capping agent so as to prevent agglomeration and characterized using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), EDX, elemental mapping and high-resolution transmission electron microscopy (HRTEM). For the measurement of electrochemical activity, the electrodes were synthesized with MWCNTs and functionalized with a conducting polymer (PANI). For the composite, the Co metal oxide provides a pseudo-capacitance which, in general, improves the performance characteristics of the electrode and has been the focus of many researchers. Further, the specific capacitance of the prepared composite was tested using cyclic voltammetry (CV) and impedance spectroscopy. The capacitive studies reveal that the composite has a synergistic effect and is observed to have the highest specific capacitance of 382 F g−1 run at a scan rate of 10 mV s−1. The composite was also found to have excellent photocatalytic degradation properties and outstanding antibacterial activity against both Gram positive and Gram negative bacterial strains. The minimum MIC (6.25 μg mL−1) and MBC (12.5 μg mL−1) values against E. coli and maximum values against B. amyloliquefaciens (25 and 50 μg mL−1) at fourth dilution were observed. Furthermore, the anticancer efficiency of the composite was tested by making use of two different cancer cell types (MCF-7 and MDA-MB-231) confirming the importance of its biological activity for biomedical applications.

Sustained drug release and electrochemical performance of ethyl cellulose-magnesium hydrogen phosphate composite

In this, a sol-gel method was applied to prepare ethyl cellulose-magnesium hydrogen phosphate (EC-MgHPO4) composite that can have potential applications in the sensory, pharmaceutical, and biomedical sectors. The formed composite was thoroughly characterized by making use of the instrumental analysis such as UV-Vis, FT-IR, HRTEM, EDAX, SEM and XRD. For the composite, the other parameters determined includes the water uptake, porosity, thickness, bulk and tapped densities, angle of repose, Carrs index and Hausner ratio. From the results, the material found to exhibit good flowing properties with a Carrs index of 11.11%, Hausner ratio of 1.125, and angle of response of 33°. The EDAX spectrum and HRTEM analysis confirmed for the composite formation and the particles size is investigated to be around 52nm. The surface porosity due to the EC matrices was confirmed by the SEM analysis, which further used for the loading of drug, Proguanil. In addition, the materials conductivity was studied by taking uni-univalent electrolyte solution (KCl and NaCl) indicated that the conductivity follows the order of KCl>NaCl, while the activation energy obtained from Arrhenius method resembled that the conductivity is strongly influenced by the electrolyte type used. We found from the analysis that, with a decrease in the size of hydrated radii of ions, the conductivity of EC-MgHPO4 material also observed to be decreased in the order K+>Na+ and the material proved to be mechanically stable and can be operated over a range of pHs, temperatures, and electrolyte solutions. Further, the drug loading and efficiency studies indicated that the material can trap up to 80% of Proguanil (antimalarial drug) applied for its loading. The Proguanil drug release profiles confirmed for the controlled and sustained release from the EC-MgHPO4 matrix, as the material can release up to 87% of its total loaded drug over a 90min period. Finally, the cell viability and proliferation studies tested against two different cell cultures of BRL-3A rat liver and H9c2 cardiomyoblasts indicated the non-toxic nature and safer applicability of the EC-MgHPO4 (25-500μg/mL, 24h). Overall, the results of the study confirm for the safer applicability of the composite towards biosensor, drug delivery, scaffolding, and bioanalytical (quality control) applications.

Graphene oxide–ZnO nanocomposite modified electrode for the detection of phenol

In the present study, a ZnO functionalized graphene oxide (GO) modified glassy carbon electrode (GO–ZnO/GCE) was used for the electrochemical sensory detection of phenol. The prepared material was characterised using cyclic voltammetry (CV), square wave voltammetry (SWV), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The parameters, such as the scan rate, pH, comparative study, stability, repeatability and interference, were optimised for the experimental study. The result of the study revealed that GO–ZnO exhibited favourable electrochemical behaviour for phenol oxidation, which was assigned to the joint efficiency of the ZnO and GO properties. An electrochemical sensor based on GO–ZnO exhibited excellent electrochemical performance towards the detection of phenol when compared to GO and bare GCE. The peak current demonstrated a linear relationship with phenol concentration in the range of 5–155 μM. Depending on the signal-to-noise characteristics (S/N = 3), the limit of detection for phenol was observed to be 2.2 nM. In addition, the electrochemical sensor showed excellent selectivity, stability and repeatability in the experimental studies. Based on our analysis, it can be considered that the GO–ZnO based phenol sensor has great potential in different applications requiring the detection of trace amounts of phenolic compounds.

Biomass Resources in Environmental and Socio-Economic Analysis of Fuel-Wood Consumption

Energy is said to be potentially at the core of modern civilization right from industrial revolution, where technology has modified and redefined the way in any individual or a group that uses the energy, but the technological advancement in all spheres continues to be dependent on its use. The prevailing trend has triggered the need for alternative, renewable and sustainable energy sources which are now being considered extensively and pursued globally to turn aside the possibility of climate change at the range of attaining a state of irreversibility. A versatile raw material, biomass, can be used for the generation of energy by means of heat production, transport fuels and many essential bio-products which directly or indirectly contributes for the current growing demands of energy. When produced and used on a sustainable basis, the biomass-based energy production acts as a carbon-neutral carrier and thus contributes for the reduction of large amounts of greenhouse gas emissions, thereby finding its way for the prevention of global warming. In most developing countries, the quantitative information available on woody biomass resources, at scales related to the procurement area. Based on the growing demands of woody biomass for energy production in the current and near future, the present report is therefore aimed to provide an in-depth information about various agencies linked to biomass resources, leading economic factors of woody biomass, methods available for the estimation of costs associated with bioenergy, etc. Further, we also discussed about the methods to estimate biomass in forest ecosystems by means of destructive sample, microwave remote sensing-based assessment, woody vegetation indices and also provided the investigation methods during the estimation of error budgets.

Recent Developments in Adsorption of Dyes Using Graphene Based Nanomaterials

Dyes are frequently let out into the environment along with wastewater sans necessary treatment. Fast, cost-effective, scientific and suitable elimination of dyes from wastewaters has been an important problem for researchers. Adsorption technique is a robust, well studied, widely employed and promising water treatment method. In the last decade, nanocarbon based adsorbents have gained attention in water treatment. These adsorbents are usually produced from low cost substrate and are found to be highly efficient than other adsorbents. Recently, graphene based nanomaterials are widely used as adsorbents to sorb various toxic organic contaminants from aqueous solutions. It showed high efficiency due to its chemical stability, structure, surface area and surface functional groups. So graphene are called as ‘miracle material’. Recently nanographene composites are proven to be a likely adsorbent for eliminating contaminants from the industrial effluents. In this chapter, we have presented briefly the synthesis of graphene and its other variants viz., GO, rGO and nano graphene composites. This chapter presents a small introduction to adsorption principles and adsorption isotherms. It explains the synthesis and use of nano graphene materials for the remediation of dyes. It also consolidates the recent literature available for dye adsorption using graphene materials and its mechanism.

Assessing Quality in Machine Foundation Using UPV Measurements

The particular effectiveness evaluates associated with 40 MVA MG collection unit basis had been completed to stop this vibration associated with basis produced below operating issue on the unit in addition to developing few splits. Just for this, this strength in addition to effectiveness associated with concrete from the unit basis became improbable. To be able to improve the strength of basis, ultrasonic pulse velocity (UPV) analyzes depending on IS: 13311-1992 (Part-1) had been completed. Case study functions unveil the concrete ended up inadequate specially around bolt grouting postures as well as other a part of basis, having surprisingly low UPV ideals along with splits at first glance in addition to necessary rehabilitations operates or even strength progress actions to further improve the strength of present unit basis with it is functioning issue.