Morphology, thermal, electrical and electrochemical stability of nano aluminium-oxide-filled polyvinyl alcohol composite gel electrolyte

In the present work, an attempt has been made to develop nano aluminium oxide (Al₂O₃)-filled polyvinyl alcohol (PVA) composite gel electrolytes. Surface morphological studies, thermal behaviour, electrochemical stability and electrical characterization of these composite gel electrolytes have been performed. An increase in the concentration of Al₂O₃ in composite gel electrolytes increases the amorphous characteristics of pure PVA. Bulk conductivity of composite gel electrolytes increases by an order of magnitude on addition of a nano filler. Maximum conductivity of 5·81 × 10^?2 S/cm is observed for 6 wt% Al₂O₃-filled polymer gel composite electrolytes. Temperature dependence of electrical conductivity shows a combination of Arrhenius and Vogel-Tamman-Fulcher (VTF) nature. Maximum current stability during oxidation and reduction cycle is noticed for 6 wt% Al₂O₃-filled PVA composite electrolyte, viz. ±1·65 V.     

Microfluidic biosensor for beta-amyloid(1-42) detection using cyclic voltammetry

Numerous studies have identified beta-amyloid(1-42) protein (Abeta42) in the cerebrospinal fluid as a potential biomarker of Alzheimer's disease. It is of particular interest to establish the diagnosis before reaching the stage of clinical severity. The current methods for studying amyloid detection, however, is often time-consuming, expensive, and labor intensive, making the analytical process very slow. Thus, a critical need exists for an analytical system that would enable the rapid investigation of amyloid formation with a very small amount of amyloidogenic peptides and reagents. In our present work, we report a simple microfluidic biosensor to analyze very small quantities of Abeta42 peptide on gold surface that were modified with Au nano-particles onto the thiol groups of self-assembled 1,6-hexandithiol cross-linkers. The vital advantage of this method includes retaining the bioactivity and environment similar to nature for protein immobilization while using minimal amounts of reagents and highly sensitive detection.     

Survey of radon and thoron in homes of Indian Himalaya

Measurements of radon, thoron and their progeny were carried out in some houses from Garhwal and Kumaun Himalayas of India using a LR-115 plastic track detector. The measurements were made in various residential houses of the area at a height of 2.5 m above the ground level using a twin chamber radon dosemeter, which can record the values of radon, thoron and their progeny separately. The concentrations of radon and thoron in these homes were found to vary from 11 to 191 and 1 to 156 Bq m(-3), respectively. The equilibrium factor between radon and progeny varies from 0.02 to 0.90, with an average of 0.26 for the region. The resulting dose rate due to radon, thoron and their decay products was found to vary from 0.02 to 0.84 μSv h(-1) with an arithmetic mean of 0.27 μSv h(-1). A detailed analysis of the distribution of radon, thoron and their decay products inside a house is also reported. The observed dose rates due to radon, thoron and progeny were found somewhat higher but well below the international recommendations.