Fibre optic sensor to detect heavy metal pollutants in water environments.

Heavy metal ion pollution emerges as a potential threat to humankind and the ecosystem due to their increased spreading into the environment. Detection of highly toxic heavy metal ions requires rapid, simple, sensitive and selective detection methods in water environments. Optical fibre sensors facilitate the remote, continuous and in-situ detection due to their inherent properties. Herein, we report a fibre optic sensor based on evanescent wave absorption to detect heavy metal ions in water environments. Fibre optic sensor has been developed by coating dithizone on the surface of an optical fibre. Selectivity of the mercury, copper and chromium ions using dithizone has been illustrated using spectroscopy based detection approach. Effect of pH on the sensor has been investigated. The possibility of simultaneous multi-ion detection has been investigated. Copper ions concentrations in water has been detected using the developed fibre optic sensor

Theoretical investigation of positional influence of FBG sensors for structural health monitoring of offshore structures.

Fibre Bragg Grating (FBG) is a key technology for condition monitoring of different offshore oil and gas structures. FBG sensors are used to sense different physical parameters such as strain, temperature, vibration, etc. This paper investigates the effect of FBG sensor positions on the reflected sensing signal, to optimise the sensor positioning plan for structural health monitoring of offshore structures. Theoretical investigations were carried out on a cantilever beam to analyze the strain effects. Effect of different cantilever beam shapes, materials and their thickness on strain was investigated. Theoretical studies were also carried out to evaluate the strain sensitivities of FBG sensors. Furthermore, micrometer displacement based strain analysis of cantilever beam was carried out using FBG sensors and electrical strain gauges to study the positional influence and compared it with the theoretical results obtained

Review on Sustainable EMI Shielding Materials Developed from Biodegradable Waste: A Waste to Wealth Strategy

Environmental pollution, one of the critical challenges, is associated with the rapid advancement of various technologies. The huge heap of waste generated as a part of the technological revolution is a main source of environmental pollution, and it is an obstacle which retards the progress of industries. Among the various types of environmental pollution, Electromagnetic interference (EMI) is also a major form which is caused by the telecommunication and electronic industry. EMI can damage the functioning of electronic devices, and it is a severe threat to our health.  Techniques to solve both these pollutions simultaneously are an emerging field of research. Recent studies introduce an efficient strategy to use recycled materials for developing EMI shielding materials. This approach can be equally beneficial for suppressing undesired EM radiations as well as controlling environmental pollution through the recycling of waste materials. This review discusses the recent developments in the strategy of designing biodegradable EMI shielding materials by the use of environmental friendly and biomass-based sustainable materials

Mechanical, dielectric and photoconducting properties of a novel non-linear optical crystal

926-930Non-linear optical single crystals of cadmium mercury tetrathiocyanate dimethylsulphoxide [CdHg(SCN)4(H6C2OS)2], (CMTD) were conveniently grown from a DMSO-water mixed solvent by slow solvent evaporation technique. The crystals were characterized by single crystal X-ray diffraction and FT IR. The grown crystals were also subjected to microhardness, dielectric and photoconductivity studies. The microhardness studies indicate that the Vickers hardness number of the crystal decreases with increase in applied load. The dielectric response of the crystal with varying frequencies is studied and reported. The photoconductivity studies confirm that the title compound has negative photoconducting natur