Iridium oxide films as propane sensors

In modern times, selection criteria of materials are solely based on its utilization. The characteristics of materials like high temperature sustainability with regard to its strength and corrosion resistance is the primary requirement to satisfy its operations. Industries categorised in sectors like energy, manufacturing, electronics etc. greatly rely on input materials and their purity decides their performance. Amongst many developed alloys, nickel-based alloys find their position in applications having temperatures from cryo to nuclear ranges. One of such unique materials, being used from minute components of semiconductor industry to huge components of marine industry is UNS N06003. It is basically Ni-Cr based alloy having greater than three-fourth fraction of nickel. For major applications wrought material is widely used, but cast material marks their positions in selected applications. This paper deals with casting of UNS N06003 and improving its quality. The reasons associated with cast defects and drawbacks of defects in terms of performance have been discussed. To minimize casting defects and produce a sound casting, this research adopts a novel approach of removal of unwanted gaseous elements. In degassing stage, molten metal is introduced with the combination of calcium-based fluxes which mainly remove the entrapped gases and lighter impurities in the form of slag. It has been found that the addition of quicklime (CaO) in combination with calcium carbide (CaC2) resulted in reduction of gaseous elements like nitrogen, phosphorus and sulphur. Up to 33% reduction of gaseous elements has been detected.

https://doi.org/10.1088/1757-899x/1225/1/012065

Study on Defect Reduction in Casting of Ni-Cr alloy (UNS N06003)

Abstract In modern times, selection criteria of materials are solely based on its utilization. The characteristics of materials like high temperature sustainability with regard to its strength and corrosion resistance is the primary requirement to satisfy its operations. Industries categorised in sectors like energy, manufacturing, electronics etc. greatly rely on input materials and their purity decides their performance. Amongst many developed alloys, nickel-based alloys find their position in applications having temperatures from cryo to nuclear ranges. One of such unique materials, being used from minute components of semiconductor industry to huge components of marine industry is UNS N06003. It is basically Ni-Cr based alloy having greater than three-fourth fraction of nickel. For major applications wrought material is widely used, but cast material marks their positions in selected applications. This paper deals with casting of UNS N06003 and improving its quality. The reasons associated with cast defects and drawbacks of defects in terms of performance have been discussed. To minimize casting defects and produce a sound casting, this research adopts a novel approach of removal of unwanted gaseous elements. In degassing stage, molten metal is introduced with the combination of calcium-based fluxes which mainly remove the entrapped gases and lighter impurities in the form of slag. It has been found that the addition of quicklime (CaO) in combination with calcium carbide (CaC 2 ) resulted in reduction of gaseous elements like nitrogen, phosphorus and sulphur. Up to 33% reduction of gaseous elements has been detected. 

The paper proposes an innovative method of using microheaters for research on cells in vitro. A method of local heating of a single culture well, compatible with an Electric Cell-substrate Impedance (ECIS) system is presented. A microheater and culture well system for cell culture was modelled. Electrical and thermal simulation of the system under operating conditions was carried out. Correct distribution of heat was observed at the site of the cell culture suspension in the medium, while not affecting the conditions in adjacent wells. As part of the experiment, a heating element of nichrome (NiCr) was created using the magnetron sputtering process. Electrical and thermal measurements of the manufactured device were carried out. It has been shown that it is possible to establish the desired temperature over the long term. In addition, the structures made were characterised by work stability, precision in maintaining the right temperature, and the possibility of being controlled with high accuracy. There is a problem with the precise and reproducible carrying out of a cell culture experiment that differs only in the process temperature. In this work, a technique for increasing the temperature locally, in a single culture well, in a medium containing eight such wells was proposed and analyzed. The use of this method will allow avoidance of the impact of potential changes in parameters other than temperature on the culture. That may occur when comparing cells grown at different temperatures by means of the ECIS (Electric Cell-substrate Impedance) method.

/pdf/analysis-of-heat-flow-for-in-vitro-culture-monitored-by-35h633qk.pdf

Analysis of Heat Flow for In Vitro Culture Monitored by Impedance Measurement

Ammonia gas sensing with tin oxide thin film sensor and coplanar microheater

The design and fabrication of nichrome based coplanar microheater for LPG sensing applications is presented in this work. Nichrome based coplanar microheater is fabricated using photolithography process. The surface morphology of DC sputtered nichrome is characterized using scanning electron microscope. Electrothermal behaviour of the fabricated microheater is characterized by varying the applied current while the thermal distribution pattern over the active heating area is recorded using thermal imaging camera. The silicon thickness under microheater active area is varied by silicon etching with different time duration in TMAH solution. Silicon thickness effect on maximum temperature of microheater is also investigated experimentally. The tin oxide (SnO2) thin film as LPG sensor is deposited on fabricated coplanar heating platform and it is tested with different amount of LPG concentration.

Preeti

Papers

Fabrication of coplanar microheater platform for LPG sensing applications