A STUDY ON GAMMA RADIATION RESPONSE OF CERIC SULFATE DOSIMETER

Nuclear radiation is highly beneficial in controlled way. On the other hand, it has shown severe damaging effects on human health when our body is directly exposed to it. To prevent its exposure or overdose several dosimeters have been synthesized with different performances. In this research work, we prepared Ceric sulfate chemical dosimeter from three different water samples of TDS value 0.00ppm, 500pm and 900ppm. These dosimeter samples were then irradiated by Cs-137 gamma radiation source at different dose rates 100Gy, 200Gy and 300Gy. Gamma radiation effect in these samples was studied for different concentrations of salt. Variations in the absorbance of dose rate verses time was plotted and measured spectrophotometricaly at 320nm after the interval of 24 hours respectively

Simultaneous strength and ductility enhancements of high thermal conductive Ag7.5Cu alloy by selective laser melting

High electrical and thermal conductive metals (HETCM) play a key role in smart electronics, green energy, modern communications and healthcare, however, typical HETCM (e.g., Ag, Au, Cu) usually have relatively low mechanical strength, hindering further applications. Selective laser melting (SLM) is a potentially transformative manufacturing technology that is expected to address the issue. Ag is the metal with the highest thermal conductivity, which induces microscale grain refinement, but also leads to high internal stresses by SLM. Here, we select Ag7.5Cu alloy as an example to demonstrate that multi-scale (micro/meso/macro) synergies can take advantage of high thermal conductivity and internal stresses to effectively strengthen Ag alloy. The mimicry of metal-hardened structures (e.g., large-angle boundary) is extended to the mesoscale by controlling the laser energy density and laser scanning strategy to manipulate the macroscale internal stress intensity and mesoscale internal stress direction, respectively, to form mesoscale large-angle "grains", resulting in multiple mutual perpendicular shear bands during fracture. The presented approach achieved a significant enhancement of yield strength (+ 145%) and ductility (+ 28%) without post-treatment. The results not only break the strength-ductility trade-off of conventional SLM alloys, but also demonstrate a multi-scale synergistic enhancement strategy that exploits high thermal conductivity and internal stresses