The implementation of hard-facing alloy on the existing materials caters the need for high-performance surfaces in terms of wear and high temperatures. The present research explore the effect of Plasma Transferred Arc Welding (PTAW) parameters and powder composition on dilution, microstructure and hardness of the commonly used hard-facing alloy Ni-Cr-Si-B powder. The hard-facing alloy was deposited with three weight proportions of boron (2.5 %, 3 % and 3.5 %). The statistical-based Grey Relational Analysis (GRA) followed by a Machine Learning Algorithm (MLA) was implemented to identify the ideal parameters and degree of significance of each parameter and for the prediction of the responses. The dilution percentage, microstructure analysis, and phase detection were estimated through elemental analysis, Scanning electron Microscopy (SEM) and X-ray Diffraction Analysis (XRD) respectively. The experimental and modelling results revealed that 400 mm/min of scanning speed, 8 gm/min of powder delivery, 14 mm of stand-off distance, and 120 A of current were the optimal parameters along with 3.5 wt% of boron powder composition to yield a better dilution, microstructure and hardness.
Inexpensive forms of tobacco are widely used in developing countries such as India. We have evaluated genotoxicity endpoints (chromosome aberrations, micronucleus frequency, comet assay) and polymorphisms of the XRCC1 and p53 genes among smokers and smokeless tobacco (SLT) users in rural Tamilnadu, South India. Cytogenetic, DNA damage and SNP analyses were performed on peripheral blood samples; micronucleus frequency was measured in peripheral blood and buccal mucosa exfoliated cells. Both categories of tobacco users had elevated levels of genotoxic damage. SNP analysis of tobacco users revealed that 17% carry the XRCC1 gln399gln genotype and 19% carry the p53 pro72pro genotype. Both genotypes are associated with increased risk of cancer.
Land being a major constrain in metro cities like Chennai has contributed to the development of closely spaced high-rise apartment complexes which lead to poor indoor air quality. Native indoor plants serve as a natural medium in absorbing air pollution entering indoors mainly through balcony spaces and also enhance the aromatic and visual quality of indoor space. This research has been carried out as a pilot study with an aim to explore the effectiveness of a planting palette comprising native flowering, air-purifying medicinal and vertical wall plants in absorbing the air pollutants in the context of an urban apartment balcony space in Chennai, Tamil Nadu, India. The level of absorption of pollutants such as carbon dioxide, carbon monoxide, total volatile organic compounds, benzene, and formaldehyde was monitored in two scenarios one planted and another non-planted balcony using Internet of Things sensors for a period of 1 month. The results observed on a Thursday for carbon dioxide, carbon monoxide, and total volatile organic compounds for non-planted balcony are 984 ppm, 392 µg/m3, and 75 µg/m3 (highest due to STP activities) when compared to planted balcony with the values 919 ppm, 335 µg/m3, and 71 µg/m3. The selected plant palette has displayed minimal absorption of formaldehyde and benzene. But both the pollutants are found to reduce gradually within 2 h in the planted balcony and 3 h in the non-planted balcony after the floor mopping activity which contributes to formaldehyde and benzene. Hence, the study proves that plants as a natural medium are inexpensive and best in absorbing air pollutants thereby improving the quality of the indoor environment.