This paper focuses on examining the ‘cutting zone temperature’ while performing turning operation
on AZ91Mg alloy using cemented carbide tools. The regression model is developed by using the RSM
techniques based on experimental results. It is revealed that the cutting speed (v) is the most dominant
factor affecting cutting zone temperature. The developed models of cutting zone temperature sufficiently
map within the range of the turning conditions considered. The adequacy and accuracy of the regression
equation is justified through ANOVA. It is found that the optimal combinations of machining parameters
minimize the cutting temperature.
Formation of spikes prevents achievement of the better material removal rate (MRR) and surface finish while using plain NaNO3 aqueous electrolyte in electrochemical machining (ECM) of die tool steel. Hence this research work attempts to minimize the formation of spikes in the selected workpiece of high carbon high chromium die tool steel using copper nanoparticles suspended in NaNO3 aqueous electrolyte, that is, nanofluid. The selected influencing parameters are applied voltage and electrolyte discharge rate with three levels and tool feed rate with four levels. Thirty-six experiments were designed using Design Expert 7.0 software and optimization was done using multiobjective genetic algorithm (MOGA). This tool identified the best possible combination for achieving the better MRR and surface roughness. The results reveal that voltage of 18 V, tool feed rate of 0.54 mm/min, and nanofluid discharge rate of 12 lit/min would be the optimum values in ECM of HCHCr die tool steel. For checking the optimality obtained from the MOGA in MATLAB software, the maximum MRR of 375.78277 mm(3)/min and respective surface roughness Ra of 2.339779 μm were predicted at applied voltage of 17.688986 V, tool feed rate of 0.5399705 mm/min, and nanofluid discharge rate of 11.998816 lit/min. Confirmatory tests showed that the actual performance at the optimum conditions was 361.214 mm(3)/min and 2.41 μm; the deviation from the predicted performance is less than 4% which proves the composite desirability of the developed models.
The purpose of this study was to assess local diagnostic reference levels (LDRLs) for full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT) mammography in India. Data from 1500 women were collected from five different mammography facilities in major cities in Tamil Nadu, India. The mean of mean glandular dose were used to arrive at an LDRL. The noted mean compressed breast thickness was 55.26 ± 3.4. The recorded mean MGDs for the five centres were 3.1 ± 0.1 and 3.8 ± 0.2 mGy for FFDM and DBT, respectively. The 75th percentile value for all five centers is 3.3 and 4.0 mGy for FFDM and DBT, respectively. The LDRLs found in the current study were also compared with those from earlier studies conducted in other nations, such as the United Kingdom, Malaysia, Morocco, and Ghana. The present study is the first of its kind to determine the LDRL for the FFDM and DBT scanners operating in the Tamil Nadu region, India, and is proposed as a starting point that will allow professionals to evaluate and optimize their practice. Furthermore, similar studies in other regions of India are necessary in order to establish National DRLs.