Some multiple integral transformations involving the H-function of several variables

AbstractThe object of the present paper is to give two general multiple integral transformations of the H-function of several complex variables, which was defined and studied elsewhere by the authors (cf., e.g., [10], [11] and [12]). It is shown how the main formulas (1,8) and (1,14) below, involving Fox's H-function ([4], p, 408) and the Laguerre polynomials, respectively, are related to each other and, of course, to a number of results given recently in the literature (see [1] and [5] through [9]). Several possible applications of the operational techniques provided by these results (and their various special cases) when viewed as multidimensional integral transformations are also indicated briefly

Extraction and separation of zinc and chromium from electroplating effluent

Toxicity of industrial effluent is mainly due to the presence of heavy metals like Zn, Cd, Cr, Pb, As, etc. The treatment of these effluents will not only reduce environmental pollution but also conserve the natural resources. Present paper reports selective extraction and separation of zinc and chromium from the electroplating effluent (~15 g/L Zn and ~30 g/L Cr) using solvent extraction technique. Initial studies were carried out from synthetic solution containing Zn (1.78 g/L) and Cr (3.6 g/L) using 10% DE2PHA diluted with kerosene. Various process parameters viz. effect of pH, time, O/A ratio, loading capacity, etc. were studied and optimized. 98.17% Zn gets extracted in 5 min at equilibrium pH 2.5 maintaining O/A ratio 1. 10% H SO was used for stripping 2 4 the loaded organic. The optimum condition for extraction was validated with the original electroplating effluent supplied by M/s Sinha Electrochemical Plant, Jamshedpur, India. Complete extraction of Zn from the original effluent takes place in 5 min at an equilibrium pH 2.5 and phase ratio (O/A) 1, leaving 99% Cr in the raffinate. From the pure solution obtained, metal or salt could be produced by evaporation,precipitation, electrowinning, crystallization, etc

Scrap computer keyboards a sustainable resource for silver (Ag) and low density oil (L D Oil)

Most neglected part of the scrap computers are the keyboards, which are generally incinerated by the informal recycling sectors creating environmental pollution and leads to the wastage of precious metallic contents present in it. Present paper is focused on a novel chemical processing technique developed to recover silver (Ag) as value added product and low density oil (L D Oil) from the computer keyboards. Initially, scrap keyboards were manually dismantled to separate Mylar sheets and the same were pyrolysed at 300 ◦C for 2 h to recover L D Oil. The obtained pyrolysed Mylar sheets was further crushed, milled and homogenized to reduce particle size (− 100 mesh). The crushed sample was leached using 2 M HNO3 at 60 ◦C in mixing time of 20 min and pulp density of 100 g/L to achieve maximum dissolution of Ag. The leaching kinetics for Ag dissolution well fitted with chemical reaction control dense constant size cylindrical particles, 1-(1-X)1/2 = kct. The obtained leach liquor was put to cementation process using metallic copper (Cu). Almost 99% of Ag gets cemented as Ag powder in 15 min at a constant solution temperature of 60 ◦C and pH 1.1. The developed bench scale process has application orientation to the industry after piloting the process

Leaching of Korean monazite for the recovery of rare earth metals

The technological innovations resulted in various applications using rare earth metals (REM), which lead to a steep increase in their demand. Monazite is the second most essential naturally occurring phosphate mineral containing REM. The present work reports the recovery of REM from Korean monazite which contained mainly 50.12% rare earth oxide and 29.4% phosphate. For the recovery of REM from monazite, the hydrometallurgical process consisting of alkaline leaching of phosphate followed by acid dissolution of REM has been reported. As the presence of phosphate decreases the leaching efficiency of REM from monazite, the studies were carried out initially for hot digestion of phosphate present in the monazite in an autoclave using sodium hydroxide, which resulted in the formation of RE oxide and soluble sodium phosphate. To get the optimum condition for phosphate decomposition by alkaline leaching, the various process parameters such as concentration of sodium hydroxide, temperature, mixing time and pulp density were studied. The obtained slurry was washed with hot water and filtered to get sodium phosphate in the solution. A maximum of 99% phosphate was removed from monazite concentrate using 50% sodium hydroxide solutions (wt./vol.) at 170oC in 4 h mixing time maintaining the pulp density of 100 g/L. From the phosphate free monazite sample, REM was leached out using hydrochloric acid. More than 95% of REM was found to be leached out using 6M HCl at constant pulp density 100 g/L, temperature 90oC and mixing time 2 h. Further studies are in progress to obtain pure solution and salts of REM from chloride leach liquor using recipitation/ solvent extraction/ ion-exchange techniques

Challenges and opportunities in mixed method data collection on mental health issues of health care workers during COVID-19 pandemic in India

Background: The present paper describes the key challenges and opportunities of mixed method telephonic data collection for mental health research using field notes and the experiences of the investigators in a multicenter study in ten sites of India. The study was conducted in public and private hospitals to understand the mental health status, social stigma and coping strategies of different healthcare personnel during the COVID-19 pandemic in India.Methods: Qualitative and quantitative interviews were conducted telephonically. The experiences of data collection were noted as a field notes/diary by the data collectors and principal investigators.Results: The interviewers reported challenges such as network issues, lack of transfer of visual cues and sensitive content of data. Although the telephonic interviews present various challenges in mixed method data collection, it can be used as an alternative to face-to-face data collection using available technology.Conclusions: It is important that the investigators are well trained keeping these challenges in mind so that their capacity is built to deal with these challenges and good quality data is obtained

Factors associated with stigma and manifestations experienced by Indian health care workers involved in COVID-19 management in India: A qualitative study

Healthcare personnel who deal with COVID-19 experience stigma. There is a lack of national-level representative qualitative data to study COVID-19-related stigma among healthcare workers in India. The present study explores factors associated with stigma and manifestations experienced by Indian healthcare workers involved in COVID-19 management. We conducted in-depth interviews across 10 centres in India, which were analysed using NVivo software version 12. Thematic and sentiment analysis was performed to gain deep insights into the complex phenomenon by categorising the qualitative data into meaningful and related categories. Healthcare workers (HCW) usually addressed the stigma they encountered when doing their COVID duties under the superordinate theme of stigma. Among them, 77.42% said they had been stigmatised in some way. Analyses revealed seven interrelated themes surrounding stigma among healthcare workers. It can be seen that the majority of the stigma and coping sentiments fall into the mixed category, followed by the negative sentiment category. This study contributes to our understanding of stigma and discrimination in low- and middle-income settings. Our data show that the emergence of fear of the virus has quickly turned into a stigma against healthcare workers