Debarati Mitra

Bio: Debarati Mitra is an academic researcher from University of Calcutta. The author has contributed to research in topics: Pervaporation & Starch. The author has an hindex of 10, co-authored 29 publications receiving 328 citations. Previous affiliations of Debarati Mitra include Bidhan Chandra Krishi Viswavidyalaya.

Study of compostable behavior of jute nano fiber reinforced biocopolyester composites in aerobic compost environment

Abstract: Jute nano fiber (JNF) reinforced biocopolyester-based composite sheets were prepared with 2% and 10 wt % filler loading and compostability tests were performed in simulated aerobic compost environment at ambient temperature for a period of 50 days. Weight loss study revealed that the incorporation of JNF enhanced the rate of degradation significantly. The unreinforced sample exhibited a steady loss in weight, whereas, the JNF reinforced samples showed three phase degradation. They had a steady weight loss up to 30 days followed by a plateau zone between 30 and 40 days and after that, there was again an increase in weight loss up to 50 days. The biodegraded samples were investigated for their change in molecular weight by Gel Permeation Chromatography (GPC). The change in structure was examined by Differential Scanning Calorimetry (DSC) and morphological change was observed by Scanning Electron Microscopy (SEM). Molecular weight study revealed the fact that Biocopolyester molecules had a significant breakdown in chain length during melt mixing with 10 wt % JNF, which was much less predominant in 2 wt % JNF loaded composites. Such a decrease in chain length and presence of 10 wt % JNF might have facilitated the biodegradation process resulting in highest weight loss. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis of biolubricant components from waste cooking oil using a biocatalytic route

Abstract: The call for “sustainable development” has laid special emphasis on the “go green” concept and thus countries worldwide are taking initiatives to procure successful “clean and green technologies”. In this milieu the uncongenial conventional mineral-oil based lubricants, causing adverse environmental impacts, can efficaciously be replaced by biodegradable vegetable oil based biolubricants. This article presents successful utilization of waste cooking oil (WCO) to synthesize biolubricant using a biocatalytic route. The developed methodology includes a two-step process of enzymatic (Candida rugosa) hydrolysis of WCO to free fatty acids (FFA), followed by biocatalytic (Novozyme 435) esterification of FFA with octanol in a solvent-free system to produce the octyl esters (desired biolubricant components). A classical method of parametric study was employed to explore the effect of different physico-chemical parameters on the esterification reaction. The reaction conditions to achieve maximum conversion (95%) in minimum time were, initial water content = 0.5 wt % of FFA, octanol: FFA molar ratio = 3:1, catalyst = 5 wt % of FFA and temperature = 60°C. Fourier Transform Infrared Spectroscopy confirmed that the product formed was ester. WCO thus serves as an alternative feedstock for biolubricant synthesis and additionally aids up in skillful waste minimization and reuse. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 933–940, 2014

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

Valorization of industrial waste and by-product streams via fermentation for the production of chemicals and biopolymers

Abstract: The transition from a fossil fuel-based economy to a bio-based economy necessitates the exploitation of synergies, scientific innovations and breakthroughs, and step changes in the infrastructure of chemical industry. Sustainable production of chemicals and biopolymers should be dependent entirely on renewable carbon. White biotechnology could provide the necessary tools for the evolution of microbial bioconversion into a key unit operation in future biorefineries. Waste and by-product streams from existing industrial sectors (e.g., food industry, pulp and paper industry, biodiesel and bioethanol production) could be used as renewable resources for both biorefinery development and production of nutrient-complete fermentation feedstocks. This review focuses on the potential of utilizing waste and by-product streams from current industrial activities for the production of chemicals and biopolymers via microbial bioconversion. The first part of this review presents the current status and prospects on fermentative production of important platform chemicals (i.e., selected C2-C6 metabolic products and single cell oil) and biopolymers (i.e., polyhydroxyalkanoates and bacterial cellulose). In the second part, the qualitative and quantitative characteristics of waste and by-product streams from existing industrial sectors are presented. In the third part, the techno-economic aspects of bioconversion processes are critically reviewed. Four case studies showing the potential of case-specific waste and by-product streams for the production of succinic acid and polyhydroxyalkanoates are presented. It is evident that fermentative production of chemicals and biopolymers via refining of waste and by-product streams is a highly important research area with significant prospects for industrial applications.