Papita Das

Bio: Papita Das is an academic researcher from Jadavpur University. The author has contributed to research in topics: Adsorption & Langmuir adsorption model. The author has an hindex of 23, co-authored 130 publications receiving 2110 citations. Previous affiliations of Papita Das include National Institute of Technology, Durgapur.

Leaf extract mediated green synthesis of silver nanoparticles from widely available Indian plants: synthesis, characterization, antimicrobial property and toxicity analysis

Abstract: In recent years, green synthesis of silver nanoparticles (AgNPs) has gained much interest from chemists and researchers. In this concern, Indian flora has yet to divulge innumerable sources of cost-effective non-hazardous reducing and stabilizing compounds utilized in preparing AgNPs. This study investigates an efficient and sustainable route of AgNP preparation from 1 mM aqueous AgNO3 using leaf extracts of three plants, Musa balbisiana (banana), Azadirachta indica (neem) and Ocimum tenuiflorum (black tulsi), well adorned for their wide availability and medicinal property. AgNPs were prepared by the reaction of 1 mM silver nitrate and 5% leaf extract of each type of plant separately. the AgNPs were duely characterized and tested for their antibacterial activity and toxicity. The AgNPs were characterized by UV-visible (vis) spectrophotometer, particle size analyzer (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS). Fourier transform infrared spectrometer (FTIR) analysis was carried out to determine the nature of the capping agents in each of these leaf extracts. AgNPs obtained showed significantly higher antimicrobial activities against Escherichia coli (E. coli) and Bacillus sp. in comparison to both AgNO3 and raw plant extracts. Additionally, a toxicity evaluation of these AgNP containing solutions was carried out on seeds of Moong Bean (Vigna radiata) and Chickpea (Cicer arietinum). Results showed that seeds treated with AgNP solutions exhibited better rates of germination and oxidative stress enzyme activity nearing control levels, though detailed mechanism of uptake and translocation are yet to be analyzed. In totality, the AgNPs prepared are safe to be discharged in the environment and possibly utilized in processes of pollution remediation. AgNPs may also be efficiently utilized in agricultural research to obtain better health of crop plants as shown by our study.

Production of biodiesel from microalgae through biological carbon capture: a review

Abstract: Gradual increase in concentration of carbon dioxide (CO2) in the atmosphere due to the various anthropogenic interventions leading to significant alteration in the global carbon cycle has been a subject of worldwide attention and matter of potential research over the last few decades. In these alarming scenario microalgae seems to be an attractive medium for capturing the excess CO2 present in the atmosphere generated from different sources such as power plants, automobiles, volcanic eruption, decomposition of organic matters and forest fires. This captured CO2 through microalgae could be used as potential carbon source to produce lipids for the generation of biofuel for replacing petroleum-derived transport fuel without affecting the supply of food and crops. This comprehensive review strives to provide a systematic account of recent developments in the field of biological carbon capture through microalgae for its utilization towards the generation of biodiesel highlighting the significance of certain key parameters such as selection of efficient strain, microalgal metabolism, cultivation systems (open and closed) and biomass production along with the national and international biodiesel specifications and properties. The potential use of photobioreactors for biodiesel production under the influence of various factors viz., light intensity, pH, time, temperature, CO2 concentration and flow rate has been discussed. The review also provides an economic overview and future outlook on biodiesel production from microalgae.

Ultrasound assisted mixed azo dye adsorption by chitosan–graphene oxide nanocomposite

Abstract: Mixed azo dyes present in various effluents may often impair adsorption efficiency thereby questioning applicability of the same in a real-time scenario. In this study, simultaneous adsorption of acid yellow 36 (AY) and acid blue 74 (AB) from their aqueous solutions was carried out with graphene oxide nanoplatelets embedded in chitosan matrix (GO–Cs–Nc) with assistance of ultrasound exposure. Results obtained were subjected to analysis for process isotherms, kinetics and thermodynamics. This process was also optimized for best results using response surface methodology (RSM) and modelled with artificial neural network (ANN). The nanocomposite was characterised both before and after adsorption using FTIR, SEM, TEM and AFM. Under the experimental conditions prescribed by RSM, 0.50 g L −1 of adsorbent was responsible for 98.18% and 98.80% removal of AY and AB respectively when exposed to 6.48 min of ultrasonic irradiation. Hence, ultrasound assisted GO–Cs–Nc proved to be a cost effective and sustainable adsorbent effective in low dosage and significantly reduced time with possible application for treatment of real industrial effluents rich in mixed dyes.

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

Principles Of Fluorescence Spectroscopy

Abstract: Thank you very much for downloading principles of fluorescence spectroscopy. As you may know, people have look hundreds times for their favorite novels like this principles of fluorescence spectroscopy, but end up in malicious downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they cope with some harmful bugs inside their desktop computer. principles of fluorescence spectroscopy is available in our digital library an online access to it is set as public so you can download it instantly. Our digital library spans in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the principles of fluorescence spectroscopy is universally compatible with any devices to read.

Remote Sensing And Image Interpretation

Abstract: Thank you very much for downloading remote sensing and image interpretation. As you may know, people have look hundreds times for their favorite novels like this remote sensing and image interpretation, but end up in malicious downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they are facing with some malicious virus inside their computer. remote sensing and image interpretation is available in our digital library an online access to it is set as public so you can get it instantly. Our book servers spans in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Merely said, the remote sensing and image interpretation is universally compatible with any devices to read.

‘Green’ synthesis of metals and their oxide nanoparticles: applications for environmental remediation

Abstract: In materials science, “green” synthesis has gained extensive attention as a reliable, sustainable, and eco-friendly protocol for synthesizing a wide range of materials/nanomaterials including metal/metal oxides nanomaterials, hybrid materials, and bioinspired materials. As such, green synthesis is regarded as an important tool to reduce the destructive effects associated with the traditional methods of synthesis for nanoparticles commonly utilized in laboratory and industry. In this review, we summarized the fundamental processes and mechanisms of “green” synthesis approaches, especially for metal and metal oxide [e.g., gold (Au), silver (Ag), copper oxide (CuO), and zinc oxide (ZnO)] nanoparticles using natural extracts. Importantly, we explored the role of biological components, essential phytochemicals (e.g., flavonoids, alkaloids, terpenoids, amides, and aldehydes) as reducing agents and solvent systems. The stability/toxicity of nanoparticles and the associated surface engineering techniques for achieving biocompatibility are also discussed. Finally, we covered applications of such synthesized products to environmental remediation in terms of antimicrobial activity, catalytic activity, removal of pollutants dyes, and heavy metal ion sensing.