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Naba Kumar Mondal

Bio: Naba Kumar Mondal is an academic researcher from University of Burdwan. The author has contributed to research in topics: Adsorption & Freundlich equation. The author has an hindex of 30, co-authored 144 publications receiving 2832 citations.


Papers
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TL;DR: In this article, the authors evaluated the antifungal properties of green synthesised silver nanoparticles (AgNPs) from Aloe vera leaf extract against two pathogenic fungus Rhizopus sp. and Aspergillus sp.
Abstract: Silver nanoparticles are receiving increasing attention in the field of agriculture. This study aims at evaluating the antifungal properties of green synthesised silver nanoparticles (AgNPs) from Aloe vera leaf extract against two pathogenic fungus Rhizopus sp. and Aspergillus sp. Results revealed that synthesised nanoparticles showed strong absorption maximum at 400 nm corresponding to the surface plasmon resonance. The prepared nanoparticles were characterized by SEM, FT-IR and UV–Vis spectroscopy. From the scanning photograph it is clear that particles are heterogeneous in shape such as rectangular, triangular and spherical with uniform distribution. FT-IR study showed sharp absorption peaks at 1,631 and 3,433 cm−1 for amide and alcoholic hydroxide groups, respectively. On the other hand, synthesised silver nanoparticles showed highest antifungal activity against Aspergillus sp. than Rhizopus sp. by application of 100 μL of 1 M silver nanoparticles with maximum inhibition of the growth of fungal hyphae. However, microscopic observation revealed that synthesised nanoparticles caused detrimental effects on conidial germination along with other deformations such as structure of cell membrane and inhibited normal budding process of both the tested species. Therefore, it has been concluded that Aloe vera leaf extract origin silver nanoparticles have tremendous potentiality towards controlling pathogenic fungus. However, further research is needed to check the efficacy of size-dependent AgNPs on different species of fungus.

189 citations

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TL;DR: In this paper, a new medium, eggshell powder has been developed for fluoride removal from aqueous solution, where adsorption was found to be pH dependent with maximum removal efficiency at 6.0.
Abstract: A new medium, eggshell powder has been developed for fluoride removal from aqueous solution. Fluoride adsorption was studied in a batch system where adsorption was found to be pH dependent with maximum removal efficiency at 6.0. The experimental data was more satisfactorily fitted with Langmuir isotherm model. The kinetics and the factor controlling adsorption process fully accepted by pseudo-second-order model were also discussed. Ea was found to be 45.98 kJmol-1 by using Arrhenius equation, indicating chemisorption nature of fluoride onto eggshell powder. Thermodynamic study showed spontaneous nature and feasibility of the adsorption process with negative enthalpy (∆H0) value also supported the exothermic nature. Batch experiments were performed to study the applicability of the adsorbent by using fluoride contaminated water collected from affected areas. These results indicate that eggshell powder can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution as well as groundwater.

162 citations

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TL;DR: Isolation of two rod-shaped Gram-positive bacteria shows ability to tolerate up to 4500 ppm and 550 ppm concentration of arsenate and arsenite in bacteria mediated arsenic bioremediation.

156 citations

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TL;DR: In this article, a study on the biosorption of methylene blue (MB) onto low-cost Lemna major biomass was conducted and the process parameters were optimized by response surface methodology (RSM).
Abstract: Water pollution due to contamination of dye containing effluents is a great threat to water body. A study on the biosorption of methylene blue (MB) onto low-cost Lemna major biomass was conducted and the process parameters were optimized by response surface methodology (RSM). A two-level, four-factor central composite design (CCD) has been employed to determine the effect of various process parameters namely initial concentration (600–1000 mg L−1), bioadsorbent dose (0.20–1.50 g/100 mL), pH (5–12) and stirring rate (250–800 rpm) on MB uptake from aqueous solution. By using this design a total of 30 biosorption experimental data were fitted. The regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination (R2) value of 0.9978 and model F-value of 953.48. The optimum conditions of initial concentration (1000 mg L−1), adsorbent dose (0.2 g), pH (5) and stirring rate (251.51 rpm) were recorded from desirability function. The adsorption isotherm data were best described by both Freundlich and Langmuir models with a maximum adsorption capacity of 488 mg MB g−1 L. major biomass at 30 °C which is higher than that available with adsorbents used by past researchers. Finally the pseudo second order kinetic model described the MB biosorption process with a good fitting (R2 = 0.999). The adsorbent was characterised by scanning electron micrograph (SEM) and Fourier transform infrared spectroscopy (FTIR).

129 citations

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TL;DR: A series of adsorption experiments (batch and column) were performed utilizing iron impregnated sugarcane carbon (Fe-SCC), a composite adsorbent, to remove arsenic from aqueous systems.
Abstract: Arsenic in drinking water has been recognized as a serious community health problem because of its toxic nature and therefore, its removal is highly essential. A series of adsorption experiments (batch and column) were performed utilizing iron impregnated sugarcane carbon (Fe–SCC), a composite adsorbent, to remove arsenic from aqueous systems. Under optimized batch conditions, the Fe–SCC could remove up to 94.5% of arsenic from contaminated water. The artificial neural network (ANN) model was developed from batch experimental data sets which provided reasonable predictive performance (R2 = 0.964; 0.963) of arsenic adsorption. In batch operation, the adsorbent dose had the most significant impact on the adsorption process. For column operation, central composite design (CCD) in response surface methodology (RSM) was applied to investigate the influence on the breakthrough time for optimization and evaluation of interacting effects of different operating variables. The perturbation plot depicted that the breakthrough time is more sensitive to initial concentration and adsorbent dose than flow rate. The optimized result obtained from bar plot revealed that the Fe–SCC was an effective and economically feasible adsorbent; whereas more than 93% desorption efficiency showed the reusability of the adsorbent. The high arsenic adsorptive removal ability and regeneration efficiency of this adsorbent suggest its applicability in industrial/household systems and data generated would help in further upscaling of the adsorption process.

101 citations


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TL;DR: 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.
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

13,333 citations

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7,335 citations

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3,734 citations

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TL;DR: A case study explores the background of the digitization project, the practices implemented, and the critiques of the project, which aims to provide access to a plethora of information to EPA employees, scientists, and researchers.
Abstract: The Environmental Protection Agency (EPA) provides access to information on a variety of topics related to the environment and strives to inform citizens of health risks. The EPA also has an extensive library network that consists of 26 libraries throughout the United States, which provide access to a plethora of information to EPA employees, scientists, and researchers. The EPA implemented a reorganization project to digitize their materials so they would be more accessible to a wider range of users, but this plan was drastically accelerated when the EPA was threatened with a budget cut. It chose to close and reduce the hours and services of some of their libraries. As a result, the agency was accused of denying users the “right to know” by making information unavailable, not providing an adequate strategic plan, and discarding vital materials. This case study explores the background of the digitization project, the practices implemented, and the critiques of the project.

2,588 citations

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2,133 citations