Application of frequency ratio (FR) model in spatial prediction of landslides in the Balason river basin, Darjeeling Himalaya

Subrata Mondal,Sujit Mandal 대한공간정보학회 2017 Spatial Information Research Vol.25 No.3

The present study aims to prepare landslide susceptibility map using frequency ratio (FR) model in the Balason river basin of Darjeeling Himalaya. Along with keeping in mind that, can the produced landslide susceptibility map yields acceptable landslide prediction accuracy or not. For that reliable landslide inventory map was prepared with a total of 295 landslide locations. The chosen landslide conditioning factors were altitude, aspect, slope angle, curvature, geology, geomorphology, soil, land use/land cover, normalized differential vegetation index, drainage density, lineament density, distance from lineament, distance to drainage, stream power index and topographic wetted index. To estimate FR value for each class of all the landslide conditioning factors pixels affected by landslide (%) and total pixels (%) were taken into account. FR model was applied to integrate all the data layers on GIS platform. The derived susceptibility map was divided into five categories i.e. very low, low moderate, high and very high which cover 17.52, 18.71, 30.35, 24.49 and 8.92% area of the basin respectively. The area under curve value of receiver operating characteristics indicates the prediction accuracy of the prepared map was 94.2% that is highly desirable. FR plots represent that there were positive relationship between landslide susceptibility classes and FR value. The prepared map will helping developers and planners to implement slope management plans, land use plans and other development action plans in this area.

Surface functionalized carbon microspheres for the recovery of copper ion from refinery wastewater

Subrata Mondal,Addisu Tadesse Derebe,Kean Wang 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.1

Micro-sized carbon spheres (CNS) were synthesized by hydrothermal process from glucose solution at 443.15 K and two different reaction times. The synthesized CNS samples were surface functionalized with hydroxyl (-OH) functional groups using NaOH treatment, and were tested in batch adsorption to remove heavy metal ion (Cu2+) from aqueous solutions. Experimental results revealed that CNS contains mostly amorphous carbon. NaOH functionalized CNS had significantly higher adsorption capacity of copper ~170×10−3 Kg Cu2+/Kg-CNS as compared to the untreated CNS. The adsorption isotherms were well fitted by the Langmuir isotherm equation. The surface morphology of the native and functionalized CNS samples was characterized by a number of techniques and based on which the adsorption of copper ion was discussed.

Aluminum or Its Alloy Matrix Hybrid Nanocomposites

Subrata Mondal 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

Aluminum or its alloys are widely used in automobile, aerospace, and marine due to their low density, good ductility, low cost,corrosion resistance etc. However, aluminum has several pit falls viz. poor strength, abrasion and wear resistance etc. Thesepit fall of aluminum can be improve by reinforcement of nanomaterials in the pure metal or alloy. Various types of nanomaterials can be used for the fabrication of light-weight aluminum/alloy matrix nanocomposites for high specifc strength,improved wear and abrasion property, better corrosion resistance etc. Recently, there is a signifcant research interest for thefabrication of nanocomposites by using more than one reinforcing materials. This article presents an overview of variousreinforcement materials used for the fabrication of aluminum or its alloy matrix based hybrid nanocomposites. Brief overview of metal matrix and specifcally aluminum matrix nanocomposites are included in the manuscript. Various processingroutes for the fabrication of hybrid nanocomposites are explained. Properties of hybrid nanocomposites with respect to thenano-reinforcement types, reinforcement concentration, morphology and microstructure are discussed. Further, potentialapplications and future trends of aluminum or its alloy matrix hybrid nanocomposites are presented. Finally, the article hasbeen concluded with several future scopes of research in the area of aluminum/alloy matrix based hybrid nanocomposites.

Stabilization of the primary sigma factor of Staphylococcus aureus by core RNA polymerase

( Rajkrishna Mondal ),( Tridib Ganguly ),( Palas K Chanda ),( Amitava Bandhu ),( Biswanath Jana ),( Keya Sau ),( Chia Y Lee ),( Subrata Sau ) 한국생화학분자생물학회 (구 한국생화학회) 2010 BMB Reports Vol.43 No.3

The primary sigma factor (σA) of Staphylococcus aureus, a potential drug target, was little investigated at the structural level. Using an N-terminal histidine-tagged σA (His-σA), here we have demonstrated that it exits as a monomer in solution, possesses multiple domains, harbors primarily α-helix and efficiently binds to a S. aureus promoter DNA in the presence of core RNA polymerase. While both N- and C-terminal ends of His- σA are flexible in nature, two Trp residues in its DNA binding region are buried. Upon increasing the incubation temperature from 25° to 40℃, ~60% of the input His-σA was cleaved by thermolysin. Aggregation of His-σA was also initiated rapidly at 45℃. From the equilibrium unfolding experiment, the Gibbs free energy of stabilization of His-σA was estimated to be +0.70 kcal mol-1. The data together suggest that primary sigma factor of S. aureus is an unstable protein. Core RNA polymerase however stabilized σA appreciably. [BMB reports 2010; 43(3): 176-181]

Bio-extract assisted in-situ green synthesis of Ag-RGO nanocomposite film for enhanced naproxen removal

Somen Mondal,Surabhi Patel,Subrata Kumar Majumder 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

The present study reports in-situ green synthesis of Ag-RGO nanocomposite film using turnip leavesextract as a reducing as well as a capping agent and its application as a highly efficient naproxen adsorbent from a contaminated aqueous solution. The nanocomposite was characterized employing XRD, Raman and FT-IR spectroscopy, FETEM and FESEM microscopy, EDS spectroscopy. The pseudo-second-order and Elovich kinetic model furnished the best correlation of the experimental data, specifying the adsorption as the rate-limiting step for naproxen (NPX) removal by Ag-RGO composite film. The Freundlich and Dubinin-Radushkevich (D-R) isotherms represented the experimental adsorption data satisfactorily, suggesting a multilayered chemical adsorption process on the heterogeneous adsorbent surfaces. The process parameters were optimized to get the maximum adsorption capacity, which was obtained as 229.25mg g1 (92.62%). The parametric effects of pHs and NPX concentrations were tested within a range of 2.50- 8.50 and 25-100mg dm3, respectively, for the contact time of 0.33-3 min at a constant temperature (298 K) and adsorbent dose (20.2mg). The feasibility of the regeneration of the materials after adsorption is based on the experimental results. The experimentally optimized process parameters were validated using response surface methodology (RSM).

Detection of the cell wall-affecting antibiotics at sublethal concentrations using a reporter Staphylococcus aureus harboring drp35 promoter - LacZ transcriptional fusion

( Rajkrishna Mondal ),( Palas K Chanda ),( Amitava Bandhu ),( Biswanath Jana ),( Chia Y Lee ),( Subrata Sau ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2010 BMB Reports Vol.43 No.7

Previously, various inhibitors of cell wall synthesis induced the drp35 gene of Staphylococcus aureus efficiently. To determine whether drp35 could be exploited in antistaphylococcal drug discovery, we cloned the promoter of drp35 (Pd) and developed different biological assay systems using an engineered S. aureus strain that harbors a chromosomally-integrated Pd - lacZ transcriptional fusion. An agarose-based assay showed that Pd is induced not only by the cell wall-affecting antibiotics but also by rifampicin and ciprofloxacin. In contrast, a liquid medium- based assay revealed the induction of Pd specifically by the cell wall-affecting antibiotics. Induction of Pd by sublethal concentrations of cell wall-affecting antibiotics was even assessable in a microtiter plate assay format, indicating that this assay system could be potentially used for high-throughput screening of new cell wall-inhibiting compounds. [BMB reports 2010; 43(7): 468-473]

Synthesis of phosphate functionalized highly porous activated carbon and its utilization as an efficient copper (II) adsorbent

Somen Mondal,Subrata Kumar Majumder 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.5

The effects of activating agents on the characteristics of the activated carbons prepared from the tea waste were investigated. A three-step chemical activation process consisting of impregnation, carbonization and the secondary activation or phosphate functionalization was followed for the synthesis of the activated carbons. The surface area and the total pore volume of the best-activated carbon prepared in the present investigation at optimized conditions were found to be 1,329m2/g and 0.4167 cm3/g. The potentiality of the copper adsorption onto the best quality activated carbon with the highest surface area and pore volume was investigated. The maximum adsorption capacity of the activated carbon was 76.22mg/gat room temperature (28 oC). The copper (II) adsorption onto the activated carbon followed the pseudo-second-order kinetics which satisfied the Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. Best activated carbon obtained from the present investigation may be recommended to use in water purification processes as a revamped copper (II) bio-adsorbent.

Detecting medicinal plants species using GPS positioning in Vidyasagar University Campus, Midnapore, West Bengal, India

Sk. Md. Abu Imam Saadi,Ismail Mondal,Subrata Sarkar,Amal Kumar Mondal,Jatisankar Bandyopadhyay 대한공간정보학회 2017 Spatial Information Research Vol.25 No.1

A portable global positioning system (GPS) unit was tested against conventional field techniques for our University Campus plot location the GPS accuracy tested against 3 benchmarks indicated that for the surrounding area the largest average displacement from true position was 48 m form the mean sea level. Five operators were instructed in the use of GPS for waypoint navigation ours University campus and seven plots were then located by each of the operators using either GPS or conventional field navigation. Results indicated that the operator with the least amount of plot-location experience was able to locate plots faster with GPS than by conventional techniques. System portability, satellite availability, canopy interference with signals, and operator biases are cited as moderate encumbrances. Our study documented the diversity of medicinal plants of Vidyasagar University campus and their adjoining area in the district of Paschim Medinipur, South West Bengal, India. This includes 117 species, 108 genera, distributed among 49 plant families under the division Marchantiophyta, Pteridophyta, Monocotyledones and Dicotyledones. Our field survey reportare represent 117 species among them some dominating family’s like- Poaceae (11), Fabaceae (10), Apocynaceae (7), Malvaceae (6), Asteraceae (5), Euphorbiaceae (5), Amarantheceae (4), Araceae (4), Acanthaceae (4). Among the 117 species, presented checklist includes herbs (62), shrubs (22), trees (22), climbers (10) and Branched thallus (1). We take step for conservation of all the plant species to protect from anthropogenic activities.

Ethnobotanical perspectives of Bakhar: an indigenous starter culture used to prepare traditionally fermented rice beverage in rural West Bengal, India

Ghosh Sudipta,Sen Sukanta K.,Mondal Subrata 한국식품연구원 2022 Journal of Ethnic Foods Vol.9 No.-

Haria, a fermented rice beverage, is commonly consumed as a traditional drink by the tribal people of rural West Bengal. This beverage is prepared by fermenting steamed rice with the starter culture tablets, known as Bakhar. It is known that some plant parts are added during Bakhar preparation that confer certain ethnomedicinal properties to the beverage as well as to Bakhar itself. An ethnobotanical survey was conducted that allowed documenting the traditional knowledge regarding this ethnic beverage preparation and it reveals that 10 plant species and one lichen species are used by the Santal tribe to prepare the Bakhar. Among them, roots of Kedar, Chaoli, rhizome of Bach, and bark of Lodh plants are essential, while other plant parts are used due to their specifc taste, favor, and therapeutic properties. But nowadays little or no plant additives are used during commercial Haria preparation for cost-efectiveness. Homemade and commercially produced Haria were investigated for their nutritional quality which revealed that homemade beverage contains more bioactive compounds, such as ascorbic acid (15.40 mg/100 ml) and favonoids (36.67 mg/100 ml), which contribute toward the antioxidant property of the beverage. This current study documents the important medicinal plants used in the starter culture, the detailed process of Bakhar and Haria preparation, and the nutritional quality of Haria highlighting its ethnomedicinal properties.

Moderately thermostable phage Ф11 Cro repressor has novel DNA-binding capacity and physicochemical properties

Malabika Das,Tridib Ganguly,Amitava Bandhu,Rajkrshna Mondal,Palas K Chanda,Biswanath Jana,Subrata Sau 한국생화학분자생물학회 2009 BMB Reports Vol.42 No.3