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Journal of Water Resource and Protection 2011年第6期3卷 363-369页

作者： Chumki Chowdhury Natasha Majumder Sanjay kumar Mandal Manab kumar Dutta Raghab Ray tapan kumar Jana 不详

Despite scarce studies have analyzed the relative growth inhibition of As (III) and As (V) to diatom, clear pattern of interspecies difference have been shown, identifying cell size as a key property determining the sensitivity of diatom to As. Evidence from cultures suggests that cell size is a key factor in determining the extent of arsenic (III) & (V) stress of diatom, with relatively lesser effects of As (V) than As (III) on small cells. Cent percent growth inhibition was observed for large size group (Coscinodiscus radiatus, Surirella, Amphipleura, Thalassiothrix, Cyclotella and Thalassiosira decipiens) relative to smaller size group (Skeletonema cf. costatum, Navicula rhombica, Amphora hyaline, Nitzschia longissima except Thalassisira. Interspecies differences in As tolerance by diatom in the mangrove ecosystem indicates cell size could be only one factor contributing to these differences. The results show that 81.7% of total arsenic was uptaken from culture media originally amended with arsenic. Looking to the extreme tolerance and arsenic removal efficiency, application of the species with smaller cell size relative to the other tested diatom for bioremediation purpose can be envisaged.

关键词： Diatoms Cell Size Arsenic (III&V) Mangrove

Salt tolerant culturable microbes accessible in the soil of the Sundarban Mangrove forest, India

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Open Journal of Ecology 2011年第2期1卷 35-40页

作者： Subhajit Das Minati De Raghab Ray Dipnarayan Ganguly tapan kumar Jana Tarun kumar De Department of Marine Science Calcutta University 35 B.C. Road Calcutta-700 019

Sundarban Mangrove forest is highly productive marine ecosystem where halophilic microbes actively participate in bio-mineralization and biotransformation of minerals. The population of aerobic halophilic microbes was studied to determine their distribution with the availability of different physicochemical parameters with increasing depth of this forest sediment. The present study revealed that microbes present in the top soil region were less tolerant to fluctuation in salinity than the middle and bottom segment. Microbes isolated from bottom segment showed higher growth rate in anaerobic condition. A decreasing trend of total microbial population and organic carbon content of soil were found with increase in depth. In contrary a reverse profile was found for salinity. A significant stratification was found to exist among microbial population and the salty nature of the soil of Sundarban Mangrove forest.

关键词： Sundarban Mangrove Forest Ecosystem Halophilic Microbes Aerobic Condition Anaerobic Condition

Monsoonal Influence on Evapotranspiration of the Tropical Mangrove Forest in Northeast India

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American Journal of Climate Change 2014年第2期3卷 232-244页

作者： Dipnarayan Ganguly Raghab Ray Natasha Majumder Chumki Chowdhury tapan kumar Jana Department of Marine Science Calcutta University Kolkata India

Evapotranspiration (ET) is an important part of the water cycle. This study reports on the monsoonal influence on the temporal variation in evapotranspiration of an extremely water conservative and salinity stressed tropical mangrove forest at the land-ocean boundary of northeast coast of India. The magnitude and dynamics of evapotranspiration (ET) exhibited seasonality dominated by monsoon and evaporation rate was greater (0.055 ± 0.015 g·m-2·s-1) during the monsoon than in pre-monsoon (0.049 ± 0.018 g·m-2·s-1) and post-monsoon (0.044 ± 0.012 g·m-2·s-1). Seasonal difference in evapotranpiration was mostly due to fluctuation of canopy resistance, which was the minimum during monsoon when relative humidity was greater than in the dry season (pre- and post-monsoon) and deficiency of water supply (ET ≈ ETeq) was minimum. Evapotranspiration in the Sundarban mangrove ecosystem is the predominant biophysical processes that recycles 67.7% of total precipitation annually to the atmosphere, and has significant monsoonal influence.

关键词： Canopy Resistance Evapotranspiration Hydrological Cycle India Mangrove Forest Monsoonal Cycle

Differential Aphid Colony Establishment in <i>Dolichos lablab</i>Varieties Correlated with Some Plant Specific Factors That Impact on Aphid Fecundity

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American Journal of Plant Sciences 2017年第4期8卷 754-769页

作者： Hossain Ali Mondal Suvendu kumar Roy Lakshmi Hijam Moumita Chakraborty Puspendu Dutta tapan kumar Hath Department of Genetics and Plant Breeding Uttar Banga Krishi Viswavidyalaya Cooch Behar India Department of Seed Science and Technology Uttar Banga Krishi Viswavidyalaya Cooch Behar India Department of Agricultural Entomology Uttar Banga Krishi Viswavidyalaya Cooch Behar India

Aphid establishes colony in the selective plant parts like vine, leaf petiole, leaflet, inflorescence, and tender fruit in Dolichos lablab Linn but not the entire plant. In this study, the aphid colony establishment in vine is focused to understand the differential resistance response between two varieties. At the early stage of aphid infestation, the aphid colony establishment was significantly different between two genotypes (p value = 0.00) and abbreviated as “resistant” variety that supported lower aphid proliferation (mean value = 48.2 ± 2.2) and “susceptible” variety that supported comparatively higher aphid proliferation (mean value = 215.5 ± 16.9). The total aphid number was significantly different between the two varieties, realized at the early infestation stage when both “antixenosis” and “antibiosis” defense mechanisms were working on. Some plant specific factors like vine diameter, wet/ dry weight ratio of vine, phloem sap pressure, the compactness of the vine, wet/dry weight ratio of leaflet, length of leaf petiole, diameter of leaflet vein were identified as modulating factors. The impact of resistant variety on aphid was also investigated for better understanding of aphid defense mechanism.

关键词： Dolichos lablab Aphid Colony Differential Vine Diameter Differential Wet/Dry Weight Ratio of Vine Differential Phloem Pressure Differential Compactness of the Vine Differential Aphid Fecundity Differential Water Content in Aphid

Effect of Copper Oxide Nano Particle on Seed Germination of Selected Crops

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Journal of Agricultural Science and Technology(A) 2012年第6期2卷 815-823页

作者： tapan Adhikari Samaresh Kundu Ashis kumar Biswas Jagadish Chandra Tarafdar Anangi Subba Rao Indian Institute of Soil Science Nabibagh Berasia Road Bhopal 462038 India Central Arid Zone Research Institute Jodhpur India

Nano particles are finding their way into the environment through deliberate and accidental actions, ecotoxicological properties and the risks of these nano particles have yet not been fully characterized. In this present investigation, experiments were carried out to know the effect of Cu oxide-nano particles （〈 50 nm） on germination and growth of seeds of soybean and chickpea. In both the crops, germination was not checked up to 2,000 ppm Cu （applied through Cu oxide-nano particles）, but the root growth was prevented above 500 ppm Cu. With increasing concentration of NPs, the elongation of the roots was severely inhibited as compared to that in control. In many cases root necrosis was occurred. Massive adsorption of Cu oxide-nano particles into the root system was responsible for the toxicity. A parallel experiment was also carried out to know the effect of copper sulphate solution on seed germination, above 200 ppm Cu, it restricted the germination of seeds, because of high salinity.

关键词： Cu-nano particles soybean chickpea.

Depth profile exploration of enzyme activity and culturable microbial community from the oxygen-starved soil of Sundarban mangrove forest, India

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Open Journal of Ecology 2011年第3期1卷 65-72页

作者： Subhajit Das Tarun kumar Sarkar Minati De Dipnarayan Ganguly Tusher Kanti Maiti Abhishek Mukherjee tapan kumar Jana Tarun kumar De 不详

Populations of culturable microbes and activities of dehydrogenase & ?-D glucosidase were found maximum in surface soil and decreased with increase in depth in Sundarban mangrove *** maximum (13.529 X 106 C.F.U g-1 dry weight of soil) and minimum (11.547 X 106 C.F.U g-1 dry weight of soil) total microbial popu- lations in surface soil were recorded during po- st-monsoon and monsoon respectively. At 60 cm depth, the lower (6.396 X 106 C.F.U g-1 dry weight of soil) and higher (8.003 X 106 C.F.U g-1 dry weight of soil) numbers of total microbial populations were observed during monsoon and post-monsoon respectively. A decreasing trend of total microbial load, enzyme activities and nutrient status with organic carbon were found with increase in depth throughout the year. Present study revealed the relationship among depth integrated variations of physico-chemical compo- nents (viz. soil temperature, pH, moisture, orga- nic-C, .nitrogen, and available-P) and microbial populations as well as activity of dehydrogenase and ?-D glucosidase enzymes.

关键词： Sundarban Mangrove Sediment Enzyme Activities Depth Microbial Populations

Continuous Wave Diode Laser Surface Texturing of Austenitic and Pearlitic Steels

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Materials Sciences and Applications 2015年第10期6卷 889-906页

作者： Sulthan Mohiddin Shariff Suresh Koppoju tapan kumar Pal Padmanabham Gadhe Shrikant Viswanath Joshi International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) Hyderabad India Department of Metallurgical and Materials Engineering Jadavpur University Kolkata India

Microstructuring of steel resulting in directional solidification and texturing, previously observed in various metallic materials during pulsed laser processing, melt-spinning, high-gradient liquid metal melting, zone melting etc., is reported for the first time in continuous wave diode laser processing of steels. Influence of laser interaction time on surface morphology/topology of austenitic manganese and pearlitic steels is investigated utilizing a wide rectangular multi-mode diode laser beam. X-ray diffraction analysis of the laser treated austenitic steel surface showed strong texturing influence, with preferred crystallographic orientation of γ-Fe crystals in the (200) plane, which increased with interaction time. In case of pearlitic steel, no such texturing influence could be observed. The free surface topologies were also observed to be different in each case, with well-aligned domes of γ-Fe observed in laser treated austenitic steel as compared to randomly oriented fine domes of metal oxides in pearlitic one. In situ surface temperature measurement during laser irradiation indicated higher temperature on pearlitic steel than in austenitic manganese steel owing to its lower effective thermal conductivity associated with higher oxide film formation.

关键词： Diode Laser Texturing Pearlitic Steel Austenitic Manganese Steel Directional Solidification Oxidation Surface Morphology Surface Topology

A Depth Wise Diversity of Free Living N<sub>2</sub>Fixing and Nitrifying Bacteria and Its Seasonal Variation with Nitrogen Containing Nutrients in the Mangrove Sediments of Sundarban, WB, India

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Open Journal of Marine Science 2013年第2期3卷 112-119页

作者： Subhajit Das Dipnarayan Ganguly Tushar Kanti Maiti Abhishek Mukherjee tapan kumar Jana Tarun Kuma De Department of Marine Science Calcutta University Kolkata India Microbiology Laboratory Department of Botany Burdwan University Burdwan India

Mangrove provides a unique ecological niche to different microbes which play various roles in nutrient recycling as well as various environmental activities. The highly productive and diverse microbial community living in mangrove ecosystems continuously transforms dead vegetation and recycle nitrogen, phosphorus, sulphur and other nutrients that can later be used by the plants. Mangrove ecosystems are rich in organic matter, and however, in general, they are nutrient-deficient ecosystems, especially of nitrogen and phosphorus. The present study investigated depth wise variation of Nitrifying bacteria, Nitrogen fixing bacteria, total bacterial population along with nitrate-nitrogen, nitrite-nitrogen and other physicochemical parameters of soil during pre-monsoon, monsoon and post-monsoon periods at three different sampling stations of mangrove sediments viz. deep forest region, rooted region and unrooted region. The microbial population was also found maximum in the deep forest sediment relative to the other two sites. Populations of cultureable microbes were found maximum in surface soil and decreased with increase in depth in Sundarban mangrove environment. A decreasing trend of total microbial load, nitrifying and nitrogen fixing bacteria with increase in depth were recorded throughout the year. Present study revealed the relationship among depth integrated variations of physicochemical components (viz. soil temperature, pH, salinity, nitrite nitrogen and nitrate nitrogen concentration) and total microbial load, nitrifying and nitrogen fixing bacteria microbial populations.

关键词： Nitrifying Bacteria N2 Fixing Bacteria Bacterial Population Mangrove Sediment

Depth Integrated Microbial Community and Physico-Chemical Properties in Mangrove Soil of Sundarban, India

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Advances in Microbiology 2012年第3期2卷 234-240页

作者： Subhajit Das Minati De Dipnarayan Ganguly Tushar Kanti Maiti Abhishek Mukherjee tapan kumar Jana Tarun Kuma De Department of Marine Science Calcutta University Kolkata India Maniktala Siksha Bhavan Kolkata India Microbiology Laboratory Department of Botany Burdwan University Burdwan India

In the Sundarban Mangrove forest microbial activities are dominantly involved in both the mineralization and decomposition processes that regulate nutrient profile in soil of different depth. It was found that besides changing the water and soil quality, monsoonal cycle plays a crucial role in regulating microbial population distribution in the mangrove soil. Statistical analyses revealed that organic carbon was the most significant factor that regulated the total microbial population. The cellulose degrading bacteria, [mean value of CFU 14.32 × 106 (gm dry weight of soil)–1] was dominant throughout the year. The sulfate reducing bacteria showed an increasing trend along depth with a minimum value at the surface i.e. 6.113 × 106 (gm dry weight of soil)–1 and 12.312 × 106 (gm dry weight of soil)–1 at a depth of 60 cm. Intensification of monsoonal cycle could heavily affect microbe dominated soil biogeochemistry and subsequent change in the regional ecology of the Sundarban Mangrove Forest.

关键词： Sundarban Mangrove Microbial Population Monsoonal Cycle Nutrient Concentration

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兼作防老剂的促进剂在各种橡胶中的性能

橡胶参考资料 1996年第3期26卷 30-36页

作者： tapan kumar Khanna Sukumar Maiti Basudam Adhikari 张官臣

防老剂的有效性取决于防老剂的化学结构及所需防护的橡胶的种类。可大批供应的防者剂有很多。作者开发了多功能促进剂和防老剂的新品种,并在有关文献中作了报道。1-(N-氧二乙撑硫代氨基甲酰基)-2-(N-氧二乙撑硫代)苯并咪唑(MBSPT)就是... 详细信息

防老剂的有效性取决于防老剂的化学结构及所需防护的橡胶的种类。可大批供应的防者剂有很多。作者开发了多功能促进剂和防老剂的新品种,并在有关文献中作了报道。1-(N-氧二乙撑硫代氨基甲酰基)-2-(N-氧二乙撑硫代)苯并咪唑(MBSPT)就是其中的一种。现已发现。

关键词：防老剂促进剂橡胶 MBSPT