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Litterfall,decomposition and nutrient release of Shorea robusta and Tectona grandis in a sub-tropical forest of West Bengal,Eastern India

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Journal of Forestry Research 2016年第5期27卷 1055-1065页

作者： Chittaranjan Das naba kumar mondal Department of Environmental Science The University of Burdwan

We studied leaf litter fall, decomposition and nutrient release patterns of Shorea robusta and Tectona grandis by using a litter bag technique to better understand the release pattern of nutrients to soil from leaf litter. Annual litterfall varied from 13.40 ± 2.56 t ha-1 a-1 for S. robusta to 11.03 ± 3.72 t ha-1 a-1 for T. grandis and the decay constant （k） of decomposed leaf litter was distinctly higher for T. grandis （2.70 ± 0.50 a-1） compared to S. robusta （2.41 ±0.30 a-1）. Biomass loss was positively correlated with the initial litter C, WSC, C/N and ash content in S. robusta and N, P and K concentration for T. grandis. Biomass was negatively correlated with lignin and L/N ratio for S. robusta and L, WSC, L/N and C/N ratio for T. grandis （P 〈 0.01）. Nutrient use efficiency （NUE） and nutrient accumulation index （NAI） of S. robusta was higher than for T. grandis. The retranslocation of bioelements from senescent leaves ranked as P 〉 N 〉 K. Annual N, P and K input to soil through litterfall differed significantly between the two species in the following order： N〉K^P. S. robusta was superior in terms of K and P return and T. grandis was superior in terms of N return. The two tree species showed a similar patterns of nutrient release （K 〉 P 〉 N） during decomposition of their leaf *** of N, K and P were the primary limiting nutrients returned to soil through litterfall with important roles in soil fertility and forest productivity.

关键词： Decay constant Lignin Litterfall Nutrientreturn Decomposition Nutrient use efficiency

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Enhanced photocatalytic activity of methylene blue using heterojunction Ag@TiO_(2)nanocomposite:Mechanistic and optimization study

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Chinese Journal of Chemical Engineering 2023年第12期64卷 49-63页

作者： Saptarshi Ghosh Kamalesh Sen Priyanka Debnath Arghadip mondal naba kumar mondal Aerosol and Nanoparticle Technology Laboratory Environmental Science and Engineering Department.Indian Institute of Technology BombayMumbai 400076India Environmental Chemistry Laboratory Department of Environmental ScienceThe University of BurdwanW.B 713104India

The objective in this study is to investigate the adsorption-degradation of the methylene blue(MB)dye using a fabricated heterojunction Ag@TiO_(2)*** batch factors used in photo catalytic reactions were pH,UV-irradiation time,temperature,catalytic dosage,and concentration of *** results showed that 0.2×10^(3) g·ml^(-1))of the catalytic dose caused the Ag@TiO_(2)adsorption to degrade by 96.67%with darks and UV *** the Langmuir-Hinshelwood model to determine the kinetic,the Ag@TiO_(2)displays a greater kinetic rate than TiO_(2)and silver nanoparticle(AgNPs).The photocatalytic degradation of MB,which is an endothermic reaction involving all catalysts,is shown by the thermodynamic parameter to have the positive value of enthalpy(ΔH°).The enthalpies observed were Ag@TiO_(2)(126.80 kJ·mol^(-1))

关键词： Heterojunction Ag@TiO_(2)nanocomposite Methylene blue dye Langmuir-Hinshelwood model Scavenger Density functional theoty

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Synthesis of silver nanoparticle with Colocasia esculenta(L.) stem and its larvicidal activity against Culex quinquefasciatus and Chironomus sp

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Asian Pacific Journal of Tropical Biomedicine 2019年第12期9卷 510-517页

作者： Arghadip mondal Amita Hajra Wasim Akram Shaikh Sukalyan Chakraborty naba kumar mondal Environmental Chemistry Laboratory Department of Environmental ScienceThe University of Burdwan713104West BengalIndia Department of Civil&Environmental Engineering Birla Institute of TechnologyMesraJharkhandIndia

Objective:To synthesize silver nanoparticles with Colocasia esculenta as a reducing agent and to evaluate their effect against Culex quinquefasciatus and Chironomus ***:The aqueous extract of Colocasia esculenta stem was used for *** synthesized nanoparticles were characterized by UV-Vis spectrophotometry,Fourier-transform infrared spectroscopy,scanning electron microscope,transmission electron microscopy,energy-dispersive X-ray spectroscopy,X-ray diffraction and Zeta potential *** toxicity of Colocasia esculenta stem extract and the synthesized silver nanoparticles was evaluated against the larval stages of target human filarial vector Culex quinquefasciatus and non-target Chironomus ***:Scanning electron microscopy and transmission electron microscopy studies revealed almost spherical shape of the synthesized silver nanoparticles with size ranging from 13-50 *** 24 hours of exposure,the LC50 and LC90 of the plant extract against 4th instars larvae of Culex quinquefasciatus were 745.56 mg/L and 1258.28 mg/L,respectively,which were higher than those of synthesized silver nanoparticles(5.17 mg/L and 17.32 mg/L after 24 h;1.58 mg/L and 13.01 mg/L after 48 h).In addition,the LC50 and LC90 of silver nanoparticles against Chironomus *** 9.71 mg/L and 23.15 mg/L after 24 h as well as 2.38 mg/L and 19.49 mg/L after 48 h,***:The aqueous stem extract of Colocasia esculenta is a good agent for synthesis of silver nanoparticles,which are almost spherical with size less than 30 *** synthesized nanoparticles show good larvicidal activity without any harmful effect on non-target species.

关键词： Silver nanoparticles Colocasia esculenta Larvicidal Culex quinquefasciatus Mortality Chironomus sp

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Application of Response Surface Methodology for Optimization of Fluoride Removal Mechanism by Newely Developed Biomaterial

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American Journal of Analytical Chemistry 2013年第8期4卷 404-419页

作者： Ria Bhaumik naba kumar mondal Soumya Chattoraj Jayanta kumar Datta Department of Environmental Science The University of Burdwan Burdwan India

The adsorption capacities of new biomaterials derived from lemon leaf (Citrus sp.) toward fluoride ions have been explored by varying different physicochemical parameters such as pH, initial concentration, adsorbent dose, contact time, stirring rate and temperature. The entire study was done through batch process. Maximum fluoride adsorption of 96.9% - 98.8% was achieved with an initial concentration of 10 mg/L. Langmuir isotherm model well expressed fluoride ad- sorption onto LLD-1, LLD-2 and LLD-3. According to correlation coefficient, the fluoride adsorption onto these 3 ad- sorbents was correlated well with pseudo-second-order kinetic model. From thermodynamic study, the spontaneous nature and feasibility of the adsorption process with negative enthalpy (ΔH0) value also supported the exothermic nature were shown. The rate of fluoride adsorption was mathematically described as a function of experimental parameters and was modeled through Box-Behnken (Response surface methodology). The results showed that the responses of fluoride adsorption were significantly affected by the quadratic term of pH, initial concentration, contact time and temperature and the statistical analysis was performed by ANOVA which indicated good correlation of experimental parameters.

关键词： Lemon Leaf Fluoride Adsorption Langmuir Isotherm Pseudo-Second-Order Kinetic Model Thermodynamic Study Response Surface Methodology

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Ground motion parameters of Shillong plateau: One of the most seismically active zones of northeastern India

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Earthquake Science 2009年第3期22卷 283-291页

作者： Saurabh Baruah Santanu Baruah naba kumar Gogoi Olga Erteleva Felix Aptikaev J. R. Kayal Geoscience Division North-East Institute of Science and Technology (CSIR) National Geophysical Research Institute Institute of Physics of the Earth School of Oceanographic Studies Jadavpur University

Strong ground motion parameters for Shillong plateau of northeastern India are examined. Empirical relations are obtained for main parameters of ground motions as a function of earthquake magnitude, fault type, source depth, velocity characterization of medium and distance. Correlation between ground motion parameters and characteristics of seismogenic zones are established. A new attenuation relation for peak ground acceleration is developed, which predicts higher expected PGA in the region. Parameters of strong motions, particularly the predominant periods and duration of vibrations, depend on the morphology of the studied area. The study measures low estimates of logarithmic width in Shillong plateau. The attenuation relation estimated for pulse width critically indicates increased pulse width dependence on the logarithmic distance which accounts for geometrical spreading and anelastic attenuation.

关键词： Shillong plateau ground motion parameter duration magnitude northeastern India

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A Retrospective Study on the Prevalence of HIV among Patients Attending a Tertiary Care Hospital of Northeast India

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World Journal of AIDS 2016年第2期6卷 65-73页

作者： naba kumar Hazarika Syed Tanwir Alam Arunjyoti Sarmah Arnabjyoti Bhagawati Department of Microbiology Gauhati Medical College & Incharge ICTC & SRL GMCH Guwahati India Department of Microbiology Gauhati Medical College Guwahati India Research Scientist I (Medical) Department of Microbiology Gauhati Medical College Guwahati India Technical Officer ICTC & SRL GMCH Guwahati India

Objective: The main objective of this study is to evaluate the prevalence of HIV infection among the clients attending ICTC, Gauhati Medical College & Hospital, Guwahati, for a period of seven years, i.e., from April 2008 to March 2015. Material & Method: A total of 40,983 clients attended ICTC, Gauhati Medical College & Hospital from the year 2008 to 2015. Serum samples were collected after taking informed consent and pre-test counseling. In India for all ICTCs, NACO (National AIDS Control Organization), a national guidelines has been followed for HIV testing, reporting and release of results with post test counseling. Results: Of the total 40,983 clients tested for HIV infection, 1919 (4.68%) were found to be HIV seropositive. Seropositivity was higher in male clients i.e. 1314 (68.47%) than female i.e. 604 (31.47%) followed by transgender (TG), i.e., 1 (0.0005%). Heterosexual route of transmission was the major route seen in 1666 clients (86.81%). Maximum HIV seropositivity was in the age group of 45 - 49 years (43.62%). Conclusion: HIV prevalence of 4.68 % among the clients attending ICTC, Gauhati Medical College & Hospital, Guwahati, puts the spotlight on the HIV burden in this part of the country and suggests the need for the scaling up of focused prevention efforts in high-risk groups.

关键词： Northeast India HIV ICTC Transgender

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