171 research outputs found

    Cosmic Ray Energy Spectrum above 1017 eV Observed at Gauhati University Mini Array

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    Biochemical changes in agarwood tree (Aquilaria malaccensis Lamk.) during pathogenesis

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    Post-infection changes in sugars, ascorbic acid, phenols and protein of agarwood tree (Aquilaria malaccensis) were investigated after inoculation with fungi such as Chaetomium globosum and Fusarium oxysporum. In healthy trees, the biochemical constituents increased, whereas in infected trees they decreased after inoculation with fungi. &nbsp

    Photo-enhanced lithium-ion batteries using metal-organic framework

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    The development of photo-enhanced lithium-ion batteries, where exposing the electrodes to light results in higher capacities, higher rate performance or self-charging, has recently gained substantial traction. The challenge in these devices lies in the realisation of photo-electrodes with good optical and electrochemical properties. Herein, we propose copperhexahydroxybenzene as the active photo-electrode material which both harvests light and stores energy. This material was mixed with reduced graphene oxide as a conductive additive and charge transfer medium to create photo-active electrodes. Under illumination, these electrodes show improved charge storage kinetics resulting in the photo-accelerated charging and discharging performance (i.e. specific capacities improvement from 107 mAh g-1 to 126 mAh g-1 at 200 mA g-1 and 79 mAh g-1 to 97 mAh g-1 at 2000 mA g-1 under 1 sun illumination as compared to dark)

    XRD and FT-IR investigations of sub-bituminous Assam coals

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    Two coal samples collected from Makum coal field, Assam, India were studied by XRD and FT-IR techniques. The X-ray diffractogram shows the existence of some crystalline carbons in Assam coals as proven by the appearance of peaks. The radial distribution functional (RDF) method was applied for the determination of structural aspects of the coals. The study indicates that the coals are lignite in type and there is no evidence of graphite-like structures. The maximum in the G(r) plots of function of radial distribution of atoms (FRDA) relates to different distances between carbon atoms of aliphatic chains. The first significant maximum relates to the C-C bond (type C-CH=CH-C), the second maximum relates to the distance between carbon atoms of aliphatic chains that are located across one carbon atom. The curve intensity profiles obtained from FRDA show quite regular molecular packets for this coal. The coals were found to be lignite in nature. FT-IR study shows the presence of aliphatic carbon, C=O and C-O stretching associated with -OH and -NH stretching vibrations. Kaolinite and quartz were also found to be major minerals in Assam coals by FTIR spectroscopy. The difference in intensities of carbonyl groups of the coal samples is likely to relate with the rank. © Indian Academy of Sciences

    Achievability of Municipal Solid Waste Compost for Tea Cultivation with Special Reference to Cadmium

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    Not AvailableMunicipal solid waste compost (MSWC) is quite often used for soil amendment in agricultural crops and yet little is known about its effect on tea (Camellia sinensis L.) cultivation. This study investigates the effect of MSWC application on cadmium (Cd) concentrations in soil, tea plants, and infusions. Different doses of MSWC are added to soil with two Tocklai vegetative (TV) tea clones (TV1 and TV23) for 2 years in pot experiments. Several fractions of Cd in amended soils, biomass yield, and Cd content in different parts of tea plants and in tea infusions are measured. Several indexes related to risk assessment are also calculated. The geo‐accumulation index values of Cd in soil amended with MSWC ranges from −1.74 to 3.12, indicating class 0 (practically uncontaminated) to class 4 (heavily contaminated) contamination level. Average daily intakes (ADI) of Cd through tea infusion produced from tea plant amended with MSWC are 8.9 × 10−6 and 9.2 × 10−6 mg kg−1 per body weight and day for men and women, respectively. These values are much lower than those given in the Joint FAO/WHO Provisional Tolerable Monthly Intake Guideline for Cd. The non‐carcinogenic risk values (also called hazard quotient) for Cd, estimated from the ADI values, are found to be 1.78 × 10−2 and 1.94 × 10−2 mg kg−1 per day for men and women, respectively, suggesting no health hazard. The results suggested the possibility of management of MSW through composting and the feasibility of compost application for tea cultivation.Not Availabl

    Studies on uracils : synthesis of novel pyrido[2,3-d]- pyrimidine oxides via ring transformation of isoxazolo[3,4-d]pyrimidine

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    The reaction of isoxazolo[3,4-d]pyrimidine 1 and cyanoolefins 2 in the presence of triethylamine (Et3N) as a catalyst afforded an unprecedented one-pot synthesis of biologically important pyrido[2,3-d]pyrimidine oxides 3 in excellent yields

    Antifungal activity and chemical composition of Citrus reticulata Blanco essential oil against phytopathogens from North East India

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    The essential oil (EO) isolated by hydro-distillation from the peel of fully matured ripen fruits of Citrus reticulata Blanco were analyzed by GC and GC 13MS. Thirty seven different components were identified constituting approximatel

    Cu(II)-catalyzed Michael addition of 1,3-dicarbonyl compounds

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