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Mandal R.,Indian Institute of Technology Kharagpur | Mandal R.,University of Pune | Pansare G.R.,University of Pune | Pansare G.R.,Haribhai V Desai College | And 3 more authors.
Journal of the Physical Society of Japan | Year: 2012

The angular distribution of the 14MeV neutrons emitted through D-T reaction was measured around the tritium target of a 14MeV neutron generator using two different sample holders and also theoretically estimated. The samples were made out of 99.99% pure Aluminium foil and irradiated with the neutrons. In the neutron irradiated aluminum samples, the gamma-ray activity, induced through the nuclear reaction Al 27(n,α)Na 24 was measured by a NaI(Tl) detector. Using one of the sample holders the axial distribution of neutron flux was also estimated. The discrepancy from the isotropic pattern was accounted for by reasons related to the in-between matrices and design of the tritium target mounting assembly. © 2012 The Physical Society of Japan.

Vidyasagar P.B.,University of Pune | Jagtap S.S.,Haribhai V Desai College | Dixit J.P.,University of Pune | Kamble S.M.,University of Pune | Dhepe A.P.,University of Pune
Microgravity Science and Technology | Year: 2014

Numerous studies have been carried out to investigate the hypergravity effect on plants, where seedlings (4–5 days old) were continuously exposed and grown under hypergravity condition. Here, we have used a novel ‘shortterm hypergravity exposure experimental method’ where imbibed caryopses (instead of seedlings) were exposed to higher hypergravity values ranging from 500 g to 2500 g for a short interval time of 10 minutes and post short-term hypergravity treated caryopses were grown under 1 g conditions for five days. Changing patterns in caryopsis germination and growth, along with various photosynthetic and biochemical parameters were studied. Results revealed the significant inhibition of caryopsis germination and growth in short-term hypergravity treated seeds over control. Photosynthesis parameters such as chlorophyll content, rate of photosynthesis (PN), transpiration rate (Evap) and stomatal conductance (Gs), along with intracellular CO2 concentration (Cint) were found to be affected significantly in 5 days old seedlings exposed to short-term hypergravity treatment. In order to investigate the cause of observed inhibition, we examined the α-amylase activity and antioxidative enzyme activities. α-amylase activity was found to be inhibited, along with the reduction of sugars necessary for germination and earlier growth in short-term hypergravity treated caryopses. The activities of antioxidant enzymes such as catalase and guaiacol peroxidase were increased in short-term hypergravity treated caryopses, suggesting that caryopses might have experienced oxidative stress upon short-term hypergravity exposure. © 2014, Springer Science+Business Media Dordrecht.

Choudhury S.P.,National Institute of Technology Meghalaya | Gunjal S.D.,University of Pune | Gunjal S.D.,Haribhai V Desai College | Kumari N.,Indian Institute of Technology Delhi | And 3 more authors.
Materials Today: Proceedings | Year: 2016

In the present contribution a simplistic synthesis of SnO2 thin film on ultrasonically cleaned soda-lime glass is outlined. Precursor solution of strength 0.1 M, 0.2 M and 0.3 M are used for the synthesis using a homemade affordable spray pyrolysis technique. An elaborate structural analysis is carried from the X-Ray diffraction data. The structural analysis is supported by the transmission electron microscopy micrograph and selected area electron diffraction pattern. The crystallite sizes are below 50 nm that makes the films suitable for nano-material application. Formation of texture is observed which indicates the preferred orientation to be the (101) plane. In comparison to techniques like pulsed laser deposition, spray pyrolysis provides better results for certain applications. The morphology of the thin films is investigated using atomic force microscopy. It revealed the control of application dependent roughness of the sample by variation of molarity of the precursor solution. Also the film is uniformly spread throughout the substrate. The optical properties are studied by UV-Visible spectroscopy that further confirms formation of nano-structures. Preliminary electrical investigation of the thin films is done by using a two probe semi-conductor characterization system and is correlated with UV-Visible result. Impedance analysis showed that with higher molarity the impedance remains constant and the barrier height remains fixed for high frequency which predicts that the films can be used for rectifying applications. © 2016 Elsevier Ltd.

Chhattise P.K.,Nowrosjee Wadia College | Chhattise P.K.,Haribhai V Desai College | Arbuj S.S.,CMET - Photonics And Advanced Materials Laboratory | Mohite K.C.,Haribhai V Desai College | And 4 more authors.
RSC Advances | Year: 2014

Herein, we have developed a novel heterogeneous catalytic system for synthesis of bis(indol-3-yl)methanes using one dimensional (1D) CdS nanorods. CdS nanorods were synthesized by a solvothermal reaction technique at 200 °C over 12 h in the presence of ethylenediamine as a solvent. The prepared 1D CdS was characterized using various spectroscopic methods. X-ray diffraction (XRD) revealed the formation of highly crystalline CdS having a wurtzite structure. FESEM analysis confirms the formation of a rod like morphology with length around 150 to 200 nm and diameter ∼15 nm. TEM also validates the formation of uniform size one dimensional (1D) CdS nanostructures. The catalytic activity of 1D CdS as a Lewis acid was investigated for the synthesis of bis(indol-3-yl)methanes (BIMs) with various substituted aldehydes and indoles within shorter reaction time affording the corresponding product in excellent yield. © 2014 the Partner Organisations.

Mene R.U.,Swami Ramanand Teerth Marathwada University | Mahabole M.P.,Swami Ramanand Teerth Marathwada University | Mohite K.C.,Haribhai V Desai College | Khairnar R.S.,Swami Ramanand Teerth Marathwada University
Journal of Alloys and Compounds | Year: 2014

Swift Heavy Ion irradiation (SHI) technique is utilized to modify the structure and surface morphology of Fe doped Hydroxyapatite (Fe-HAp) thick films for CO and CO2 gas sensing applications. Nano-crystalline HAp is synthesized by wet chemical precipitation route and ion exchange process is employed to replace of Ca ion with Fe ions. Thick film Fe-HAp sensors, having variable Fe doping concentrations, are prepared by using screen printing technique. The Fe-HAp thick films are irradiated using Ag7+ ion (100 MeV) with variable ion fluences ranging from 3 × 1010 to 3 × 1013 ions/cm2 for modifying the sensor surface. Structural and morphological changes with respect to ion fluence are observed by means of XRD, SEM and AFM analysis. The parameters such as operating temperature, response/recovery time, and uptake capacity for pristine and modified Fe-HAp sensors are experimentally determined. The investigations reveal that the SHI irradiated Fe-HAp film (3 × 1011 ions/cm 2) shows improved gas sensing characteristics at relatively lower operating temperature in comparison to pristine film. It is concluded that Fe-HAp film can be a potential candidate for developing low cost, energy saver and high performance CO and CO2 sensor. © 2013 Elsevier B.V. All rights reserved.

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