Jorhāt, India
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Borthakur T.,Jagannath Barooah College | Sarma R.,Jagannath Barooah College
Applied Physics A: Materials Science and Processing | Year: 2017

We have investigated the effect of perylene interlayer between the organic/electrode interface on the electrical performance of a top contact pentacene-based OTFT. We have found the performance enhancement of the OTFT device. The OTFT devices with perylene layer show better field effect mobility and on–off ratio than that of having only metal electrodes. It also lowers the subthreshold slope and threshold voltage compared to single-layered OTFT devices. © 2017, Springer-Verlag Berlin Heidelberg.


Boruah R.,Tezpur University | Gogoi A.,Jagannath Barooah College | Rajkhowa P.,Hong Kong University of Science and Technology | Rajkhowa P.,Tezpur University | And 2 more authors.
Plasmonics | Year: 2016

An online web application was developed for the study of surface plasmon resonance (SPR) of different materials using angular and wavelength modulation. The present web application investigates the optical characteristics of the spectral and angular responses of a Kretschmann SPR sensor configuration that is widely applied for biological and chemical sensing by using the characteristic transmission matrix (CTM) method. The accuracy, efficiency, and reliability of the web application were validated by comparing the results generated by using the web application with other benchmark theoretical results and results of SPR experiments with standard samples. © 2016 Springer Science+Business Media New York


Gogoi A.,Jagannath Barooah College | Rajkhowa P.,Hong Kong University of Science and Technology | Rajkhowa P.,Tezpur University | P. Saikia G.,Gauhati University | And 2 more authors.
Journal of Quantitative Spectroscopy and Radiative Transfer | Year: 2014

Development of an online web application to simulate and display plane wave scattering from small particles is presented. In particular, the computation of angular variation of the scattering properties (scattering matrix elements, scattering coefficients, single scattering albedo etc.) of particulate matter by using the Mie theory and the T-matrix method was incorporated in the application. Comparison of the results generated by using the web application with other reported benchmark results has shown that the web application is accurate and reliable for electromagnetic scattering computations. © 2014 Elsevier Ltd.


Ahmed G.A.,Tezpur University | Gogoi A.,Jagannath Barooah College
Journal of Quantitative Spectroscopy and Radiative Transfer | Year: 2014

The analysis of optical scattering data of interstellar carbonaceous graphite dust analog at 543.5. nm, 594.5. nm and 632.8. nm laser wavelengths by using an original laboratory light scattering setup is presented. The setup primarily consisted of a laser source, optical units, aerosol sprayer, data acquisition system and associated instrumentation. The instrument measured scattered light signals from 10° to 170° in steps of 1°. The results of the measurements of the volume scattering function β(θ) and degree of linear polarization P(θ) of the carbonaceous graphite dust particles that were sprayed in front of the laser beam by using an aerosol sprayer were subsequently compared with theoretically generated Mie plots with estimated parameters. © 2013 Elsevier Ltd.


Das S.K.,Jagannath Barooah College | Sabhapondit S.,Tocklai Experimental Station | Ahmed G.,Gauhati University | Das S.,Tocklai Experimental Station
Biochemical Genetics | Year: 2013

To verify the quality of triploid varieties of Camellia tea species at the secondary metabolite level, we tested caffeine and catechin profiles of 97 F1 segregating progenies in two breeding populations with a common tetraploid parent and diploid parents of two geographic and varietal origins. Catechin and caffeine levels of the triploid progenies were quantified and compared against their diploid parent. Some of the progenies showed better performance than their diploid parent. Most of the progenies of the diploid C. sinensis × tetraploid cross showed heterosis for caffeine and EGCG. Progenies of the C. assamica subsp. lasiocalyx × tetraploid cross showed heterosis for +C, EC, EGC, and TC. The genomic contributions of the diploid parent seem to be the main factor in the variation between the two populations. Our studies showed quantitative enhancement of some of the quality-related parameters in tea, providing a platform to refocus on this classical breeding approach for developing quality cultivars in tea. © 2013 Springer Science+Business Media New York.


Baruah P.,Institute of Advanced Study in Science and Technology IASST | Saikia R.R.,Jagannath Barooah College | Baruah P.P.,Gauhati University | Deka S.,Institute of Advanced Study in Science and Technology IASST
Environmental Science and Pollution Research | Year: 2014

Chlorophyll plays a pivotal role in the plant physiology and its productivity. Cultivation of plants in crude oil contaminated soil has a great impact on the synthesis of chlorophyll pigment. Morpho-anatomy of the experimental plant also shows structural deformation in higher concentrations. Keeping this in mind, a laboratory investigation has been carried out to study the effect of crude oil on chlorophyll content and morpho-anatomy of Cyperus brevifolius plant. Fifteen-day-old seedling of the plant was planted in different concentrations of the crude oil mixed soil (i.e., 10,000, 20,000, 30,000, 40,000, and 50,000 ppm). A control setup was also maintained without adding crude oil. Results were recorded after 6 months of plantation. Investigation revealed that there is a great impact of crude oil contamination on chlorophyll content of the leaves of the experimental plant. It also showed that chlorophyll a, chlorophyll b, and total chlorophyll content of leaves grown in different concentrations of crude oil were found to be lower than those of the control plant. Further, results also demonstrated that chlorophyll content was lowest in the treatment that received maximum dose of crude oil. It also showed that chlorophyll content was decreased with increased concentration of crude oil. Results also demonstrated that there was a reduction in plant shoot and root biomass with the increase of crude oil concentration. Results also revealed that the shoot biomass is higher than root biomass. Morphology and anatomy of the experimental plant also show structural deformation in higher concentrations. Accumulation of crude oil on the cuticle of the transverse section of the leaves and shoot forms a thick dark layer. Estimation of the level of pollution in an environment due to oil spill is possible by the in-depth study of the harmful effects of oil on the morphology and anatomy and chlorophyll content of the plants grown in that particular environment. © 2014, Springer-Verlag Berlin Heidelberg.


Sarma R.,Jagannath Barooah College | Saikia D.,Jagannath Barooah College | Konwar K.,Jagannath Barooah College | Baishya B.,Jagannath Barooah College
Indian Journal of Physics | Year: 2010

A study of Pentacene OTFTs using La2O3 as gate insulator is presented. The device characteristics were studied and analyzed. The OTFTs exhibit p-type conductivity with field effect mobility 6.5 × 10-6 m2/V.s, ON/OFF ratio 1.4 × 102, sub-threshold swing 2 mV/decade and hole concentration 4.5 × 10 17 cm-3. The SEM and XRD analysis on the semiconductor film are also reported. © 2010 IACS.


Boruah M.J.,Tezpur University | Gogoi A.,Jagannath Barooah College | Ahmed G.A.,Tezpur University
Planetary and Space Science | Year: 2016

The computation of the light scattering properties of size and shape distributed interstellar graphite dust analogues using discrete dipole approximation (DDA) is presented. The light scattering properties of dust particles of arbitrary shapes having sizes ranging from 0.5 to 5.0 μm were computed using DDSCAT 7.3.0 software package and an indigenously developed post-processing tool for size and shape averaging. In order to model realistic samples of graphite dust and compute their light scattering properties using DDA, different target geometries were generated to represent the graphite particle composition in terms of surface smoothness, surface roughness and aggregation or their combination, for using as the target for DDSCAT calculations. A comparison of the theoretical volume scattering function at 543.5 nm and 632.8 nm incident wavelengths with laboratory simulation is also presented in this paper. © 2016 Elsevier Ltd. All rights reserved.


Mazumder N.,National Yang Ming University | Gogoi A.,Jagannath Barooah College | Buragohain A.K.,Tezpur University | Ahmed G.A.,Tezpur University | Choudhury A.,Tezpur University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

Siliceous frustules were extracted from a representative fresh water diatom species (Cyclotella sp.) by treating with aqueous hydrochloric (HCl) acid. The structural characterizations of cleaned frustules were examined by scanning electron microscope (SEM). The microscopy images showed that the diatoms have a regular circular shape and are of almost equal size (average length is 9Î=m and average width is 3 μm). From energy dispersive X -ray spectroscopy (SEM-EDS) spot analysis it was confirmed that the frustules isolated from diatoms are composed mainly of silicon in the form of amorphous silica (SiO2). The bond information of chemical substances of diatom frustules was carried out at ambient temperature by means of Fourier Transform Infrared (FTIR) Spectroscopy. FTIR spectrum as recorded in transmittance mode showed the characteristic peaks for diatom biosilica, including for Si-O-Si stretching vibration at 1057 and 776 cm-1. Photoluminescence (PL) measurements of diatom frustules were performed at room temperature and it was observed that they emitted strong blue PL centered at 440nm when excited with ultraviolet (UV) radiation. © 2014 SPIE.


PubMed | Jagannath Barooah College
Type: Journal Article | Journal: Biochemical genetics | Year: 2013

To verify the quality of triploid varieties of Camellia tea species at the secondary metabolite level, we tested caffeine and catechin profiles of 97 F(1) segregating progenies in two breeding populations with a common tetraploid parent and diploid parents of two geographic and varietal origins. Catechin and caffeine levels of the triploid progenies were quantified and compared against their diploid parent. Some of the progenies showed better performance than their diploid parent. Most of the progenies of the diploid C. sinensis tetraploid cross showed heterosis for caffeine and EGCG. Progenies of the C. assamica subsp. lasiocalyx tetraploid cross showed heterosis for +C, EC, EGC, and TC. The genomic contributions of the diploid parent seem to be the main factor in the variation between the two populations. Our studies showed quantitative enhancement of some of the quality-related parameters in tea, providing a platform to refocus on this classical breeding approach for developing quality cultivars in tea.

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