Fabrication and electrical characterization of Au/p-Si/STO/Au contact

R.K. Gupta,K. Ghosh,P.K. Kahol 한국물리학회 2009 Current Applied Physics Vol.9 No.5

Au/STO/p-Si/Au structure is fabricated using pulsed laser deposition technique at room temperature. The current–voltage (I–V) characteristics of the device show rectification behavior. Various junction parameters such as ideality factor, barrier height and series resistance is determined using conventional forward bias I–V characteristics, Cheung method and Norde’s function. Au/STO/p-Si/Au structure shows non-ideal diode characteristics with the value of ideality factor of ~ 5.1 and barrier height of ~ 0.40 eV.

Preparation and characterization of highly conducting and transparent Al doped CdO thin films by pulsed laser deposition

R.K. Gupta,K. Ghosh,R. Patel,S.R. Mishra,P.K. Kahol 한국물리학회 2009 Current Applied Physics Vol.9 No.3

Highly conducting and transparent aluminum doped CdO thin films were deposited using pulsed laser deposition technique. The effect of growth temperature on structural, electrical, and optical properties was studied. It is observed that the film orientation changes from preferred (111) plane to (200) plane with increase in growth temperature. The electrical resistivity of the films was found to increase with increase in growth temperature. The low resistivity of 4.3 × 10-5 Ωcm and high transparency (~85%) was obtained for the film grown at 150 ℃. The band gap of the films varies from 2.74 eV to 2.84 eV.

Aberration in the structural paradigm of lens protein α crystallin by UV-C irradiation

R. K. Ghosh,T. Kar,B. Dutta,A. Pathak,R. Rakshit,R. Basak,A. Das,K. Waheeda,P. Basak,M. Bhattacharyya 한국응용생명화학회 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.3

The conformation of lens protein α crystallin was investigated using different spectroscopic techniques under normal and UV-C-irradiated condition. The structural elucidation of commercially available lens protein α crystallin under the effects of UV-C irradiation has never been reported earlier. To study the effects of irradiation on the lens protein, we used UV–visible spectroscopy, CD spectroscopy, and steady-state and time-resolved fluorescence measurements along with FTIR study, under increasing doses of UV-C irradiation. Using the secondary and tertiary structural changes as parameters for detecting conformational perturbation, we investigated the structural paradigm shift in the lens protein α crystallin. Increasing doses of UV-C radiation resulted in decreasing β sheet content of α crystallin from 30 to 10%. The fluorescence profile confirmed the formation of ROS species in the protein upon extensive exposure to UV-C irradiation. These results inferred UV-C irradiation may induce alteration of secondary structure of the lens protein leading to impaired biological functioning.

Aberration in the structural paradigm of lens protein α crystallin by UV-C irradiation

Ghosh, R.K.,Kar, T.,Dutta, B.,Pathak, A.,Rakshit, R.,Basak, R.,Das, A.,Waheeda, K.,Basak, P.,Bhattacharyya, M. The Korean Society for Applied Biological Chemistr 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.3

The conformation of lens protein ${\alpha}$ crystallin was investigated using different spectroscopic techniques under normal and UV-C-irradiated condition. The structural elucidation of commercially available lens protein ${\alpha}$ crystallin under the effects of UV-C irradiation has never been reported earlier. To study the effects of irradiation on the lens protein, we used UV-visible spectroscopy, CD spectroscopy, and steady-state and time-resolved fluorescence measurements along with FTIR study, under increasing doses of UV-C irradiation. Using the secondary and tertiary structural changes as parameters for detecting conformational perturbation, we investigated the structural paradigm shift in the lens protein ${\alpha}$ crystallin. Increasing doses of UV-C radiation resulted in decreasing ${\beta}$ sheet content of ${\alpha}$ crystallin from 30 to 10%. The fluorescence profile confirmed the formation of ROS species in the protein upon extensive exposure to UV-C irradiation. These results inferred UV-C irradiation may induce alteration of secondary structure of the lens protein leading to impaired biological functioning.

Comparative Transcriptomic Analyses by RNA-seq to Elucidate Differentially Expressed Genes in the Muscle of Korean Thoroughbred Horses

Ghosh, M.,Cho, H. W.,Park, J. W.,Choi, J. Y.,Chung, Y. H.,Sharma, N.,Singh, A. K.,Kim, N. E.,Mongre, R. K.,Huynh, D. Springer Science + Business Media 2016 Applied biochemistry and biotechnology Vol.180 No.3

<P>The athletic abilities of the horse serve as a valuable model to understand the physiology and molecular mechanisms of adaptive responses to exercise. We analyzed differentially expressed genes in triceps brachii muscle tissues collected from Eonjena Taeyang and Jigusang Seryeok Thoroughbred horses and their co-expression networks in a large-scale RNA-sequence dataset comparing expression before and after exercise. High-quality horse transcriptome data were generated, with over 22 million 90-bp pair-end reads. By comparing the annotations, we found that MYH3, MPZ, and PDE8B genes in Eonjena Taeyang and PDE8B and KIF18A genes in Jigusang Seryeok were upregulated before exercise. Notably further, we observed that PPP1R27, NDUFA3, TNC, and ANK1 in Eonjena Taeyang and HIF1A, BDNF, ADRB2, OBSCN, and PER3 in Jigusang Seryeok have shown upregulation at the postexercise period. This investigation suggested that genes responsible for metabolism and oxidative phosphorylations associated with endurance and resistance exercise were highly expressed, whereas genes encoding structural proteins were generally suppressed. The expression profile of racehorses at pre- and postexercise will provide credible reference for further studies on biological effects such as responses to stress and adaption of other Thoroughbred horse, which might be useful for selective breeding for improvement of traits in commercial production.</P>

Fan Loops Observed by<i>IRIS</i>, EIS, and AIA

Ghosh, Avyarthana,Tripathi, Durgesh,Gupta, G. R.,Polito, Vanessa,Mason, Helen E.,Solanki, Sami K. American Astronomical Society 2017 The Astrophysical journal Vol.835 No.2

<P>A comprehensive study of the physical parameters of active region fan loops is presented using the observations recorded with the Interface Region Imaging Spectrometer (IRIS), the EUV Imaging Spectrometer (EIS) on board Hinode, and the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO). The fan loops emerging from non-flaring AR. 11899 (near the disk center) on 2013 November 19 are clearly discernible in AIA 171 angstrom images and in those obtained in Fe VIII and Si VII images using EIS. Our measurements of electron densities reveal that the footpoints of these loops are at an approximately constant pressure with electron densities of log N-e = 10.1cm(-3) at log [T/K]=5.15 (O IV), and log N-e = 8.9 cm(-3) at log[T/K]=6.15 (Si X). The electron temperature diagnosed across the fan loops by means of EM-Loci suggest that two temperature components exist at log[T/K]=4.95 and 5.95 at the footpoints. These components are picked up by IRIS lines and EIS lines, respectively. At higher heights, the loops are nearly isothermal at log[T/K]=5.95, which remained constant along the loop. The measurement of the Doppler shift using IRIS lines suggests that the plasma at the footpoints of these loops is predominantly redshifted by 2-3 km s(-1) in C II, 10-15 km s(-1) in Si IV, and 15-20 km s(-1) in O IV, reflecting the increase in the speed of downflows with increasing temperature from log[T/K]=4.40 to 5.15. These observations can be explained by low-frequency nanoflares or impulsive heating, and provide further important constraints on the modeling of the dynamics of fan loops.</P>

High-Field Solenoid Development for Axion Dark Matter Search at CAPP/IBS

Gupta, R.,Anerella, M.,Ghosh, A.,Sampson, W.,Schmalzle, J.,Konikowska, D.,Semertzidis, Y. K.,Shin, Y. Institute of Electrical and Electronics Engineers 2016 IEEE transactions on applied superconductivity Vol.26 No.4

<P>Construction and test results of a 100-mm-bore solenoid made with the high-temperature superconductor (HTS) producing a peak field of over 10 T are presented. This is the first step toward building a very high field solenoid (35-40 T) one of the key components of the proposed state-of-the-art facility for dark matter search at the Center for Axion and Precision Physics Research, Institute for Basic Science in Korea. The coils made with HTS are expected to provide a field of similar to 25 T, and the coils made with low-temperature superconductors are expected to provide a field of 10-15 T. REBCO HTS tapes were provided by SuNAM along with the measurements at 20 K in 3.5- to 4-T applied field. The Brookhaven National Laboratory measured several samples at 4 K in the applied field of 4-8 T. This paper will present a series of test results of the conductor, six pancake coils, and the fully assembled solenoid.</P>

Synthesis and Characterization of Homo Binuclear Macrocyclic Complexes of UO₂(VI), Th(IV), ZrO(IV) and VO(IV) with Schiff-Bases Derived from Ethylene diamine/Orthophenylene Diamine, Benzilmonohydrazone and Acetyl Acetone

Mohapatra, R.K.,Ghosh, S.,Naik, P.,Mishra, S.K.,Mahapatra, A.,Dash, D.C. Korean Chemical Society 2012 대한화학회지 Vol.56 No.1

A series of homo binuclear complexs of the type $[M_2(L/L^')(NO_3)n].mH_2O$, [where $M=U{O_2}^{2+},\;Th^{4+},\;ZrO^{2+}$] and $[(VO)_2(L/L^')(SO_4)_2]{\cdot}2H_2O$, L=1,5,6,9,12,15,16,20 octaaza-7,813,14-tetraphenyl-2,4,17,19-tetramethyl-1,4,6,8,12,14,16,19-docosaoctene (OTTDO) or L'=10:11;21:22-dibenzo-1,5,6,9,12,15,16,20-octaaza-7,813,14-tetraphenyl-2,4,17,19-tetramethyl-1,4,6,8,12,14,16,19-docosaoctene (DOTTOT), n=4 for $U{O_2}^{2+}$, $ZrO^{2+}$ n=8 for $Th^{4+}$ m=1,2,3 respectively, have been synthesized in template method from ethylenediamine/orthophenylene diamine, benzil monohydrazone and acetyl acetone and characterized on the basis of elemental analysis, thermal analysis, molar conductivity, magnetic moment, electronic, infrared, $^1H$-NMR studies. The results indicate that the VO(IV) ion is penta co-ordinated yielding paramagnetic complexes; $UO_2(VI)$, ZrO(IV) ions are hexa co-ordinated where as Th(IV) ion is octa co-ordinated yielding diamagnetic complexes of above composition. The fungi toxicity of the ZrO(IV) and VO(IV) complexes against some fungal pathogen has been studied.

DNA barcoding reveals host associated genetic diversity of ‘tea mosquito bug’ Helopeltis theivora (Miridae: Heteroptera) from India

K.N. Chandrashekara,R. Raj Kumar,Vikas Kumar,Dhriti Banerjee,Shantanu Kundu,Biswatosh Ghosh,Kaomud Tyagi 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.3

The tea mosquito bug, Helopeltis theivora Waterhouse (Miridae: Heteroptera) is a polyphagous pest that affects a number of economically important crops in India. Partial sequences of mitochondrial cytochrome c oxidase 1 (mtCOI) were used to study host associated genetic variation on H. theivora collected from tea (Camellia sinensis L.), cashew (Anacardiumoccidentale L.), acalypha (Acalypha indica L.) and cocoa (Theobroma cacao L.). The results suggest that host plants have a significant effect on the genetic variation of bugs collected from two wide geographical locations (South India and North-East India). Haplotyping data analysis of mtCOI reveals six host plant specific haplotypes of H. theivorawith minimumgenetic divergence (0.8%) between two haplotypeswithin tea as compared to other plants (2.6–11.1%). Further phylogenetic (NJ, ML and BA) analysis evidence three host specific distinct clades. The most surprising result that emerged from our studies is the harmony between clustering of H. theivora and host plant phylogeny. The results indicate that host plants do have selection pressure and substantial effect on genetic variation in H. theivora and such adaptive evolution may have repercussions for IPM (Integrated Pest Management) strategies of H. theivora in India.

Characterisation of Microstructure, Texture and Mechanical Properties in Ultra Low-Carbon Ti-B Microalloyed Steels

R. Shukla,S. K. Ghosh,D. Chakrabarti,S. Chatterjee 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.1

In the present study, thermo-mechanical controlled processing followed by water quenching has been utilisedto produce ultra low-carbon microalloyed steel in a laboratory scale. The variation in microstructure andcorresponding mechanical properties at the selected range of finish rolling temperatures (FRT), (850-750 °C)has been evaluated. The microstructures of the steels consisted of polygonal ferrite, acicular ferrite as well asgranular bainite with the average ferrite grain sizes less than 5 μm. Finish rolling at 850°C produced weaktexture. α-fibre and γ-fibre intensified with the decrease in finish rolling temperature to 800°C. Intensitiesof the beneficial texture components such as, {554}<225> and {332}<113> also reached the highest valueat 800°C. Ferrite deformation texture i.e. α-fibre dominated at 750°C FRT. The characteristic ferrite - bainitemicrostructure with fine ferrite grain size and uniform distribution of fine TiC particles (< 50 nm) resulted inhigh yield strength (405-507 MPa), moderate tensile strength (515-586 MPa) and high total elongation (19-22%)for the selected range of finish rolling temperatures. Fairly good impact toughness value in the range of 63-74Jwas obtained at subzero temperature (-40 °C) in the sub-size sample. The above strength - ductility - toughnesscombination boosts the potentiality of developed steel for the pipeline application.