Remarkable Increase in Field Effect Mobility of Amorphous IZTO Thin-Film Transistors With Purified ZrO_x Gate Insulator

Bukke, Ravindra Naik,Avis, Christophe,Naik, Mude Narendra,Jang, Jin IEEE 2018 IEEE electron device letters Vol.39 No.3

<P>We report the effect of purification of ZrO<SUB>x</SUB> precursor on the performance of solution processed amorphous indium–zinc–tin oxide thin-film transistors with a ZrO<SUB>x</SUB> gate insulator, which is processed at the maximum temperature of 300 °C in air. By purification, the saturation mobility ( <TEX>$\mu _{\textit {sat}}$</TEX>) increases from 2.45 ± 0.83 to 15.42 ± 4.01 cm<SUP>2</SUP>V<SUP>−1</SUP>s<SUP>−1</SUP>, subthreshold swing decreases from 141.44 ± 14.08 to 87.90 ± 11.05 mV/decade and drain current ON/OFF ratio increases from ~10<SUP>7</SUP> to ~10<SUP>9</SUP>. The leakage currents are remarkably reduced by using purified ZrO<SUB>x</SUB> as a gate insulator. The improvement is mainly due to the reduced impurities and less oxygen vacancies in ZrO<SUB>x</SUB>.</P>

Synthesis and Structure–Activity Relationship Study of Chemical Probes as Hypoxia Induced Factor-1α/Malate Dehydrogenase 2 Inhibitors

Naik, Ravi,Won, Misun,Ban, Hyun Seung,Bhattarai, Deepak,Xu, Xuezhen,Eo, Yumi,Hong, Ye Seul,Singh, Sarbjit,Choi, Yongseok,Ahn, Hee-Chul,Lee, Kyeong American Chemical Society 2014 Journal of medicinal chemistry Vol.57 No.22

<P>A structure–activity relationship study of hypoxia inducible factor-1α inhibitor 3-aminobenzoic acid-based chemical probes, which were previously identified to bind to mitochondrial malate dehydrogenase 2, was performed to provide a better understanding of the pharmacological effects of LW6 and its relation to hypoxia inducible factor-1α (HIF-1α) and malate dehydrogenase 2 (MDH2). A variety of multifunctional probes including the benzophenone or the trifluoromethyl diazirine for photoaffinity labeling and click reaction were prepared and evaluated for their biological activity using a cell-based HRE-luciferase assay as well as a MDH2 assay in human colorectal cancer HCT116 cells. Among them, the diazirine probe <B>4a</B> showed strong inhibitory activity against both HIF-1α and MDH2. Significantly, the inhibitory effect of the probes on HIF-1α activity was consistent with that of the MDH2 enzyme assay, which was further confirmed by the effect on <I>in vitro</I> binding activity to recombinant human MDH2, oxygen consumption, ATP production, and AMP activated protein kinase (AMPK) activation. Competitive binding modes of LW6 and probe <B>4a</B> to MDH2 were also demonstrated.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jmcmar/2014/jmcmar.2014.57.issue-22/jm501241g/production/images/medium/jm-2014-01241g_0020.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jm501241g'>ACS Electronic Supporting Info</A></P>

Mass-yield distributions of fission products from photo-fission of natPb induced by 50-70 MeV bremsstrahlung

Naik, Haladhara,Kim, Guinyun,Goswami, Ashok,Singh, Sarbjit,Manchanda, Vijay Kumar,Raj, Devesh,Ganesan, Srinivasan,Oh, Young Do,Lee, Hee-Seock,Kim, Kyung Sook,Lee, Man-Woo,Cho, Moo-Hyun,Ko, In Soo,Namk Springer-Verlag 2010 JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY Vol.283 No.2

Incidence and Intensity of Root Disease Complex due to Nematode and Soilborne Fungal Pathogens in Mulberry (Morus alba L.)

Naik, Vorkady Nishitha,Sharma, Dinesh Dutta,Govindaiah, Govindaiah Korean Society of Sericultural Science 2008 International Journal of Industrial Entomology Vol.16 No.2

A preliminary survey on the incidence and intensity of root disease complex (association of Meloidogyne incognita and root rot pathogens) was carried out in the sericultural areas of Karnataka. A total of 280 mulberry gardens were surveyed in 14 districts of Karnataka belonging to different types of soil (red sandy, red loamy and black cotton), farming systems (irrigated and rainfed), varieties (V-1, K-2, Local and S-13) and age of the plants (0-5, 5-10 and 10-15 years). It was observed that the association of M. incognita with Botryodiplodia theobromae and Fusarium solani causes the root disease complex in mulberry. Of the 280 gardens visited, 94 were infested with the disease complex and incidence was recorded as 33.6%. The higher intensity of root disease complex was observed when the root system had more than 100 galls/plant with infection of mixed population of B. theobromae and F. solani in sandy soil under irrigated farming. The 5-10 years old mulberry plantation with V-I variety was found to be most susceptible to root disease complex. Districts like Mysore, Kolar, Mandya, Tumkur, Chitradurga and Bangalore were observed as sensitive areas. Further, the wounds caused by M. incognita in mulberry roots favour the easy entry of root rot pathogens, which increased the severity of the disease very fast.

An Investigation of the Learning Styles of South Korean Business Students

Naik, Bijayananda,Girish, V.G. KNU The Institute of Management Economy Research 2012 Asia-Pacific Journal of Business Vol.3 No.1

The Index of Learning Styles (ILS) instrument based on the Felder-Silverman Learning Style Model was used to determine distribution of learning styles of 125 South Korean business students enrolled in a South Korean institution of higher education. Results show that greater proportion of South Korean business students surveyed in this study prefer sensing over intuitive, visual over verbal, reflective over active, and global over sequential learning styles. The majority of business students have a balanced learning style in all four dimensions of the Felder-Silverman model. Among the students that do not have a balanced learning style, students with sensing, visual, reflective, and global learning styles dominate. Gender difference in learning style preference was not statistically significant for any of the four dimensions.

Electrical and structural properties of Pd/V/<i>n</i>‐type InP (111) Schottky structure as a function of annealing temperature

Naik, S. Sankar,Rajagopal Reddy, V.,Choi, Chel‐,Jong,Bae, Jong‐,Seong John Wiley Sons, Ltd. 2012 Surface and interface analysis Vol.44 No.1

<P><B>Abstract</B></P><P>Palladium/Vanadium (Pd/V) Schottky structures are fabricated on <I>n</I>‐type InP (100) and the electrical, structural and surface morphological characteristics have been studied at different annealing temperatures. The extracted barrier height of as‐deposited Pd/V/<I>n</I>‐InP Schottky diode is 0.59 eV (I–V) and 0.79 eV (C–V), respectively. However, the Schottky barrier height of the Pd/V Schottky contact slightly increases to 0.61 eV (I–V) and 0.84 eV (C–V) when the contact is annealed at 200 °C for 1 min. It is observed that the Schottky barrier height of the contact slightly decreases after annealing at 300, 400 and 500 °C for 1 min in N<SUB>2</SUB> atmosphere. From the above observations, it is clear that the electrical characteristics of Pd/V Schottky contacts improve after annealing at 200 °C. This indicates that the optimum annealing temperature for the Pd/V Schottky contact is 200 °C. Basing on the auger electron spectroscopy and X‐ray diffraction results, the formation of Pd‐In intermetallic compound at the interface may be the reason for the increase of barrier height upon annealing at 200 °C. The formation of phosphide phases at the Pd/V/<I>n</I>‐InP interface could be the reason for the degradation in the barrier heights after annealing at 300, 400 and 500 °C. From the AFM results, it is evident that the overall surface morphology of the Pd/V Schottky contacts is fairly smooth. Copyright © 2011 John Wiley & Sons, Ltd.</P>

Independent isomeric-yield ratio of 89m,gNb from 93Nb(γ, 4n), natZr(p, xn), and 89Y(α, 4n) reactions

Naik, Haladhara,Goswami, Ashok,Kim, Guinyun,Kim, Kwangsoo,Yang, Sung-Chul,Sahid, Muhammad,Zaman, Muhammad,Lee, Manwoo,Shin, Sung-Gyun,Cho, Moo-Hyun Springer-Verlag 2014 Journal of radioanalytical and nuclear chemistry Vol.299 No.3

Nitrogen doping on the core-shell structured Au@TiO₂ nanoparticles and its enhanced photocatalytic hydrogen evolution under visible light irradiation

Naik, Gautam Kumar,Majhi, Sanjit Manohar,Jeong, Kwang-Un,Lee, In-Hwan,Yu, Yeon Tae Elsevier 2019 JOURNAL OF ALLOYS AND COMPOUNDS Vol.771 No.-

<P><B>Abstract</B></P> <P>The current study concerns about the large band gap of TiO<SUB>2</SUB> for its use as photocatalysts. The photocatalytic activity of core-shell structured Au@TiO<SUB>2</SUB> nanoparticles were enhanced by the doping of nitrogen. The nitrogen doping has been done by simple hydrothermal method taking ethylenediamine as the precursor for nitrogen. The crystals structure of TiO<SUB>2</SUB> shell remained unaltered even with the introduction of nitrogen. The photocatalytic activity of the prepared samples were evaluated towards the hydrogen evolution from photocatalytic water splitting under solar light irradiation. It was found that nitrogen doped core-shell structured Au@TiO<SUB>2</SUB> nanoparticles (Au@N-TiO<SUB>2</SUB>) showed higher photocatalytic activity with an average H<SUB>2</SUB> evolution rate of 4880 μmol h<SUP>−1</SUP>g<SUP>−1</SUP>, which is 3.79 times more than that of bare TiO<SUB>2</SUB> in 4 h under xenon light irradiation. The relationship among the other samples was in order of Au@N-TiO<SUB>2</SUB> > Au@TiO<SUB>2</SUB> > N-TiO<SUB>2</SUB> > TiO<SUB>2</SUB>. This enhanced photocatalytic activity of Au@N-TiO<SUB>2</SUB> can be responsible for the formation of an plasmonic photocatalyst and the formation of an impurity band between the conduction band (CB) and the valence band (VB) of TiO<SUB>2</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nitrogen (N) was doped on the core-shell structured Au@TiO<SUB>2</SUB> nanoparticles. </LI> <LI> N was doped via a low temperature microwave assisted hydrothermal process. </LI> <LI> N doped Au@TiO<SUB>2</SUB> core-shell are highly absorbed in whole of the solar spectrum. </LI> <LI> There was no morphological distortion during N doping. </LI> <LI> Synthesized catalysts are highly efficient for photocatalytic hydrogen evolution. </LI> </UL> </P>

Methyl 3-(3-(4-(2,4,4-Trimethylpentan-2-yl)phenoxy)-propanamido)benzoate as a Novel and Dual Malate Dehydrogenase (MDH) 1/2 Inhibitor Targeting Cancer Metabolism

Naik, Ravi,Ban, Hyun Seung,Jang, Kyusic,Kim, Inhyub,Xu, Xuezhen,Harmalkar, Dipesh,Shin, Seong-Ah,Kim, Minkyoung,Kim, Bo-Kyung,Park, Jaehyung,Ku, Bonsu,Oh, Sujin,Won, Misun,Lee, Kyeong American Chemical Society 2017 Journal of medicinal chemistry Vol.60 No.20

<P>Previously, we reported a hypoxia-inducible factor (HIF)-1 inhibitor LW6 containing an (aryloxyacetylamino)benzoic acid moiety inhibits malate dehydrogenase 2 (MDH2) using a chemical biology approach. Structure–activity relationship studies on a series of (aryloxyacetylamino)benzoic acids identified selective MDH1, MDH2, and dual inhibitors, which were used to study the relationship between MDH enzyme activity and HIF-1 inhibition. We hypothesized that dual inhibition of MDH1 and MDH2 might be a powerful approach to target cancer metabolism and selected methyl-3-(3-(4-(2,4,4-trimethylpentan-2-yl)phenoxy)propanamido)-benzoate (<B>16c</B>) as the most potent dual inhibitor. Kinetic studies revealed that compound <B>16c</B> competitively inhibited MDH1 and MDH2. Compound <B>16c</B> inhibited mitochondrial respiration and hypoxia-induced HIF-1α accumulation. In xenograft assays using HCT116 cells, compound <B>16c</B> demonstrated significant in vivo antitumor efficacy. This finding provides concrete evidence that inhibition of both MDH1 and MDH2 may provide a valuable platform for developing novel therapeutics that target cancer metabolism and tumor growth.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jmcmar/2017/jmcmar.2017.60.issue-20/acs.jmedchem.7b01231/production/images/medium/jm-2017-01231h_0018.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jm7b01231'>ACS Electronic Supporting Info</A></P>

Evidence of Late Pleistocene earthquake from the Central Segment of Ulsan Fault

Naik Sambit Prasanajit,Ohsang Gwon,Kiwoong Park,Hyeonjo Shin,Young-Seog Kim 대한지질학회 2021 대한지질학회 학술대회 Vol.2021 No.10

Due to lack of surface-rupturing earthquakes during the instrumental earthquake recording time, the Korean peninsula has not been considered as seismically active country. Although there are several historic records of seismic damage, especially along with the southeastern part of the Korean Peninsula, the locations and sizes of most of these earthquakes are not well constrained. The historical record suggests the southeastern part of the Korean peninsula have experienced several damaging earthquakes including the recent 2016 Gyeongju and 2017 Pohang earthquakes. Since Pliocene, this area is under the compressional tectonic regime, which resulted in the formation of Yangsan-Ulsan Fault System. The Yangsan Fault has relatively clear geometry and well preserved morphological feature, and more studies have done along this fault than the Ulsan Fault with more complex structural characteristics. Although the central part of the Ulsan fault is one of most well studied area in terms of paleoseismology, most of the studies are confined to outcrop scale. There is ambiguity still remains towards the trace of the fault lines and recurrence interval of surface rupturing earthquakes in historical past. This study is an attempt to trace the Ulsan Fault line and understand the recurrence interval of earthquakes along the central part of the Ulsan fault. Considering this aim, detailed geomorphic mapping and paleoseismic study has been conducted at 2 sites near Hwalsung-ri, close to Gyeongju city. The Trenches were named as Hwalsung-ri North and Hwalsung-ri South. The present paleoseismic study reveals evidences of multiple earthquakes history along the central segment of the Ulsan fault near Hwalsung-ri. The crosscutting relationship of the exposed stratigraphic units at Hwalsung-ri North suggests the fault has been reactivated more than four times with evidences of four earthquake events whereas the Hwalsung-ri South site shows the evidences of three faulting events. Due to unavailability of suitable material and presence of pebbles we were not able to obtain ages for all the lithounits exposed in the trench. With this constraints, the Hwalsung-ri north site shows evidences of the most recent event occur after 103±2 ka whereas the Hwalsung-ri south trench suggests the most recent event occurred after 61±3 ka. This will help us to understand the past seismicity along the central segment of the Ulsan Fault and to trace the exact location of Ulsan fault which is one of the most potentially dangerous faults in Korea.