Study on Microtexture and Martensite Formation of Friction Stir Lap-welded DP 590 Steel within A1 to A3 Temperature Range

Das, H.,Lee, K. J.,Hong, S. T. SPRINGER INTRNATIONAL 2017 JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE Vol.26 No.7

<P>Friction stir lap welding of dual phase 590 steel has been successfully performed within the A1 to A3 temperature range upon adjusting the process parameters. The microstructures and the texture have been characterized using scanning electron microscopy and electron back scattered diffraction analysis. The martensite volume fraction increases with an increasing travel speed from 100 to 300 mm/min for a constant tool rotational speed of 300 rpm. Under severe deformation and high strain rate during friction stir welding, the grain orientation < 101 > shifts toward the < 111 > and < 001 > directions compared to the base metal. The base metal shows gamma fiber components, whereas the friction stir welded specimen shows strong brass with weak cube fibers.</P>

Investigation of Mine Closure Planning aat Adge Fluorspar Mine

Dash DARINCHULUUN,Dagva MYAGMAARSUREN,Ulaanbaatar BATGEREL,Gombosuren YADAMSUREN,Sang Soo LEE 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

An Empirical Analysis of Evolved Radial Basis Function Networks and Support Vector Machines with Mixture of Kernels

Dash, Ch. Sanjeev Kumar,Sahoo, Pulak,Dehuri, Satchidananda,Cho, Sung-Bae World Scientific 2015 INTERNATIONAL JOURNAL ON ARTIFICIAL INTELLIGENCE T Vol.24 No.4

Synthesis and Characterization of Homobinuclear Complexes of UO_2(VI), Th(IV), ZrO(IV) and VO(IV) with Schiff-Base Monohydrazone Derivatives

Dash, D.C.,Mohapatra, R.K.,Ghosh, S.,Naik , P. Korean Chemical Society 2008 대한화학회지 Vol.52 No.5

Synthesis and Characterization of Homobinuclear Complexes of UO₂(VI), ZrO(IV) and Th(IV) ions with 3-Benzylidine/Furfurylidine/(Pyridyl/Thienyl-2'-methylene) imino-5-p-sulphonamido phenyl azo-2-thiohydantoins

Dash, D.C.,Mahapatra, A.,Naik, P.,Mohapatra, R.K.,Naik, S.K. Korean Chemical Society 2011 대한화학회지 Vol.55 No.3

[$M_2L(NO_3)_n(H_2O)_m$]의 일반식을 갖는 일련의 동종이핵 착물을 합성하여 원소분석, 열분석, 몰 전기전도도, 자기모멘트 및 분광학적 방법(IR, UV-vis 및 $^1H$-NMR)을 통해 특성을 조사하였다. 이 경우, 일반식에 있어서 M=$UO_2$(VI), ZrO(IV), Th(IV); L=3-benzylidine-imino-5-p-sulphonamido phenyl azo-2-thiohyatoin(bispt), 3-furfurylidine-imino-5-psulphonamido phenyl azo-2-thiohydantoin(fispt),3-pyridyl-2'-methylene-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin (pmispt) 및 3-thienyl-2'-methylene-imino-5-p-sulphoanamido phenyl azo-2-thiohydantoin(tmispt); Th(IV)에 대해서 n=8 그 외의 것에 대해서는 n=4, bispt에 대해서는 m=4 그 외의 것에 대해서는 m=3을 의미한다. 이러한 결과에서 얻은 정보를 통해 리간드들은 4배위를 하는 것으로 확인되었는데, 즉 한 중심금속은azomethine 질소 및 카르보닐 산소에 배위되는 반면, 또 다른 중심금속은 아조 질소 및 thioimido 질소에 배위되어 위의 조성을 갖는 동종이핵 착물을 이룬다. 몇 가지 병원균에 대한 리간드와 그들의 지르코닐 착물의 독성 연구도 수행하였다. A series of homobinuclear complexes of the type [$M_2L(NO_3)_n(H_2O)_m$] where M=$UO_2$(VI), ZrO(IV), Th(IV); L=3-benzylidine-imino-5-p-sulphonamido phenyl azo-2-thiohyatoin(bispt), 3-furfurylidine-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(fispt),3-pyridyl-2'-methylene-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(pmispt) and 3-thienyl-2'-methylene-imino-5-p-sulphoanamido phenyl azo-2-thiohydantoin(tmispt); n=8 for Th(IV) and 4 for others, m=4 for bispt and 3 for others have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductance, magnetic moment and spectroscopic data (IR, electronic and $^1H$-NMR). In the light of this information, the ligands can be visualized as tetradentate co-ordinating through azomethine nitrogen, carbonyl oxygen to one metal centre where as azo nitrogen and thioimido nitrogen to the other metal centre yielding homo binuclear complexes of the above composition. The fungi toxicity of the ligands & their zirconyl complexes against some fungal pathogen has been studied.

Magnetoresistance Versus Oxygen Deficiency in Epi-stabilized SrRu _{1 − <i>x</i>} Fe _<i>x</i> O _{3 − <i>δ</i>} Thin Films

Dash, Umasankar,Acharya, Susant Kumar,Lee, Bo Wha,Jung, Chang Uk Springer US 2017 Nanoscale research letters Vol.12 No.1

<P>Oxygen vacancies have a profound effect on the magnetic, electronic, and transport properties of transition metal oxide materials. Here, we studied the influence of oxygen vacancies on the magnetoresistance (MR) properties of SrRu<SUB>1 − <I>x</I></SUB>Fe<SUB><I>x</I></SUB>O<SUB>3 - <I>δ</I></SUB> epitaxial thin films (<I>x</I> = 0.10, 0.20, and 0.30). For this purpose, we synthesized highly strained epitaxial SrRu<SUB>1 − <I>x</I></SUB>Fe<SUB><I>x</I></SUB>O<SUB>3 − <I>δ</I></SUB> thin films with atomically flat surfaces containing different amounts of oxygen vacancies using pulsed laser deposition. Without an applied magnetic field, the films with <I>x</I> = 0.10 and 0.20 showed a metal–insulator transition, while the <I>x</I> = 0.30 thin film showed insulating behavior over the entire temperature range of 2–300 K. Both Fe doping and the concentration of oxygen vacancies had large effects on the negative MR contributions. For the low Fe doping case of <I>x</I> = 0.10, in which both films exhibited metallic behavior, MR was more prominent in the film with fewer oxygen vacancies or equivalently a more metallic film. For semiconducting films, higher MR was observed for more semiconducting films having more oxygen vacancies. A relatively large negative MR (~36.4%) was observed for the <I>x</I> = 0.30 thin film with a high concentration of oxygen vacancies (<I>δ</I> = 0.12). The obtained results were compared with MR studies for a polycrystal of (Sr<SUB>1 − <I>x</I></SUB>La<SUB><I>x</I></SUB>)(Ru<SUB>1 − <I>x</I></SUB>Fe<SUB><I>x</I></SUB>)O<SUB>3</SUB>. These results highlight the crucial role of oxygen stoichiometry in determining the magneto-transport properties in SrRu<SUB>1 − <I>x</I></SUB>Fe<SUB><I>x</I></SUB>O<SUB>3 − <I>δ</I></SUB> thin films.</P>

Large magnetoresistance in LaFeO₃-substituted SrRuO₃ epitaxial thin films

Dash, Umasankar,Acharya, Susant Kumar,Cho, Seong Won,Lee, Suyoun,Lee, Kyoungjun,Chae, Seung Chul,Cho, Myung Rae,Jung, Chang Uk Elsevier 2017 Journal of alloys and compounds Vol.724 No.-

<P><B>Abstract</B></P> <P>In this work, the magnetotransport properties of epitaxial Sr<SUB>1-<I>x</I> </SUB>La<SUB> <I>x</I> </SUB>Ru<SUB>1-<I>x</I> </SUB>Fe<SUB> <I>x</I> </SUB>O<SUB>3</SUB> (<I>x</I> = 0.05, 0.10, 0.20, and 0.30) thin films grown by pulsed laser deposition on SrTiO<SUB>3</SUB> (001) substrates were investigated. Compared to doping Fe into the Ru<SUP>4+</SUP> site of SrRuO<SUB>3</SUB>, doping LaFeO<SUB>3</SUB> into SrRuO<SUB>3</SUB> resulted in an increase in the zero-field resistivity. A larger zero-field resistivity value in magnetic perovskite oxide is, in many cases, favorable for obtaining high magnetoresistance. The films (0.0 ≤ <I>x</I> ≤ 0.10) showed metallic behavior and ferromagnetic ordering, although the resistivity increased and the ferromagnetic transition temperature <I>T</I> <SUB>C</SUB> decreased with an increase in <I>x</I>. The thin film with <I>x</I> = 0.20 displayed a clear metal-to-insulator phase transition at low temperature and also displayed a well-defined resistivity minimum. This upturn in the resistivity curve is associated with the large electron-electron interaction present in the material. The magnetoresistance values increased as <I>x</I> increased, and we observed a large negative magnetoresistance (MR = −35%) for the thin film with <I>x</I> = 0.30. The observed high MR values are associated with spin fluctuation of the mobile electronic carriers in the material.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sr<SUB>1-<I>x</I> </SUB>La<SUB> <I>x</I> </SUB>Ru<SUB>1-<I>x</I> </SUB>Fe<SUB> <I>x</I> </SUB>O<SUB>3</SUB> epitaxial thin films were grown by PLD. </LI> <LI> The structural and magnet-transport properties of thin films were investigated. </LI> <LI> Metal-insulator transition was found in Sr<SUB>0.8</SUB>La<SUB>0.2</SUB>Ru<SUB>0.8</SUB>Fe<SUB>0.2</SUB>O<SUB>3</SUB> thin film. </LI> <LI> The upturn of <I>ρ</I> of Sr<SUB>0.8</SUB>La<SUB>0.2</SUB>Ru<SUB>0.8</SUB>Fe<SUB>0.2</SUB>O<SUB>3</SUB> film was explained by e-e interactions. </LI> <LI> Magnetoresistance up to ∼35% were found for Sr<SUB>0.7</SUB>La<SUB>0.3</SUB>Ru<SUB>0.7</SUB>Fe<SUB>0.3</SUB>O<SUB>3</SUB> film. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Dynamics of Foreign Aid and Human Development in South and South-East Asia: Analyzing the Effectiveness of Macro-Institutional Factors

Dash Devi Prasad,Sethi Narayan,Barik Paresh Chandra 한국국제경제학회 2023 International Economic Journal Vol.37 No.4

Does foreign aid impede or catalyze human development in South and South-East Asia post-1990s? We argue that foreign aid impacts human development negatively in the region overall due to the structural differences in infrastructure development, democratic regimes, patterns of external debt, trading intensity and other macroeconomic factors. Our empirical evidence further justifies that other than aid, improvements in infrastructure sectors and quality of democratic settings beget human development in the region. Considering further angles of external debt and domestic investment into the picture, we find that rising external debt negates, improves domestic investment and accelerates human development. While comparing both regions, we find a noticeable difference in the impacts of macro-institutional factors on human development. However, the impacts of aid on human development remain insignificant.

A Concise and Efficient Total Synthesis of Militarinone D

Dash, Uttam,Sengupta, Sandip,Sim, Taebo WILEY‐VCH Verlag 2015 EUROPEAN JOURNAL OF ORGANIC CHEMISTRY Vol.2015 No.18

<P><B>Abstract</B></P><P>A highly stereoselective, concise (14 steps longest linear sequence and 20 steps overall), and efficient (15 % overall yield) synthesis of militarinone D has been accomplished. The key reactions utilized in the sequence are enzymatic desymmetrization, <I>cis</I>/<I>trans</I> isomerization, Horner–Wadsworth–Emmons olefination, and addition of an organolithium species to a highly conjugated chiral aldehyde. The simplicity of the strategy may enable its utilization in the large‐scale production of this target. Moreover, the strategy utilized to design the route should be applicable to the preparation of analogs that bear a variety of substituted pyridinone core structures.</P>

Influence of Temperature and Humidity on Pregnancy Rate of Murrah Buffaloes under Subtropical Climate

Dash, Soumya,Chakravarty, A.K.,Sah, V.,Jamuna, V.,Behera, R.,Kashyap, N.,Deshmukh, B. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.7

Heat stress has adverse effects on fertility of dairy animals. Decline in fertility is linearly associated with an increase in combination of both temperature and humidity. The purpose of this study was to investigate the relationship between temperature humidity index (THI) and the pregnancy rate of Murrah buffaloes in a subtropical climate. The effects of genetic and non-genetic factors viz., sire, parity, period of calving and age group at first calving were found non-significant on pregnancy rate. The effect of THI was found significant (p<0.001) on pregnancy rate of Murrah buffaloes calved for first time and overall pregnancy rate. The threshold THI affecting the pregnancy rate was identified as THI 75. The months from October to March showed THI<75 and considered as non heat stress zone (NHSZ), while months from April to September were determined as heat stress zone (HSZ) with $THI{\geq}75$. The lowest overall pregnancy rate (0.25) was obtained in July with THI 80.9, while the highest overall pregnancy rate (0.59) was found in November with THI 66.1. May and June were identified as critical heat stress zone (CHSZ) within the HSZ with maximum decline (-7%) in pregnancy rate with per unit increase in THI. The highest overall pregnancy rate was estimated as 0.45 in NHSZ with THI value 56.7 to 73.2. The pregnancy rate was found to have declined to 0.28 in HSZ with THI 73.5 to 83.7. However, the lowest pregnancy rate was estimated as 0.27 in CHSZ with THI value 80.3 to 81.6.