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>

The dynamics of glassy behavior in SrRu1-Fe O3 heterostructure

Dash Umasankar,Pradhan Soumen,Rao M.S. Ramachandra,Veillon F.,Prellier W.,Jung Chang Uk 한국물리학회 2024 Current Applied Physics Vol.58 No.-

We report the magnetic interactions in SrRu1-xFexO3 epitaxial thin films. All the films showed a single-phase and good step-terrace structure with minimal surface roughness. The X-ray photoelectron spectra of Fe and Ru revealed that both transition metal elements exist in the films as Fe3+ and Ru4+. With Fe doping, the itinerant ferromagnetic behavior and ferromagnetic transition temperature gradually decreased, but the coercivity field increased. The magnetic interplay between Fe3+-O-Fe3+ is coined as antiferromagnetic. There was another interaction between Ru4+-O-Fe3+ which is best described as ferromagnetic. Furthermore, the magnetic frustration in our films caused by the doped Fe resulted in dynamic glassy behavior. On the other hand, the epitaxial strain from the imminent SrTiO3 substrate along with change in oxygen vacancy might have strong evidence for the spin-glass nature in our thin films.

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>

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.-

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.

A rigorous investigation of BiMnO₃ ferroelectricity through a development of a novel way to stabilize twin free and monoclinic thin film

Dash, U.,Raveendra, N.V.,Jung, C.U. Elsevier Sequoia 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.684 No.-

Bulk BiMnO<SUB>3</SUB> has a monoclinic structure and exhibits ferromagnetic properties below Tc~105 K. The existence of ferroelectricity was one of the hottest issues in this compound. To investigate the ferroelectricity in BiMnO<SUB>3</SUB>, a good film with low-enough leakage is highly required. However the reported quality of BiMnO<SUB>3</SUB> thin films has shown critical dependence on stoichiometry. Previously, we reported that a BiMnO<SUB>3</SUB> thin film grown on top of a SrTiO<SUB>3</SUB> (001) substrate has good stoichiometry, as well as bulk-quality ferromagnetic properties, but our results did not demonstrate the Q-E hysteresis curves. However, we could not exclude the possibility that non-ferroelectricity observed in the BiMnO<SUB>3</SUB> film is partly due to the tetragonal symmetry enforced by the strong epitaxial strain of the substrate since the ferroicity in most oxides accompanies with or equivalently originates from crystal symmetry breaking and/or lowering. In the present work, we used a SrTiO<SUB>3</SUB> (110) substrate with an anisotropic in-plane atomic arrangement to stabilize the BiMnO<SUB>3</SUB> thin film having the symmetry lower than tetragonal symmetry. After observing the stabilization of twined monoclinic phase in the BiMnO<SUB>3</SUB> film, we solved the twin problem by trying a novel substrate; i.e., miscut SrTiO<SUB>3</SUB> (110) substrate. The physical properties for the stoichiometric, twin-free, monoclinic BiMnO<SUB>3</SUB> thin film were notably similar to those reported for the stoichiometric BiMnO<SUB>3</SUB> bulk with monoclinic symmetry. We believe this new data more rigorously demonstrates the absence of ferroelectricity in stoichiometric monoclinic BiMnO<SUB>3</SUB>.

Evaluation of classical ayurvedic medicine “Sukumaram Kasayam” in a rat model of letrozole induced polycystic ovaries

Dash Sujit,Kanungo Sunil Kumar,Mishra Bishwanath,Sahoo Amaresh Chandra,Senapati Aswini Kumar,Pattnaik Sangyarani 경희대학교 융합한의과학연구소 2021 Oriental Pharmacy and Experimental Medicine Vol.21 No.4

PCOS is considered as common endocrine diseases among the females in their regenerative age. The purpose of the study was to analyze phytochemicals by GC–MS followed by the pharmacological evaluation of Sukumaram Kasayam on PCOS induced rats. GC–MS analysis of Sukumaram Kasayam was accomplish to identify phytoconstituents. Twenty-four female rats were used (n = 6/group) in the study consisting of healthy control (Group-I). The experimental groups were divided into 3 subgroups, including rats with PCOS which received no treatment (Group-II), PCOS group (Group-III and Group-IV) was administered daily dose of Clomifene citrate 200 mg/kg and Sukumaram Kasayam 0.5 ml/kg for 3 weeks, respectively. In all experimental groups, oral dose of 1 mg/kg letrozole for 21 days to induce PCOS. After treatment period, rats were anesthetized, blood sex hormone and lipid profile was carried. The GC–MS analysis identified Butane, 1, 1-diethoxy-3-, (+)-2-Bornanone abundant compound in formulation. The PCOS induced rats were treated with Clomiphene citrate, Sukumaram Kasayam, the testosterone decreased significantly (P < 0.01), progesterone increased significantly (P < 0.01), estradiol increased significantly (P < 0.01), the serum LH decreased (P < 0.05), the FSH levels were decreased significantly (P < 0.01). In case of the lipid profile the result showed that the triglyceride, cholesterol, LDL decreased significantly (P < 0.01), whereas the HDL increased significantly (P < 0.01) in comparison to PCOS control rats. Results concluded that Sukumaram Kasayam has beneficial effect on levels of the testosterone, progesterone, estradiol, LH, and FSH in alleviating the complications of PCOS.

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>

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>

Inhibition of AP-1 by SARI negatively regulates transformation progression mediated by CCN1

Dash, R,Su, Z-Z,Lee, S-G,Azab, B,Boukerche, H,Sarkar, D,Fisher, P B Macmillan Publishers Limited 2010 Oncogene Vol.29 No.31

Enhanced expression of the CCN family of secretory integrin-binding proteins correlates with many essential components of the cancerous state, including tumor cell adhesion, proliferation, invasion and migration. Consequently, CCN1 expression is elevated in various cancers, including breast cancer, and its expression directly correlates with poor patient prognosis. Using subtraction–hybridization, combined with induction of cancer cell terminal differentiation, we cloned SARI (suppressor of activator protein (AP)-1, regulated by interferon (IFN)), an IFN-β-inducible, potent tumor suppressor gene that exerts cancer-selective growth inhibitory effects. Forced expression of SARI using an adenovirus (Ad.SARI) inhibits AP-1 function and downregulates CCN1 expression in multiple cancer lineages, resulting in a profound inhibition in anchorage-independent cell growth and tumor cell invasion. Overexpression of SARI reduces CCN1-promoter activity through inhibition of AP-1 binding. Accordingly, SARI selectively blocks expression of the transformed state in rat embryo fibroblast cells that stably overexpress c-Jun. These results illustrate that SARI inhibits AP-1 transactivating factor binding to the cis-element of the CCN1 promoter, possibly through its interaction with c-Jun. Overall, SARI can directly inhibit CCN1-induced transformation by inhibiting the transcription of CCN1, as well as indirectly by inhibiting the expression of c-Jun (and hence blocking AP-1 activity). In these contexts, transformed cells ‘addicted’ to AP-1 activity are rendered susceptible to SARI-mediated inhibition of expression of the transformed phenotype.