Electrical and Magnetic Properties of <tex> ${\rm Sr}({\rm Ru},{\rm Cr}){\rm O}_{3}$</tex> Thin Films

Ramana, E. Venkata,Park, Hong Woo,Jung, C. U. IEEE 2010 IEEE transactions on magnetics Vol.46 No.6

<P> Cr-doped <TEX>${\rm SrRuO}_{3}$</TEX> (SRCO) thin films were grown on an <TEX>${\rm SrTiO}_{3}$</TEX> (STO) (001) substrate using a pulsed laser deposition method in order to study the effects of the Cr doping. Measurements of the out-of-plane lattice constant and the electrical and magnetic properties indicate that Cr is incorporated into the B-site of the SRO lattice. Magnetic hysteresis measurements reveal a ferromagnetic nature with a saturation magnetization of about 0.75 <TEX>$\mu_{\rm B}/{\rm Ru}$</TEX>. The magnetization measurement of <TEX>${\rm Sr}({\rm Ru}_{0.9}{\rm Cr}_{0.1}){\rm O}_{3}$</TEX> showed a ferromagnetic transition temperature <TEX>$T_{\rm C}=165\ {\rm K}$</TEX>. This <TEX>$T_{\rm C}$</TEX> value is about 13 K higher than that reported for <TEX>${\rm SrRuO}_{3}$</TEX> thin films. The <TEX>$T_{\rm C}$</TEX> enhancement due to Cr doping in <TEX>${\rm SrRuO}_{3}$</TEX> thin film was less than that observed for the bulk sample. Electrical resistivity measurements of the SRCO thin films reveal metallic behavior, with a much larger residual resistivity of <TEX>$\sim 260\ \mu\Omega\ {\rm cm}$</TEX> compared to 26 <TEX>$\mu\Omega$</TEX> cm for <TEX>${\rm SrRuO}_{3}$</TEX> thin films. </P>

Insights into the signal transduction pathways of mouse lung type II cells revealed by transcription factor profiling in the transcriptome

Ramana, Chilakamarti V. Korea Genome Organization 2019 Genomics & informatics Vol.17 No.1

Alveolar type II cells constitute a small fraction of the total lung cell mass. However, they play an important role in many cellular processes including trans-differentiation into type I cells as well as repair of lung injury in response to toxic chemicals and respiratory pathogens. Transcription factors are the regulatory proteins dynamically modulating DNA structure and gene expression. Transcription factor profiling in microarray datasets revealed that several members of AP1, ATF, $NF-{\kappa}B$, and C/EBP families involved in diverse responses were expressed in mouse lung type II cells. A transcriptional factor signature consisting of Cebpa, Srebf1, Stat3, Klf5, and Elf3 was identified in lung type II cells, Sox9+ pluripotent lung stem cells as well as in mouse lung development. Identification of the transcription factor profile in mouse lung type II cells will serve as a useful resource and facilitate the integrated analysis of signal transduction pathways and specific gene targets in a variety of physiological conditions.

Endovascular Therapy for Ischemic Stroke

Ramana M R Appireddy,Andrew M Demchuk,Mayank Goyal,Bijoy K Menon,Muneer Eesa,Philip Choi,Michael D. Hill 대한신경과학회 2015 Journal of Clinical Neurology Vol.11 No.1

The utility of intravenous tissue plasminogen activator (IV t-PA) in improving the clinical outcomes after acute ischemic stroke has been well demonstrated in past clinical trials. Thoughmultiple initial small series of endovascular stroke therapy had shown good outcomes as compared to IV t-PA, a similar beneficial effect had not been translated in multiple randomizedclinical trials of endovascular stroke therapy. Over the same time, there have been parallel advances in imaging technology and better understanding and utility of the imaging in therapy ofacute stroke. In this review, we will discuss the evolution of endovascular stroke therapy followed by a discussion of the key factors that have to be considered during endovascular stroketherapy and directions for future endovascular stroke trials.

Commercial Policy with Vertical Product Differentiation

( Ramana Polavarapu ),( Ashish Vaidya ) 세종대학교 경제통합연구소 1996 Journal of Economic Integration Vol.11 No.2

We examine the nature of commercial and domestic policy (tariffs, taxes/ subsidies, and quality restrictions) in a model of vertical product differentiation. A foreign firm competes with a domestic firm in the latter`s market, producing products of varying quality, and competing in prices. We show that a specific tariff on the foreign firm raises overall welfare in the domestic economy, while an ad valorem tariff has a similar effect only when the foreign firm produces the lower quality product. Tariffs on the foreign firm typically induce the domestic firm to upgrade the quality of its product, when it produces the lower quality product. A subsidy is always the optimal policy towards the domestic firm. If quality restrictions are imposed on the foreign firm, the domestic firm upgrades quality, and overall welfare in the domestic economy is once again higher (JEL: F12, F13)

An Experimental Study on FRC Infilled Steel Tubular Columns under Eccentric Loading

S. Ramana Gopal 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.3

Concrete filled Steel tubular columns have become more popular as the requirements on the performance of steel structures increased as in case of tall buildings all over the world. These types of columns offer a number of advantages attaining economy in the construction and have been used in variety of applications. Because of their excellent ductility these have been used in earthquake resistant structures. This paper presents an experimental study on the behavior of both plain and fiber reinforced concrete filled slender steel tubular columns eccentrically loaded in compression to failure. The composite columns have different lengths varied from 11D to 28D and diameter to thickness ratio of the steel tube is 38. The column strength, load-strain relationships, load-mid height deflection relationships and failure modes were measured from the tests. Companion tests on six numbers of similar empty steel tubes were also undertaken to highlight the beneficial effects of composite column. The study has shown that fiber reinforced concrete filled steel tubular slender columns offer a significant increase in the column strength and ductility compared with plain concrete filled steel tubular slender columns.

Impact of low temperature plasma annealing for flexible, transparent and conductive ITO/PEDOT:PSS composite electrode

Vivekanandan Ramana,Yong-Hwan Choa,Jin-Hyeok Park,Han-Ki Kima 한국진공학회 2020 한국진공학회 학술발표회초록집 Vol.2020 No.8

Analysis of Priority Countries and Products for Indonesian Export Diversification in Latin America

Febria Ramana,Lili Retnosari 한국유통과학회 2018 The Journal of Industrial Distribution & Business( Vol.9 No.8

Purpose - Indonesian economy often receives negative impact from external factors, particularly through trade linkage. To mitigate that impact, the export market and product diversification should be established. Latin America is one of the potential regions to augment the Indonesian export market. Research design, data, and methodology - This study attempts to classify the potential market and product for Indonesian export, particularly in Latin America, by using panel regression, trade complementarity, and export similarity index over the period 2000-2015. Regression was also used to examine whether the presence of the Indonesian Trade Promotion Center (ITPC) can support diversification. Results - Based on regression results, those indexes established Chile, Uruguay, Suriname, and Ecuador as the priority countries with the products: animal and vegetable oils, fats and waxes; chemicals and related products; miscellaneous manufactured articles; commodities and transactions. Conclusions - The results of the regression concludes that the trade complementarity index gave a significant positive effect to boost Indonesian export, whereas, the export similarity index gave a significant negative effect. The regression also conclude that ITPC gave a significant positive impact on Indonesian export. For instance, the government should prioritize those countries and products and also develop ITPC there to optimize Indonesian export.

Tests on fiber reinforced concrete filled steel tubular columns

S. Ramana Gopal,P. Devadas Manoharan 국제구조공학회 2004 Steel and Composite Structures, An International J Vol.4 No.1

This paper deals with the strength and deformation of both short and slender concrete filled steel tubular columns under the combined actions of axial compression and bending moment. Sixteen specimens were tested to investigate the effect of fiber reinforced concrete on the ultimate strength and behavior of the composite column. The primary test parameters were load eccentricity and column slenderness. Companion tests were also undertaken on eight numbers of similar empty steel tubes to highlight the synergistic effects of composite column. The test results demonstrate the influence of fiber reinforced concrete on the strength and behavior of concrete filled steel tubular columns.

Experimental and Analytical Study for Plastic Moment Capacity of Beam–Beam Splice Connection

V. Ramana Kollipara,T. D. Gunneswara Rao 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.4

In this paper, both experimental and analytical investigations are presented for the evaluation of yield moment capacity of the extended end plate connections under pure fl exural loading. Four point loading system is adopted to simulate the pure bending condition. For the experimental study a beam–beam splice connection is made by joining hollow tubular sections (HTS) using bolted end plate connections. The parameters varied for the experimental investigation are cross sectional dimensions of HTS, thickness of end plate, diameter of bolt and thickness of weld. In the analytical study, yield line theory is used for the prediction of yield moment equations of the connection for a particular modes of failure. Finally, the proposed analytical equations are validated by comparing the analytical results with the experimental results. It is found that the experimental results are in proximity with the analytical results.

Design optimization of 3PRS parallel manipulator using global performance indices

S. Ramana Babu,V. Ramachandra Raju,K. Ramji 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.9

This paper presents an optimal kinetostatic design method for a general 3PRS (Prismatic-revolute-spherical) spatial parallel manipulator by formulating a multi-objective optimization problem considering the performance indices are as the objective functions. Three performance criteria--Global conditioning index (GCI), Global stiffness index (GSI) and workspace volume-were formulated and the effect of actuator layout angle on the performance indices was studied. A multi-objective evolutionary algorithm based on the Control elitist non-dominated sorting genetic algorithm (CENSGA) was adopted to find the final approximation set. The optimal geometric parameters that yield minimal compliance with larger workspace volume and improved dexterity are suggested for a general 3PRS parallel manipulator. For the optimal design, it is shown that global isotropy and global stiffness of the platform is improved at the cost of workspace reduction.