Deposition rate dependent phase/mechanical property evolution in zirconia and ceria-zirconia thin film by EB-PVD technique

Arunkumar, P.,Aarthi, U.,Sribalaji, M.,Mukherjee, B.,Keshri, Anup Kumar,Tanveer, Waqas Hassan,Cha, Suk-Won,Babu, K. Suresh Elsevier 2018 Journal of alloys and compounds Vol.765 No.-

<P><B>Abstract</B></P> <P>Pure zirconia (ZrO<SUB>2</SUB>) and ceria (16 mol%) stabilized zirconia (CeSZr) thin films were prepared by electron beam physical vapor deposition with varying deposition rates (1, 4 and 8 Å/s) in order to correlate the phase changes to the mechanical property. X-ray diffraction and Raman spectra results indicate the presence of mixed monoclinic and tetragonal phases in ZrO<SUB>2</SUB> film, but tetragonal phase dominated at lower deposition rate. However, irrespective of the deposition rate, cerium addition to ZrO<SUB>2</SUB> resulted in complete stabilization of tetragonal phase. Depending on the presence of dual (ZrO<SUB>2</SUB>) or single (CeSZr) phase, either surface cracks or well-connected grain structure was observed in SEM, respectively. Thus, CeSZr film showed a four-fold increase in hardness in comparison to ZrO<SUB>2</SUB>, which can be attributed to the complete stabilization of tetragonal phase that hinders the crack propagation along the grain. Plastic deformation of CeSZr film was found to be 1.80 × 10<SUP>−2</SUP> GPa, which is about ∼55% higher as compared to pure ZrO<SUB>2</SUB> film (8.04 × 10<SUP>−3</SUP> GPa). Thus, the development of CeSZr coating may lead to better surface protection of many components.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Zirconia and ceria (16 mol%) stabilized zirconia (CeSZr) films deposited by EB-PVD. </LI> <LI> ZrO2 thin film showed mixed tetragonal and cubic structure. </LI> <LI> CeSZr thin film formed with single phase tetragonal structure. </LI> <LI> CeSZr film exhibited a four-fold increase in hardness in comparison to ZrO2 film. </LI> <LI> Deposition rate and chemistry influence the mechanical property of films. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Synchrophasor-Based Line Protection for Single Phase-Ground Faults

Babu N. V. Phanendra,Babu P. Suresh,Roy Saptarshi,Babu T. Sudhakar,Bharadwaj Anil 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

Synchrophasor measurement data enhances the transmission line protection. This paper proposes an improved line protection against single phase-ground faults using synchronized phasor data. This algorithm prevents the relay mal-operation caused by high fault resistance. This algorithm calculates the phase difference between relay point voltage and fault point voltage based on the relation between negative sequence of relay point current and fault point current. After, the calculated phase difference between relay point voltage and fault point voltage will be compared with set point voltage phase referred from the relay point voltage phase. The fault detection action will be taken according to a certain phase difference relation between fault point voltage and set point voltage. This method is then applied to a practical single machine single line system. The results show that the suggested algorithm could determine in-line faults accurately with less computational time. It also has proved that this method is immune to the fault resistance, system conditions.

An Improved Steady-State Model of an Interline Power Flow Controller for the Multi-Transmission System

Suresh Babu Daram,P.S.Venkataramu,M.S.Nagaraj 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.5

Flexible AC Transmission System (FACTS), under different conditions, are being incorporated in a power system for the improvement of active power flow along with voltage at each bus. Among the many FACTS devices, Interline Power Flow Controller (IPFC) is one of its kind, that has the capability of controlling multi-transmission systems. In this paper, an Improved Power Injection Model (IPIM) of Interline Power Flow Controller (IPFC) has been introduced. This model was included to Newton-Raphson (NR) method of load flow solution. The proposed model is tested on the standard test systems. The results of standard 5-bus system, IEEE-14 bus system is presented for the purpose of demonstration.

Optimization of process parameters in friction stir welding of aluminium matrix SiC-Al2O3 composites by genetic algorithm

P. Gopi Krishnan,B. Suresh Babu,K. Siva 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.2

Friction stir welding (FSW) grabs more attention since the past decade among the researchers worldwide due to its excellentcharacteristics such as no emission of fumes, no filler material, comparatively economical and so on. Friction stir weldingis effectively used in bringing better joint without any appreciable defects in light materials such as Aluminium, Magnesiumetc., Experiments in FSW of materials with high density such as steel, copper alloys etc., have also been tried out. Theselection of proper welding parameters determines a good weldment. In this work, Aluminium matrix hybrid compositewas manufactured through stir casting with the matrix AA7010 and reinforcements SiC and Al2O3. The hybrid compositeworkpieces were subjected to friction stir welding process by varying the process parameters such as tool rotation speed,welding speed and axial force using Taguchi L27 orthogonal array. Tensile strength of FS welded composite was examinedand regression analysis was done. Genetic Algorithm technique was used to optimize the weld tensile strength within thedesign space of 53 = 125 alternatives of parametric combinations. The study focuses on the improvement of the tensilestrength of the welded specimens.

Structure dependent luminescence, peroxidase mimetic and hydrogen peroxide sensing of samarium doped cerium phosphate nanorods

Vinothkumar, G.,I. L., Arun,Arunkumar, P.,Ahmed, Waseem,Ryu, Sangbong,Cha, Suk Won,Babu, K. Suresh The Royal Society of Chemistry 2018 Journal of Materials Chemistry B Vol.6 No.41

<P>Rare earth phosphates have been used extensively in luminescent phosphors, bio-imaging, catalysis, and sensors. However, there is a need to correlate the structural-chemical changes associated with stability and performance. In the present work, hydrothermally synthesized CePO4:Smx (<I>x</I> = 0, 5 and 10 mol%) nanorods were annealed at different temperatures to understand the modulations in structure as well as optical and enzyme mimetic properties. As prepared samarium doped cerium phosphate (SCP) nanorods crystallized in a hydrated hexagonal structure transformed into an anhydrous hexagonal and a monoclinic structure on annealing at 400 °C and 800 °C, respectively. Though temperature did not affect the rod-like morphology of the SCP, the lattice strain changed from compressive to tensile. Monoclinic SCP exhibited excellent emission until 5% Sm<SUP>3+</SUP> doping while the quenching effect dominated at 10% Sm<SUP>3+</SUP>. Monoclinic SCP samples demonstrated higher peroxidase-like enzymatic activity in comparison to natural enzyme HRP and hexagonal SCP. A mechanism for the enhanced peroxidase-like activity of the monoclinic structure was proposed based on the fluorescence property of terephthalic acid and the surface peroxo complex using Raman spectroscopy. Fluorimetric detection based on the luminescent quenching effect of the monoclinic SCP nanorods treated with different concentrations of hydrogen peroxide showed a linear response from 0 to150 μM concentration with a detection limit (LOD) of 3.17 μM H2O2. Our results demonstrate the importance of structure for enzyme mimetic activity.</P>

Ionic Radii and Concentration Dependency of RE³⁺ (Eu³⁺, Nd³⁺, Pr³⁺, and La³⁺)-Doped Cerium Oxide Nanoparticles for Enhanced Multienzyme-Mimetic and Hydroxyl Radical Scavenging Activity

Vinothkumar, G.,Rengaraj, S.,Arunkumar, P.,Cha, Suk Won,Suresh Babu, K. American Chemical Society 2019 The Journal of Physical Chemistry Part C Vol. No.

<P>The antioxidant activity of cerium oxide nanoparticles (CNPs) depends on the concentration of oxygen vacancies and Ce<SUP>3+</SUP> active sites. In the present work, we report the impact of 5 mol % trivalent rare-earth-doped (RE<SUP>3+</SUP> = Eu<SUP>3+</SUP>, Nd<SUP>3+</SUP>, Pr<SUP>3+</SUP>, and La<SUP>3+</SUP>) CNPs on the oxidation state modulation and antioxidant property with respect to ionic radii. An increase in the lattice parameter, strain, and oxygen vacancy concentration was observed as a function of ionic radii. Among the various dopants in CNPs, La<SUP>3+</SUP> with higher ionic radii having smaller crystallite size (7.9 nm) and higher vacancy displayed better peroxidase, oxidase, and hydroxyl radical (HO<SUP>•</SUP>) scavenging activities. The kinetic parameters for the peroxidase and oxidase activities were found to be superior with <I>K</I><SUB>m</SUB> = 0.217 and 0.261 mM, respectively, for 5 mol % La<SUP>3+</SUP>-doped CNPs. To divulge the role of dopant concentration on the structural properties, we also explored using 10 and 20 mol % La<SUP>3+</SUP> doping in CNPs. Because of the smaller crystallite size (6.7 nm) and higher defect level (3.12 × 10<SUP>21</SUP> cm<SUP>-3</SUP>), 20% La<SUP>3+</SUP> doping showed superior peroxidase and oxidase activities, as shown by the low <I>K</I><SUB>m</SUB> values. CNPs exhibit both peroxidase and oxidase activities in a concentration-dependent manner. Moreover, CNPs exhibit concentration-dependent peroxidase and oxidase activities that can be selectively activated for various theranostic applications. Thus, our results demonstrate the crucial role of ionic radii and the concentration of RE<SUP>3+</SUP> dopants on defect formation in CNPs for improved antioxidant properties of ceria.</P> [FIG OMISSION]</BR>

Study on effect of welding speed on friction stir welded aluminium metal matrix hybrid composite

P. Gopi Krishnan,B. Suresh Babu,S. Madhu,S. J. Gowrishankar,C. Bibin,S. Saran,S. Shree Ram,A. R. Sri Hari,S.Vidyasagar 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.5

The development of aluminum series matrix hybrid composites with ceramic reinforcements has recently caught the interestof new researchers. The addition of more than one or two reinforcements in aluminium alloy leads to the fabrication of theAluminium Metal Matrix Hybrid Composite (AMMHC). The present investigation is aimed at the development of newlydeveloped AMMHC followed by friction stir welding for obtaining the improved mechanical properties. The stir castedAA6063 with reinforcement of 5%, 10% and 15% wt. Silicon Carbide (SiC) and 10% wt. Boron Carbide (B4C) werefabricated by stir casting technique and the AMMHC with 10% each of SiC and B4C showed higher mechanical properties. Further the AMMHC are joined by friction stir welding (FSW) route. A prime experimental work has been tried out in theFSW process by varying welding speed (20, 30, 40, 50 and 60 mm/min). The effect of welding speed on AMMHCs were studiedon macro and microstructural observations followed by micro hardness and ultimate tensile. Strength, in which 40 mm/minof welding speed gives better properties than other processing condition. The weldment reveals the better joint strength withthe presence of fine particle dispersion in the microstructure.

User Behaviour Profiling in Cloud using One Class SVM : A Review

Vijaya Lakshmi Paruchuri,S. Suresh Babu,P S V S Sridhar,Debnath Bhattacharyya,Hye-Jin Kim 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.9

Distributed computing guarantees to on a very basic level change the way we utilize PCs and get to and store our own specific and business data. With these new registering and correspondences models develop new data security challenges. Existing information security structures, for instance, encryption have fizzled in imagining information theft strikes, particularly those executed by an insider to the cloud supplier. We propose a substitute methodology for securing information in the cloud utilizing adversarial mimic improvement. We screen data access in the cloud and perceive unpredictable data access outlines. Right when unapproved access is suspected and after that confirmed using test questions, we dispatch a disinformation strike by giving back a considerable measure of fake information to the attacker. This secures against the misuse of the customer's real data. Trials coordinated in a neighbor-hood archive setting give confirmation this technique may give unprecedented levels of customer data security in a Cloud space.

Optimization of friction stir welding process parameters on AA 6063-SiC-B4C hybrid metal matrix composites by genetic algorithm

R. Srinivasan,B. Suresh Babu,P. Prathap,Ruban Whenish,R. Soundararajan,G. Chandramohan 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.1

Friction Stir Welding (FSW) is a metal joining process has its own benefits over fusion welding processes. FSW AluminiumMetal Matrix Composites (AMMC) replaced conventional metals for structural applications in aerospace, automobile andmarine sectors. In this present investigation, process parameters of FSW for joining AA 6063-SiC-B4C hybrid MMCs wereoptimized in order to achieve maximum tensile strength. Initially, AMMC was manufactured through stir casting with thematrix AA 6063 and reinforcements SiC and B4C. The hybrid MMC work pieces were subjected to FSW process by varyingthe process parameters such as tool rotation speed, welding speed and axial force using Taguchi L27 orthogonal array. Tensilestrength of hybrid composite was examined and regression analysis were done using MINITAB V17 software. GeneticAlgorithm technique was used to optimize the tensile strength with FSW parametric combinations. The optimum parametersfor FSW of AA6063-SiC-B4C hybrid composites were Tool rotational speed (TRS) – 1050 rpm; Axial Force (AF) – 10 kN andWeld Speed (WS) – 45 mm/min obtained. The optimal parameters were applied to experimental study and the results werevalidated.

Breeding of New Productive Bivoltine Hybrid, CSR12 $\times$ CSR6 of Silkworm Bombyx mori L.

Datta, R.K.,Basavaraja, H.K.,Reddy, N.Mal,Kumar, S.Nirmal,Kumar, N.Suresh,Babu, M.Ramesh,Ahsan, M.M.,Jayaswal, K.P. Korean Society of Sericultural Science 2001 International Journal of Industrial Entomology Vol.3 No.2

With an objective of evolving quantitatively and qualitatively superior bivoltine breeds/hybrids of silkworm Bombyx mori L. for tropical conditions, breeding work was initiated in Central Sericultural Research and Training Institute, Mysore during 1992 by utilizing two Japanese hybrids namely BNl8$\times$BCS25 and Shunrei$\times$Shogetsu along with Indian evolved breed, KA. The breed CSR12 which is characterized with sex-limited larval marking and white oval cocoons was evolved from the Japanese hybrid BNl8 ${\times}$ BCS25 by crossing with KA, while the breed CSR6 which is characterized with normal marking (marked larvae) and white dumbbell cocoons was extracted from the Japanese commercial hybrid Shunrei${\times}$Shogetsu through continuous inbreeding coupled with selection. After fixation, these breeds along with other newly evolved breeds were subjected to hybrid study under optimum environmental conditions in the laboratory for expression of full potential of the genotypes. These hybrids were evaluated by Multiple Trait Evaluation Index (Mano et al., 1993). The hybrid CSR12${\times}$CSR6 was selected based multiple trait evaluation index value. The hybrid CSR12$\times$CSR6 recorded survival of 96.0%, shell weight of 50.0 cg, shell ratio of 24.3%, raw silk percentage of 19.6, filament length of 1,216 m, boil off loss of 22.4% and renditta of 5.1. On the other hand, the control hybrid (KA ${\times}$ NB4D2) has recorded survival of 90.6%, shell weight of 42.1 cg, shell ratio of 20.4%, raw silk percentage of 15.9, filament length of 999 m, boil off loss of 24.8% and renditta of 6.3. The hybrid CSR12$\times$CSR6 was authorized during 1997 by Central Silk Board, Government of India for commercial exploitation during favourable months based on national level race authorization test.