Noble metals functionalized reduced graphene oxide as an efficient optical limiter: a combined experimental and theoretical investigation

Saravanan M.,Kandasamy Manikandan,Suresh K.,Chakraborty Brahmananda,George Sajan D.,Girisun T. C. Sabari,Potheher I. Vetha,Parthasarathy V. 한국탄소학회 2024 Carbon Letters Vol.34 No.6

Copper, silver, and gold-reduced graphene oxide nanocomposite (Cu-rGO, Ag-rGO, and Au-rGO) were fabricated via the hydrothermal method, which shows unique physiochemical properties. Environment friendly electromagnetic radiation was employed to synthesize rGO from GO. The nonlinear optical phenomenon of noble metal decorated rGO is predominantly due to excited state absorption, which arises from surface plasmon resonance and increases in defects at the surface due to Cu, Ag, and Au incorporation. It is found that the third-order nonlinear absorption coefficient was in the order of 10−10 m/W, with notable enhancements in the third-order properties of Au-rGO compared to other nanocomposites and their respective counterparts. Functionalizing rGO induces defect states (sp3), increasing NLO response. Cu, Ag, and Au exhibit higher Surface-Enhanced Raman Scattering (SERS) activity due to rGO-induced structural modifications. SERS signals are influenced by dominant signals from Au nanorods. The electronic structures for pure and doped rGO were investigated through Density Functional Theory (DFT). The computed partial density of states (PDOS) confirms the enhancement of the state in Au-doped rGO is due to the charge transference from Au to C 2p orbital. The optical absorption spectra and PDOS reveal the possibility of free carrier absorption enhancement in Au which validates experimentally observed higher two-photon absorption (β) value of Au-doped rGO. The tuning of nonlinear optical and SERS behaviour with variation in the noble metal upon rGO provides an easy way to attain tuneable properties which are exceedingly required in both optoelectronics and photonics applications.

Advanced analysis of cyclic behaviour of plane steel frames with semi-rigid connections

Saravanan, M.,Arul Jayachandran, S.,Marimuthu, V.,Prabha, P. 국제구조공학회 2009 Steel and Composite Structures, An International J Vol.9 No.4

This paper presents the details of an advanced Finite Element (FE) analysis of a plane steel portal frame with semi-rigid beam-to-column connections subjected cyclic loading. In spite of several component models on cyclic behaviour of connections presented in the literature, works on numerical investigations on cyclic behaviour of full scale frames are rather scarce. This paper presents the evolution of an FE model which deals comprehensively with the issues related to cyclic behaviour of full scale steel frames using ABAQUS software. In the material modeling, combined kinematic/isotropic hardening model and isotropic hardening model along with Von Mises criteria are used. Connection non-linearity is also considered in the analysis. The bolt slip which happens in friction grip connection is modeled. The bolt load variation during loading, which is a pivotal issue in reality, has been taken care in the present model. This aspect, according to the knowledge of the authors, has been first time reported in the literature. The numerically predicted results using the methodology evolved in the present study, for the cyclic behaviour of a cantilever beam and a rigid frame, are validated with experimental results available in the literature. The momentrotation and deflection responses of the evolved model, match well with experimental results. This proves that the methodology for evolving the steel frame and connection model presented in this paper is closer to real frame behaviour as evident from the good comparison and hence paves the way for further parametric studies on cyclic behaviour of flexibly connected frames.

Almost $\zeta$- contraction on $M$- metric space

M. Pitchaimani,K. Saravanan 강원경기수학회 2020 한국수학논문집 Vol.28 No.2

In this paper, we initiate the concept of almost $\zeta $- contractions via Simulation functions to find fixed points on $M$- metric spaces, and prove some related fixed points results for such mappings. Moreover an illustration is provided to show the applicability of our obtained results.

Experimental investigations on composite slabs to evaluate longitudinal shear strength

Saravanan, M.,Marimuthu, V,Prabha, P.,Arul Jayachandran, S.,Datta, D. 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.13 No.5

Cold-formed steel profile sheets acting as decks have been popularly used in composite slab systems in steel structural works, since it acts as a working platform as well as formwork for concreting during construction stage and also as tension reinforcement for the concrete slab during service. In developing countries like India, this system of flooring is being increasingly used due to the innate advantage of these systems. Three modes of failure have been identified in composite slab such as flexural, vertical shear and longitudinal shear failure. Longitudinal shear failure is the one which is difficult to predict theoretically and therefore experimental methods suggested by Eurocode 4 (EC 4) of four point bending test is in practice throughout world. This paper presents such an experimental investigation on embossed profile sheet acting as a composite deck where in the longitudinal shear bond characteristics values are evaluated. Two stages, brittle and ductile phases were observed during the tests. The cyclic load appears to less effect on the ultimate shear strength of the composite slab.

Effect of Ni and Si addition on electrical, tribological and corrosion behavior of novel Cu-Zn alloy

Saravanan. R,Suresh. P,Prabu. M,Bagyalakshmi. Pd 한양대학교 세라믹연구소 2022 Journal of Ceramic Processing Research Vol.23 No.4

The goal of this research is to evaluate the electrical, dry sliding wear and corrosion behaviour of copper-zinc alloy reinforcedwith Ni and Si through Powder Metallurgy (P/M) technique. Six different wt. % of novel copper-zinc alloy are considered forthis research study namely 90Cu-10Zn, 88.16Cu-10Zn-1.5Ni-0.34Si, 85Cu-15Zn, 83.16Cu-15Zn-1.5Ni-0.34Si, 80Cu-20Zn and78.16Cu-20Zn-1.5Ni-0.34Si. The fabricated composites were characterized by using Scanning Electron Microscope (SEM) withEnergy Dispersive Spectroscopy (EDS) line mapping. The electrical, wear and corrosion behaviour of the fabricatedcomposites was assessed. The hardness of the fabricated composites was evaluated using Vickers Hardness Tester. Theelectrical conductivity was assessed using four-point probe tester. The result shows a significant improvement on electrical andtribological properties by increasing the wt.% of Zn, Ni and Si led of the composites. The research results concludes that78.16Cu-20Zn-1.5Ni-0.34Si composite possessed better hardness about 287 HV and the electrical conductivity about 121%IACS. The investigation result shows that Zn acts as a vital role to enhance the properties in all aspects. Also, theexperimentation results portrays that Cu-20Zn-1.5Ni-0.34Si composite possessed better specific wear rate and coefficient offriction such as 1.85 * 105 mm3/N-m and 0.29 respectively.

Replaceable Fuses in Earthquake Resistant Steel Structures: A Review

M. Saravanan,Rupen Goswami,G. S. Palani 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.3

In earthquake-prone regions, steel structures are considered to be one of the best choices due to inherent material properties in terms of homogeneity and ductility. In the conventional seismic design of steel structures, prevalent specifi cations recommend that the column and joints should be strong enough such that the inelastic action or damage occurs in the beams in lateral load resisting frames. By following these design provisions, structural collapse can be prevented in the event of severe earthquakes to ensure occupant safety. However, repair and rehabilitation of damaged primary members is a challenging task and also time-consuming process, resulting in severe inconvenience to the occupants. To simplify the repair works in earthquake resistant steel structures after the event of severe earthquakes, recent research work is concentrated on designing structures to have localized inelastic damages at intended locations, which will dissipate the seismic energy and can be easily replaced after the event of a strong earthquake, so that normal life of the occupants can be restored immediately with lesser cost of repair. This paper presents a critical review of the state-of-the-art related to steel lateral load resisting systems comprising of replaceable fuses that help in the easy repair of steel structures following strong earthquakes.

In vitro antibacterial activity of nanoemulsion formulation on biofilm, AHL production, hydrolytic enzyme activity, and pathogenicity of Pectobacterium carotovorum sub sp. carotovorum

Joe, M.M.,Benson, A.,Saravanan, V.S.,Sa, T. Academic Press 2015 Physiological and molecular plant pathology Vol.91 No.-

In the present investigation the in vitro activity of nanoemulsion (AUSN1) was evaluated against the plant pathogen Pectobacterium carotovorum sub sp. carotovorum causing the soft rot disease in numerous horticultural crops. With AUSN1 nanoemulsion treatment, minimum inhibitory concentration (MIC) of 0.09 mg ml<SUP>-1</SUP>, minimum bacteriostatic concentration (MBC) of 1.30 mg ml<SUP>-1</SUP> and zone of inhibition of 2.90 cm was observed against P. carotovorum. This formulation was able to reduce the bacterial population by 32.2-51.6%, under biofilm formation condition and a complete elimination of population under normal cultivation conditions. When subjected AUSN1 treatment, reduction in biofilm formation, swarming and swimming motility was observed in P. carotovorum strain and also inhibited the N-acyl homoserine lactones (AHL) activity by 13.27-62.3% and AHL production by 32.4-76.13%. Reduction in exo polysaccharide (EPS) synthesis and hydrolytic enzymes production in P. carotovorum strain was observed due to AUSN1 treatment. Reduced hydrophobicity (36.9-56.4%) and adhesion to polystyrene (22.9-47.5%) and potato tuber surfaces (19.5-46.8%) was observed with AUSN1 treatment. All these collective evidences clearly show that, under laboratory conditions, AUSN1 treatment was able to inhibit the soft root incidence in potato tubers.

Comparative Study on Solubilization of Zn and Other insoluble Compounds by Gluconacetobacter diazotrophicus and Certain PGPR's

V.S.Saravanan(V.S.사라바난),M.Madhaiyan(M.마두하이안),M.Thangaraju(M.탕가라쥬),T. M. Sa(사동민) 한국토양비료학회 2006 한국토양비료학회 학술발표회 초록집 Vol.2006 No.10

Genetic Distance among South Indian Breeds of Zebu Cattle Using Random Amplified DNA Markers

Ramesha, K.P.,Saravanan, T.,Rao, M.K.,Appannavar, M.M.,Obi Reddy, A. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.3

Random Amplified Polymorphic DNA (RAPD) assay was conducted to identify polymorphic markers in Amrithmahal, Krishna Valley, Hallikar, Deoni, Khillari, Ongole and Malnad Gidda breeds of South Indian cattle using twenty six primers. Of the 93 RAPD markers obtained, 53 were present in all breeds, 22 were individual specific and 18 were polymorphic for different breeds. Dual purpose breeds viz., Krishna Valley and Ongole showed less genetic divergence between them as compared to their genetic divergence from draft breeds viz., Amrithmahal, Hallikar and Khillari. Malnad Gidda was found to be a distinctly different from others studied.

Molecular Characterization of Hallikar Breed of Cattle Using Microsatellite Markers

Kumar, S. Naveen,Jayashankar, M.R.,Nagaraja, C.S.,Govindaiah, M.G.,Saravanan, R.,Karthickeyan, S.M.K. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.5

Molecular characterization of Hallikar, the native cattle breed of Karnataka, was undertaken using 19 cattle specific, highly polymorphic microsatellite markers recommended by FAO. The genomic DNA was subjected to PCR amplification and alleles were resolved through six per cent denaturing PAGE with a 10 bp DNA ladder followed by silver staining. Genotyping of animals was done based on allele size. The number of alleles ranged from three to nine with allele sizes ranging from 102 bp to 294 bp. These alleles were distributed in the frequency range between 0.0306 and 0.8673 in the population. The mean observed number of alleles was $6.368{\pm}1.4225$. The mean observed and expected heterozygosities were $0.7515{\pm}0.1734$ and $0.7850{\pm}0.1381$, respectively. The high heterozygosity observed implies presence of higher genetic variability within Hallikar breed. The PIC (Polymorphism Information Content) values ranged from 0.2322 (ETH152) to 0.8654 (ETH225). The percentage of polymorphic loci obtained was 100 as all the 19 microsatellite markers were found to be polymorphic. Except for ETH152, all the other loci had high PIC values, indicating that these markers are highly informative for characterization of Hallikar breed. The population was tested for Hardy-Weinberg equilibrium at 19 microsatellite loci, and at 74 per cent of the loci the population was found to be in disequilibrium.