Use of DNA barcoding in wildlife forensics: a study of sambar deer (Rusa unicolor)

Suresh Kumar U,Sanil George,Ratheesh R.V,George Thomas 한국산림과학회 2012 Forest Science And Technology Vol.8 No.4

This paper reports a case in which a wildlife range officer had suspected that some people had killed a sambar deer (Rusa unicolor). Cooked meat and dried skin were seized from the suspects and forwarded to our laboratory for DNA testing to resolve the identity of the animal. Mitochondrial cytochrome C oxidase subunit 1 (CO1) analysis revealed that the cooked meat and skin of the animal were of a sambar deer by comparing the sequences with the reference sequence of R. unicolor generated in our laboratory. The study illuminates the use of barcode sequences and reference databases in wildlife forensic applications.

Material-dependent thermoelastic damping limited quality factor and critical length analysis with size effects of micro/nanobeams

R. Resmi,V. Suresh Babu,M. R. Baiju 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

Micro/nanobeam-based resonators have found extensive applications in the micro/nanoelectromechanical system industry. Thermoelastic damping (TED) is a major energy loss issue in micro/nanobeam resonators that limits their important performance parameter, namely, the TED limited quality factor (Q TED ). The critical length (L c ) of a micro/nanobeam is another significant parameter that accounts for the maximum peak in the energy dissipation curve at which Q TED assumes a minimum value. To evaluate Q TED and Lc explicitly when the size of devices is scaled down, size effects play a decisive role and classical theories are inadequate. In this work, a higher-order theory, namely, modified couple stress theory (MCST), is used to overcome the size effects by including one internal material length scale parameter (l). The material-dependent thermoelastic coupled equations for a deflected Euler-Bernoulli microbeam are presented using variational and Hamilton principles. Moreover, the solutions for Q TED are developed on the basis of a complex frequency approach with the appropriate material indices. The effects of material length scale parameters, material performance indices, mechanical boundary conditions (clamped-clamped, simply supported, and cantilever types), mode switching, and plane stress/strain conditions on Q TED and Lc are analyzed. Numerical results are extracted from the analytical expressions by using MATLAB R2015a to quantify thermoelastic energy dissipation. The numerically computed Q TED and L c values are fully investigated to design high-performance resonators. The analyses verify that Q TED is enhanced by optimizing the structural material and augmenting the material length scale parameter. The material order in which Q TED is enhanced is the same for classical theories and MCST, i.e., it is inversely related to the TED index parameter. The influences of boundary types and mode switching on Q TED are relatively less in accordance with the analysis. The effect of plane stress condition compared with that of plane strain condition on Q TED is also remarkable. The L c of the beam is determined to be dependent on the thermal diffusion length of the material used. From an adequate material point of view, poly-silicon has been proven to provide the maximum quality factor while silicon carbide yields the maximum L c . These observations are significant and extremely helpful when designing low-loss micro/nanobeam resonators with superior performance by suitably selecting their geometry and structural materials.

Development of Self-lubricating Nickel Based Composite Clad using Microwave Heating in Improving Resistance to Wear at Elevated Temperatures

G. Suresh,M. R. Ramesh,M. S. Srinath 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

This paper reports on a study of the high-temperature tribological performance of self-lubricating nickel-based compositeclad. A porous and crack free clad containing matrix, reinforcement, and lubricant phase is developed on titanium 31 alloyusing microwave irradiation. The microstructure of both NiCrSiB/WC and NiCrSiB/WC/Ag/BaF2 clad revealed very goodmetallurgical bonding with the substrate. The average microhardness of NiCrSiB/WC and NiCrSiB/WC/Ag/BaF2 clad is710.58 HV and 650.25 HV respectively, is comparatively higher than the titanium 31 substrate (320 HV). The addition of Agand BaF2solid lubricants in the clad endowing clad to operate at a broad temperature range. Compared with the NiCrSiB/WCclad, solid lubricant encapsulate clad has shown very low friction coefficient and wear rates. The sliding wear characteristicsof the clad were investigated by varying load and temperatures. The results revealed that oxide phases (NiO and Cr3O)andlubricant phases (Ag and BaWO4)formed at low and high temperatures are adequate to reduce delamination and material loss.

Electrochemical synthesis and surface protection of polypyrrole-CeO₂ nanocomposite coatings on AA2024 alloy

Kumar, A. Madhan,Babu, R. Suresh,Ramakrishna, Suresh,de Barros, Ana L.F. Elsevier 2017 Synthetic metals Vol.234 No.-

<P><B>Abstract</B></P> <P>A facile approach based on electrochemical polymerization was used to synthesize polypyrrole/CeO<SUB>2</SUB> (PPy/CeO<SUB>2</SUB>) nanocomposite on an AA2024 alloy surface. CeO<SUB>2</SUB> nanoparticles (NPs) embedded in the PPy matrix were observed using FESEM micrographs with EDX analysis. IR and UV–vis spectroscopy were used to characterize the synthesized PPy/CeO<SUB>2</SUB> nanocomposite. The Raman spectra reflected the interactions between the π-conjugated structure of PPy and CeO<SUB>2</SUB> NPs. TGA thermograms revealed improved thermal stability of the synthesized nanocomposite and were used to determine the amount of nano ceria incorporated in the PPy matrix. The electrochemical corrosion behavior of the coated alloys in 0.6M NaCl solution was examined through potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) measurements. From these electrochemical studies, a larger shift of E<SUB>corr</SUB> in the positive direction with a high amount of CeO<SUB>2</SUB> in the nanocomposite was obtained, as well as a maximum corrosion protection efficiency of 99.64% by incorporating 3% of CeO<SUB>2</SUB> NPs in the PPy coatings. EIS studies also confirmed the enhanced corrosion protection behavior of PPy/CeO<SUB>2</SUB> coatings with higher R<SUB>ct</SUB>, R<SUB>f</SUB> and lower CPE<SUB>dl</SUB> values compared to those of pure PPy coatings. The results showed that the PPy coatings with CeO<SUB>2</SUB> nanoparticles can be potential coating materials for the corrosion protection of AA2024 alloys substrates.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polypyrrole coatings with nanoceria were prepared through electrochemical route. </LI> <LI> Raman studies confirm the interaction between π-conjugated PPy & nano CeO<SUB>2</SUB>. </LI> <LI> TGA reveals improved thermal stability of the synthesized nanocomposite. </LI> <LI> Uniform distribution of nano CeO<SUB>2</SUB> was confirmed by EDX mapping analysis. </LI> <LI> Corrosion test confirms better surface protection of PPy/Ce than pure PPy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

New Unsymmetric Dinuclear Copper(II) Complexes of Trans-disubstituted Cyclam Derivatives: Spectral, Electrochemical, Magnetic, Catalytic, Antimicrobial, DNA Binding and Cleavage Studies

R. Prabu,A. Vijayaraj,R. Suresh, L. Jagadish,V. Narayanan,L. Jagadish,V. Kaviyarasan 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.5

Six new binuclear copper(II) complexes have been prepared by template condensation of the dialdehydes 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-a) and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-b) with appropriate aliphatic diamines, and copper(II) perchlorate. The structural features of the complexes have been confirmed by elemental analysis, IR,UV-vis and mass spectra etc. The electrochemical behavior of all the copper(II) complexes show two irreversible one electron reduction process. The room temperature magnetic moment studies depict the presence of an antiferromagnetic interaction in the binuclear complexes. The catechol oxidation and hydrolysis of 4-nitrophenylphosphate were carried out by using the complexes as catalyst. The antimicrobial screening data show good results. The binding of the complexes to calf thymus DNA (CT DNA) has been investigated with absorption and emission spectroscopy. The complex [Cu2L^(1a)] displays significant cleavage property of circular plasmid pBR322 DNA in to linear form. Spectral, electrochemical, magnetic and catalytic studies support the distortion of the copper ion geometry that arises as the macrocyclic ring size increases.

Experimental Analysis and Mechanical Properties of Fly-ash Loaded E-Glass Fiber Reinforced IPN (Vinylester/polyurethane) Composite

R. Ganesamoorthy,G. Suresh,K.R. Padmavathi,J. Rajaparthiban,R. Vezhavendhan,G. Bharathiraja 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10

The influence of lignite flyash into the interpenetrating polymer network (IPN) matrix is thoroughly investigatedin this study. The standard weight ratio of E-Glass fiber have been chosen as the reinforcement into the IPN (vinylester/polyurethane) matrix, along with the varying loading of flyash as 0 %, 1 %, 3 %, 5 %, 7 %, 9 % (wt. ratio) respectively,fabricated through the hand lay-up technique. In order to completely understand the physical properties of the flyash loadedIPN composite (E-glass fiber reinforcement) specimen’s tests like differential thermal analysis (DTA), Tensile, Flexural,Compression, Impact, HDT (Heat Deflection Test), and wear test is performed. It was interesting to note that, upon loadingthe flyash into the matrix, the test result confirms that, there was a precipitous increase in the physical strength of all thespecimens’ up to the level of 5 % flyash loading except compressive and Barcoal hardness. Moreover to completely knowabout the bonding and de-bonding strength (flyash & matrix) of the fractured surfaces scanning electron microscope (SEM)analysis has been carried out. Out of all, the 5 % flyash loaded specimens have showed unique characteristics in physicalstrength, wear resistance and enhanced thermal stability as compared with the remaining set of flyash loaded samples.

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.

Pre clinical studies of Streblus asper Lour in terms of behavioural safety and toxicity

R. B. Suresh Kumar,A. Puratchikodi,Angelene Prasanna,Narayan Dolai,Piyali Majumder,U. K. Mazumder,P. K. Haldar 경희대학교 융합한의과학연구소 2011 Oriental Pharmacy and Experimental Medicine Vol.11 No.4

Streblus asper Lour (Family: Moraceae) is a medicinal plant wildly grows in most part of Asian countries. It has many traditional uses like leprosy, piles,diarrhoea, dysentery, elephantiasis, cancer etc. This present study was relates in terms of behavioural safety and toxicity studies of methanol and petroleum ether extracts of S. asper. Brine Shrimps lethality bioassay method was established for the present study and cytotoxicity was reported in terms of 50% lethality concentration (LC_(50)). Different concentrations of drug solutions were added to the Brine Shrimps, surviving shrimps were counted after 24 h and 50% lethality concentration (LC_(50)) were assessed. Acute toxicity was studied on Swiss albino mice after single dose. Sub-Chronic toxicity was performed for 28 days and assessed with biochemical and histopathological parameters. On cytotoxicity studies of brine shrimps it was found methanol extract of S. asper (MESA) was weakly toxic, may be due to the presence of cardiac glycosides and bioactive compounds, however petroleum ether extract of S. asper (PESA) was non toxic. But, in case of acute and sub-acute toxicity study both extracts were found to be non-toxic.

Hard Carbon and Carbon Nanotube Composites for the Improvement of Low-Voltage Performance in Na Ion Batteries

Suresh Babu, R.,Pyo, Myoungho The Electrochemical Society 2014 Journal of the Electrochemical Society Vol.161 No.6

<P>In this work, we report the facile synthesis of sugar hard carbon (SHC)/multi-walled carbon nanotube (MWNT) composites (SHC/MWNT) and comparisons of electrochemical performance with that of pristine SHC when used as anodes in sodium ion batteries (SIBs). Composites with various contents of MWNTs were prepared via the simple mechanical mixing of MWNTs with a SHC precursor, to control the nanopore density and enhance the reversible sodium insertion/desertion at low charge/discharge (C/D) voltages. The incorporation of well-dispersed MWNTs in the SHC media decreased the crystallite sizes of the SHC and increased the meso-to-macropore densities in the composites, which eventually contributed to an improvement in the reversible capacity and cyclability of the composite. At the optimal MWNT content (5%), the composite showed a reversible capacity of 300 mAh·g<SUP>−1</SUP> at 20 mA·g<SUP>−1</SUP>, in contrast to 221 mAh·g<SUP>−1</SUP> for the SHC. This trend was maintained after 50 C/D cycles, delivering a high capacity of 280 mAh·g<SUP>−1</SUP>, relative to 220 mAh·g<SUP>−1</SUP> for the SHC. The noticeable improvement for Na storage capability in the SHC/MWNT mostly resulted from an increase of nanopore density, which extended the low-voltage plateau for great reversible capacity and high capacity retention, and also contributed to an enhancement in rate capability.</P>

New Unsymmetric Dinuclear Copper(II) Complexes of Trans-disubstituted Cyclam Derivatives: Spectral, Electrochemical, Magnetic, Catalytic, Antimicrobial, DNA Binding and Cleavage Studies

Prabu, R.,Vijayaraj, A.,Suresh, R.,Jagadish, L.,Kaviyarasan, V.,Narayanan, V. Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.5

Six new binuclear copper(II) complexes have been prepared by template condensation of the dialdehydes 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-a) and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-b) with appropriate aliphatic diamines, and copper(II) perchlorate. The structural features of the complexes have been confirmed by elemental analysis, IR, UV-vis and mass spectra etc. The electrochemical behavior of all the copper(II) complexes show two irreversible one electron reduction process. The room temperature magnetic moment studies depict the presence of an antiferromagnetic interaction in the binuclear complexes. The catechol oxidation and hydrolysis of 4-nitrophenylphosphate were carried out by using the complexes as catalyst. The antimicrobial screening data show good results. The binding of the complexes to calf thymus DNA (CT DNA) has been investigated with absorption and emission spectroscopy. The complex [$Cu_2L^{1a}$] displays significant cleavage property of circular plasmid pBR322 DNA in to linear form. Spectral, electrochemical, magnetic and catalytic studies support the distortion of the copper ion geometry that arises as the macrocyclic ring size increases.