Zinc Metal Solubilization by Gluconacetobacter diazotrophicus and Induction of Pleomorphic Cells

( Saravanan ),( Venkatakrishnan Sivaraj ),( Jabez Osborne ),( Munusamy Madhaiyan ),( Lazar Mathew ),( Jong Bae Chung ),( Ki Sup Ahn ),( Tong Min Sa ) 한국미생물생명공학회 2007 Journal of microbiology and biotechnology Vol.17 No.9

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.

ZnO nanoparticles with different concentrations inside organic solar cell active layer

Saravanan, Shanmugam,Ismail, Yasser A.M.,Silambarasan, Murugesan,Kishi, Naoki,Soga, Tetsuo Techno-Press 2016 Advances in energy research Vol.4 No.4

In the present work, ZnO nanoparticles (NPs) have been dispersed alone in the same solvent of the active layer for improving performance parameters of the organic solar cells. Different concentrations of the ZnO NPs have been blended inside active layer of the solar cell based on poly(3-hexylthiophene) (P3HT), which forms the hole-transport network, and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which forms the electron-transport network. In the present investigations, the ZnO NPs may represent an efficient tool for improving light harvesting through light scattering inside active layer, electron mobility, and electron acceptance strength which tend to improve photocurrent and performance parameters of the investigated solar cell. The fill factor (FF) of the ZnO-doped solar cell increases nearly 14% compared to the non-doped solar cell when the doping is 50%. The present investigations show that ZnO NPs improve power conversion efficiency of the solar cell from 1.23% to 1.64% with increment around 25% that takes place after incorporation of 40% as a volume ratio of the ZnO NPs inside P3HT:PCBM active layer.

An in silico approach to evaluate the polyspecificity of Escherichia coli methionyl tRNA synthetase

Saravanan prabhu NADARAJAN,Sam MATHEW,Hyungdon YUNE 한국생물공학회 2012 한국생물공학회 학술대회 Vol.2012 No.4

Oral glucose tolerance test for preoperative assessment of liver function in liver resection

Saravanan Manickam Neethirajan,Raghavendra Rao Rachapoodivenk 한국간담췌외과학회 2017 Annals of hepato-biliary-pancreatic surgery Vol.21 No.1

Backgrounds/Aims: We intended to determine the role of the Oral glucose tolerance test (OGTT), in addition to volumetry, in preoperative assessment of patients undergoing liver resection. Methods: This was a prospective study conducted at a tertiary care hospital, between February 2009 and February 2011. OGTT curve (parabolic/linear), linearity index (LI) and Parenchymal Hepatic Resection Rate (PHRR) were correlated with postoperative outcomes in terms of postoperative liver failure (PLF), by 50-50 criteria, morbidity, mortality and hospital stay. Results: Of the 33 patients included in the study, 23 (69.7%) patients underwent major liver resections. Hepatocellular carcinoma (30.3%) was the leading indication. The overall postoperative morbidity rate was 72.7%, but major complications occurred in 3 (9.1%) patients only. There was no 90-day mortality. The 50-50 criteria were met by 3 patients undergoing major resection. Significant correlation was noted between the linear OGTT curve and the overall hospital stay (12.1 days vs. 9.6 days in parabolic; p=0.04). Patients with linear OGTT met the 50-50 criteria more often (18%) than those having a parabolic curve (4.5%; p=0.25). Although the OGTT was more often linear with occurrence of morbidity (41.7% vs 11.1%), major morbidity (66.7% vs 30%) and PLF by 50-50 criteria (66.7% vs 30%), it was not statistically significant. The linearity index was marginally lower (0.9 vs 1.2) in the presence of major morbidity and PLF by 50-50 criteria. Conclusions: Linear OGTT affects the PLF and major morbidity, therein impacting the hospital stay. OGTT LI and PHRR can help predict postoperative outcome for a given extent of liver resection.

Superhydrophobic and Self-Cleaning Natural Leaf Powder/Poly(methylhydroxysiloxane) Hybrid Micro-Nanocomposites

Saravanan Nagappan,하창식 한국고분자학회 2014 Macromolecular Research Vol.22 No.8

Superhydrophobic and self-cleaning hybrid micro-nanocomposite was prepared using a tree leaf (Ailanthusaltissima) powder and polysiloxane. The functional group and the chemical compositions in the hybrid micronanocompositeswere analyzed by Fourier transform infra-red spectroscopy, 29Si cross polarization magic anglespinning nuclear magnetic resonance spectroscopy, X-ray diffraction pattern and X-ray photoelectron spectroscopy. The composites showed micro-nano hierarchical surface morphology and excellent superhydrophobicity on anysubstrate, regardless of the coating processes (drop coating, spin coating and dip coating, followed by solventevaporation). The surface maintained the superhydrophobicity at high temperatures (400-500 ºC) and becamesuperhydrophilic at 600 ºC. The prepared hybrids have a mesoporous structure, and excellent non-stick and selfcleaningproperties.

Long-term exposure to waterborne nonylphenol alters reproductive physiological parameters in economically important marine fish

Saravanan, Manoharan,Nam, Sang-Eun,Eom, Hye-Jin,Lee, Do-Hee,Rhee, Jae-Sung Elsevier 2019 COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLO Vol.216 No.-

<P><B>Abstract</B></P> <P>Low concentrations of nonylphenol (NP) in aquatic environment can induce drastic effects on the endocrine system in animals. In this study, we examined the modulatory effects of NP on reproductive and physiological parameters in juveniles of the red seabream and black rockfish following waterborne NP exposure (0, 1, 10, and 50 μg L<SUP>−1</SUP>) for 60 days. In red seabream exposed to 50 μg L<SUP>−1</SUP> NP, plasma levels of 17β-estradiol (E2) and 11-ketotestosterone (11-KT) were significantly lower at 30 and 60 days, while E2 levels were slightly higher in 10 μg L<SUP>−1</SUP>-exposed individuals at day 30. Similarly, significantly lower levels of E2 and 11-KT were observed in 10 and 50 μg L<SUP>−1</SUP>-exposed black rockfish at 60 days, whereas the E2 level was higher in 1 μg L<SUP>−1</SUP>-exposed individuals at day 30. After exposure to NP, plasma and mRNA levels of vitellogenin (VTG) were significantly higher in both species at 30 and 60 days, similar to the inducible effects from synthetic estrogen. Plasma cortisol levels were significantly elevated by relatively higher concentrations of NP (10 and 50 μg L<SUP>−1</SUP>) at 30 and 60 days. Finally, 60 days of exposure of 50 μg L<SUP>−1</SUP> NP significantly decreased the gonadosomatic index (GSI) and increased the hepatosomatic index (HSI) in both species. The results obtained from this study provide an evidence of the endocrine disrupting potential of waterborne NP on early stages of economically important marine fish. The NP-triggered endocrine modulation can induce effects on the development of reproductive and metabolic organs in fish species.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Direct evidence on accumulation of waterborne NP in marine fish blood. </LI> <LI> Strong endocrine disruption potential of NP on juvenile stage of marine fish. </LI> <LI> Analysis of NP-triggered stress induction and modulation of somatic parameters. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Highly Transparent, Hydrophobic Fluorinated Polymethylsiloxane/Silica Organic-Inorganic Hybrids for Anti-Stain Coating

Saravanan Nagappan,최면천,성기주,박성수,Madhappan Santha Moorthy,추상욱,이원기,하창식 한국고분자학회 2013 Macromolecular Research Vol.21 No.6

Organic-inorganic hybrids were synthesized using polymethylhydrosiloxane, 2,2,3,4,4,4 hexafluorobutylmethacrylate and tetraethyl orthosilicate with a platinum catalyst. The resulting hybrids formed transparent thin films on glass substrate by spin coating. The functional groups, molecular structure, surface morphology and chemical composition of the hybrids were analyzed by 1H nuclear magnetic resonance spectroscopy (NMR), 29Si MASNMR spectroscopy, high resolution scanning electron microscopy with energy-dispersive X-ray spectroscopy,atomic force microscopy, and X-ray photoelectron spectroscopy. The thermal stability, mechanical scratch resistance,static and advancing/receding dynamic contact angles were measured by thermogravimetry, the pencil hardness test and a drop shape analysis system. The prepared hybrid thin films exhibited good transparency, hydrophobicity,as well as good mechanical and anti-stain properties.

Recent progress for direct synthesis of dimethyl ether from syngas on the heterogeneous bifunctional hybrid catalysts

Saravanan, K.,Ham, Hyungwon,Tsubaki, Noritatsu,Bae, Jong Wook Elsevier 2017 Applied catalysis. B, Environmental Vol.217 No.-

<P><B>Abstract</B></P> <P>The recent rising demand of renewable energies and climate changes has been driving intensive academic researches into new chemical routes to sustainable and clean fuel productions in order to meet the demands of industrial evolution by solving energy crisis due to limited fossil fuel reservoirs and increasing environmental pollutants. Dimethyl ether (DME) is a multi-purpose synthetic fuel and chemical that can be used as an excellent alternative to diesel fuel and liquefied petroleum gas (LPG). The present review paper briefly provides an overview of the recent developments for a direct synthesis of DME from synthesis gas (syngas, CO+H<SUB>2</SUB>) over some hybridized bifunctional heterogeneous catalysts composed of copper-based hydrogenation catalysts with solid acid components such as alumina or zeolites mainly, where the catalytic activities significantly depend on its properties influenced by synthesis protocols, porosities, surface areas, interactions of active metals with supports, distributions of metal particles on the supports and so on. We have also briefly covered the hydrogenation of CO<SUB>2</SUB>, a model reaction for the utilization of CO<SUB>2</SUB> containing in syngas, to produce DME and thereby significantly mitigate its environmental impacts. Furthermore, the catalytic performances of the direct synthesis of DME by hydrogenation of carbon oxides were explained in terms of the acid sites of the solid acid catalysts and surface area of metallic copper nanoparticles in the hybridized bifunctional catalysts with their preparation protocols.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dimethyl ether (DME) is a multi-purpose alternative synthetic fuel for diesel and liquefied petroleum gas. </LI> <LI> Recent direct DME synthesis from syngas was overviewed over hybridized bifunctional catalysts. </LI> <LI> Surface acidity and metallic sites for CO or CO<SUB>2</SUB> hydrogenation to DME are crucial factors. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Thermally Stable Superhydrophobic Polymethylhydrosiloxane Nanohybrids with Liquid Marble-Like Structure

Saravanan Nagappan,조남주,이원기,하창식 한국고분자학회 2017 Macromolecular Research Vol.25 No.5

We prepared novel hybrid materials by in situ self-hydroxylation and condensation of polymethylsiloxane (PMHS) with multi-walled carbon nanotubes (MWCNTs). The hybrid material showed superhydrophobic and non-stick properties, mesoporous structure, and liquid marble-like non-stick water droplet behavior. Moreover, we found that the in situ addition of MWCNTs to the PMHS would increase the thermal stability of the hybrid material. Thermal stability of the hybrid is enhanced by increasing the percentage of MWCNTs to the PMHS. The superhydrophobic hybrid powder covered non-stick water droplet showed anti-icing behavior for long time. The hybrids also showed oils sorption behavior and easy reusable property. The obtained results suggest that the thermally stable superhydrophobic hybrid mesoporous materials with anti-icing, oils sorption properties can be easily synthesized and used for various applications.