38 results on '"S. Sureshkumar"'
Search Results
2. Microbiological quality evaluation of aerobic and vacuum packed broiler chicken carcass under different frozen temperature storage
- Author
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S Sureshkumar, K Sivakumar, V Chandirasekaran, A Irshad, N Murali, and P Sivakumar
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Vacuum packed ,animal structures ,Chemistry ,Frozen temperature ,Significant difference ,Broiler ,food and beverages ,Microbiological quality ,Food science ,Vacuum packing ,Shelf life - Abstract
Freezing is the process of extending the shelf life of broiler chicken meat. Since frozen meat is getting popular among the consumers, a study was undertaken to estimate the psychrophilic count, Streptococcal count and yeast and mould count in the frozen broiler chicken meat samples stored at -12 oC, -18oC, -24oC under aerobic and vacuum packaging for one year. There is a significant difference between (P
- Published
- 2020
3. Di-butyltin(<scp>iv</scp>) complexes with azo-carboxylates: synthesis, characterization, crystal structures and their anti-diabetic assay
- Author
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Khaidem Kennedy Singh, Waldemar Maniukiewicz, S. Sureshkumar Singh, Keisham Surjit Singh, Paresh Debnath, and Lesław Sieroń
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Coordination sphere ,010405 organic chemistry ,chemistry.chemical_element ,General Chemistry ,Crystal structure ,010402 general chemistry ,Ring (chemistry) ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Trigonal bipyramidal molecular geometry ,Crystallography ,Bipyramid ,chemistry ,Octahedron ,Materials Chemistry ,Tin ,Coordination geometry - Abstract
Dibutyltin(IV) complexes 1–3 were synthesized by the reaction of either dibutyltin(IV) oxide or dibutyltin(IV) dichloride with azo-carboxylic acid ligands viz. 2/4-(2-hydroxynaphthylazo)-benzoic acids in different stoichiometric reaction ratios. The complexes were characterized by elemental analysis and UV, IR and multinuclear [1H, 13C and 119Sn]-NMR spectroscopy. The geometry and mode of coordination around tin atoms in the complexes in the solid state were determined by X-ray crystal structure analysis. Complex 1 exhibited a dinuclear structure with a distorted square-pyramidal geometry around each Sn atom. Compound 2 showed a bis[dicarboxylatotetraorganodistannoxane] type structure {[R2Sn(O2CR′)]2O}2 that contained a centrosymmetric Sn2O4 core in which the Sn2O2 ring was connected to the exo-cyclic tin atom through μ3-oxo O-atoms. The coordination geometry around exo- and endo-cyclic tin atoms was intermediate between square-pyramidal and trigonal bipyramidal and distorted octahedral, respectively. In 3, the coordination sphere around the tin atom adopted a skew-trapezoidal bipyramidal geometry. The 119Sn NMR study suggested a 5-coordinate structure in complexes 1 and 3 in the solution state, while in 2 the geometry around exo- and endo-cyclic tin atoms was found to be a five and six coordinate structure, respectively. Thus, the solid state structure of 1 and 2 is retained in solution, while in 3 the solid state structure is dissociated. The anti-diabetic activity of the complexes was also studied and the results of the assays showed significant activity of compound 2 compared to 1 and 3.
- Published
- 2020
4. Effects of the Inclusion of Dietary Organic Acid Supplementation with Anti-Coccidium Vaccine on Growth Performance, Digestibility, Fecal Microbial, and Chicken Fecal Noxious Gas Emissions
- Author
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S Sureshkumar, JH Park, and IH Kim
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Veterinary medicine ,Population ,SF1-1100 ,Feed conversion ratio ,Animal science ,Lactobacillus ,SF600-1100 ,Dry matter ,education ,Feces ,chemistry.chemical_classification ,Meal ,education.field_of_study ,growth performance ,biology ,broilers ,Gas emissions ,biology.organism_classification ,Animal culture ,QL1-991 ,chemistry ,Animal Science and Zoology ,Zoology ,Organic acid ,anti-coccidium - Abstract
A total of 792 conventional healthy 1-day-old Ross 308 broilers chicks (mixed gender) with average body weight of 42.30±1.14 g (mean ± SD) were used in the experiment, which lasted for 35 days. Chicks were randomly allotted into one of four treatment diets, each one having 11 replicate cages with 18 birds each, being fed corn-soybean meal (SBM) based diets. Dietary treatments were CON (basal diet with unvaccinated birds); OA = CON + 0.1% organic acids; ACB = CON + anti-coccidium vaccine; OAACV = CON + 0.1% organic acid + anti-coccidium vaccine. Significant results were observed, with improved body weight (p=0.059; 0.064; 0.034) during days 1-7, 8-21, and overall, respectively. Significant effects were also observed on the feed conversion ratio (p=0.037) through the overall experiment, with no effects on feed intake on OAACV as compared to other treatment groups. Total track digestibility of dry matter (p=0.049) improved significantly in the OAACV treatment group. Additionally, beneficial effects were observed in the OAACV treatment group, with improvements in fecal microbial population (increased lactobacillus) and reduced NH3 gas emissions. Broilers fed the OAACV treatment tended to display reduced drip loss in the meat samples analyzed on days 5 and 7 (p=0.067, 0.072). In summary, our findings revealed that dietary inclusion of organic acid supplementation with anti-coccidium had a beneficial effect on broilers affected by coccidian infection, also improving growth performance, digestibility, fecal Lactobacillus counts, and reducing NH3.
- Published
- 2021
5. Design of a potent anticancer lead inspired by natural products from traditional Indian medicine
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Mohane Selvaraj Coumar, Shu Yu Lin, Hsing Pang Hsieh, C. Suresh Yadav, P. R. Gajurel, Mariasoosai Ramya Chandar Charles, S. Sureshkumar Singh, Safiulla Basha Syed, Hemant Arya, and Sathananthan Kannadasan
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Biological Products ,0303 health sciences ,biology ,Traditional medicine ,Indian medicine ,030303 biophysics ,Drug target ,Clerodendrum colebrookianum ,Apoptosis ,General Medicine ,Molecular Dynamics Simulation ,biology.organism_classification ,Molecular Docking Simulation ,03 medical and health sciences ,chemistry.chemical_compound ,Aglycone ,chemistry ,Structural Biology ,Docking (molecular) ,Molecular Biology - Abstract
Among the plant constituents of Clerodendrum colebrookianum Walp., acteoside, martinoside, and osmanthuside β6 interact with ROCK, a drug target for cancer. In this study, aglycone fragments of these plant constituents (caffeic acid, ferulic acid, and p-coumaric acid) along with the homopiperazine ring of fasudil (standard ROCK inhibitor) were used to design hybrid molecules. The designed molecules interact with the key hinge region residue Met156/Met157 of ROCK I/II in a stable manner according to our docking and molecular dynamics simulations. These compounds were synthesized and tested in vitro in SW480, MDA-MB-231, and A-549 cancer cell lines. The most promising compound was chemically optimized to obtain a thiourea analog, 6a (IC50 = 25 µM), which has >3-fold higher antiproliferative activity than fasudil (IC50 = 87 µM) in SW480 cells. Treatment with this molecule also inhibits the migration of colon cancer cells and induces cell apoptosis. Further, SPR experiments suggests that the binding affinity of 6a with ROCK I protein is better than that of fasudil. Hence, the drug-like natural product analog 6a constitutes a highly promising new anticancer lead. Communicated by Ramaswamy H. Sarma
- Published
- 2019
6. Effect of Different Storage Conditions and Duration on Physico Chemical Characteristics of Chevon
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S. Karthikeyan, S. Sureshkumar, V. Chandirasekaran, and S. Karthika
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Animal science ,Chemistry ,Duration (project management) - Published
- 2019
7. Impedance Spectroscopy-Based Reduced Graphene Oxide-Incorporated ZnO Composite Sensor for H2S Investigations
- Author
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T. Subba Rao, V. Balasubramani, T. M. Sridhar, and S. Sureshkumar
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Materials science ,business.industry ,Graphene ,General Chemical Engineering ,Composite number ,Oxide ,Measure (physics) ,General Chemistry ,Article ,law.invention ,Dielectric spectroscopy ,lcsh:Chemistry ,chemistry.chemical_compound ,lcsh:QD1-999 ,chemistry ,law ,Optoelectronics ,business - Abstract
Electrochemical impedance spectroscopy (EIS) has been applied to measure the H2S gas response of the sensor fabricated on reduced graphene oxide (rGO)-incorporated nano-zinc oxide (n-ZnO) composites. These nanocomposites were prepared by a facile one-step solution route at room temperature. The structural, surface morphological, and elemental analyses of the composite material have been investigated. EIS was carried out to study the H2S gas-sensing properties of fabricated sensors. The developed sensor showed an optimal H2S gas response to various concentrations ranging from 2 to 100 ppm at 90 °C. The H2S gas-sensing performances of pure n-ZnO and various concentrations of rGO-incorporated n-ZnO were evaluated. The H2S gas-sensing results showed that n-ZnO/rGO composites exhibited high response when compared to pure n-ZnO. The enhanced H2S response was speculated to be ascribed due to two factors. First, rGO creates reactive sites for H2S molecule adsorption. Second, rGO has great electrical conductivity compared to n-ZnO that enables the active transport of electrons from H2S gas on interaction with the sensing layer, resulting in enhanced gas response at 90 °C temperatures.
- Published
- 2019
8. Meat and Fat Quality of Salem Black Goat meat Reared under Different Rearing Systems
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J. Muralidharan, P. Senthilkumar, S. Sureshkumar, and D. Jayanthi
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chemistry.chemical_classification ,Animal science ,chemistry ,food and beverages ,Soil Science ,Semi intensive ,Plant Science ,Biology ,Muscle fibre ,Proximate composition ,Agronomy and Crop Science ,Breed ,Polyunsaturated fatty acid - Abstract
Background: The work was carried out to complementary contribution to the comprehensive study of the recently recognised promising Salem Black goat breed’s meat quality raised under intensive and semi intensive systems at different age for both sexes. Methods: The study was conducted on sixty four, three months old Salem Black goat kids (32 males and 32 females) by allotting randomly as16 kids in each group in a 2 X 2 factorial design. Results: The pH value for meat was significantly (P less than 0.05) higher at 9 months male animals. Meat redness (a*) value increased and the lightness (L*) and yellowness (b*) values significantly (P less than 0.01) decreased with age. The shear force indicates that male had significantly (P less than 0.01) higher value. Meat at 6 months had significantly (P less than 0.01) higher sarcomere length. Hydroxyproline content was significantly (P less than 0.01) higher with lower muscle fibre diameter in intensively reared male kids meat. Acid insoluble ash, ether extract and PUFA contents were significantly (P less than 0.05) increased with age in meat. Intensively reared animals had significantly (P less than 0.05) low level of SFA and high level of PUFA, MUFA and PUFA/SFA ratio than semi-intensively reared animals. The intensively reared animal shows better meat quality, more nutritious than semi intensively reared animal meat.
- Published
- 2020
9. Synthesis and characterization of novel reduced graphene oxide supported barium niobate (RGOBN) nanocomposite with enhanced ferroelectric properties and thermal stability
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M. Vinolia, S. Sureshkumar, M. Infant Shyam Kumar, Eunice Jerusha, and S. Shahil Kirupavathy
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Nanocomposite ,Materials science ,Graphene ,Band gap ,Superlattice ,Oxide ,chemistry.chemical_element ,Barium ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Ferroelectricity ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,Thermal stability ,Electrical and Electronic Engineering ,0210 nano-technology - Abstract
Novel reduced graphene oxide/barium niobate (RGOBN) nanocomposites were synthesized by hydrothermal method. The microstructure and morphology of graphene oxide, barium niobate and reduced graphene oxide/barium niobate was analysed by X-ray diffraction (XRD), FTIR, FTRaman, high resolution scanning electron microscopy and EDAX. XRD analysis showed that Barium Niobate samples are in perovskite phases, and the lattice parameters a, b and c almost decreased linearly with the increase of graphene nanosheets. The optical studies reveal the band gap of the nanocomposite to be 2.86 eV. Thermal studies show that RGOBN has high thermal stability than graphene. The remanant polarization and coercive electric field (0.0892 µC cm−2, −10.81 kV cm−1) of RGOBN nanocomposite superlattices calculated using P–E curve showed the strong hybrid interactions between graphene and barium niobate (BN) by decreasing leakage current density from 10−7 to 10−8 Acm−2. Graphene when incorporated into BN nanocubes increased the ferroelectric property almost two times than pure BN nanostructures. The squareness of polarization is also calculated for RGOBN and compared with that of BN.
- Published
- 2018
10. Growth Performance of Large White Yorkshire Pigs Fed with Concentrate Diet Incorporated with Brewer’s Spent Grains, Moringa oleifera and Rice Gluten Meal
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D. Anandha Prakash Singh, S. Sureshkumar, Sivasubramanian Ramakrishnan, and S. Durga
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0106 biological sciences ,chemistry.chemical_classification ,Meal ,0402 animal and dairy science ,Large white ,04 agricultural and veterinary sciences ,Biology ,040201 dairy & animal science ,01 natural sciences ,Gluten ,Moringa ,Animal science ,chemistry ,010606 plant biology & botany - Published
- 2018
11. Synthesis, Characterization and Antidiabetic Activity of Some Water Soluble Zn(II) Complexes with (E)-N-(Thiophen-2-ylmethylene)anilines
- Author
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Khaidem Kennedy Singh, Debabrata Paria, Keisham Surjit Singh, Sajal Kundu, and S. Sureshkumar Singh
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Water soluble ,Chemistry ,General Chemistry ,Nuclear chemistry - Published
- 2018
12. Hydrophobic structural modification of chitosan and its impact on nanoparticle synthesis – A physicochemical study
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S. Sureshkumar, B. Venkatachalapathy, and B. Jothimani
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Polymers and Plastics ,Sonication ,Organic Chemistry ,Nanoparticle ,macromolecular substances ,02 engineering and technology ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Nanomaterials ,carbohydrates (lipids) ,Chitosan ,chemistry.chemical_compound ,chemistry ,Chitin ,Chemical engineering ,Nano ,Materials Chemistry ,engineering ,Organic chemistry ,Amine gas treating ,Biopolymer ,0210 nano-technology - Abstract
Chitin is a naturally occurring fully N-acylated biopolymer which cannot be converted into nanomaterial easily due to its inherent rigidity and chemical inertness. These properties limit the utility of chitin in nanomaterial-based applications. Therefore, our aim in the present work was, to prepare chitin like fully N-acylated derivatives with a hydrophobic moiety and study the impact on nanoparticles synthesis. We report such a fully substituted derivative, N-(Thiophene-2-acetyl)chitosan, its characterization and physicochemical studies of the nanoparticles synthesized. The study confirms that the hydrophobic structural modification of chitosan improves the processability of the material and defines the nanoparticles synthesis. This kind of organic nanoparticles, stable under wide pH range due to amine group protection of chitosan, can be used as nano- reinforcement material to enhance the properties of various composites.
- Published
- 2017
13. Synthesis and Characterization of Surface Modified, Fluorescent and Biocompatible ZnS Nanoparticles with a Hydrophobic Chitosan Derivative
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S. Sureshkumar, B. Jothimani, and B. Venkatachalapathy
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Sociology and Political Science ,Biocompatibility ,Clinical Biochemistry ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Chitosan ,chemistry.chemical_compound ,Rhodamine B ,Mucoadhesion ,Spectroscopy ,technology, industry, and agriculture ,021001 nanoscience & nanotechnology ,Zinc sulfide ,0104 chemical sciences ,Clinical Psychology ,chemistry ,Chemical engineering ,Surface modification ,0210 nano-technology ,Law ,Social Sciences (miscellaneous) ,Macromolecule - Abstract
The introduction of a hydrophobic moiety on chitosan enhances the self-assembling properties, mucoadhesion, the permeability of the macromolecule and aids in target specific delivery. Our group synthesized a hydrophobic trans N-(6,6-Dimethyl-2-hepten-4-ynyl)chitosan derivative (CSD) and studied the surface modification of ZnS nanoparticles in a single pot reaction. X-ray diffraction studies and FESEM imaging confirms the nano size and morphology of the surface modified Zinc sulfide nanoparticles (ZnS-CSD NPs). The proposed ZnS-CSD NPs showed excellent emission at 457 nm. Photostability studies indicate that the surface modified ZnS-CSD NPs possess better photostability than Rhodamine B and FITC. Cell viability tests confirmed the biocompatibility of the modified nanoparticles. All these features of ZnS- CSD NPs makes these candidates an excellent choice in a wide range of in vitro or in vivo studies as fluorescent biological labels.
- Published
- 2017
14. Convective heat transfer in a nanofluid-saturated porous cavity with the effects of various aspect ratios and thermal radiation
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M. Muthtamilselvan and S. Sureshkumar
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Convection ,Finite volume method ,Convective heat transfer ,Chemistry ,Darcy number ,Thermodynamics ,02 engineering and technology ,Mechanics ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Nusselt number ,010305 fluids & plasmas ,Electronic, Optical and Magnetic Materials ,Physics::Fluid Dynamics ,Nanofluid ,Thermal radiation ,0103 physical sciences ,Heat transfer ,Materials Chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
This article reports a fundamental numerical study made to understand the effects of aspect ratio and thermal radiation in a porous cavity filled with nanofluid. The vertical walls of the cavity are insulated while the bottom and top horizontal walls are maintained at constant but different temperatures. The governing equations are solved by using a finite volume method (FVM) on a uniformly staggered grid system. The effects of the pertinent parameters, namely, Richardson number, aspect ratio, radiation parameter, Darcy number, and solid volume fraction are investigated in detail. The computational results are presented in the form of isotherm, streamline, midplane velocity, and Nusselt numbers. The effects of solid volume fraction and thermal radiation are not significant for and 0.5. In general, the results indicate that the convective mechanism is suppressed by radiation, which causes a reduction in the overall heat transfer rate. It is also found that the overall heat transfer rate increases w...
- Published
- 2016
15. Chitosan mediated gold nanoparticles against pathogenic bacteria, fungal strains and MCF-7 cancer cells
- Author
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Franck Quero, A.K. Kumaraguru, R. Kalaivani, Manoj Singh, Muthuchamy Maruthupandy, Thillaichidambaram Muneeswaran, S. Sureshkumar, C.M. Ramakritinan, and M. Anand
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Cell Survival ,Metal Nanoparticles ,Antineoplastic Agents ,02 engineering and technology ,Microbial Sensitivity Tests ,Microscopy, Atomic Force ,Biochemistry ,Chitosan ,03 medical and health sciences ,chemistry.chemical_compound ,Dynamic light scattering ,Anti-Infective Agents ,Structural Biology ,Spectroscopy, Fourier Transform Infrared ,Animals ,Humans ,MTT assay ,Surface plasmon resonance ,Fourier transform infrared spectroscopy ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,Bacteria ,Cell Death ,Acridine orange ,technology, industry, and agriculture ,Fungi ,General Medicine ,021001 nanoscience & nanotechnology ,chemistry ,Colloidal gold ,MCF-7 Cells ,Spectrophotometry, Ultraviolet ,Gold ,0210 nano-technology ,Ethidium bromide ,Nuclear chemistry - Abstract
In the present study, we report cytotoxic and antimicrobial potential of gold nanoparticles (Au NPs) synthesized using chitosan derived from squilla shell wastes. Here we adopted ecofriendly approach for the synthesis of Au NPs and characterized them using UV–visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, atomic force microscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) methods. The UV–visible spectroscopic analysis revealed an absorption peak at 529 nm, which represents the Surface Plasmon Resonance of Au NPs. TEM analysis showed that the biosynthesized Au NPs were spherical in shape with an average size of 80 to 82 nm. Interestingly, the biosynthesized Au NPs showed antimicrobial activity against selected Gram-positive and negative bacterial isolates and also showed activity against fungal pathogens. Further, the cytotoxic effect of the synthesized Au NPs against MCF-7 cell lines was assessed by MTT assay with IC50 value of 250 μg mL−1. In addition, double staining of treated MCF-7 cells with acridine orange and ethidium bromide shows that the Au NPs exert apoptosis mediated cytotoxicity.
- Published
- 2019
16. Synthesis, structural characterization, Hirshfeld surface analysis and in vitro-antimicrobial activities of triphenyltin (IV) compounds of azo-carboxylates derived from 2- or 4-amino benzoic acids and naphthalen-1 or 2-ol
- Author
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Lesław Sieroń, Waldemar Maniukiewicz, Paresh Debnath, S. Sureshkumar Singh, Keisham Surjit Singh, Swastika Sharma, and Pratima Debnath
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010405 organic chemistry ,Organic Chemistry ,Tetrahedral molecular geometry ,chemistry.chemical_element ,Nuclear magnetic resonance spectroscopy ,Crystal structure ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Analytical Chemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Trigonal bipyramidal molecular geometry ,Monomer ,chemistry ,Hydroxide ,Antibacterial activity ,Tin ,Spectroscopy - Abstract
Synthesis of three new triphenyltin(IV) compounds 1–3 were reported by the reaction of azo-carboxylic acid ligands viz.2/4-(2-hydroxynaphthylazo)-benzoic acids [compounds 1 and 2] or 2-(4-hydroxynaphthylazo)-benzoic acid [compound 3] with triphenyltin(IV) hydroxide. The compounds were completely characterized with the help of elemental analysis, IR and multinuclear [1H, 13C and 119Sn]-NMR spectroscopy. The mode of coordination and geometry around tin atoms in compounds 1 and 3 were determined by X-ray crystallography. Compounds 1 and 3 exhibited monomeric structure with intermediate deformation between the trigonal bipyramidal and square-pyramidal geometry or distorted tetrahedral geometry around tin atom respectively. Hirshfeld surface analysis for both structures was also performed. The main difference between 1 and 3 is observed for stacking interactions. 119Sn NMR spectral study of all the compounds suggested that the compounds adopted 4-coordinated tetrahedral structures in solution. The antimicrobial activities of the compounds showed effective antibacterial activity against S. aureus and antifungal activity against F. oxysporum. The antimicrobial activity of these compounds was found to be higher than the tested standard compounds against some selected microbes.
- Published
- 2021
17. Synthesis, characterisation and anti-diabetic activities of triorganotin(IV) azo-carboxylates derived from amino benzoic acids and resorcinol: Crystal structure and topological study of a 48 membered macrocyclic-tetrameric trimethyltin(IV) complex
- Author
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Manojit Roy, Janmoni Kalita, Subhadip Roy, Keisham Surjit Singh, and S. Sureshkumar Singh
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010405 organic chemistry ,Ligand ,Crystal structure ,Nuclear magnetic resonance spectroscopy ,010402 general chemistry ,Topology ,Resonance (chemistry) ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Trigonal bipyramidal molecular geometry ,chemistry.chemical_compound ,Monomer ,chemistry ,Materials Chemistry ,Carboxylate ,Physical and Theoretical Chemistry ,Triethylamine - Abstract
Triorganotin(IV) complexes of azo-carboxylic acids derived from amino benzoic acids and resorcinol were synthesized by the reaction of 2/4-(2,4-dihydroxy-phenylazo)-benzoic acids with appropriate triorganotin(IV) chlorides [R = Me (1 and 3), Ph (2 and 4) and Bu (5)] in presence of triethylamine. The characterisation of the complexes was accomplished by elemental analyses, UV, IR and multinuclear (1H, 13C and 119Sn) NMR spectroscopy. Structure of compound 3 was established by X-ray crystal structure analysis. X-ray crystal structure of 3 revealed that the compound exhibits a 48 membered macrocyclic-tetrameric structure with trigonal bipyramidal geometry around the tin atoms in which the three methyl groups occupy the equatorial positions while the apical positions are being occupied by the oxygen atom of carboxylate group of one ligand and the phenoxide oxygen atom of another ligand. The coordination network in 3 has also been analysed from the topological viewpoint. All the complexes display a sharp singlet 119Sn resonance in the range specified for the four coordinate structures suggesting that complexes have tetrahedral structures in solution. The five coordinate structure of the complexes in solid state dissociated into monomeric species with four coordinate structures in solution. Anti-diabetic activities of the complexes were studied and the results showed that the compounds 2, 3 and 4 exhibited effective activity even higher than the standard compound.
- Published
- 2016
18. Synthesis and characterization of gadolinium-doped ZnSe quantum dots for fluorescence imaging of cancer cells
- Author
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S. Sureshkumar, B. Venkatachalapathy, T. M. Sridhar, and B. Jothimani
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Fluorescence-lifetime imaging microscopy ,Materials science ,General Chemical Engineering ,Gadolinium ,Doping ,technology, industry, and agriculture ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,Characterization (materials science) ,chemistry.chemical_compound ,chemistry ,Quantum dot ,Cancer cell ,0210 nano-technology ,Ethylene glycol - Abstract
Gadolinium-doped ZnSe (Gd:ZnSe) quantum dots (Qds) were synthesized using ethylene glycol as a stabilizing agent. The fluorescence spectrum exhibited an emission peak at 435 nm for ZnSe, whereas the Gd-doped ZnSe exhibited a green emission at 547 nm. In vitro imaging studies of MCF-7 cancer cells were carried out using fluorescent probes constructed using Gd-ZnSe folate.
- Published
- 2016
19. Synthesis, characterization and anti-diabetic assay of diorganotin(<scp>iv</scp>) azo-carboxylates: crystal structure and topological studies of azo-dicarboxylic acid ligand and its cyclic tetranuclear dimethyltin(<scp>iv</scp>) complex
- Author
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Janmoni Kalita, Keisham Surjit Singh, Manojit Roy, Subhadip Roy, and S. Sureshkumar Singh
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chemistry.chemical_classification ,010405 organic chemistry ,Ligand ,chemistry.chemical_element ,General Chemistry ,Crystal structure ,010402 general chemistry ,Topology ,Ring (chemistry) ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Trigonal bipyramidal molecular geometry ,chemistry.chemical_compound ,Dicarboxylic acid ,chemistry ,Materials Chemistry ,Molecule ,Tin ,Benzoic acid - Abstract
Diorganotin(IV) complexes with (E)-5-((2-carboxyphenyl)diazenyl)-2-hydroxy benzoic acid [H3L] were synthesized by reacting the sodium salt of the azo-dicarboxylic acid ligand [Na2HL] with an appropriate diorganotin(IV) dichloride [R = 1 (Me), 2 (Bu) and 3 (Ph)] in anhydrous methanol. The complexes were characterized using elemental analysis, UV, IR, NMR and mass spectrometry. 119Sn NMR study of complexes 1 and 2 indicates the presence of exo-and endo-cyclic tin atoms in the complexes and both the tin atoms are suggested to have 5-coordinate geometry in solution; in complex 3, a single 119Sn-resonance was observed in the range specified for a 4-coordinate structure. The molecular structure of H3L and its dimethyltin(IV) complex {[Me2SnHLSnMe2]O}2 (1) were determined using X-ray crystallography. The structure of 1 reveals that the compound is a centro-symmetric cyclic tetranuclear tin complex which contains a Sn2O4 core. In the structure, the central Sn2O2 ring is connected to two exo-cyclic tin atoms by two μ3-oxo oxygen atoms. Each exo- and endo-cyclic tin atom exhibited a five coordinate distorted trigonal bipyramidal geometry and suggested that the five coordinate structure of the complex in the solid state is also retained in solution. Topological studies of the azo-dicarboxylic acid ligand [H3L] and its cyclic tetranuclear dimethyltin(IV) complex were also carried out. The H-bonding network in H3L has been topologically classified as 2-periodic three-dimensional KIa. For the molecular packing in 1, a multilevel topological description is provided. Finally, the complexes have been screened for α-glucosidase enzyme inhibition assay as an indicator for their anti-diabetic properties and the results of the tests showed that they had better anti-diabetic activity than the standard drug acarbose.
- Published
- 2016
20. Synthesis, characterization, crystal structures and anti-diabetic activity of organotin (IV) complexes with 2-(4-hydroxynaphthylazo)-benzoic acid
- Author
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Lesław Sieroń, Ray J. Butcher, Paresh Debnath, S. Sureshkumar Singh, Keisham Surjit Singh, Thokchom Sonia Devi, and Waldemar Maniukiewicz
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010405 organic chemistry ,Ligand ,chemistry.chemical_element ,Crystal structure ,Nuclear magnetic resonance spectroscopy ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Trigonal bipyramidal molecular geometry ,Pentagonal bipyramidal molecular geometry ,chemistry ,Materials Chemistry ,Molecule ,Carboxylate ,Physical and Theoretical Chemistry ,Tin - Abstract
Three new organotin(IV) complexes 1–3 were synthesized by the reaction of 2-(4-hydroxynaphthylazo)-benzoic acid with bis-tributyltin(IV) oxide (1), dibutyltin(IV) oxide (3) or trimethyltin(IV) chloride (2), respectively. The complete characterization of the complexes was accomplished by elemental analysis, IR and multinuclear [1H- and 13C- and 119Sn-] NMR spectroscopy. The crystal structures of all the complexes were elucidated with the help of X-ray single crystal diffraction analysis. The geometry around tin atoms in 1 and 2 was trigonal bipyramidal geometry where the equatorial plane was occupied by the three alkyl groups (Bu or Me) and the axial positions in 1 were being occupied by carboxylate and phenoxide oxygen atoms giving rise to a polymeric structure. In 2, a hydroxy oxygen atom bridges two tin atoms occupying axial position while the other axial positions in each tin atom were being occupied by a carboxylate oxygen atom or oxygen atom of a water molecule respectively thereby completing trigonal bipyramidal geometry. The structure of 3 was a di-nuclear complex with six-coordinate distorted skew trapezoidal and seven-coordinate pentagonal bipyramidal geometry around the tin atoms, respectively. In the dinuclear structure, one of the tin atoms is coordinated by a terminal azo-ligand while the other tin atom is coordinated by two terminal azo-ligands. In addition to this, another azo-carboxylate ligand bridges the two atoms in the dinuclear structure. The NMR study showed that in the solution the complexes 1 and 2 adopted four-coordinate geometry, while in 3 there is five-coordinate structure. Complexes 1 and 3 were screened for their antidiabetic activities against α-glucosidase enzyme and results of the assay found that compound 3 exhibited significant inhibition activity.
- Published
- 2020
21. Synthesis, structural characterization and antimicrobial activities of triorganotin(IV)azo-carboxylates derived from ortho/para-amino benzoic acids and β-naphthol
- Author
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Waldemar Maniukiewicz, Lesław Sieroń, S. Sureshkumar Singh, Keisham Surjit Singh, Tage Yama, Ray J. Butcher, Ankit Das, and Paresh Debnath
- Subjects
chemistry.chemical_classification ,chemistry.chemical_element ,Crystal structure ,Medicinal chemistry ,Dissociation (chemistry) ,Inorganic Chemistry ,chemistry.chemical_compound ,Trigonal bipyramidal molecular geometry ,chemistry ,Materials Chemistry ,Amine gas treating ,Carboxylate ,Physical and Theoretical Chemistry ,Tin ,Single crystal ,Alkyl - Abstract
Triorganotin (IV) complexes 1–3 were synthesized by the reaction of azo-carboxylic acid viz. 2/4-(2-hydroxynaphthylazo)benzoic acids with appropriate triorganotin(IV) chlorides [R = Me (compounds 1 and 2) and Bu (compound 3)] in presence of triethyl amine base. The complexes were characterized by elemental analysis, IR and multinuclear (1H and 13C- and 119Sn)-NMR spectroscopy. The structures and mode of coordination around tin ions in the complexes were determined by single crystal X-ray crystallography. The complexes exhibit trigonal bipyramidal geometry around tin atoms where the base of the equatorial plane is being occupied by the three alkyl groups [Me or Bu] while the axial positions are occupied by carboxylate oxygen atoms in 2 and in case of 1 and 3, by carboxylate and phenoxide oxygen atoms, respectively. It has been found that, the crystal structure of 1 or 3 is a cyclic dimeric, whereas 2 exhibits a polymeric structure. The 119Sn NMR studies show that all complexes have four-coordinate structures indicating dissociation of these complexes in solution state. The complexes were also screened for their antimicrobial activity and the compound 3 was found to exhibit effective antimicrobial activity.
- Published
- 2019
22. Marker assisted selection of low phytic acid trait in maize (Zea maysL.)
- Author
-
S. Vellaikumar, V. G. Shobana, P. Nagarajan, S. Sureshkumar, Ramachandran Balagopal, G. Vijayalakshmi, Arumugam U. Thangavelu, Senthil Natesan, K. N. Ganesan, M. Raveendran, and P. Tamilkumar
- Subjects
Genetics ,Phytic acid ,food and beverages ,Introgression ,General Medicine ,Marker-assisted selection ,Biology ,symbols.namesake ,chemistry.chemical_compound ,Agronomy ,chemistry ,Genetic marker ,Backcrossing ,Genotype ,Mendelian inheritance ,symbols ,Allele - Abstract
Maize is the third important major food crop. Breeding for low phytate maize genotypes is an effective strategy for decreasing the content of kernel phytic acid (a chelator of cations such as Ca(2+) and Fe(3+) ) and thereby increasing the bioavailability of nutritive minerals in human diet and animal feed. Previous studies have established that a mutant plant with a lpa2-2 allele accumulates less phytic acid in seeds. Therefore, the marker assisted backcross breeding (MABB), which involves introgression of lpa2-2 recessive allele (which confer low phytate trait) from a lpa2-2 mutant line into a well-adapted line using backcrosses and selection of lines possessing lpa2-2 allele in each backcross population using molecular markers, is an effective strategy for developing low phytate maize. So far, no studies have developed any lpa2-2 allele specific molecular markers for this purpose. Here, using backcross and selfed progenies, obtained by crossing low phytate mutant line 'EC 659418' (i.e. donor of lpa2-2 allele) into agronomically superior line 'UMI395', we have validated that a SSR marker 'umc2230', located 0.4 cM downstream of lpa2-2, cosegregate, in a Mendelian fashion, with low phytic acid trait. Therefore umc2230 can be dependably used in MABB for the development of low phytate maize.
- Published
- 2014
23. Effect of Culture Media and Growth Hormones on Callus Induction in Aquilaria malaccensis Lam., a Medicinally and Commercially Important Tree Species of North East India
- Author
-
S. Sureshkumar Singh, Moitreyee Saikia, and Karuna Shrivastava
- Subjects
chemistry.chemical_classification ,Germplasm ,biology ,Endangered species ,biology.organism_classification ,chemistry.chemical_compound ,Tissue culture ,chemistry ,Auxin ,Callus ,Botany ,General Earth and Planetary Sciences ,Kinetin ,Medicinal plants ,Aquilaria malaccensis ,General Environmental Science - Published
- 2013
24. An Efficient Protocol for Callus Induction in Aquilaria malaccensis Lam. Using Leaf Explants at Varied Concentrations of Sucrose
- Author
-
Moitreyee Saikia, Singh, S. Sureshkumar, and Karuna Shrivastava
- Subjects
food.ingredient ,biology ,Agarwood ,engineering.material ,biology.organism_classification ,chemistry.chemical_compound ,food ,chemistry ,Callus ,Botany ,engineering ,Aquilaria ,Agar ,Kinetin ,Sugar ,Aquilaria malaccensis ,Explant culture - Abstract
Aquilaria malaccensis Lam. (Family: Thy melaeaceae), co mmonly known as agarwood, eagle wood or Gaharu is a co mmercially important tree species of northeast India. The Aquilaria tree is categorised as critically endangered in Ind ia. This species is being continuously exploited due to its precious heartwood which is the source of expensive agar oil used in the production of high grade perfu mes as well as in trad itional medicines. The main aim of this study was to establish a speedy callus production protocol fro m Aquilaria malaccensis which may serve as an important option for direct extraction of agar o il. For this purpose, large scale p roduction of callus tissue is needed. An efficient callus regeneration protocol was established through leaf pro liferation in Aquilaria malaccensis Lam. using Murashige and Skoog mediu m supplemented with least amount of plant growth hormones (2,4 D, NAA, Kinetin & BAP) at varied concentrations of sucrose (2-5%). Callus could be initiated in all the treat ments of hormones and sugar levels; however, the best callus growth was obtained in the MS med iu m supplemented with BAP (0.5 mg/l) + NAA (3mg/l) g iving the h ighest fresh (7.368g) and dry cell b io mass (2.170g) at the optimu m sucrose concentration (4%) after 45-60 days of incubation.
- Published
- 2012
25. In Silico Investigations of Chemical Constituents of Clerodendrum colebrookianum in the Anti-Hypertensive Drug Targets: ROCK, ACE, and PDE5
- Author
-
S. Sureshkumar Singh, Hemant Arya, Dinakar R. Ampasala, Safiulla Basha Syed, and Mohane Selvaraj Coumar
- Subjects
0301 basic medicine ,Drug ,Clerodendrum ,media_common.quotation_subject ,In silico ,Health Informatics ,030204 cardiovascular system & hematology ,Pharmacology ,Molecular Dynamics Simulation ,Peptidyl-Dipeptidase A ,Ligands ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Computer Simulation ,Molecular Targeted Therapy ,Mode of action ,Antihypertensive Agents ,media_common ,Cyclic Nucleotide Phosphodiesterases, Type 5 ,rho-Associated Kinases ,Natural product ,biology ,Chemistry ,Clerodendrum colebrookianum ,biology.organism_classification ,Computer Science Applications ,Molecular Docking Simulation ,030104 developmental biology ,Docking (molecular) ,Chemical constituents ,Anti hypertensive drug - Abstract
Understanding the molecular mode of action of natural product is a key step for developing drugs from them. In this regard, this study is aimed to understand the molecular-level interactions of chemical constituents of Clerodendrum colebrookianum Walp., with anti-hypertensive drug targets using computational approaches. The plant has ethno-medicinal importance for the treatment of hypertension and reported to show activity against anti-hypertensive drug targets-Rho-associated coiled-coil protein kinase (ROCK), angiotensin-converting enzyme, and phosphodiesterase 5 (PDE5). Docking studies showed that three chemical constituents (acteoside, martinoside, and osmanthuside β6) out of 21 reported from the plant to interact with the anti-hypertensive drug targets with good glide score. In addition, they formed H-bond interactions with the key residues Met156/Met157 of ROCK I/ROCK II and Gln817 of PDE5. Further, molecular dynamics (MD) simulation of protein-ligand complexes suggest that H-bond interactions between acteoside/osmanthuside β6 and Met156/Met157 (ROCK I/ROCK II), acteoside and Gln817 (PDE5) were stable. The present investigation suggests that the anti-hypertensive activity of the plant is due to the interaction of acteoside and osmanthuside β6 with ROCK and PDE5 drug targets. The identified molecular mode of binding of the plant constituents could help to design new drugs to treat hypertension.
- Published
- 2016
26. High-Resolution Mass Spectrometry in Metabolite Identification
- Author
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Mayur K. Ladumor, S. Sureshkumar Singh, K. Bhavsar, Shristy Tiwari, Shalu Jhajra, Amol Patil, and Bhagwat Prasad
- Subjects
0301 basic medicine ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Chromatography ,Data acquisition ,chemistry ,Metabolite ,010401 analytical chemistry ,Identification (biology) ,01 natural sciences ,0104 chemical sciences - Published
- 2016
27. Rheology and microstructure of polymer-modified asphalt nanocomposites
- Author
-
Giovanni Polacco, Ali Topal, M. S. Sureshkumar, and Burak Sengoz
- Subjects
chemistry.chemical_classification ,Materials science ,Styrene-butadiene ,Nanocomposite ,Polymer nanocomposite ,Metals and Alloys ,Ethylene-vinyl acetate ,Polymer ,Condensed Matter Physics ,Microstructure ,chemistry.chemical_compound ,chemistry ,Rheology ,Asphalt ,Materials Chemistry ,Physical and Theoretical Chemistry ,Composite material - Abstract
Asphalt modification with polymers has utilized the advantages of nanotechnology including nanoclays as one of the components in addition to polymers. This led to the metamorphosis of polymer-modified asphalts into a new class of material called polymer-modified asphalt nanocomposites which offer the cumulative characteristic features obtained by the polymer modification of asphalt as well as the innovative properties experienced from polymer nanocomposites. Polymer-modified asphalt nanocomposites including styrene butadiene and ethylene vinyl acetate have revealed additional features which were not available in polymer-modified asphalts. The compositional complexity provides a great challenge in addressing the structure–property relations prevailing in these materials. This paper describes microstructural features as determined by Qwin Plus Software analysis and the rheological properties on compositional changes.
- Published
- 2012
28. Combined advanced oxidation and biological treatment of tannery effluent
- Author
-
Chitra Kalyanaraman, E. Ravindranath, G. Prea Samita Mary, Rangasamy Suthanthararajan, S. V. Srinivasan, P. S. Sureshkumar, and K. Sri Balakameswari
- Subjects
Pollutant ,Economics and Econometrics ,Environmental Engineering ,Chemistry ,Membrane fouling ,Advanced oxidation process ,Batch reactor ,Chemical oxygen demand ,Management, Monitoring, Policy and Law ,General Business, Management and Accounting ,Environmental chemistry ,Environmental Chemistry ,Sewage treatment ,Reverse osmosis ,Effluent - Abstract
During leather processing in tanneries, considerable amount of wastes with organic and inorganic pollutants are generated. For removal of these pollutants and recovery of water, biological treatment methods and reverse osmosis (RO) based membrane technologies are adopted. While recovering water from treated tannery effluent using RO membranes, presence of residual organics, dye molecules, and other impurities in the effluent have been reported as the major drawback which leads to membrane fouling and failure. In this study, an attempt was made to improve the quality of the treated tannery effluent by subjecting the secondary treated tannery effluent by ozonation alone and ozonation of primary and secondary treated tannery effluent followed by aerobic biological Sequential Batch Reactor (SBR). Maximum color reduction of 98% at pH value of 12 with ozonation alone was observed for secondary treated tannery effluent. Ozonation of secondary treated tannery effluent followed by further biological treatment in aerobic SBR increased the chemical oxygen demand (COD) removal rate and resulted in COD values less than 300 mg/L. In case of primary treated tannery effluent, maximum COD reduction of 64% was achieved in SBR.
- Published
- 2011
29. Studies on the feasibility of recycled polystyrene doped with NLO active meta -Nitroaniline for optoelectronics applications
- Author
-
R.K.P. Singh, R. C. Aiyer, K. Raghunatha Reddy, M. S. Sureshkumar, Yuvraj Singh Negi, Jagdish W. Dadge, Rajendra Kumar Goyal, and A. Pratheepkumar
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,business.industry ,Scanning electron microscope ,Doping ,Second-harmonic generation ,Polymer ,Laser ,law.invention ,Nitroaniline ,chemistry.chemical_compound ,Optical microscope ,chemistry ,law ,Optoelectronics ,Polystyrene ,business - Abstract
A Guest-Host system based on meta-Nitroaniline (m-NA) and recycled polystyrene (RPS) susceptible to generate nonlinear optically (NLO) active property such as second harmonic generation (SHG) has been prepared. Pure, sublimed, optical grade, crystalline m-NA is used as a guest and RPS from the disposable packaging waste as available utilized as the host polymer. In this paper we report the effect of NLO active m-NA on the bulk and optical properties of RPS. The purified m-NA was incorporated from 1-10wt% in the RPS polymer matrix by conventional solution casting method. Thin, transparent, freestanding films obtained were characterized with optical microscope, scanning electron microscope (SEM), viscosity measurement, and UV-Visible (UV-Vis) spectroscopy for bulk properties evaluation and Nd:YAG laser studies for optoelectronics application such as SHG through frequency doubling.
- Published
- 2010
30. Internal structure and linear viscoelastic properties of EVA/asphalt nanocomposites
- Author
-
M. S. Sureshkumar, Jiri Stastna, Sara Filippi, Ludovit Zanzotto, Giovanni Polacco, and Igor B. Kazatchkov
- Subjects
chemistry.chemical_classification ,Materials science ,Nanocomposite ,Polymers and Plastics ,Organic Chemistry ,General Physics and Astronomy ,Polymer ,Viscoelasticity ,chemistry.chemical_compound ,Montmorillonite ,chemistry ,Rheology ,Asphalt ,Materials Chemistry ,Composite material ,Ternary operation ,Dispersion (chemistry) - Abstract
The effect of the addition of two different organoclays as a third component in polymer-modified asphalts has been investigated. Ternary mixtures were prepared by adding clay and poly(ethylene-co-vinyl acetate) to the asphalt, either separately, or in the form of a premixed master batch. The performed characterizations allowed the determination of how the two methods of mixing influence the interactions between asphalt and polymer and therefore the final rheological properties. In particular, it was shown that the clay had a compatibilizing effect on asphalt and polymer and that a high compatibility between clay and polymer led to a better dispersion of the polymer in the asphalt, thus influencing the final rheological properties of the studied systems.
- Published
- 2010
31. Electron beam irradiation of LLDPE and PDMS rubber blends: Studies on the physicomechanical properties
- Author
-
Golok B. Nando, Radhashyam Giri, Kinsuk Naskar, M. S. Sureshkumar, K. S. S. Sarma, Sunil Sabharwal, and Y. K. Bharadwaj
- Subjects
Materials science ,Polymers and Plastics ,General Chemical Engineering ,Organic Chemistry ,Izod impact strength test ,Compatibilization ,Polyethylene ,Linear low-density polyethylene ,Crystallinity ,chemistry.chemical_compound ,Natural rubber ,chemistry ,visual_art ,Ultimate tensile strength ,visual_art.visual_art_medium ,Composite material ,Thermoplastic elastomer - Abstract
Blends of semicrystalline linear low-density polyethylene and amorphous polydimethyl siloxane rubber were prepared by varying the blend ratios from 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70 to 0:100 by melt-blending technique in an internal mixer under previously optimized process conditions using Taguchi methodology. The molded sheets were subjected to electron beam irradiation under varying radiation doses starting from 100, 200, 300, 400 to 500 kGy in an accelerator. The physicomechanical properties of the blends before and after electron beam radiation have been studied, and the optimum dose required for each blend ratio for optimum physicomechancial properties has been investigated. A radiation dose of 100 to 300 kGy is found to be sufficient for obtaining the best balance in tensile strength and tensile impact strength properties. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 27:98–107, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20120
- Published
- 2009
32. Potential Applications of Polystyrene in Optoelectronics
- Author
-
M. S. Sureshkumar, Rajendra Kumar Goyal, and Yuvraj Singh Negi
- Subjects
Flexibility (engineering) ,chemistry.chemical_classification ,Fabrication ,Materials science ,Polymers and Plastics ,business.industry ,General Chemical Engineering ,Organic Chemistry ,Polymer ,Chromophore ,Casting ,Active devices ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Optoelectronics ,Polystyrene ,Photonics ,business - Abstract
Organic polymer based materials are becoming the workhorse in the area of photonics and optoelectronics. These materials are rapidly replacing their inorganic counter parts due to their flexibility in manufacturing combined with the ease in fabrication and manufacturing. Polystyrene, being a low cost commercial commodity plastic material has been utilized as one of the important polymeric material for various NLO active devices. Guest-Host systems based on polystyrene and NLO active chromophores have been extensively studied. As a host polymer it can easily accommodate the NLO guest molecules by simple modification by solution casting and other processes. Thus, polystyrene based NLO active systems offers a relatively cost-effective NLO active systems. Recent investigations have confirmed the suitability of disposable recycled polystyrene as a host polymer to accommodate NLO active chromophores that can lead to dirt-cheap NLO active device materials. This review summarizes the applications of polystyrene based materials in the area of Optoelectronics. The fundamental aspects pertaining to Guest-Host NLO chromophore is also discussed. Some of the recent investigation about the usage of recycled polystyrene system is highlighted.
- Published
- 2008
33. Studies on the properties of EPDM–CSE blend containing HTPB for case-bonded solid rocket motor insulation
- Author
-
C. M. Bhuvaneswari, M. S. Sureshkumar, S. D. Kakade, and Mukul Gupta
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,EPDM rubber ,Ethylene propylene rubber ,Polymer ,Elastomer ,law.invention ,Neoprene ,Polybutadiene ,Natural rubber ,chemistry ,law ,visual_art ,visual_art.visual_art_medium ,Polymer blend ,Composite material - Abstract
Elastomeric blends based on ethylene propylene diene (EPDM) rubber as a primary polymer have been investigated for the thermal insulation of case-bonded solid rocket motors (SRMs) cast with composite propellant containing hydroxy terminated polybutadiene (HTPB) as a polymeric binder. EPDM rubber found as an attractive candidate for the thermal insulation of case-bonded SRM due to the advantages such as low specific gravity, improved ageing properties, and longer shelf life. In spite of these advantages, EPDM, a non-polar rubber, lacks sufficient bonding with the propellant matrix. Bonding properties are found to improve when EPDM is blended with other polar rubbers like polychloroprene, chlorosulphonated polyethylene (CSE), etc. This type of polar polymer when blended with EPDM rubber enhances the insulator-to-propellant interface bonding. In the present work, an attempt has been made to study the properties of EPDM–CSE based insulator by incorporating HTPB, a polar polymer as well as a polymeric binder, as an additive to the EPDM–CSE blend by varying the HTPB concentration. Blends prepared were cured and characterized for rheological, mechanical, interface, and thermal properties to study the effect of HTPB addition. This paper reports the preliminary investigation of the properties of EPDM–CSE blend containing HTPB, as a novel and futuristic elastomeric insulation for case-bonded SRM containing HTPB as propellant binder. Copyright © 2007 John Wiley & Sons, Ltd.
- Published
- 2008
34. Ethylene-propylene Diene Rubber as a Futuristic Elastomer for Insulation of Solid Rocket Motors
- Author
-
S. D. Kakade, Manoj Gupta, C. M. Bhuvaneswari, and M. S. Sureshkumar
- Subjects
Materials science ,Diene ,Mechanical Engineering ,General Chemical Engineering ,Biomedical Engineering ,General Physics and Astronomy ,Insulator (electricity) ,Ethylene propylene rubber ,Elastomer ,Erosion rate ,Computer Science Applications ,chemistry.chemical_compound ,chemistry ,Natural rubber ,visual_art ,Forensic engineering ,visual_art.visual_art_medium ,Electrical and Electronic Engineering ,Solid-fuel rocket ,Composite material - Abstract
The study carried out so far on the application of ethylene-propylene diene rubber (EPDM) in the field of insulation of case bonded solid rocket motors has been reviewed. The various studies by the authors (unpublished work) have also been reported. All these findings bring out the excellent potential of EPDM as insulator in view of its ageing resistance, low-temperature flexibility, low erosion rate, and low specific gravity.
- Published
- 2006
35. Effect of Water Activity on the Physico-chemical, Microbiological and Sensory Qualities of Buffalo Meat Sausage Stored under Ambient Temperature
- Author
-
A. Kalaikannan ., S. Sureshkumar ., K. Dushyanthan, and V. Venkataramanujam .
- Subjects
Water activity ,Chemistry ,Sensory system ,Food science ,Food Science ,Buffalo meat - Published
- 2006
36. Synthesis and characterization of gold-chitosan nanocomposite and application of resultant nanocomposite in sensors
- Author
-
Manjusha Mathew, Neelakandapillai Sandhyarani, and S. Sureshkumar
- Subjects
Materials science ,Polymers ,Nanoparticle ,Metal Nanoparticles ,Nanotechnology ,Biosensing Techniques ,Phase Transition ,Nanocomposites ,Colloid and Surface Chemistry ,Microscopy, Electron, Transmission ,Limit of Detection ,Physical and Theoretical Chemistry ,Electrodes ,Detection limit ,chemistry.chemical_classification ,Chitosan ,Nanocomposite ,Spectrophotometry, Atomic ,Reproducibility of Results ,Surfaces and Interfaces ,General Medicine ,Polymer ,Electrochemical Techniques ,Hydrogen-Ion Concentration ,Electrochemical gas sensor ,Chemical engineering ,chemistry ,Lead ,Transmission electron microscopy ,Colloidal gold ,Gold ,Cyclic voltammetry ,Biotechnology - Abstract
Chitosan gold nanocomposite (CGNC) was synthesized in a single step process and the pH dependent properties of the composite were investigated. The structure of the polymer was pH dependent and gelation of the polymer observed at pH 4–5. Transmission electron microscopy (TEM) analysis showed that the distribution of gold nanoparticles within unit area varied with the gelation of the polymer, without affecting the size of the nanoparticles. The resulting CGNC system was explored for its use as a sensor for the detection of lead. It was found that lead could be detected at a concentration of 1 μM by absorption spectroscopy. The CGNC was electrodeposited on a gold electrode and the deposited film was used for the detection of lead using cyclic voltammetry. Lead could be detected with a detection limit of 10 μM. The fabrication reproducibility for four sensor electrodes showed a relative standard deviation (RSD) of 2.09% for the determination of 1 mM lead nitrate. The developed sensor system showed high reproducibility, stability and satisfactory selectivity.
- Published
- 2011
37. Effect of nisin and butylated hydroxy anisole on storage stability of buffalo meat sausage
- Author
-
K. Dushyanthan, V. Venkataramanujam ., A. Kalaikannan ., and S. Sureshkumar .
- Subjects
chemistry.chemical_compound ,chemistry ,Short Communication ,Food preservation ,TBARS ,Total Viable Count ,Food science ,Vacuum packing ,Butylated hydroxyanisole ,Shelf life ,Nisin ,Food Science ,Buffalo meat - Abstract
The water activity of buffalo meat sausage was adjusted to 0.88 using humectants and by heat treatment. Nisin and butylated hydroxyanisole (BHA) were added to study the shelf life of sausage. The treatments were nisin 100 ppm + BHA 100 ppm (T3); nisin 100 ppm (T2); BHA 100 ppm (T1) and control (T0) without nisin and BHA. The sausages were vacuum packaged in polyethylene terephthalate (PET-poly) pouch and stored for 7 days at ambient conditions (35 ± 2°C, 70-80% RH). The pH of sausage increased during storage whereas the moisture content was higher in treatment T1. Tyrosine value was lowest (18.1 mg%) in T3. There was no significant difference among T0 and T1. The thiobarbituric acid reactive substances (TBARS) number of T1 and T3 were lower than that of T0 and T2. Nisin and BHA together exhibited a significant inhibitory effect on total viable count, staphylococcal, streptococcal and anaerobic counts. There was no significant difference in the yeast and mould counts among T1-T3. T3 had a better appearance, flavour, texture and overall acceptability scores up to 5 days. The product (T3) was acceptable up to 5(th) day of storage at 35 ± 2°C and 70-80% RH.
- Published
- 2010
38. ICONE15-10213 EDDY CURRENT FLOW SENSOR DEVELOPMENT AND TESTING FOR LMFBR SODIUM PUMPS
- Author
-
R. Veerasamy, S. K. Dash, S. Sureshkumar, G. Vaidyanathan, K. Gurumoorthi, C. Asokane, N.S. Sivakumar, S. Chandramouli, G. Padmakumar, and B.K. Sreedhar
- Subjects
chemistry ,law ,Sodium ,Nuclear engineering ,Eddy current ,chemistry.chemical_element ,Environmental science ,Flow sensor ,law.invention - Published
- 2007
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