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181.
Uwe Gohs Andreas Leuteritz Kinsuk Naskar Sebastian Volke Sven Wiessner Gert Heinrich 《Macromolecular Symposia》2010,296(1):589-595
Polymer modification with high energy electrons is well-established in polymer industry and used for degradation, cross-linking, grafting, curing, and polymerization. These applications use local and temporal precise input of energy in order to generate excited atoms or molecules as well as ions for subsequent molecule changes via radical induced chemical reactions. Reactive electron beam (EB) processing combines melt mixing process and chemical reaction simultaneously. For this purpose, a 1.5 MeV electron accelerator was directly coupled to an internal mixer in order to induce chemical reactions by energy input via high energy electrons under dynamic conditions of melt mixing of different polymer compounds. In the present study, reactive EB processing was used for the development of a flame retardant polyethylene composite as well as Thermoplastic Vulcanizate. The influence of absorbed dose as well as electron energy and electron treatment time was studied. Increased values of both tensile strength and elongation at break of polymer compounds indicated in-situ compatibilization upon reactive EB processing. 相似文献
182.
Subhendu NaskarMaitreyee Banerjee Abhijit HazraShyamal Mondal Arindam MaityRupankar Paira Krishnendu B. SahuPritam Saha Sukdeb BanerjeeNirup B. Mondal 《Tetrahedron letters》2011,52(13):1527-1531
A high yielding environmentally benign protocol has been developed for the synthesis of pyrrolo[2,1-a]isoquinoline using chromone-3-carboxaldehyde, isoquinoline and phenacyl bromide/bromoacetic acid ester as reagents in aqueous micellar medium. The method is operationally simple and more effective compared to the previous methods in terms of the yield of the products as well as the reaction time. 相似文献
183.
Aswathy Thuruthil Raju Biswaranjan Dash Pranab Dey Sujith Nair Kinsuk Naskar 《先进技术聚合物》2020,31(10):2390-2402
Nanotechnology has been explored recently as a means of enhancing the properties of conventional elastomers for engineering applications. In the current study, the effect of nanofillers on air impermeability properties of Brominated isobutylene‐isoprene rubber (BIIR)/Epoxidized natural rubber (ENR) blend has analyzed for automotive applications. The ENR chosen is ENR 25 and ENR 50 (25 and 50% epoxidation) and prepared the blends in a ratio of 75:25 (BIIR:ENR), and from both blend based composites, a part of carbon black replaced with graphene nanoplatelets (GNP). The physical and thermal properties were compared for both binary blend nanocomposites to study the level of exfoliation and reinforcement behavior of GNP. Morphology studies were employed to reveal the level of interaction between GNP and carbon black in both blends. The influence of epoxidation in the formation of nanostructures in both blends have been evaluated, and the effect of nanostructures on air permeability properties was studied. The air impermeability of BIIR‐ENR 50 nanocomposites were improved with increasing platelet concentration, a 30% improvement in air permeability is obtained for BIIR‐ENR 50 composites over BIIR ‐ENR 25. 相似文献
184.
Sudip?Biswas Susmita?Pradhan Hemanta?Naskar Rajib?Bandyopadhyay Panchanan?PramanikEmail author 《Mikrochimica acta》2018,185(11):513
Titanium dioxide nanoparticles (NPs) were synthesized by a sol-gel method from hexafluorotitanic acid using poly(ethylene glycol) as a capping agent. The crystal structure and morphology of the NPs were characterized by X-ray diffraction, FESEM, and TEM. The NPs were used to modify a graphite paste electrode for simultaneous determination of uric acid (UA) and guanine (GU). The effect of calcination temperature on crystal structure and electrocatalytic activity was investigated. The electrochemical responses to UA and GU at bare GP, TiO2–350/GP, and TiO2–600/GP electrodes were compared. The DPV oxidation peaks of UA and GU were found to be strongest at around 304 and 673 mV, respectively, against Ag/AgCl reference electrode, and this are well separated for effective simultaneous determination. UA and GU can be simultaneously determined by this method. Response is linear within the range 0.1–500 μM and 0.1–40 μM for UA and GU, respectively. The detection limits are 70 nM for UA and 50 nM for GU (at an S/N? ratio of?3). The TiO2–600/GP electrode showed excellent analytical performance when analyzing spiked urine and serum samples. 相似文献
185.
This report presents the design and synthesis of a novel fused triazolyl 2-quinolinone (FTQuon) nucleoside as a new generation of angularly widened unnatural nucleobase surrogate with two possible H-bonding faces-one H-bond acceptor and another donor. The synthesis via a tandem CuAAC-Ullmann coupling, the study of photophysical properties and theoretical calculation in the context of DNA are the main contents of this report. The newly designed nucleoside shows interesting photphysical property with slight blue shifted solvatochromicity. It also shows pH sensitive emission. All the theoretical DNA duplexes containing the FTQuon show right?handed B-form helicity as revealed from a molecular dynamics simulation using Schrodinger Macromodel. A theoretical (DFT) study indicates a good stabilizing property of FTQuon via pairing with natural pyrimidine bases. It also shows good interaction property with BSA protein signalled via a switch on fluorescence response. 相似文献
186.
Kamala Mitra Subhendu Biswas Shyamal Kumar Chattopadhyay C. Robert Lucas Bibhutosh Adhikary 《Journal of chemical crystallography》2007,37(8):567-571
Syntheses and X-ray structural characterizations of two new luminescent imidazopyridinium derivatives, 2-(phenyl)-N(3)-(4(methyl)phenyl)-imidazo[1,5a]
pyridinium perchlorate (1) and 2-(pyridyl)-N(3)-(4-(chloro)phenyl)-imidazo[1,5a] pyridinium perchlorate (2) are reported. The compounds are prepared in one step from N-(4-(methyl)phenyl) pyridine-2-aldimine and N-(4-(chloro)phenyl)
pyridine-2-aldimine respectively in a transformation mediated by Mn(OAc)2-KMnO4 mixture. It is found that the molecular structures of the two compounds are similar. In the solid state, 1 forms a three-dimensional network through a series of hydrogen bonds between the cations and anions in the lattice while
2 forms a similar but less extensively linked network. The substitution of hydrogen at the 2-position of the imidazopyridinium
ring by phenyl or 2-(pyridyl) affects the nature of their first excited states as detected by changes in their emission and
absorption spectra. 相似文献
187.
Ajay K. Bose Maghar S. Manhas Subhendu N. Ganguly Suhas Pednekar Arun Mandadi 《Tetrahedron letters》2005,46(17):3011-3013
A water-based biphasic reaction process has been developed for conducting exothermic reactions without organic solvents. This procedure is rapid, simple, and suitable for small scale synthesis as well as larger (multi-molar) scale reactions. The preparation of several hundred grams of clofibric acid and analogues by this eco-friendly and energy-efficient procedure is described. Smaller amounts of these compounds were prepared by the friction-activated ‘Grindstone Chemistry’ method described previously. 相似文献
188.
Naba K. Mondal Saurabh D. Rindani Kaustubh Agashe Pankaj Agrawal B. Ananthanarayan Ketevi Assamagan Alfred Bartl Subhendu Chakrabarti Utpal Chattopadhyay Debajyoti Choudhury Eung-Jin Chun Prasanta K. Das Siba P. Das Amitava Datta Sukanta Dutta Jeff Forshaw Thomas Gajdosik Dilip K. Ghosh Rohini M. Godbole Monoranjan Guchait Partha Konar Sabine Kraml Manas Maity Kajari Mazumdar Naba K. Mondai Biswarup Mukhopadhyaya Meenakshi Narain Santosh K. Rai Sreerup Raychaudhuri Saurabh D. Rindani D. P. Roy Seema Sharma Ritesh K. Singh Rishikesh Vaidya 《Pramana》2004,63(6):1331-1353
This is a summary of the projects undertaken by the working group I on high energy and collider physics. 相似文献
189.
1,3,5-tri-Oxygenated benzenes can serve as substrates for the Petasis boronic acid reaction, providing a practical synthetic route for the two CC bond formation of α-(1,3,5-tri-oxygenated phenyl)carboxylic acids. The scope and limitations of this method have been examined. 相似文献
190.
Sumita Naskar Subhendu Naskar Mike G.B. Drew Serge I. Gorelsky Benedikt Lassalle-Kaiser Ally Aukauloo Dipankar Mishra Shyamal Kumar Chattopadhyay 《Polyhedron》2009,28(18):4101-4109
Six Ru(II) complexes of formula [Ru(L)2(PPh3)2] have been prepared where LH = 4-(aryl)thiosemicarbazones of thiophen-2-carbaldehyde. X-ray crystal structures of five of the complexes are reported. In all the complexes ruthenium is six coordinate with a distorted octahedral cis-P2, cis-N2, trans-S2 donor environment, and each of the two thiosemicarbazone ligands are coordinated in a bidentate fashion forming a four membered chelate ring. The complexes undergo a one-electron oxidation at ~0.5 V vs. Ag/AgCl. The EPR spectrum of the electrochemically oxidized solution at 100 K shows a rhombic signal, with transitions at g1 = 2.27, g2 = 2.00 and g3 = 1.80. DFT calculations on one of the complexes suggest that there is 35% ruthenium and 17% sulfur orbital contribution to the HOMO. These results suggest that the assignment of metal atom oxidation states in these compounds is not unambiguous. 相似文献