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141.
M. Nagaraj 《Liquid crystals》2016,43(13-15):2244-2253
ABSTRACTSpontaneous or induced chiral symmetry breaking in achiral systems is unusual and understanding the origin of such a phenomenon has been an important area of research for several years. The optically isotropic mesophases exhibited by unconventional liquid crystals are one of the most interesting systems to investigate spontaneous chiral symmetry breaking in liquid crystal mesophases formed by achiral moieties. The dark conglomerate (DC) phases are one such optically isotropic family of phases. In this paper, a detailed account of the tendency of bent-core mesogens to form a variety of polar smectic phases, the formation of DC phases due to layers deformations and the general optical, electrical, physical properties of the DC phases are given. An example of a DC phase which exhibit distinct electro-optic properties is described with the nature of dynamics of the response and physical reasons responsible for such behaviour. The challenges and prospects of the DC phases are discussed for their potential applications in novel devices. 相似文献
142.
Indranil Biswas Subramaniam Senthamarai Kannan Donihakalu Shankar Nagaraj 《Comptes Rendus Mathematique》2017,355(4):452-454
Let be the wonderful compactification of a simple affine algebraic group G of adjoint type defined over . Let be the closure of a maximal torus . We prove that the group of all automorphisms of the variety is the semi-direct product , where is the normalizer of T in G and D is the group of all automorphisms of the Dynkin diagram, if . Note that if , then and so in this case . 相似文献
143.
Dr. Shakeel A. Shahid Dr. Madhu Nagaraj Nandini Chauhan Dr. Trent W. Franks Dr. Benjamin Bardiaux Dr. Michael Habeck Dr. Marcella Orwick‐Rydmark Prof. Dirk Linke Dr. Barth‐J. van Rossum 《Angewandte Chemie (International ed. in English)》2015,54(43):12602-12606
MAS‐NMR was used to study the structure and dynamics at ambient temperatures of the membrane‐anchor domain of YadA (YadA‐M) in a pellet of the outer membrane of E. coli in which it was expressed. YadA is an adhesin from the pathogen Yersinia enterocolitica that is involved in interactions with the host cell, and it is a model protein for studying the autotransport process. Existing assignments were sucessfully transferred to a large part of the YadA‐M protein in the E. coli lipid environment by using 13C‐13C DARR and PDSD spectra at different mixing times. The chemical shifts in most regions of YadA‐M are unchanged relative to those in microcrystalline YadA‐M preparations from which a structure has previously been solved, including the ASSA region that is proposed to be involved in transition‐state hairpin formation for transport of the soluble domain. Comparisons of the dynamics between the microcrystalline and membrane‐embedded samples indicate greater flexibility of the ASSA region in the outer‐membrane preparation at physiological temperatures. This study will pave the way towards MAS‐NMR structure determination of membrane proteins, and a better understanding of functionally important dynamic residues in native membrane environments. 相似文献
144.
Shweta J. Malode Nagaraj P. Shetti Sharanappa T. Nandibewoor 《Journal of solution chemistry》2010,39(3):417-430
The oxidation of ketorolac (KET) by diperiodatocuprate(III) (DPC) in aqueous alkaline medium at a constant ionic strength
of 0.10 mol⋅dm−3 was studied spectrophotometrically at 298 K. The reaction is of first order in [DPC] and has less than unit order in both
[KET] and [alkali], and negative fractional order in [periodate]. The oxidation reaction in alkaline medium has been shown
to proceed via a DPC-ketorolac complex, which decomposes slowly in a rate determining step followed by other fast steps to
give the products. The main products were identified by spot test, IR and GC-MS spectral studies. The reaction constants involved
in the different steps of the mechanism were calculated at different temperatures, which yielded thermodynamic quantities
for different steps of the reaction scheme. The activation parameters with respect to the slow step of the mechanism were
computed and discussed; thermodynamic quantities were also determined. 相似文献
145.
Clover detector has been used as a Compton polarimeter to measure the linear polarization of γ-rays produced in heavy ion
fusion reaction. The polarization sensitivity of the clover detector has been measured over γ-ray energies ranging from 386
to 1368 ke V. The E1 multipolarity of the 1117 keV transition in 99Rh has been established using this polarimeter. This has resulted in the assignment of negative parity to the band head at
3710 keV in 99Rh. 相似文献
146.
Peptides corresponding to the hydrophobic region of signal sequences have been synthesized by the solid-phase method employing the transesterification method of cleavage from the resin. The protected peptides thus obtained were purified easily by column chromatography on silica gel with varying proportions of methanol and chloroform as eluants. 相似文献
147.
A large number of macrocycles containing alternating repeats of cystine diOMe(-NH-CH(CO(2)Me)-CH(2)-S-)(2) and either a conformationally rigid aromatic/alicyclic moiety or a flexible polymethylene unit (X) in the cyclic backbone with ring size varying from 13- to 78-membered have been examined by spectral ((1)H NMR, FT-IR, CD) and X-ray crystallography studies for unusual conformational preferences. While (1)H NMR measurements indicated a turnlike conformation for all macrocycles, stabilized by intramolecular NH.CO hydrogen bonding, as also supported by FT-IR spectra in chloroform, convincing proof for beta-turn structures was provided by circular dichroism studies. Single-crystal X-ray studies on 39-membered cyclo (Adm-L-Cyst)(3) revealed a double-helical fold (figure-eight motif) for the macrocycle. Only a right-handed double helix was seen in the macrocycle constructed from L-cystine. The mirror-image macrocycle made up of D-cystine units exhibited a double helix with exactly the opposite screw sense, as expected. The enantiomeric figure-eights were stabilized by two intramolecular NH. CO hydrogen bonds and exhibited identical (1) H NMR and FT-IR spectra. The CD spectra of both isomers had a mirror-image relationship. The present results have clearly brought out the importance of cystine residues in inducing turn conformation that may be an important deciding factor for the adoption of topologically important structures by macrocycles containing multiple S-S linkages. 相似文献
148.
LetY be a smooth projective curve degenerating to a reducible curveX with two components meeting transversally at one point. We show that the moduli space of vector bundles of rank two and odd determinant on Ydegenerates to a moduli space onX which has nice properties, in particular, it has normal crossings. We also show that a nice degeneration exists when we fix the determinant. We give some conjectures concerning the degeneration of moduli space of vector bundles onY with fixed determinant and arbitrary rank. 相似文献
149.
S Nagaraj H C Jain P K Joshi S D Paul R Palit H V Panchal B S Naidu A Chatterjee A Navin 《Pramana》2001,57(1):219-222
A recoil mass spectrometer (RMS) has been designed, fabricated and installed at the 15° S beam-line of the Pelletron at TIFR.
The RMS consists of a quadrupole doublet just after the target chamber followed by an ‘electrostatic deflector’, a magnetic
dipole and a second electrostatic deflector. The recoils produced in the 12C + 58Ni reaction using 60 MeV 12C beam were focussed with the help of electric and magnetic fields and detected in a strip detector placed at the focal plane
of the RMS. Further testing of the spectrometer to obtain mass resolution and efficiency are in progress. 相似文献
150.
Coal is an important fuel used in boiler furnaces. There are problems like unburnt coal and solid wastes like ash contain
arsenic, selenium, chromium and cadmium while using it. In order to avoid all such difficulties, aluminium metal powder in
various grain sizes mixed with pulverized coal and burned. aluminium metal powder is one of the pyrotechnics having higher
calorific value and low ignition temperature. The thermal behavior of aluminium powder along with coal is recorded in DTA.
The collected ashes were tested in Scanning Electron Microscope and X-Ray Diffraction meter. The SEM results show that coal
ash is having granular and regular structure. All the particles have a size range from 5 to 8 μm. On the other hand, the aluminium
coal mixture ash shows a fibrous matrix and the particles are irregular. In XRD graph, the peaks in the graph show orientation
of atoms in particular plane and angle. The coal ash has a lot of peaks, but the maximum count value reaches only to 340.97.
However the value of counts reaches a maximum of 1,539.06 for aluminium ash. This denotes high atom orientation in a single
lattice plane. 相似文献