983 resultados para CHLORO-SIDE-GROUP


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India's energy demand is increasing rapidly with the intensive growth of economy. The electricity demand in India exceeded the availability, both in terms of base load energy and peak availability. The efficient use of energy source and its conversion and utilizations are the viable alternatives available to the utilities or industry. There are essentially two approaches to electrical energy management. First at the supply / utility end (Supply Side Management or SSM) and the other at the consumer end (Demand Side Management or DSM). This work is based on Supply Side Management (SSM) protocol and consists of design, fabrication and testing of a control device that will be able to automatically regulate the power flow to an individual consumer's premise. This control device can monitor the overuse of electricity (above the connected load or contracted demand) by the individual consumers. The present project work specially emphasizes on contract demand of every consumer and tries to reduce the use beyond the contract demand. This control unit design includes both software and hardware work and designed for 0.5 kW contract demand. The device is tested in laboratory and reveals its potential use in the field.

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The crystal structures of nine peptides containing gamma(4)Val and gamma(4)Leu are described. The short sequences Boc-gamma(4)(R)Val](2)-OMe 1, Boc-gamma(4)(R)Val](3)-NHMe 2 and Boc-gamma(4)(S)Val-gamma(4)(R)Val-OMe 3 adopt extended apolar, sheet like structures. The tetrapeptide Boc-gamma(4)(R)Val](4)-OMe 4 adopts an extended conformation, in contrast to the folded C-14 helical structure determined previously for Boc-gamma(4)(R)Leu](4)-OMe. The hybrid alpha gamma sequence Boc-Ala-gamma(4)(R)Leu](2)-OMe 5 adopts an S-shaped structure devoid of intramolecular hydrogen bonds, with both alpha residues adopting local helical conformations. In sharp contrast, the tetrapeptides Boc-Aib-gamma(4)(S)Leu](2)-OMe 6 and Boc-Leu-gamma(4)(R)Leu](2)-OMe 7 adopt folded structures stabilized by two successive C-12 hydrogen bonds. gamma(4)Val residues have also been incorporated into the strand segments of a crystalline octapeptide, Boc-Leu-gamma(4)(R)Val-Val-(D)Pro-Gly-Leu-gamma(4)(R)Val-Val-OMe 8. The gamma gamma delta gamma tetrapeptide containing gamma(4)Val and delta(5)Leu residues adopts an extended sheet like structure. The hydrogen bonding pattern at gamma residues corresponds to an apolar sheet, while a polar sheet is observed at the lone delta residue. The transition between folded and extended structures at gamma residues involves a change of the torsion angle from the gauche to the trans conformation about the C-beta-C-alpha bond.

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We use Floquet theory to study the maximum value of the stroboscopic group velocity in a one-dimensional tight-binding model subjected to an on-site staggered potential varying sinusoidally in time. The results obtained by numerically diagonalizing the Floquet operator are analyzed using a variety of analytical schemes. In the low-frequency limit we use adiabatic theory, while in the high-frequency limit the Magnus expansion of the Floquet Hamiltonian turns out to be appropriate. When the magnitude of the staggered potential is much greater or much less than the hopping, we use degenerate Floquet perturbation theory; we find that dynamical localization occurs in the former case when the maximum group velocity vanishes. Finally, starting from an ``engineered'' initial state where the particles (taken to be hard-core bosons) are localized in one part of the chain, we demonstrate that the existence of a maximum stroboscopic group velocity manifests in a light-cone-like spreading of the particles in real space.

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This paper presents the first microwave spectroscopic investigation on hexafluoroisopropanol (HFIP). A pulsed nozzle Fourier transform microwave spectrometer has been used to determine the rotational constants for HFIP as A = 2105.12166(18) MHz, B = 1053.99503(12) MHz, and C = 932.33959(13) MHz. In addition, five isotopologues of HFIP have been observed experimentally to determine the accurate structure of HFIP. The observed spectrum could be assigned to the most stable conformer of HFIP, called antiperiplanar. Available spectroscopic information and ab initio calculations on five prototype molecules helped in exploring the torsional behavior of molecules having a CF3-C-CF3 group. Two-dimensional potential energy surfaces have been analyzed for all molecules, which explained the presence/absence of doubling in the rotational transitions. With the help of natural bond orbital (NBO) analysis, reasons for the conformational preference of HFIP have been explained.

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3,4-Dichlorophenol (1) crystallizes in the tetragonal space group I4(1)/a with a short axis of 3.7926 (9) angstrom. The structure is unique in that both type I and type II Cl.....Cl interactions are present, these contact types being distinguished by the angle ranges of the respective C-Cl....Cl angles. The present study shows that these two types of contacts are utterly different. The crystal structures of 4-bromo-3-chlorophenol (2) and 3-bromo-4-chlorophenol (3) have been determined. The crystal structure of (2) is isomorphous to that of (1) with the Br atom in the 4-position participating in a type II interaction. However, the monoclinic P2(1)/c packing of compound (3) is different; while the structure still has O-H....O hydrogen bonds, the tetramer O-H.....O synthon seen in (1) and (2) is not seen. Rather than a type I Br....Br interaction which would have been mandated if (3) were isomorphous to (1) and (2), Br forms a Br....O contact wherein its electrophilic character is clearly evident. Crystal structures of the related compounds 4-chloro-3-iodophenol (4) and 3,5-dibromophenol (5) were also determined. A computational survey of the structural landscape was undertaken for (1), (2) and (3), using a crystal structure prediction protocol in space groups P2(1)/c and I4(1)/a with the COMPASS26 force field. While both tetragonal and monoclinic structures are energetically reasonable for all compounds, the fact that (3) takes the latter structure indicates that Br prefers type II over type I contacts. In order to differentiate further between type I and type II halogen contacts, which being chemically distinct are expected to have different distance fall-off properties, a variable-temperature crystallography study was performed on compounds (1), (2) and (4). Length variations with temperature are greater for type II contacts compared with type I. The type II Br....Br interaction in (2) is stronger than the corresponding type II Cl....Cl interaction in (1), leading to elastic bending of the former upon application of mechanical stress, which contrasts with the plastic deformation of (1). The observation of elastic deformation in (2) is noteworthy; in that it finds an explanation based on the strengths of the respective halogen bonds, it could also be taken as a good starting model for future property design. Cl/Br isostructurality is studied with the Cambridge Structural Database and it is indicated that this isostructurality is based on shape and size similarity of Cl and Br, rather than arising from any chemical resemblance.

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A series of 2,5-di(4-aryloylaryloxymethyl)-1,3,4-oxadiazoles 9a-j were obtained via multistep synthesis from hydroxybenzophenones 4a-e. The cytotoxicity of compounds 9a-j was evaluated against human leukemia cell lilies (K562 and CEM). The compounds exhibited moderate to good anti-cancer activity with compounds 9b and 9i having a chloro group exhibiting the best activity (IC50 = 10 mu M). Compound 9i exhibited activity against both the cell lines and 9b only exhibited activity against CEM. Further, a lactate dehydrogenase (LDH) assay and DNA fragmentation studies of the compounds 9a-j were also performed. (C) 2013 Elsevier Masson SAS. All rights reserved.

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We carried out a large-scale phylogenetic analysis of fejervaryan (dicroglossid frogs with `Fejervaryan lines' on the ventral side of the body) frogs, distributed in South and SE Asia, using published and newly generated sequences of unidentified individuals from the northern Western Ghats. The results corroborate the presence of a larger fejervaryan clade with a sister relationship to a clade composed of Sphaerotheca. Two sister clades could be discerned within the lager fejervaryan clade. The unidentified individuals formed a monophyletic group and showed a strong support for a sister relationship with Minervarya sahyadris. The species was found to be highly divergent (16S rRNA-4% and tyr-1%) from its sister lineage Minervarya sahyadris, and the clade composed of these two lineages were found to be deeply nested within the larger clade of Fejervarya. Based on this, the genus Minervarya Dubois, Ohler and Biju, 2001 is synonymized under the genus Fejervarya Bolkay, 1915. The unidentified lineage is recognized, based on phylogenetic position, genetic divergence and morphological divergence, as a distinct species and named here as Fejervarya gomantaki sp. nov. The presence of rictal glands was observed to be a synapomorphic character shared by the nested clade members, Fejervarya sahyadris and Fejervarya gomantaki sp. nov. Based on the presence of rictal gland and small size, Minervarya chilapata, a species from a lowland region in the Eastern Himalayas, is synonymized under Fejervarya and evidence for morphological separation from the new species, Fejervarya gomantaki sp. nov. is provided. For the fejervaryan frogs, currently three generic names (Frost, 2015) are available for the two phylogenetic subclades; the genus Fejervarya Bolkay, 1915 for the species of fejervaryan frogs having distribution in the South East Asia; the genus Zakerana Howlader, 2011 for the species of fejervaryan frogs having distribution in the South Asia and the genus Minervarya Dubois, Ohler and Biju, 2001 nested within the `Zakerana clade'. In the phylogenetic analysis Minervarya sahyadris, the new species described herein as Fejervarya gomantaki sp. nov. are nested within the `Zakerana clade', if the `Zakerana clade' for the fejervaryan frogs having distribution in the South Asia is provided a generic status the nomen `Minervarya' should be considered as per the principle of priority of the ICZN Code. Taking into consideration the overlapping distribution ranges of members of the sister clades within the larger fejervaryan clade and the absence of distinct morphological characteristics, we also synonymize the genus Zakerana Howlader, 2011, a name assigned to one of the sister clades with members predominantly distributed in South Asia, under the genus Fejervarya Bolkay, 1915. We discuss the need for additional sampling to identify additional taxa and determine the geographical ranges of the members of the sister clades within Fejervarya to resolve taxonomy within this group.

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In this paper, we propose a H.264/AVC compressed domain human action recognition system with projection based metacognitive learning classifier (PBL-McRBFN). The features are extracted from the quantization parameters and the motion vectors of the compressed video stream for a time window and used as input to the classifier. Since compressed domain analysis is done with noisy, sparse compression parameters, it is a huge challenge to achieve performance comparable to pixel domain analysis. On the positive side, compressed domain allows rapid analysis of videos compared to pixel level analysis. The classification results are analyzed for different values of Group of Pictures (GOP) parameter, time window including full videos. The functional relationship between the features and action labels are established using PBL-McRBFN with a cognitive and meta-cognitive component. The cognitive component is a radial basis function, while the meta-cognitive component employs self-regulation to achieve better performance in subject independent action recognition task. The proposed approach is faster and shows comparable performance with respect to the state-of-the-art pixel domain counterparts. It employs partial decoding, which rules out the complexity of full decoding, and minimizes computational load and memory usage. This results in reduced hardware utilization and increased speed of classification. The results are compared with two benchmark datasets and show more than 90% accuracy using the PBL-McRBFN. The performance for various GOP parameters and group of frames are obtained with twenty random trials and compared with other well-known classifiers in machine learning literature. (C) 2015 Elsevier B.V. All rights reserved.

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A hitherto unseen rotation of the isopropyl group in the solid state, predicted to be forbidden based on theoretical investigations, is reported. This C-C rotation observed during the temperature dependent single-crystal-to-single-crystal transformation is attributed to the concomitant changes in molecular structure and intermolecular packing.

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In this paper we prove weighted mixed norm estimates for Riesz transforms on the Heisenberg group and Riesz transforms associated to the special Hermite operator. From these results vector-valued inequalities for sequences of Riesz transforms associated to generalised Grushin operators and Laguerre operators are deduced.

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We examine the deflected mirage mediation supersymmetry breaking (DMMSB) scenario, which combines three supersymmetry breaking scenarios, namely anomaly mediation, gravity mediation and gauge mediation using the one-loop renormalization group invariants (RGIs). We examine the effects on the RGIs at the threshold where the gauge messengers emerge, and derive the supersymmetry breaking parameters in terms of the RGIs. We further discuss whether the supersymmetry breaking mediation mechanism can be determined using a limited set of invariants, and derive sum rules valid for DMMSB below the gauge messenger scale. In addition we examine the implications of the measured Higgs mass for the DMMSB spectrum.

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Network theory has become an excellent method of choice through which biological data are smoothly integrated to gain insights into complex biological problems. Understanding protein structure, folding, and function has been an important problem, which is being extensively investigated by the network approach. Since the sequence uniquely determines the structure, this review focuses on the networks of non-covalently connected amino acid side chains in proteins. Questions in structural biology are addressed within the framework of such a formalism. While general applications are mentioned in this review, challenging problems which have demanded the attention of scientific community for a long time, such as allostery and protein folding, are considered in greater detail. Our aim has been to explore these important problems through the eyes of networks. Various methods of constructing protein structure networks (PSN) are consolidated. They include the methods based on geometry, edges weighted by different schemes, and also bipartite network of protein-nucleic acid complexes. A number of network metrics that elegantly capture the general features as well as specific features related to phenomena, such as allostery and protein model validation, are described. Additionally, an integration of network theory with ensembles of equilibrium structures of a single protein or that of a large number of structures from the data bank has been presented to perceive complex phenomena from network perspective. Finally, we discuss briefly the capabilities, limitations, and the scope for further explorations of protein structure networks.

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In the last few years, there has been remarkable progress in the development of group III-nitride based materials because of their potential application in fabricating various optoelectronic devices such as light emitting diodes, laser diodes, tandem solar cells and field effect transistors. In order to realize these devices, growth of device quality heterostructures are required. One of the most interesting properties of a semiconductor heterostructure interface is its Schottky barrier height, which is a measure of the mismatch of the energy levels for the majority carriers across the heterojunction interface. Recently, the growth of non-polar III-nitrides has been an important subject due to its potential improvement on the efficiency of III-nitride-based opto-electronic devices. It is well known that the c-axis oriented optoelectronic devices are strongly affected by the intrinsic spontaneous and piezoelectric polarization fields, which results in the low electron-hole recombination efficiency. One of the useful approaches for eliminating the piezoelectric polarization effects is to fabricate nitride-based devices along non-polar and semi-polar directions. Heterostructures grown on these orientations are receiving a lot of focus due to enhanced behaviour. In the present review article discussion has been carried out on the growth of III-nitride binary alloys and properties of GaN/Si, InN/Si, polar InN/GaN, and nonpolar InN/GaN heterostructures followed by studies on band offsets of III-nitride semiconductor heterostructures using the x-ray photoelectron spectroscopy technique. Current transport mechanisms of these heterostructures are also discussed.

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The Continuum in the variation of the X-Z bond length change from blue-shifting to red-shifting through zero-shifting in the X-Z---Y complex is inevitable. This has been analyzed by ab-initio molecular orbital calculations using Z= Hydrogen, Halogens, Chalcogens, and Pnicogens as prototypical examples. Our analysis revealed that, the competition between negative hyperconjugation within the donor (X-Z) molecule and Charge Transfer (CT) from the acceptor (Y) molecule is the primary reason for the X-Z bond length change. Here, we report that, the proper tuning of X-and Y-group for a particular Z-can change the blue-shifting nature of X-Z bond to zero-shifting and further to red-shifting. This observation led to the proposal of a continuum in the variation of the X-Z bond length during the formation of X-Z---Y complex. The varying number of orbitals and electrons available around the Z-atom differentiates various classes of weak interactions and leads to interactions dramatically different from the H-Bond. Our explanations based on the model of anti-bonding orbitals can be transferred from one class of weak interactions to another. We further take the idea of continuum to the nature of chemical bonding in general. (C) 2015 Wiley Periodicals, Inc.

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Nonprotein amino acids are being extensively used in the design of synthetic peptides to create new structure mimics. In this study we report the effect of methylene group insertions in a heptapeptide Boc-Ala(1)-Leu(2)-Aib(3)-Xxx(4)-Ala(5)-Leu(6)-Aib(7)-OMe which nicely folds into a mixed 3(10)-/-helical structure when Xxx= Ala. Analogs of this peptide have been made and studied by replacing central Xxx(4) residue with Glycine (-residue), -Alanine (-la), -aminobutyric acid (Gaba), and epsilon-aminocaproic acid (epsilon-Aca). NMR and circular dichroism were used to study the solution structure of these peptides. Crystals of the peptides containing alanine, -la, and Gaba reveal that increasing the number of central methylene (-CH2-) groups introduces local perturbations even as the helical structure is retained. (c) 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 720-732, 2015.