University of Hyderabad

About: University of Hyderabad is a education organization based out in Hyderabad, India. It is known for research contribution in the topics: Catalysis & Crystal structure. The organization has 6446 authors who have published 13005 publications receiving 237641 citations. The organization is also known as: Hyderabad Central University & HCU.

Highly Luminescent Violet- and Blue-Emitting Stable Perovskite Nanocrystals

Abstract: Among the lead halide perovskites, photoluminescence quantum yield (PLQY) of violet-emitting CsPbCl3 nanocrystals (NCs) is the lowest (<5%). This is an impediment to the development of perovskite-b...

Optical absorption and fluorescence studies on imidazolium ionic liquids comprising the bis (trifluoromethanesulphonyl)imide anion

Abstract: Optical absorption and fluorescence behaviour of two rigorously purified imidazolium ionic liquids, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazoliumbis(trifluoromethanesulfonyl)imide are studied in the neat condition and in solution. Non-negligible absorption in the UV region with a long tail extending into the visible region is the main feature of the absorption. Excitation wavelength-dependent two-component fluorescence characterizes the emission behaviour of these liquids. That ion association gives rise to the long absorption tail and shifting fluorescence maximum, which appears to be common to most of the imidazolium ionic liquids, is evident from the effect of the conventional solvents

Identification and characterization of annexin gene family in rice

Abstract: Plant annexins are Ca2+-dependent phospholipid-binding proteins and are encoded by multigene families. They are implicated in the regulation of plant development as well as protection from drought and other stresses. They are well characterized in Arabidopsis, however no such characterization of rice annexin gene family has been reported thus far. With the availability of the rice genome sequence information, we have identified ten members of the rice annexin gene family. At the protein level, they share 16–64% identity with predicted molecular masses ranging from 32 to 40 kDa. Phylogenetic analysis of rice annexins together with annexins from other monocots led to their classification into five different orthologous groups and share similar motif patterns in their protein sequences. Expression analysis by real-time RT-PCR revealed differential temporal and spatial regulation of these genes. The rice annexin genes are also found to be regulated in seedling stage by various abiotic stressors including salinity, drought, heat and cold. Additionally, in silico analysis of the putative upstream sequences was analyzed for the presence of stress-responsive cis-elements. These results provide a basis for further functional characterization of specific rice annexin genes at the tissue/developmental level and in response to abiotic stresses.

Artificial neural network modeling of composition–process–property correlations in austenitic stainless steels

Abstract: This paper discusses the application of artificial neural network modeling in austenitic stainless steels research, including: (i) correlation between chemical composition, process variables and flow stress of austenitic stainless steels under hot compression; (ii) constitutive flow behavior of type AISI 304L stainless steel during hot torsion; (iii) microstructural evolution during dynamic recrystallization of alloy D9; (iv) correlation between chemical composition and tensile properties of alloy D9. Multilayer perceptron based feed-forward networks have been trained by comprehensive in-house datasets. Very good performances of the neural networks are achieved. Various effects are modeled, among which are: (i) influence of alloy composition and processing parameters on flow behavior of austenitic stainless steels; (ii) effect of strain rate on torsional flow behavior of 304L stainless steel; (iii) combined influence of temperature and strain on dynamic recrystallization behavior of alloy D9. The simulated results are found to be consistent with the metallurgical trends. Finally, the issue of neural network's "black box" approach to modeling is addressed.

Organic chlorine as a hydrogen-bridge acceptor: evidence for the existence of intramolecular O--H...Cl--C interactions in some gem-alkynols.

Abstract: The acceptor capabilities of "organic" halogen, CX (X=F, Cl, Br, I), with respect to hydrogen bonding are controversial, and unactivated organic chlorine is generally deemed to be a poor acceptor. Hydrogen bridges of the type O--H...Cl--C are uncommon and occur mainly in an intramolecular situation when the donor group is sterically hindered, so that the formation of intermolecular interactions is difficult. In this paper, intramolecular O--H...Cl--C interactions in a series of chloro-substituted gem-alkynols are studied. We describe various features of this interaction using crystallographic, spectroscopic and computational methods. The O--H...Cl--C interaction occurs in five of the six compounds under consideration here (CDDA, 14DDDA, 15DDDA, 18DDDA, 15MKA). Solution (1)H NMR spectroscopy shows that the interaction is intramolecular and that it is a true hydrogen bond. DFT calculations give a stabilisation energy around 4.0 kcal mol(-1). In the crystal structures of the compounds studied, the intramolecular O--H...Cl--C interactions fit into the overall scheme of cooperative interactions. These structures may be derived from that of the unsubstituted compound DDA by means of synthon exchange and the O--H...Cl--C interaction fares surprisingly well in the presence of competing stronger acceptors. The crystal structures show an unusual degree of modularity for compounds that generally form interactions that are weak and variable. It is noteworthy that the so-called "weak" acceptor, organic chlorine, is able to sustain a good intramolecular hydrogen bridge that is of an attractive and stabilizing nature and which is of potential importance in crystal engineering and supramolecular chemistry.