Climate change vulnerability profiles for North East India

Climate change vulnerability profiles are developed at the district level for agriculture, water and forest sectors for the North East region of India for the current and projected future climates. An index-based approach was used where a set of indicators that represent key sectors of vulnerability (agriculture, forest, water) is selected using the statistical technique principal component analysis. The impacts of climate change on key sectors as represented by the changes in the indicators were derived from impact assessment models. These impacted indicators were utilized for the calculation of the future vulnerability to climate change. Results indicate that majority of the districts in North East India are subject to climate induced vulnerability currently and in the near future. This is a first of its kind study that exhibits ranking of districts of North East India on the basis of the vulnerability index values. The objective of such ranking is to assist in: (i) identifying and prioritizing the most vulnerable sectors and districts; (ii) identifying adaptation interventions, and (iii) mainstreaming adaptation in development programmes.

Structure of the benzene center dot center dot center dot ICI complex: A UVPES and ab initio molecular orbital study

UVPES studies and ab initio and DFT computations have been done on the benzene...ICl complex; electron spectral data and computed orbital energies show that donor orbitals are stabilized and acceptor orbitals are destabilized due to complexation. Calculations predict an oblique structure for the complex in which the interacting site is a C=C bond center in the donor and iodine atom in the acceptor, in full agreement with earlier experimental reports. BSSE-corrected binding energies closely match the enthalpy of complexation reported, and the NBO analysis clearly reveals the involvement of the pi orbital of benzene and the sigma* orbital of ICl in the complex.

High microwave susceptibility of NaH2PO4 center dot 2H(2)O: Rapid synthesis of crystalline and glassy phosphates with NASICON-type chemistry

High microwave susceptibility of NaH2PO4 . 2H(2)O has been discovered, This hydrated acid phosphate of sodium can be heated upto 1000 K or more when exposed to 2.45 GHz microwaves. Using this, a novel microwave-assisted preparation of a number of important crystalline and glassy materials with NASICON-type chemistry has been accomplished in less than 8 min which is only a fraction of the time required for conventional synthetic procedures, The present single-shot approach to the preparation of phosphates is attractive in terms of its simplicity, rapidity, and general applicability, A ''step-ladder'' heating mechanism has been proposed to account for the high microwave absorbing ability of NaH2PO4 . 2H(2)O.

Evidence for Permo-Triassic collision in Far East Asia: The Korean collisional orogen

Eclogites from paragneiss in the Korean Peninsula are characterized by a peak pressure assemblage of garnet + omphacite + quartz + rutile, that is overprinted by multiphase symplectites involving augite, amphibole, orthopyroxene, ilmenite and plagioclase and by a similar high-pressure assemblage with a pronounced absence of the omphacite component in clinopyroxene formed during the peak and orthopyroxene in the retrograde stage. Eclogites were metamorphosed at a minimum pressures of not, vert, similar 20–23 kbar at temperatures of not, vert, similar 840–1000 °C, equivalent to a crustal depth of not, vert, similar 70–75 km, whereas high-pressure granulite in Late Paleozoic rocks underwent metamorphic conditions of not, vert, similar 18–19 kbar at not, vert, similar 950 °C with a minimum crustal depth of not, vert, similar 60–65 km. The presence of the eclogites and high-pressure granulite suggests deep-seated subduction of crustal complexes with metamorphism at different crustal levels. The eclogites were exhumed quickly resulting in near- isothermal decompression. On the other hand, the multistage exhumation of the high-pressure granulites suggests retrograde overprinting after initial decompression. The similarity of these petrological characteristics, metamorphic conditions and also the regional structural styles with those of the Sulu belt (China) strongly suggests the existence of a Permo-Triassic Alpine-type “Korean collision belt” in Far East Asia. This model provides a better understanding of the paleogeograpic evolution of Permo-Triassic East Asia, including a robust tectonic correlation of the Korean collision belt with the Qinling–Dabie–Sulu collision belt.

Studies of phosphazenes. 28. Reactions of pentachloro- and pentafluoro(triphenylphosphazenyl)cyclotriphosphazenes with sodium methoxide. Mechanistic aspects and their implications for nucleophilic displacement at a tetrahedral phosphorus(V) center

Abstract is not available.

Effect of rodents on seed fate of five hornbill-dispersed tree species in a tropical forest in north-east India

Hornbills are important dispersers of a wide range of tree species. Many of these species bear fruits with large, lipid-rich seeds that could attract terrestrial rodents. Rodents have multiple effects on seed fates, many of which remain poorly understood in the Palaeotropics. The role of terrestrial rodents was investigated by tracking seed fate of five horn bill-dispersed tree species in a tropical forest in north-cast India. Seeds were marked inside and outside of exclosures below 6-12 parent fruiting trees (undispersed seed rain) and six hornbill nest trees (a post-dispersal site). Rodent visitors and seed removal ere monitored using camera traps. Our findings suggest that several rodent species. especially two species of porcupine were major on-site seed predators. Scatter-hoarding was rare (1.4%). Seeds at hornbill nest trees had lower survival compared with parent fruiting trees, indicating that clumped dispersal by hornbills may not necessarily improve seed survival. Seed survival in the presence and absence of rodents varied with tree species. Some species (e.g. Polyalthia simiarum) showed no difference, others (e.g. Dysoxylum binectariferum) experienced up to a 64%. decrease in survival in the presence of rodents. The differing magnitude of seed predation by rodents can have significant consequences at the seed establishment stage.

Trifurcated (four-center) hydrogen bond in solid state crystal structure of 5'-amino-5'-deoxyadenosine p-toluenesulfonate

The crystal structure of 5'-amino-5'-deoxyadenosine (5'-Am.dA) p-toluenesulfonate has been determined by X-ray crystallographic methods. It belongs to the orthorhombic space group P2(1)2(1)2(1) with a = 7.754(3)Angstrom, b = 8.065(1)Angstrom and c = 32.481(2)Angstrom. This nucleoside side shows a syn conformation about the glycosyl bond and C2'-endo-C3'-exo puckering for the ribose sugar. The orientation of N5' atom is gauche-trans about the exocyclic C4'-C5' bond. The amino nitrogen N5' forms a trifurcated hydrogen bond with N3, O9T and O4' atoms. Adenine bases form A.A.A triplets through hydrogen bonding between N6, N7 and N1 atoms of symmetry related nucleoside molecules.

Vertical distribution of aerosols over the east coast of India inferred from airborne LIDAR measurements

The information on altitude distribution of aerosols in the atmosphere is essential in assessing the impact of aerosol warming on thermal structure and stability of the atmosphere.In addition, aerosol altitude distribution is needed to address complex problems such as the radiative interaction of aerosols in the presence of clouds. With this objective,an extensive, multi-institutional and multi-platform field experiment (ICARB-Integrated Campaign for Aerosols, gases and Radiation Budget) was carried out under the Geosphere Biosphere Programme of the Indian Space Research Organization (ISRO-GBP) over continental India and adjoining oceans during March to May 2006. Here, we present airborne LIDAR measurements carried out over the east Coast of the India during the ICARB field campaign. An increase in aerosol extinction (scattering + absorption) was observed from the surface upwards with a maximum around 2 to 4 km. Aerosol extinction at higher atmospheric layers (>2 km) was two to three times larger compared to that of the surface. A large fraction (75-85%) of aerosol column optical depth was contributed by aerosols located above 1 km. The aerosol layer heights (defined in this paper as the height at which the gradient in extinction coefficient changes sign) showed a gradual decrease with an increase in the offshore distance. A large fraction (60-75%) of aerosol was found located above clouds indicating enhanced aerosol absorption above clouds. Our study implies that a detailed statistical evaluation of the temporal frequency and spatial extent of elevated aerosol layers is necessary to assess their significance to the climate. This is feasible using data from space-borne lidars such as CALIPSO,which fly in formation with other satellites like MODIS AQUA and MISR, as part of the A-Train constellation.

Theoretical Investigation on the Effect of Different Nitrogen Donors on Intramolecular Se center dot center dot center dot N Interactions

The effect of different donor nitrogen atoms on the strength and nature of intramolecular Se center dot center dot center dot N interactions is evaluated for organoselenium compounds having N,N-dimethylaminomethyl (dime), oxazoline (oxa) and pyridyl (py) substituents. Quantum chemical calculations on three series of compounds [2-(dime)C6H4SeX (1a-g), 2-(oxa)C6H4SeX (2a-g), 2- (py)C6H4SeX (3-ag); X=Cl, Br, OH, CN, SPh, SePh, CH3] at the B3LYP/6-31G(d) level show that the stability of different conformers depends on the strength of intramolecular nonbonded Se center dot center dot center dot N interactions. Natural bond orbital (NBO), NBO deletion and atoms in molecules (AIM) analyses suggest that the nature of the Se center dot center dot center dot N interaction is predominantly covalent and involves nN ->sigma*(Se-X) orbital interaction. In the three series of compounds, the strength of the Se center dot center dot center dot N interaction decreases in the order 3>2>1 for a particular X, and it decreases in the order Cl > Br > OH>SPh approximate to CN approximate to SePh>CH3 for all the three series 1-3. However, further analyses suggest that the differences in strength of Se center dot center dot center dot N interaction in 1-3 is predominantly determined by the distance between the Se and N atoms, which in turn is an outcome of specific structures of 1, 2 and 3, and the nature of the donor nitrogen atoms involved has very little effect on the strength of Se center dot center dot center dot N interaction. It is also observed that Se center dot center dot center dot N interaction becomes stronger in polar solvents such as CHCl3, as indicated by the shorter r(Se center dot center dot center dot N) and higher E-Se center dot center dot center dot N values in CHCl3 compared to those observed in the gas phase.

Modulating the preferred O-H center dot center dot center dot O hydrogen-bonding motif in a conformationally constrained environment through hydroxy-group derivatization

The crystal structures of three conformationally locked esters, namely the centrosymmetric tetrabenzoate of all-axial per-hydronaphthalene- 2,3,4a, 6,7,8a-hexaol, viz. trans-4a, 8a-dihydroxyperhydronaphthalene-2,3,6,7-tetrayl tetrabenzoate, C38H34O10, and the diacetate and dibenzoate of all-axial perhydronaphthalene-2,3,4a, 8a-tetraol, viz. (2R*,3R*,4aS*,8aS*)-4a, 8a-dihydroxyperhydronaphthalene-2,3-diyl diacetate, C-14-H22O6, and (2R*, 3R*, 4aS*, 8aS*)-4a, 8a-dihydroxyperhydronaphthalene- 2,3-diyl dibenzoate, C24H26O6, have been analyzed in order to examine the preference of their supramolecular assemblies towards competing inter-and intramolecular O-H center dot center dot center dot O hydrogen bonds. It was anticipated that the supramolecular assembly of the esters under study would adopt two principal hydrogen-bonding modes, namely one that employs intermolecular O-H center dot center dot center dot O hydrogen bonds (mode 1) and another that sacrifices those for intramolecular O-H center dot center dot center dot O hydrogen bonds and settles for a crystal packing dictated by weak intermolecular interactions alone (mode 2). Thus, while the molecular assembly of the two crystalline diacyl derivatives conformed to a combination of hydrogen-bonding modes 1 and 2, the crystal packing in the tetrabenzoate preferred to follow mode 2 exclusively.

Supramolecular Organization in Tetra Aqua (mu-8-Hydroxyquinoline-5-sulfonate) Barium (II) and Ag center dot center dot center dot I Interactions in a Pseudopolymorphic Form of (7-Iodo-8-hydroxyquinoline-5-sulfonate) Silver (I) Monohydrate

The complexes, Ba (HQS) (H2O)(4) (HQS = 8-hydroxyquinoline-5-sulfonic acid) (1) and Ag (HIQS) (H2O) (Ferron = 7-iodo-8-hydroxyquinoline-5-sulfonic acid) (2) have been synthesized and characterized by X-ray diffraction analysis and spectroscopic studies. In compound 1, Ba2+ ion has a nine-coordinate monocapped antiprismatic geometry. In compound 2, Ag+ has distorted tetrahedral coordination and Ag center dot center dot center dot I interactions generate the supramolecular architectures. The complexes have been characterized by FT-IR and UV-Visible measurements. In both the structures, the inversion-related organic ligands are stacked over one another leading to three-dimensional networks.

Analysis of shore line protection works in tsunami hit areas of east coast of India

Evaluation and design of shore protection works in the case of tsunamis assumes considerable importance in view of the impact it had in the recent tsunami of 26th December 2004 in India and other countries in Asia. The fact that there are no proper guidelines have made in the matters worse and resulted in the magnitude of damage that occurred. Survey of the damages indicated that the scour as a result of high velocities is one of the prime reasons for damages in the case of simple structures. It is revealed that sea walls in some cases have been helpful to minimize the damages. The objective of this paper is to suggest that design of shore line protection systems using expected wave heights that get generated and use of flexible systems such as geocells is likely to give a better protection. The protection systems can be designed to withstand the wave forces that corresponding to different probabilities of incidence. A design approach of geocells protection system is suggested and illustrated with reference to the data of wave heights in the east coast of India.

N-H center dot center dot center dot O and C-H center dot center dotcenter dot O interaction mimicry in the 1:1 molecular complexes of 5,5-diethylbarbituric acid with urea and acetamide

The analogy between N-H center dot center dot center dot O and C-H center dot center dot center dot O intermolecular interactions is studied with variable temperature (180-100 K) single crystal X-ray diffraction analysis.5,5-Diethylbarbituric acid (barbital) forms isostructural molecular complexes (co-crystals) with urea (1) and acetamide (2) that respectively contain these analogous interactions.The behaviour of these two interactions as a function of temperature is very similar. This indicates that the C-H center dot center dot center dot O bond in barbital acetamide plays a similar chemical and structural role as does the N-H center dot center dot center dot O bond in barbital urea. The close relationship between these interactions and their comparable nature is further adduced from the formation of a ternary solid solution (3) of barbital, urea and acetamide. The fact that the C-H center dot center dot center dot O interaction in barbital acetamide is weaker than the N-H center dot center dot center dot O interaction in barbital urea is shown by the fact that acetamide is under expressed and urea is over expressed with respect to the quantities of these substances present in solution prior to crystallization of these ternary crystals.

Structural and optical properties of (100-x)Li2B4O7 center dot x(Ba5Li2Ti2Nb8O30) glasses and glass nanocrystal composites

Optically clear glasses of various compositions in the system (100-x)Li2B4O7 center dot x(Ba5Li2Ti2Nb8O30) (5 <= x <= 20, in molar ratio) were fabricated by splat quenching technique. Controlled heat-treatment of the as-quenched glasses at 500 degrees C for 8 h yielded nanocrystallites embedded in the glass matrix. High Resolution Transmission Electron Microscopy (HRTEM) of these samples established the composition of the nano-crystallites to be that of Ba5Li2Ti2Nb8O30. B-11 NMR studies revealed the transformation of BO4 structural units into BO3 units owing to the increase in TiO6 and NbO6 structural units as the composition of Ba5Li2Ti2Nb8O30 increased in the glass. This, in turn, resulted in an increase in the density of the glasses. The influence of the nominal composition of the glasses and glass nanocrystal composites on optical band gap (E-opt), Urbach energy (Delta E), refractive index (n), molar refraction (R-m), optical polarizability (alpha(m)) and third order non-linear optical susceptibility (chi(3)) were studied.

Probing Fluorine Interactions in a Polyhydroxylated Environment: Conservation of a C-F center dot center dot center dot H-C Recognition Motif in Presence of O-H center dot center dot center dot O Hydrogen Bonds

Three conformationally locked fluorinated polycyclitols have been specially crafted on a rigid trans-decalin backbone, employing a surprisingly facile pyridine-poly(hydrogen fluoride)-mediated stereospecific epoxide ring opening as the key reaction. Molecula design of the three fluorinated probes under study focused on providing an efficient platform for (a) evaluating the ability of covalently bonded fluorine, vis-a-vis the isosteric hydroxy group, to act as a H-bond acceptor and (b) examining the possibility for an organic fluorine moiety, placed suitably in a spatially invariant position, to engage an 1,3-diaxial OH functionality in a purported intramolecular O-H center dot center dot center dot F hydrogen bond. The present endeavour reveals that C(sp(3))-F center dot center dot center dot H-C(sp(3)) hydrogen bonds, though weak and lesser investigated, can indeed be observed and supramolecular recognition motifs, involving such interactions, can be conserved even in crystal structures laden with stronger O-H center dot center dot center dot O hydrogen bonds.