Characterization and Characteristics of mechanochemically synthesized amorphous fast ionic conductor 50 SISOMO (50AgI-25Ag2O-25MoO3)

Mechanochemically synthesized amorphous 50SISOMO [50AgI-25Ag_2O-25MoO_3] fast ionic conductor shows high ionic conductivity of ~ 6x10^-3 {\Omega}^-1 cm-1 at room temperature. The highest ionic conductivity is achieved for 36 h milled sample, which is more than three orders of magnitude higher than that of crystalline AgI at room temperature. The samples are thermally stable at least up to ~70 {\deg}C. Thermoelectric power studies on 50 SISOMO amorphous fast ionic conductors (a-SIC) have been carried out in the temperature range 300-330K. Thermoelectric power (S) is found to vary linearly with the inverse of the absolute temperature, and can be expressed by the equation -S = [(0.19 \times 10^3/T) + 0.25] mV/K. The heat of transport (q*) of Ag+ ion i.e. 0.19 eV is nearly equal to the activation energy (E) i.e. 0.20 eV of Ag+ ion migration calculated from the conductivity plots indicating that the material has an average structure. This is also in consonance with earlier theories on heats of transport of ions in ionic solids.Comment: Presented in the "National Symposium on Advances in Material Science" held at Gorakhpur, India during 17-19 March 200

Fractional Hereditariness of Lipid Membranes: Instabilities and Linearized Evolution

In this work lipid ordering phase changes arising in planar membrane bilayers is investigated both accounting for elas- ticity alone and for effective viscoelastic response of such assemblies. The mechanical response of such membranes is studied by minimizing the Gibbs free energy which penalizes perturbations of the changes of areal stretch and their gradients only [1]. As material instabilities arise whenever areal stretches characterizing homogeneous configurations lie inside the spinoidal zone of the free energy density, bifurcations from such configurations are shown to occur as oscillatory perturbations of the in-plane displacement. Experimental observations [2] show a power-law in-plane viscous behavior of lipid structures allowing for an effective viscoelastic behavior of lipid membranes [3], which falls in the framework of Fractional Hereditariness. A suitable generalization of the variational principle invoked for the elasticity is applied in this case, and the corresponding Euler-Lagrange equation is found together with a set of bound- ary and initial conditions. Separation of variables allows for showing how Fractional Hereditariness owes bifurcated modes with a larger number of spatial oscillations than the corresponding elastic analog. Indeed, the available range of areal stresses for material instabilities is found to increase with respect to the purely elastic case. Nevertheless, the time evolution of the perturbations solving the Euler-Lagrange equation above exhibits time-decay and the large number of spatial oscillation slowly relaxes, thereby keeping the features of a long-tail type time-response.Comment: 21 pages, 11 figures, special issu

On the Syntax of Multiple Sluicing and What It Tells Us about Wh-Scope Taking

Across many languages multiple sluicing obeys a clause-mate constraint. This can be understood on the empirically well-supported assumption that covert phrasal wh-movement is clause-bounded and subject to superiority. We provide independent evidence for syntactic structure at the ellipsis site and for locality constraints on movement operations within the ellipsis site. The fact that the distribution of multiple sluicing is substantially narrower than that of multiple wh-questions, on their single-pair as well as their pairlist reading, entails that there must be mechanisms for scoping in-situ wh-phrases that do not rely on covert phrasal wh-movement. We adopt the choice functional account for single-pair readings. For pair-list readings, we develop a novel functional analysis, argue for the functional basis of pair-list readings, and present a new perspective on pair-list readings of questions with quantifiers

Liquefaction Analysis of a Bridge Site in Assam (India)

A rail-cum-road bridge with approach embankments is to be constructed on the Brahmputra river near Bogobil in Assam (India). The project site is located in Brahmputra’s alluvial plain and lies in an area of very high seismic hazard (zone V of Indian seismic zone map as per IS: 1893-1984) and traverse through the liquefiable ground. A two-level earthquake design criterion has been used: safety-evaluation ground motion of PGA of 0.6g, and a functional-evaluation ground motion of 0. lg. The liquefaction analysis has been carried using a “simplified procedure” originally developed by Seed and Idriss and progressively revised, extended and refined by others. The soil stratigraphy beneath the embankment consists of about 10m of recent alluvium of very loose to medium dense sand and silty soil overlying up to about 30m of medium to very dense deposits of sand and silty sand. Below this layer a dense to very dense sandy layer is encountered. The liquefaction assessment has been carried out for maximum embankment height of 2 lm which is to be constructed on the existing ground surface. The analysis indicated that the liquefaction is not likely to occur for functional evaluation motion. Soil strata under the embankments are liable to liquefy due to ground motion with PGA of 0.6g up to depths of about 14-18m with a total soil settlement of up to about 260 mm. Embankment stability has also been considered when the soil strata underlying the embankment undergo liquefaction. For this analysis, liquefiable soil layers have been assigned only the residual strength. For static case (i.e., no earthquake), the factor of safety ranges from 1.18 to 1.39. The bridge and abutments are founded on well foundations seated at about 55m below the river bed, conforming to minimum scour depth and grip length requirements. The average and normalized N-values at the bridge foundation levels are 86 and 39, respectively and, therefore, the bridge foundations are not susceptible to liquefaction

Damage Tolerance and NDE of Polymeric Composites

As composites are being used as primary load bearing members, the increased understanding of damage tolerance of the material is becoming important. When load is applied to a structure containing a crack or damage, a small area ahead of the crack undergoes very high stress. These stresses cause further damage in this small zone. Initially this damage is at the microlevel: in isotropic materials the microdamage is in the form of slippage and microcracks at grain boundary; in composites the microdamage constitutes of matrix microcracks, matrix-fiber interface cracks and fiber pull out. The size of this damage zone varies depending on the material type and the damage tolerance i.e. energy absorbed by the damage zone is directly proportional to the damage zon

Spatial Distributions of Multiple Dust Components in the PPN/PN Dust Shells

We investigate spatial distributions of specific dust components in the circumstellar shells of a proto-planetary nebula candidate, HD 179821, and a planetary nebula, BD$+30^{\circ}$3639, by means of spectral imaging. With high-resolution ground-based images and ISO spectra in the mid-infrared, we can derive ``dust feature only'' maps by subtracting synthesized continuum maps from the observed images at the feature wavelength. Such spatially detailed information will help to develop models for the evolution of dust grains around evolved stars.Comment: 4 pages + 7 figures, to appear in the proceedings of the conference, "Post-AGB Objects (proto-planetary nebulae) as a Phase of Stellar Evolution", Torun, Poland, July 5-7, 2000, eds. R. Szczerba, R. Tylenda, and S.K. Gorny. Figures have been degraded to minimize the total file siz