Owing to optical refraction, external rays that are incident upon a high-refractive-index medium fall within a small internal cone angle. A one-dimensionally periodic Bragg structure can reflect over an angular acceptance range that is greater than the small internal refraction cone, if the internal refractive-index contrast is sufficient. Thus Winn et al. [Opt. Lett. (to be published)] charted...

In-situ testing techniques have proven to be successful in improving the speed and reliability of geotechnical investigations. One of the most common in-situ methods in engineering geology and site investigation is Cone Penetration Test (CPT), which is mainly used for characterization of soils, as it is a robust, simple, fast, reliable and economic test that can provide continuous soundings of ...

the purpose of this study was the introduction of seed accumulation index as a new approach in the evaluation of soil seed bank consistency in the populus caspica in noor reserved forest park. sampling were made above ground vegetation at peak vegetation cover during june 2010 by systematic- selective method. soil samples were collected during late june, late november and early february by hamm...

to study the effects of soil amendments on physical and hydraulic properties of a saline-sodic sandy clay loam soil, a field experiment was carried out as a complete block design with three replications. the treatments in this research consisted of control (b), 10 ton ha-1 gypsum (g), 10 ton ha-1 urban solid compost (c), three levels of vinyl alcohol acrylic acid (s1= 0.05%, s2= 0.1%, s3= 0.2%)...

Soil-geomorphic studies indicate that six major allostratigraphic units occur in Crater Flat, Nevada, adjacent to Yucca Mountain. These units are, from youngest to oldest, Crater Flat, Little Cones, Late Black Cone, Early Black Cone, Yucca, and Solitario. Presence and degree of differentiation of Av, Ak, Bw, Bt, Btk, Btkq, and Bqkm genetic soil horizons characterize units, confirm relative ages...

This paper presents conditions for the existence and multiplicity of positive solutions for a boundary value problem of a nonlinear fractional differential equation. We show that it has at least one or two positive solutions. The main tool is Krasnosel'skii fixed point theorem on cone and fixed point index theory.

Zero index materials where sound propagates without phase variation, holds a great potential for wavefront and dispersion engineering. Recently explored electromagnetic double zero index metamaterials consist of periodic scatterers whose refractive index is significantly larger than that of the surrounding medium. This requirement is fundamentally challenging for airborne acoustics because the ...

The Morrison-Kawamata cone conjecture predicts that the actions of the automorphism group on the effective nef cone and the pseudo-automorphism group on the effective movable cone of a klt Calabi-Yau pair (X,∆) have finite, rational polyhedral fundamental domains. Let Z be an n-dimensional Fano manifold of index n − 1 such that −KZ = (n − 1)H for an ample divisor H. Let Γ be the base locus of a...

This paper aims to study the influence of soil-structure interaction on plastic energy demand spectra directly derived from the energy-balance equations of soil-shallow-foundation structure with respect to an ensemble of far-field strong ground motions obtained from Pacific Earthquake Engineering Research (PEER) database and recorded on alluvium soil. The superstructure is modeled as a single-d...