In this paper, the effects of horizontal stress and dimensions of barrier pillars on the stability of drifts hr been investigated. An elastoplastic hybrid finite/boundary element program has been used. A plastic analysis of stresses in barrier pillars above the drifts in one of the underground coal mines with inclined seams is examined. Computed stresses and safety factor controur lines around ...

Directional antennas offer many potential advantages for wireless networks such as increased network capacity, extended transmission range and reduced energy consumption. Exploiting these advantages requires new protocols and mechanisms at various communication layers to intelligently control the directional antenna system. With directional antennas, many trivial mechanisms, such as neighbor di...

The identification of breeding sites of sand flies is of great epidemiological interest. A soil emergence trap for investigating potential sand fly breeding sites is described. The trap was tested in two rural areas in the Mogi Guaçu River Valley where the American cutaneous leishmaniasis is an endemic disease. Seventy-three sand fly individuals of three species, Lutzomyia intermedia s. l., L. ...

In this paper, we present a new spectral light transport model for sand. The model employs a novel approach to simulate light interaction with particulate materials which yields both the spectral and spatial (bi-directional reflectance distribution function, or BRDF) responses of sand. Furthermore, the parameters specifying the model are based on the physical and mineralogical properties of san...

In this research, investigation the impact of water levels, velocity on drift depth pillars bridges in Garmian region was studied. The levels and were recorded for periods, different stretches between months December 2018 March 2019. study dealt with most important postural relationships that can be used to estimate future around pillars. Description site studying within includes measurements b...

Present study took into account the relationship between surface soil moisture of intertidal zone and its spectral reflectance and the relationship between surface soil moisture and the relative elevation of intertidal zone to extract ‘ridges’. It can represent the main morphological character of radial sand ridges, and find specific spectral bands to diagnose much ‘drier’ points of sand ridges...

We investigate the validity and failure of Liouville theorems and Harnack inequalities for parabolic and elliptic operators with low regularity coefficients. We are particularly interested in operators of the form ∂t−∆+ b ·∇ resp. −∆+ b ·∇ with a divergence-free drift b. We prove the Liouville theorem and Harnack inequality when b ∈ L∞(BMO) resp. b ∈ BMO−1 and provide a counterexample demonstra...