in order to study the effect of elevation on quantitative and qualitative characteristics of the humid forests of guilan shafaroud, series 17, 16 and 7 were selected that fall in to three height classes; class 1 (‏less than 500 m), class 2 (‏500 – 1000 m) and class 3 (‏1000 – 1600 m). in height class 1, 2 and 3 sample plots were determined as 4, 15 and 20 respectively and each sample plot was 0...

When 4-dimensional general relativity is extended by a 3-dimensional grav-itational Chern-Simons term an apparent violation of diffeormorphism invari-ance is extinguished by the dynamical equations of motion for the modified theory. The physical predictions of this recently proposed model show little evidence of symmetry breaking, but require the vanishing of the Pontryagin density.

Many systems can be modeled with hard and various size spheres, therefore packing and geometrical structures of such sets are of great importance. In this paper, rigid spherical particles distributed in different sizes are randomly packed in confined spaces, using a parallel algorithm. Mersenne Twister algorithm was used to generate pseudorandom numbers for initial coordination of particles. Di...

The effect of a uniform electric field on interfacial properties of dipolar-quadrupolar fluids is investigated by using the density-functional theory. As in the case of purely dipolar fluids the (thermodynamic) surface tension is always altered by the external field, regardless of the direction of the field. However, unlike the purely dipolar fluids, for two given external fields with the same ...

We have calculated the phonon frequencies of KC1 along symmetry directions using an approach which is a combination of the frozen phonon and force constants methods. We also calculated Griineisen parameters for all modes at X and L points in the Brillouin zone. Finally, the slope of acoustic dispersion curves around zone center were used to calculate the three independent elastic coefficien...

In this work, hydroxyapatite/silica nanopowders were granulated to fabricate plasma sprayable feedstocks. For this purpose, the wet powders obtained by heating a hydroxyapatite/silica slurry were stirred and sieved. To realize the feedstock application in the plasma spray process, powders were deposited on titanium substrate. The morphology of granulated feedstock and sprayed coating was ...

The band-gap problem and other systematic failures of approximate exchange-correlation functionals are explained from an analysis of total energy for fractional charges. The deviation from the correct intrinsic linear behavior in finite systems leads to delocalization and localization errors in large and bulk systems. Functionals whose energy is convex for fractional charges such as the local d...