The effect of aquaculture effluents on water quality parameters of Haraz River

In this study, a water quality model of Haraz basin was used as an evaluative tool to estimate the spatial distribution of variables that are related to water quality and nutrient loads of the Haraz River. Previous studies performed in this river indicate that trout culture activity along the Haraz River have led to various changes in the water quality parameters. In the present work, the possible effects of two additional fish farms with a production capacity of 50 tons, located on the Haraz within 1 km distance from each other were evaluated in terms of their effects on the streams water quality. A water quality model was developed in order to investigate the spatial distribution of water quality variables. The model also used to estimate the dissolved oxygen (DO), biological oxygen demand (BOD5) and nutrients along the stream

Hawking-Page transition in holographic massive gravity

We study the Hawking-Page transition in a holographic model of field theories with momentum dissipation. We find that the deconfinement temperature strictly decreases as momentum dissipation is increased. For sufficiently strong momentum dissipation, the critical temperature goes to zero, indicating a zero-temperature deconfinement transition in the dual field theory.Comment: 17 pages, 1 figure, uncomment \newcommand*{\ShowCalculations}{} in the tex file for additional details. Journal version (PRD). Presentation clarified, reference added, and line spacing and title update

Finite-size effects in lead scandium tantalate relaxor thin films

Large electromechanical effects in relaxor ferroelectrics are generally attributed to the collective response of an ensemble of correlated, nanometer-sized polar structures induced by chemical and charge disorder. Here, we study finite-size effects on such polar order (i.e., how it evolves when sample dimensions approach the polarization correlation length) in 7-70-nm-thick films of the relaxor ferroelectric PbSc0.5Ta0.5O3. Temperature-dependent polarization studies reveal a linear suppression of the polarization and nonlinearity associated with relaxor order as the film thickness decreases to ≈30 nm. Below this thickness, however, the suppression rapidly accelerates, and polarization is completely absent by film thicknesses of ≈7 nm, despite the continued observation of a broad peak in dielectric permittivity and frequency dispersion. Diffuse-scattering measurements reveal the diffuse-scattering symmetry, and analysis suggests the films have a polarization correlation length of ≈23 nm. Taken together, it is apparent that reduction of sample size and the resulting distribution of polar structures drive suppression and eventual quenching of the electrical response of relaxors, which may be attributed to increasing dipole-dipole and dipole-interface interactions

The role of architecture of diplomacy in development of "smart interactions" explaining the “communicative action” among the embassies of the United States

Diplomacy is the most important character of the foreign policy. Embassy buildings also have a unique situation, as nations’ physical embodiments abroad and a dimension of foreign policy. These buildings represent "a body of relations between countries". This study focused on the variables in the communicative action of the embassies; and with a qualitative study, communicative action among the embassies of the United States has been analyzed. The results demonstrate that; "the Agents of Diplomacy" as the mastermind of national power, "consciously" can gain the architecture of diplomacy, in order to provide national goals. This is an active and effective participation between "Deputies of Diplomacy, Architects, and Builders (international contractors)". Also the "Smart Interaction", is a "Rational Action", based on "Generalizable Interests" among Actors, with taking advantage of the "Generative Rules", and optimal use of "Language".Keywords: Diplomacy, Embassy, Medium, Smart Interactio

Large Polarization and Susceptibilities in Artificial Morphotropic Phase Boundary PbZr1−xTixO3 Superlattices

The ability to produce atomically precise, artificial oxide heterostructures allows for the possibility of producing exotic phases and enhanced susceptibilities not found in parent materials. Typical ferroelectric materials either exhibit large saturation polarization away from a phase boundary or large dielectric susceptibility near a phase boundary. Both large ferroelectric polarization and dielectric permittivity are attained wherein fully epitaxial (PbZr0.8Ti0.2O3)n/(PbZr0.4Ti0.6O3)2n (n = 2, 4, 6, 8, 16 unit cells) superlattices are produced such that the overall film chemistry is at the morphotropic phase boundary, but constitutive layers are not. Long- (n ≥ 6) and short-period (n = 2) superlattices reveal large ferroelectric saturation polarization (Ps = 64 µC cm−2) and small dielectric permittivity (εr ≈ 400 at 10 kHz). Intermediate-period (n = 4) superlattices, however, exhibit both large ferroelectric saturation polarization (Ps = 64 µC cm−2) and dielectric permittivity (εr = 776 at 10 kHz). First-order reversal curve analysis reveals the presence of switching distributions for each parent layer and a third, interfacial layer wherein superlattice periodicity modulates the volume fraction of each switching distribution and thus the overall material response. This reveals that deterministic creation of artificial superlattices is an effective pathway for designing materials with enhanced responses to applied bias

Black hole thermalization rate from brane anti-brane model

We develop the quasi-particle picture for Schwarzchild and far from extremal black holes. We show that the thermalization equations of the black hole is recovered from the model of branes and anti-branes. This can also be viewed as a field theory explanation of the relationship between area and entropy for these black holes. As a by product the annihilation rate of branes and anti-branes is computed.Comment: 11 pages, late

The Viscosity Bound Conjecture and Hydrodynamics of M2-Brane Theory at Finite Chemical Potential

Kovtun, Son and Starinets have conjectured that the viscosity to entropy density ratio $\eta/s$ is always bounded from below by a universal multiple of $\hbar$ i.e., $\hbar/(4\pi k_{B})$ for all forms of matter. Mysteriously, the proposed viscosity bound appears to be saturated in all computations done whenever a supergravity dual is available. We consider the near horizon limit of a stack of M2-branes in the grand canonical ensemble at finite R-charge densities, corresponding to non-zero angular momentum in the bulk. The corresponding four-dimensional R-charged black hole in Anti-de Sitter space provides a holographic dual in which various transport coefficients can be calculated. We find that the shear viscosity increases as soon as a background R-charge density is turned on. We numerically compute the few first corrections to the shear viscosity to entropy density ratio $\eta/s$ and surprisingly discover that up to fourth order all corrections originating from a non-zero chemical potential vanish, leaving the bound saturated. This is a sharp signal in favor of the saturation of the viscosity bound for event horizons even in the presence of some finite background field strength. We discuss implications of this observation for the conjectured bound.Comment: LaTeX, 26+1 Pages, 4 Figures, Version 2: references adde