Sharif Digital Repository

One of the miscellaneous units that are frequently used in water and wastewater systems is flush tank. Flush tank increases the self cleaning velocity in the conduit, and helps to clear the conduits from deposits and contaminations. While these units have been used for many years, there is not enough information about the hydraulic performance of these units in respect to the discharge, distance from the tank and the pipe hydraulics. In this paper the experimental results from observed hydrographs at different distances from the flush tank in a pipe has been presented. The variables include; volume of releasing water (or inlet hydrograph), upstream head, pipe diameter (3 cm), pipe length and... 

Let D be a t-(v, k, λ) design and let N i(D), for 1≤i≤t, be the higher incidence matrix of D, a (0, 1)-matrix of size(v/i×b), where b is the number of blocks of D. A zero-sum flow of D is a nowhere-zero real vector in the null space of N1(D). A zero-sum k-flow of D is a zero-sum flow with values in {1,..., ±(k-1)}. In this article, we show that every non-symmetric design admits an integral zero-sum flow, and consequently we conjecture that every non-symmetric design admits a zero-sum 5-flow. Similarly, the definition of zero-sum flow can be extended to Ni(D), 1≤i≤t. Let D=t - (v.k,(v-t/k-t))be the complete design. We conjecture that Nt(D) admits a zero-sum 3-flow and prove this conjecture... 

For a given quantum field theory, provided the area of the entangling surface is fixed, what surface maximizes entanglement entropy? We analyze the answer to this question in four and higher dimensions. Surprisingly, in four dimensions the answer is related to a mathematical problem of finding surfaces that minimize the Willmore (bending) energy and eventually to the Willmore conjecture. We propose a generalization of the Willmore energy in higher dimensions and analyze its minimizers in a general class of topologies Sm×Sn and make certain observations and conjectures that may have some mathematical significance  

Steady blood flow through a circular artery with rigid walls is studied by COSSERAT Continuum Mechanical Approach. To obtain the additional viscosities coefficients, feed forward multi-layer perceptron (MLP) type of artificial neural networks (ANN) and the results obtained in previous empirical works is used. The governing filed equations are derived and solution to the Hagen-Poiseuilli flow of a COSSERAT fluid in the artery is obtained analytically by Homotopy Perturbation Method (HPM) and numerically using finite difference method. Comparison of analytical results with numerical ones showed excellent agreement. In addition microrotation and the velocity profile along the radius are... 

We have presented a set of laws of entanglement thermodynamics for TT¯-deformed CFTs and in general for T2-deformed field theories. In particular, the first law of this set, states that although we are dealing with a non-trivial deformed theory, the change of the entanglement entropy is simply translated to the change of the bending energy of the entangling surface. We interpret this energy as the energy of decomposition. Probing the whole spectrum of the deformed theory, a second law also results, which suggests an inequality that the first law is derived from its saturation limit. We explain that this second law guarantees the preservation of the unitarity bound. The thermodynamical form... 

We use holographic methods to study the entanglement entropy for excited states in a two dimensional conformal field theory. The entangling area is a single interval and the excitations are produced by in and out vertex operators with given scaling dimensions. On the gravity side we provide the excitations by turning on a scalar field with an appropriate mass. The calculation amounts to using the gravitational background, with a singular boundary, to find the one point function of the vertex operators. The singular boundary is taken care of by introducing a nontrivial UV regulator surface to calculate gravitational partition functions. By means of holographic methods we reproduce the field... 

Abstract: We propose a holographic model for local quench in 1 + 1 dimensional Conformal Field Theory (CFT). The local quench is produced by joining two identical CFT’s on semi-infinite lines. When these theories have a zero boundary entropy, we use the AdS/Boundary CFT proposal to describe this process in terms of bulk physics. Boundaries of the original CFT’s are extended in AdS as dynamical surfaces. In our holographic picture these surfaces detach from the boundary and form a closed folded string which can propagate in the bulk. The dynamics of this string is governed by the tensionless Yo-Yo string solution and its subsequent evolution determines the time dependence after quench. We use... 

The aim of this paper is to investigate the application of solid oxide fuel cell (SOFC) as the prime mover of a combined heat and power (CHP) system. In this paper, four hybrid systems are proposed to improve the performance of CHP and compare with baseline condition. Capacity design and operation strategy of hybrid systems are applied to a case study of a greenhouse located in Mahabad, Iran and optimized by using technical, economic and environmental objective functions. Levelized cost of energy (LCOE) and CO2 emission rate are considered as the objective functions. For LCOE optimization, three scenarios are considered to evaluate the impacts of future energy prices and CO2 tax. In scenario... 

In odd dimensions the integrated conformal anomaly is entirely due to the boundary terms [1]. In this paper we present a detailed analysis of the anomaly in five dimensions. We give the complete list of the boundary conformal invariants that exist in five dimensions. Additionally to 8 invariants known before we find a new conformal invariant that contains the derivatives of the extrinsic curvature along the boundary. Then, for a conformal scalar field satisfying either the Dirichlet or the conformal invariant Robin boundary conditions we use the available general results for the heat kernel coefficient a5, compute the conformal anomaly and identify the corresponding values of all boundary... 

In the presence of boundaries, the quantum anomalies acquire additional boundary terms. In odd dimensions, the integrated conformal anomaly, for which the bulk contribution is known to be absent, is nontrivial due to the boundary terms. These terms became a subject of active study in the recent years. In the present paper, we continue our previous study [1,2] and compute explicitly the anomaly for fermions in dimensions d=3, 4 and 5. The calculation in dimension 5 is new. It contains both contributions of the gravitational field and the gauge fields to the anomaly. In dimensions d=3 and 4, we reproduce and clarify the derivation of the results available in the literature. Imposing the...