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    Temperature effects on quantum cloning of states and entanglement

    , Article Physics Letters, Section A: General, Atomic and Solid State Physics ; Volume 373, Issue 8-9 , 2009 , Pages 821-825 ; 03759601 (ISSN) Baghbanzadeh, S ; Rezakhani, A. T ; Sharif University of Technology
    Performances of the symmetric universal and phase-covariant cloning transformations and entanglement cloners - qubit case - are investigated when the initial state of the hardware or the original state to be cloned is weakly coupled to a thermal environment. Different behaviors of each of these transformations are analyzed and contrasted with the ideal cases. © 2009 Elsevier B.V. All rights reserved  

    Anomalous magnetic moment of hot quarks, inverse magnetic catalysis, and reentrance of the chiral symmetry broken phase

    , Article Physical Review D - Particles, Fields, Gravitation and Cosmology ; Vol. 90, issue. 10 , 2014 ; ISSN: 15507998 Fayazbakhsh, S ; Sadooghi, N ; Sharif University of Technology
    The effect of the anomalous magnetic moment of quarks on thermodynamic properties of the chiral condensate is studied, using a two-flavor Nambu-Jona-Lasinio model at finite temperature T, chemical potential μ, and in the presence of a uniform magnetic field eB. To this purpose, the Schwinger linear-in-B ansatz for the anomalous magnetic moment of quarks is considered in terms of the nonperturbative Bohr magneton. In a two-dimensional flavor space, it leads to the correction TSch=κQeB in the energy dispersion relation of quarks. Here, Q is the quark charge matrix. We consider three different sets for κ, and numerically determine the dependence of the constituent quark mass on T,μ, and eB for... 

    Ising model on the edge-dual of random networks

    , Article Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics ; Volume 69, Issue 6 , 2004 , Pages 10- ; 1063651X (ISSN) Ramezanpour, A ; Sharif University of Technology
    We consider the Ising model on the edge dual of uncorrelated random networks with arbitrary degree distribution. These networks have a finite clustering in the thermodynamic limit. High- and low-temperature expansions of Ising model on the edge dual of random networks are derived. A detailed comparison of the critical behavior of Ising model on scale free random networks and their edge dual is presented. © 2004 The American Physical Society  

    Temperature dependence study of nonocontact AFM images using molecular dynamics simulations [electronic resource]

    , Article Int. Journal of Modern Physics ; 2012, Vol. 5, pp. 418-432 Nejat Pishkenari, H. (Hossein) ; Meghdar, Ali ; Sharif University of Technology
    The effect of temperature on the noncontact atomic force microscopy (NC-AFM) surface imaging is investigated with the aid of molecular dynamics (MD) analysis based on the Sutton-Chen (SC) interatomic potential. Particular attention is devoted to the tip and sample flexibility at different temperatures. When a gold coated probe is brought close to the Au (001) surface at high temperatures, the tip and surface atoms are pulled together and their distance becomes smaller. The tip and sample atoms displacement varies in the different environment temperatures and this leads to the different interaction forces. Along this line, to study the effect of temperature on the resulting images, we have... 

    Biofiltration of hexane vapor: Experimental and neural model analysis

    , Article Clean - Soil, Air, Water ; Volume 39, Issue 9 , 2011 , Pages 813-819 ; 18630650 (ISSN) Zamir, M ; Halladj, R ; Saber, M ; Ferdowsi, M ; Nasernejad, B ; Sharif University of Technology
    Biofiltration is a commonlypracticed biological technique to remove volatile compounds from waste gas streams. From an industrial view-point, biofilter (BF) operation should be flexible to handle temperatures and inlet load (IL) variations. A compost BF was operated at different temperatures (30-45°C) and at various inlet loading rates (ILR; 8-598gm -3h -1) under intermittent loading conditions. Complete removal of n-hexane was observed at 30 and 35°C at ILRs up to 330gm -3h -1. Besides, 20-75% of the pollutant was removed at 40°C, corresponding to the different ILs applied to the BF. Increasing the temperature to 45°C decreased the removal efficiency (RE) significantly. A feed forward... 

    Mathematical modeling and simulation of hollow fiber membranes for separation of gas mixtures: Case study with separation of H 2S/CH 4 by polyphenylene oxide (PPO) hollow fiber module

    , Article 19th International Congress of Chemical and Process Engineering, CHISA 2010 and 7th European Congress of Chemical Engineering, ECCE-7, Prague, 28 August 2010 through 1 September 2010 ; 2010 Niknejad, S. M. S ; Savoji, H ; Soltanieh, M ; Sharif University of Technology
    A mathematical model has been developed that is based the dual sorption in the dense layer and pore flow in the porous layer. In the porous layer a resistance model is applied where four mechanisms, i.e., Knudsen, Viscous, Slip, and Surface flows, are superimposed. Steady-state, constant pressure along the membrane and constant physical properties are assumed. Its application to the separation of H 2S/CH 4 gas mixtures as a sour gas in natural gas sweetening by using a PPO hollow fiber module is put forward. The Quasi Newton method is used to determine the parameters of membrane transport model for the case of H 2S/CH 4 separation. The H 2S and CH 4 permeances increased by increasing the... 

    Thermally induced failure mechanism transition and its correlation with short-range order evolution in metallic glasses

    , Article Extreme Mechanics Letters ; Volume 9 , 2016 , Pages 215-225 ; 23524316 (ISSN) Jafary Zadeh, M ; Tavakoli, R ; Srolovitz, D. J ; Zhang, Y. W ; Sharif University of Technology
    Elsevier Ltd 
    The effect of temperature on the short-range order (SRO) structures, deformation mechanisms and failure modes of metallic glasses (MGs) is of fundamental importance for their practical applications. However, due to lack of direct structural information at the atomistic level from experiments and the absence of previous molecular dynamics (MD) simulations to reproduce experimental observations over a wide range of temperature, this issue has not been well understood. Here, by carefully constructing the atomistic models of Cu64Zr36 and Fe80W20 MGs, we are able to reproduce the major deformation modes observed experimentally, i.e. single shear banding (SB) at low temperatures, multiple... 

    Synthesis of pyrochlore free PMN-PZT ceramics via a seeding method

    , Article Sensors and Actuators, A: Physical ; Volume 141, Issue 2 , 2008 , Pages 463-470 ; 09244247 (ISSN) Moetakef, P ; Ali Nemati, Z ; Sharif University of Technology
    Pyrochlore free (x)PMN-(1 - x)PZT ceramics were synthesized successfully by a seeding method. In this method, the mixture of PbO, MgO and Nb2O5 was added to the prepared PZT sol to from PMN-PZT gel. The gel was fired to vaporize the organic contents of gel and obtain powder. Two-step sintering process was used to produce pyrochlore free ceramics. The samples produced by this method showed higher relative densities, lower sintering temperature and higher dielectric properties relative to the mixed oxide method, mostly due to the higher homogeneity of the prepared powder. The measured dielectric properties of PZT-rich and PMN-rich materials were high while the other samples exhibited low... 

    A Temperature Dependant Multiscale Modeling of Crack Growth in Nano Materials

    , M.Sc. Thesis Sharif University of Technology Imani, Arman (Author) ; Khoei, Amir Reza (Supervisor)
    The fact that materials and crack behave differently under different temperatures, brings a need for further investigation in this field. Recent studies regarding this behavior are mainly based on molecular dynamic method. While this method garuntee a highpercicion, the computational costs of this method can be high when dealing with crack propagation problem. Taking advantage of multiscale methods allows us to overcome this challenge by reducing the calculation time while providing acceptable results. In this research a multi-scale method capable of considering thermal effects has been developed. A concurrent model is created by using theory of elasticity for continuum part and taking... 

    Non-catalytic condensation of aromatic aldehydes with aniline in high temperature water

    , Article Green Chemistry Letters and Reviews ; Volume 5, Issue 3 , Mar , 2012 , Pages 403-407 ; 17518253 (ISSN) Ahmadi, S. J ; Hosseinpour, M ; Sadjadi, S ; Sharif University of Technology
    T&F  2012
    The synthesis of diamino triphenyl methanes from aniline and aromatic aldehydes was conducted in near critical water and supercritical water. The reaction parameters, such as temperature, density, and reaction time, have been studied. Significant acceleration of the condensation reaction of aniline and aromatic aldehydes can be achieved by using high temperature water, especially near the critical point, in the absence of any acid catalysts. It has been demonstrated that high temperature water act effectively in the place of conventional acid catalysts  

    High temperature mechanical properties of triple phase steels

    , Article Materials Letters ; Volume 61, Issue 4-5 , 2007 , Pages 1023-1026 ; 0167577X (ISSN) Akbarpour, M. R ; Sharif University of Technology
    A 0.15% C-1.2% Si-1.7% Mn steel was intercritically annealed at 780 °C for 5 min and then isothermally held at 400 °C for 4 min followed by oil quenching to room temperature and the annealed microstructure consist of 75% ferrite, 15% bainite and 10% retained austenite was produced. Samples of this steel with triple phase structure were tensile tested at temperature range of 25-450 °C. Stress-strain curves showed serration flow at temperature range of 120-400 °C and smooth flow at the other temperatures. All of the stress-strain curves showed discontinuous yielding at all testing temperatures. Both yield and ultimate tensile strength decreased with increasing temperature, but there exists a... 

    Thermal control of the size and crystalline phase of CdS nanoparticles

    , Article Nanotechnology ; Volume 17, Issue 15 , 2006 , Pages 3812-3816 ; 09574484 (ISSN) Sedaghat, Z ; Taghavinia, N ; Marandi, M ; Sharif University of Technology
    CdS nanoparticles were grown using CdSO4 and Na 2S2O3 as the precursors and thioglycerol (TG) as the capping agent. TG was shown to exhibit a catalytic role in the reaction and also acted as a capping agent. It was demonstrated that size growth is linearly related to the temperature of the reaction, i.e.the sizes can be controllably adjusted by temperature. The crystalline phase of the nanocrystals was also dependent on the temperature of growth: higher temperature favours the cubic phase. The pH also plays an important role in nanoparticle growth, as lower pH leads to a higher release rate of sulfur species. At pH as high as 10, the growth rate remains slow even at boiling temperature. This... 

    Effective compton cross section in non-degenerate high-temperature media

    , Article Journal of Quantitative Spectroscopy and Radiative Transfer ; Volume 95, Issue 1 , 2005 , Pages 61-69 ; 00224073 (ISSN) Shekh Momeni, F ; Samimi, J ; Sharif University of Technology
    The effective compton cross section in a non-degenerate plasma (n≪{((kT/c)2 + 2mkT)/h2}3/2) is investigated in a wide range of temperatures. The results show a decreasing behavior with temperatures especially for kT ≫ mec2. The results may be important in phenomena like accretion discs or ultra-relativistic blast waves in GRB models, where the emitted radiation has to pass through a medium containing high-energy electrons. © 2004 Elsevier Ltd. All rights reserved  

    Thermal entanglement of spins in the Heisenberg model at low temperatures

    , Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 70, Issue 5 A , 2004 , Pages 052307-1-052307-5 ; 10502947 (ISSN) Asoudeh, M ; Karimipour, V ; Sharif University of Technology
    The entanglement between two spins in the ferromagnetic Heisenberg chain at low temperatures was calculated. It was shown that if a magnetic field is applied to a ferromagnetic Heisenberg chain, then pairwise entanglement develops between spins at arbitrary given states. It was also shown that the entanglement profile is a Gaussian with a characteristic length depending on the temperature and the coupling between spins only when the ground state and the one-particle states are populated. The magnetic field was shown to affect only the amplitude of the profile and not its characteristic length  

    The Impact of Temperature on Surface Activity and Stability of Surface Modified Nano Particles

    , M.Sc. Thesis Sharif University of Technology Masoudi, Ghasem (Author) ; Mohammadi, Ali Asghar (Supervisor)
    Surface modification is an important property of nano particles. In this project surface of silica nano particles modified with hydrophobic and hydrophilic groups to imrprove surface activity of nano particles. Purpose of this project is to study surface activity of surface modified silica nano particles in different temperatures from 20 to 70 degree centigrade. Also effect of salt and time on the surface activity is studied. At first nano particles modified just with haydrophobic groups and then just with hydrophilic groups (hydrophobic and hydrophilic nano particles) and after that, the surface modification done with both hyadrophilic and hydrophobic groups (amphiphilic nanoparticles).... 

    Effects of Nano Metallic Catalysts on The Life-Time and Efficiency of Proton Exchange Membrane Fuel Cells

    , M.Sc. Thesis Sharif University of Technology Hosseinpour, Milad (Author) ; Vesaghi, Mohammad Ali (Supervisor)
    The Fuel cell is an energy converter which converts the chemical energy of a chemical reaction to electricity and heat directly and without any pollution. One of the most important types of fuel cells is the proton exchange membrane (PEM) fuel cell. The importance of PEM fuel cells is a result of their high energy density, quick start up ability, lower operating temperature, high efficiency and low or zero emissions. Catalysts play an important role in both costs and durability of PEM fuel cells. Alloying the Pt with other metals can increase the activity of the catalysts of the fuel cells and also reduces the amount of costly Pt. In this study, the nanoparticles of Ni were added to the... 

    Photo-detector diode based on thermally oxidized TiO2 nanostructures/p-Si heterojunction

    , Article Journal of Applied Physics ; Volume 119, Issue 1 , 2016 ; 00218979 (ISSN) Hosseini, Z. S ; Shasti, M ; Ramezani Sani, S ; Mortezaali, A ; Sharif University of Technology
    American Institute of Physics Inc 
    Titanium oxide (TiO2)-based photodetectors were fabricated using a thermal oxidation technique. The effect of two different annealing temperatures on morphology, structure, and I-V characteristics has been investigated. TiO2/Si heterostructure exhibited diode-like rectifying I-V behavior both in dark and under illumination. Dependence in photoresponse on annealing temperature was observed that was related to effective surface area of quasi-one-dimensional TiO2 nanostructures. Fabricated TiO2/Si diodes in 850 °C as the lower annealing temperature showed higher responsivity and sensitivity compared with grown ones in 950 °C (R850 °C/R950 °C ∼ 5 and S850 °C/S950 °C ∼ 1.6). Rather good... 

    Enhancing bioleaching and iron oxidation efficiency of native strain of acidithiobacillus ferrooxidans, by optimizing the ambient growth conditions

    , Article Pollution Research ; Volume 28, Issue 3 , 2009 , Pages 329-336 ; 02578050 (ISSN) Arabian, D ; Nemati, F ; Roostaazad, R ; Shitole, M. G ; Gade, W. N ; Sharif University of Technology
    In this study, we have investigated the bioleaching potential of a native strain of Acidithiobacillus ferrooxidans isolated from zinc and lead sulfide mines under varied ambient conditions of growth and substrate consumption. In the process of standardizing growth conditions to improve iron oxidation, bioleaching of zinc and lead is also found to be enhanced. The effects of pH, temperature, initial inoculum, Fe2+ and ammonium sulphate concentration on growth and bio-oxidation efficiency of the bacteria have been evaluated. The results indicate that the optimum pH required for the growth of the bacterium is 1.8; however, the same for maximum efficiency is 1.5. It is also found that pH has a... 

    Three-dimensional structures in experimental density currents

    , Article 2007 5th Joint ASME/JSME Fluids Engineering Summer Conference, FEDSM 2007, San Diego, CA, 30 July 2007 through 2 August 2007 ; Volume 1 SYMPOSIA, Issue PART A , March , 2007 , Pages 781-787 ; 0791842886 (ISBN); 9780791842881 (ISBN) Firoozabadi, B ; Afshin, H ; Safaaee, E ; Sharif University of Technology
    Density currents are continuous currents which move down-slope due to the fact that their density is greater than that of ambient water. The density difference is caused by temperature differences, chemical elements, dissolved materials, or suspended sediment. Many researchers have studied the density current structures, their complexities and uncertainties. However, there is not a detailed 3-D turbulent density current data set perfectly. In this work, the structure of 3-dimensional salt solution density currents is investigated. A laboratory channel was used to study the flow resulting from the release of salt solution into freshwater over an inclined bed. The experiments were conducted... 

    Synthesis and study of a new class of red pigments based on perovskite YAlO3 structure

    , Article Ceramics International ; Volume 33, Issue 8 , December , 2007 , Pages 1427-1433 ; 02728842 (ISSN) Shirpour, M ; Faghihi Sani, M. A ; Mirhabibi, A ; Sharif University of Technology
    A red pigment has been prepared by substituting chromium ions in aluminum ion sites in YAlO3 perovskite structure. In a first step, effect of various mineralizers on YAlO3 formation has been investigated, which resulted in decrease of formation temperature down to 1400 °C. In the next step, a red pigment corresponding to YAl1-yCryO3 (y = 0.05), has been prepared by heating a mixture containing Y2O3, Al2O3 and Cr2O3 at 1500 °C for 6 h. Later, effect of the doped chromium amount on the pigment redness (a*) has been studied. The highest redness has been obtained when y was 0.04(YAl1-yCryO3). Application of the prepared red pigment in low and high temperature glazes, demonstrated its high...