Sharif Digital Repository

The proof of the first Carnot theorem in classical thermodynamics is revisited in this study. The underlying conditions of a general proof of this principle presented by Senft (1978 Phys. Educ. 13 35-37) are explored and discussed. These conditions are analysed in more detail using a physical description of heat and work to present a simpler proof of the first principle prior to using the violation of the second law of thermodynamics. Finally, a new simple proof is also presented based on Gibbs relation. This discussion will benefit the teaching of classical thermodynamics and promote better understanding of the proof of the first Carnot theorem in general form  

According to a well-known approach in quantum thermodynamics, the characteristics of a system in a process can be estimated by calculating work in the process. Here, we are going to show that this approach cannot provide with us a clear depiction of the second law of thermodynamics in some specific (but simple) processes  

In this paper a thermodynamical derivation of the quantum potential is proposed. Within the framework of Bohmian mechanics we show how the quantum potential can be derived, by adding an additional informational degree of freedom to the ordinary degrees of freedom of a physical system. Such a derivation uses the First Law of thermodynamics for this additional degree of freedom and basic equilibrium thermodynamics methods. By doing that, one may associate a temperature to each wave function. Features and behavior of this temperature in different situations is studied. © 2019 Elsevier B.V  

In this study, the perturbed hard sphere chain equation of state is utilized to calculate the activity of water in binary and ternary solutions of polyethylene glycol (PEG), salt and water. The liquid density of the binary and ternary solutions is also predicted. To estimate the water activity in PEG-water binary systems, a linear correlation is obtained for the binary interaction parameter between water and PEG. Then, using this correlation and without introducing any additional binary parameters, the water activities are predicted in ternary solutions of water, salt and PEG with different molecular weights (MW). Our results show that the mean absolute average relative deviation (AARD %) of... 

Correlations lie at the heart of almost all scientific predictions. It is therefore of interest to ask whether there exist general limitations to the amount of correlations that can be created at a finite amount of invested energy. Within quantum thermodynamics such limitations can be derived from first principles. In particular, it can be shown that establishing correlations between initially uncorrelated systems in a thermal background has an energetic cost. This cost, which depends on the system dimension and the details of the energy-level structure, can be bounded from below but whether these bounds are achievable is an open question. Here, we put forward a framework for studying the... 

In this article, we present a brief and elementary review of quantum thermodynamics and its achievements and challenges. This review includes an introduction to some fundamental concepts such as internal energy, heat, work, entropy, entropy production, thermal equilibrium, second law of quantum thermodynamics, relation between thermodynamics and information theory, as well as a discussion of how quantum effects such as entanglement and correlations affect performance of quantum heat engines. © 2019 by the authors. Licensee MDPI, Basel, Switzerland  

A molecule within the nonporous polymeric membrane moves in response to the local driving force and has no memory of how it entered the membrane or how the local gradients were generated. This means that a properly formulated model of transport within the membrane should be equally applicable to dialysis, pervaporation or vapour permeation. The phenomenological approach of irreversible thermodynamics was used to develop transient models of dialysis and pervaporation. The model developed in this study were validated against transient dialysis and pervaporation data for ethanol-water/silicone rubber system. A critical assessment was obtained by recovering the model parameters from the dialysis... 

The Carnot, Diesel, Otto, and Brayton power cycles are reconsidered endoreversibly in finite time thermodynamics (FTT). In particular, the thermal efficiency of these standard power cycles is compared to the well-known results in classical thermodynamics. The present analysis based on FTT modelling shows that a reduction in both the maximum and minimum temperatures of the cycle causes the thermal efficiency to increase. This is antithetical to the existing trend in the classical references. Under the assumption of endoreversibility, the relation between the efficiencies is also changed to ηCarnot > ηBrayton > ηDiesel > ηOtto, which is again very different from the corresponding classical... 

The functionalized copper oxide–zinc oxide nanocomposite (FCZN) was synthesized and characterized using Fourier transform infrared, scanning electron microscopy, X-ray diffraction, X-ray fluorescence, and BET. Dye removal from aqueous solution was done in a batch system using FCZN as an adsorbent. The effects of adsorbent dosage, initial dye concentration, pH, temperature, and additive salts on dye removal were investigated. Isotherms, kinetics, and thermodynamics of dye adsorption were studied. Equilibrium and kinetic data were fitted by Langmuir isotherm and pseudo-second-order kinetic, respectively. The thermodynamic data showed that dye adsorption was spontaneous, endothermic, and... 

The doping reaction of boron nitride and carbon nanotubes with aluminium atom was theoretically investigated. ONIOM method and PM6 method have been used to evaluate the thermochemistry of doping reactions of single walled boron nitride nanotubes and carbon nanotubes. The enthalpy changes, Gibbs free energy changes, of studied doping reactions were evaluated at different temperatures. All nanotubes were single-walled and finite length with hydrogen saturation in the terminal atoms. The thermodynamic calculations based on the ONIOM and PM6 levels results showed (8,0)CNT is the best candidate for Al-doping reaction.result suggest the aluminum doped boron nitride nanotubes and carbon nanotubes... 

The solution equilibria of magnesium (II) complex formed with bidentate ligand of dopamine in acidic media (pH=∼4-∼6) have been studied in cosolvent systems at 15, 25, 35 ± 0.1° C and 1=0.2 mol.dm-3 sodium chloride, using phosphate buffer, with spectrophotometric methods. Evidence for the 2:1 complex was not observed for magnesium. The stability constant of the complex was determined KMg(HL)+ = ∼9 and the resulting free-energy changes obtained. The protonation constant of dopamine was determined under the above conditions. The results are discussed in terms of the effect of solvent on protonation and complexation  

In this paper we analyze the relationship between entropy and information in the context of the mixing process of two identical ideal gases. We will argue that entropy has a special information-based feature that is enfolded in the statistical entropy, but the second law does not include it directly. Therefore, in some given processes in thermodynamics where there is no matter and energy interaction between the system and the environment, the state of the system may go toward a situation of lower probability to increase the observer's information about the environment. This is a kind of information-based interaction in which the total entropy is not constrained by the second law  

Asphaltene precipitation and deposition is one of the main problems in some of the oil fields. The deposited asphaltene results in partial or total blockage of the wellstring and reducing or completely seizing oil production. Asphaltene deposition problems have been experienced in the field for a long time. Although, the asphaltene precipitation has been studied thoroughly and different parameters that effects this process has been investigated but little work has been carried out in the asphaltene deposition across the production system of flowing oil well. This paper introduces a new comprehensive model for description of asphaltene deposition behavior in wellstring. The mechanisms of... 

Thermodynamics of extraction of Zn2+ from sulfuric acid media contacting to a mixture of DEHPA and MEHPA diluted with 80 wt% aromatic - aliphatic kerosene with a constant DEHPA to MEHPA ratio is investigated at different acidities, concentrations and temperatures. As a result, the extraction reaction is found to be endothermic with a zinc distribution factor that increases with increasing of the temperature, acidity of the solution and the concentration of the extradant. The mechanism of the extraction reaction is shown to be different for pH > 1 with that at pH <1. The pH of the aqueous media has also an important influence on progressing of the extraction reaction  

In this Letter we compute the leading order correction due to small statistical fluctuations around equilibrium, to the Cardy-Verlinde entropy formula (which is supposed to be an entropy formula of conformal field theory in any dimension) of a topological Reissner-Nordström black hole in de Sitter space. © 2003 Published by Elsevier B.V  

Traditionally energy systems were analyzed technically, but current environmental issues and considerations have put new constraints on the planning and managing of energy systems. Such an exergoeconomic and exergoenvironmental analysis were born. This analysis is aimed to describe the necessity and application of a new concept in environmental liability accounting based on physical quantities to overcome the weaknesses of the developed allocation methods and the internalization of external environmental damages. The proposed method is modified in environmental analysis to consider the effect of non-energy flows on a macro-surface energy system. As a case study, this method is tuned for a... 

In this paper, the effect of turbine stage efficiency on fuel consumption of both gas turbines and aerial engines is assessed quantitatively. At the beginning of the gas generator optimization to decrease the fuel consumption, it is necessary to analyze the sensitivity of fuel consumption to its main components efficiencies. This will guide us which component is more important to be optimized. Here a zero-dimensional analysis has been done to determine the effect of turbine stage efficiency on the fuel consumption. Results of this analysis are evaluated in the context of thermodynamic cycle of a gas turbine generator and an aerial engine. As an example, it is shown that if the efficiency of... 

Recently, a new potential model has been proposed for the intermolecular interactions of model pure fluids and it was shown that the derived Equation Of State (EOS), based on this potential, can properly predict the thermodynamic properties of these.fluids. In addition to simplicity and, to some extent, the realistic form, this potential has a parameter (α) which controls the range of the attraction tail. In the first part of this study, the proposed potential and derived EOS are extended to binary mixtures of model fluids. In a similar manner to that of the pure fluids, the results obtained are consistent with the data available from simulation studies. In the second part, after... 

In this paper, the application of neural networks for simulation and optimization of the cogeneration systems has been presented. CGAM problem, a benchmark in cogeneration systems, is chosen as a case study. Thermodynamic model includes precise modeling of the whole plant. For simulation of the steady sate behavior, the static neural network is applied. Then using dynamic neural network, plant is optimized thermodynamically. Multi layer feed forward neural networks is chosen as static net and recurrent neural networks as dynamic net. The steady state behavior of CGAM problem is simulated by MFNN. Subsequently, it is optimized by dynamic net. Results of static net have excellence agreement...