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This research aims to provide new information about the mechanical behavior of double-stranded DNA (dsDNA). For this purpose, a series of extended atomic resolution molecular dynamics (MD) simulations of DNA dodecamer is performed. The MD calculations are carried out using Generalized Born solvent-accessible surface area method and Langevin dynamics. The stress-strain curves of DNA obtained under various pulling rates and pulling angles are analyzed, and the role of pulling angle and velocity in determining biomechanical properties of short dsDNA is discussed. The results illustrate that how much the behavior of DNA under action of tensile forces could be complicated. By means of at base pair level analyses of the molecule conformation during the stretching processes, the structural stability of the DNA molecule subjected to the angled pulling with different pulling rates and different pathways to the dsDNA rupture are studied. The structural stability of dsDNA can be dependent on the pulling velocity and pulling angle. Whereas the DNA stability can decrease significantly with the reduction of pulling velocity, stretching the DNA under different angles has different unpredictable effects on its structural stability.

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One of the most important achievements of the Carnot was creating a limit for heat engines; this limitation is a criterion for measuring and comparing the performance of heat engines. Classical thermodynamics studies completely the equilibrium and reversible processes but transfer phenomena effects have been ignored, while in the real irreversible process, there are finite time processes and finite size systems. On the other hand, the close relationship between thermodynamics, fluid mechanic and heat transfer has caused thermodynamics to move from theoretical analysis toward a comprehensive and real analysis. Another point is that all the practical processes are irreversible. This study analyzed the irreversible combined cycle in finite time thermodynamics. The combined cycle studied consists two endoreversible cycles and three thermal sources. The irreversibility has occurred between the subsystems and the thermal sources and sink on the system boundaries. By solving algebraic equations, obtained dimensionless total power and efficiency were calculated based on dimensionless variables. The MATLAB programming code is used to solve algebraic equations. Finally, it is obtained that the thermal efficiency and dimensionless total power functions of the heat sources temperature, working fluid temperature and thermal conductance. Also, the effects of each dimensionless variable were investigated to the proportion of dimensionless total power and efficiency. In this study, the parameter study has been used for improving the irreversible combined cycle in the finite time thermodynamics. In addition, Optimization results have shown that the maximum dimensionless total power and thermal efficiency associated with it are 0.086102 and 47.81%, respectively.

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Limited data exist about the production of extruded linseed as a feed ingredient in farm animal nutrition. The objective of this study was to produce and evaluate extruded linseed mixed with alfalfa hay, pistachio by-products, and sugar beet pulp or corn grain in different proportions of linseed: alfalfa hay: pistachio by-products at ratios of 70:15:15, 70:20:10, 70:10:20, and 80:10:10 for quality parameters and in situ rumen Dry Matter (DM) degradability. Using a completely randomized design, the treatment containing alfalfa hay had higher Extrusion Effectiveness (EE), Water Holding Capacity (WHC), and Angle of Repose (AR), but lower Oil Loss (OL) and Bulk Density (BD) than other treatments (P< 0.05). There were no differences among extruded linseed products with different ratios of linseed: alfalfa: pistachio by-products for EE, WHC, and AR (P> 0.05). The treatment with an 80:10:10 ratio had the highest OL among all treatments and the treatment with a 70:15:15 ratio had lower BD than the others (P< 0.05). The DM degradability parameters of extruded products was affected by the absorbents and the treatment containing alfalfa hay had higher potential DM degradability than other treatments (P< 0.05). In conclusion, extruded treatment with alfalfa hay had the highest EE, oil retention capacity and potential rumen DM degradability compared to other treatments. In addition, extruded linseed product with an 80:10:10 ratio of linseed: alfalfa hay: pistachio by-products had higher OL than the other ratios.

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In this paper, performance analysis and optimization of a trigeneration system based on different thermodynamic criteria such as energy and exergy efficiency, power and dimensionless power have been investigated. The trigeneration system consists of three subsystems which including the solar subsystem, Kalina subsystem and lithium bromide-water absorption chiller subsystem. The proposed system uses solar energy generates power, cooling and domestic water heating. Power is introduced as a tool for understanding thermodynamic concepts of limited time. Dimensionless power is defined as the ratio of power to the product of total thermal conductivity and minimum temperature of the system. Dimensionless power can be used as a tool to understand the concepts of finite time thermodynamics. The exergy analysis has shown that the most exergy destruction is related to boiler. As a result, energy and exergy efficiencies, capital cost rates and dimensionless power are 17.77%, 18.82% and 9.63 dollars per hour, 0.01781 respectively. Sensitivity analysis has shown that increasing parameters such as ambient temperature, solar radiation, the dimensionless mass flow rate of the Kalina cycle, collector inlet temperature and pressure ratio of the Kalina cycle increase energy and exergy efficiencies. Also increasing pressure ratio the of Kalina Cycle, reducing the dimensionless mass flow rate of the Kalina cycle, the ambient temperature and collector inlet temperature has led to increased dimensional power. In addition, the optimization criteria such as energy efficiency, exergy efficiency, power and dimensional power have been compared. The results showed that power and dimensional power are the best thermodynamic optimization criteria.

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In a thermoelectric air-handling unit, a number of thermoelectric modules with forced convection heat sinks are used. In this research, it is tried to investigate the effect of module arrangement and air flow pattern on thermal performance of the system. For this purpose, the thermal performance of an air-handling unit including four thermoelectric modules with three different heat sinks layouts; parallel, series with unidirectional flow and series with counter flow were compared. The entropy analysis has been used to study the thermal performance and pressure drop imposed on the system. In addition, the effect of the electric current applied to the modules and the hot and cold air flows on the coefficient of performance of the system has been studied for three different layouts. Results indicated that, heat sinks layout and air flow pattern through the fins have significant effects on the thermal performance of a thermoelectric air-handling unit. The coefficient of performance for cooling and heating in the series arrangement are 1.4 and 1.1 times of those in parallel arrangement, respectively. The results of the entropy analysis showed that although the pressure drop imposed on the system in the layout of the series is greater than the parallel arrangement, this cannot reduce the advantage of using the series layout.