摘要：
This paper developed a novel approach to determine averaged binary potential field (ABPF) from compressibility factor. After the concepts of intermolecular potential field and idealized symmetric fluid were introduced, relevant thermodynamical analytical expressions for the fluid were derived. Especially, a new equation relating the compressibility factor with the ABPF was obtained. And then, the obtained equation was applied to five typical fluids: argon, methane, methanol, benzene and water, which covers spherical, nonpolar and polar molecules. It was found that all the ABPFs of the five fluids exhibited a combination of the potential of soft sphere ball and/or the potential of standard Lennard-Jones' form taught in textbooks, and can be accurately fitted to the linear combination of odd Chebyshev polynomials up to the fifth degree. These results have not only shown the fruitfulness and application value of the approach, but also suggested an alternative way to explore the intermolecular interactions in the averaged field's manner. (C) 2019 Elsevier B.V. All rights reserved.
关键词：
Averaged intermolecular potential field;Equation of state;Extended Lennard-Jones potential;Symmetric fluid
摘要：
This paper developed the conceptual model of symmetric extended Lennard-Jones fluid based on an extended Lennard-Jones potential function. Therein, important relationships between averaged intermolecular potential field (AIPF) and thermodynamic properties were presented, in which the equation of state was included. These formulas can not only predict the p-V-T properties of argon, nitrogen, carbon monoxide and methane that are representatives of spherical, polar and non-polar molecular fluids in acceptable accuracy, but also physically interpret the p-V-T properties from the AIPF. Obtained results have theoretical significance and can serve as reference or base in the analysis and computation of the p-V-T properties of simple fluids. (C) 2019 Elsevier B.V. All rights reserved.
摘要：
To avoid deficiencies of traditional electrocoagulation process, electrocoagulation process powered by renewable photovoltaic energy has been directly employed to remove Ni from wastewater. Results show that under the solar irradiation intensity (SII) of 750 - 30 W/sq m, Al electrode has higher Ni removal efficiency (NRE) than graphite and Ti and its NRE was almost 100% in 40 min. An optimum distance of 20 mm was determined for the electrode gap. NRE in 40 min almost decreased from 99.6% to 78.8% when initial Ni2+ concentration increased from 100 to 300 mg/L. Under the SII of 610 - 40 W/sq m, solution containing SO42- of 3.4 mmol/L got the highest NRE, while wastewater containing Cl- of 6.8 mmol/L had the lowest. Also, effluent, including SO42- of 1.7 and Cl- of 3.4 mmol/L, showed a higher NRE as well. NRE in 40 min increased when output power of the photovoltaic panel changed from 30 to 90 W, but did not show an obviously increasing tendency when the power improved further to 120 W.
摘要：
Through general property tests, rheological measurements, SEM observations and weight changes after immersion, electrochemical methods and water vapor transmission tests, a waterborne zinc-rich coating from sodium silicate solution catalyzed by ammonium acetate was characterized. Results showed that the formula catalyzed by ammonium acetate overcame the poor water resistance of other non-catalyzed coatings, while binding the zinc powder in the film. The zinc-rich film had the basic features required for a zinc-rich primer to be useful and was electrochemically cathodically protective during tests. The acetate anion from ammonium acetate resulted not only in little early corrosion while catalyzing the formation of zinc silicate before cure but also stronger corrosion protection during the immersion test on the cured film. The velocity of water vapor transmission and the amount of acetate anions present decreased with time until a stable value was achieved after approximately 6 days.
期刊：
Natural Gas Industry B,2017年4(2):100-105 ISSN：2352-8540
通讯作者：
Xiaohong Yang
作者机构：
[Xiaohong Yang; Shunxi Zhang; Weiling Zhu] School of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan, Hubei 430023, China
通讯机构：
[Xiaohong Yang] S;School of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan, Hubei 430023, China
关键词：
Natural gas;Viscosity;New model;Temperature;Density;Composition;Kinetic theory of gases;Relative deviation;Accurate calculation
摘要：
Viscosity of natural gas is a basic and important parameter, of theoretical and practical significance in the domain of natural gas recovery, transmission and processing. In order to obtain the accurate viscosity data efficiently at a low cost, a new model and its corresponding functional relation are derived on the basis of the relationship among viscosity, temperature and density derived from the kinetic theory of gases. After the model parameters were optimized using a lot of experimental data, the diagram showing the variation of viscosity along with temperature and density is prepared, showing that: ① the gas viscosity increases with the increase of density as well as the increase of temperature in the low density region; ② the gas viscosity increases with the decrease of temperature in high density region. With this new model, the viscosity of 9 natural gas samples was calculated precisely. The average relative deviation between these calculated values and 1539 experimental data measured at 250–450 K and 0.10–140.0 MPa is less than 1.9%. Compared with the 793 experimental data with a measurement error less than 0.5%, the maximum relative deviation is less than 0.98%. It is concluded that this new model is more advantageous than the previous 8 models in terms of simplicity, accuracy, fast calculation, and direct applicability to the CO2 bearing gas samples.
摘要：
Using immersion tests, viscosity measurements, FTIR and SEM, as well as biodegradation tests, biodegradable tung oil coatings were investigated. Results showed that the curing times for different formulae decreased as the amount of catalyst increased. During the curing process, there was an initial induction period where the viscosity remained more or less the same, and after a certain time, a sharp increase in viscosity was observed. The steady viscosity increased with time, revealing a continuous autoxidation process. Microorganisms in the soil attacked the surfaces of the tung oil films either uniformly on the whole plate or at specific weak points, leading to decreased volume, blurring of the small humps as well as holes. The weak point on the crosslinked chain was located at the carbonyl-containing groups, where chemical biodegradation occurred more easily and faster. (C) 2015 Elsevier B.V. All rights reserved.
关键词：
Fluidic fuel;Viscosity;Temperature;Interaction potential;Momentum transfer
摘要：
Viscosity is a first and foremost function both for theory and application. By approximating the interaction potential of molecule in fluidic fuel as constant and proposing a new method to calculate the momentum transfer by means of the radius of averaged volume per molecule, an equation of viscosity versus temperature was derived, which were found in good agreement with a lot of data from gaseous to liquid fuels by the curve fit. The equation also predicted that the viscosity initially decreased with temperature and then slowly increased in the high temperature region. When using it as correlation equation for the dependence of viscosity on temperature, it was able to cover more fluids from gaseous to liquid fuels. (C) 2015 Elsevier Ltd. All rights reserved.
