Kinematic Viscosity of R410A and R407C Refrigerant−Oil Mixtures in the Saturated Liquid Phase with Lubricant Mass Fraction in the Range of (0 to 0.0001)

2010 ◽  
Vol 55 (8) ◽  
pp. 2886-2889 ◽  
Author(s):  
Ying Zhang ◽  
Maogang He
2013 ◽  
Vol 13 (4) ◽  
pp. 1733-1749 ◽  
Author(s):  
G. de Boer ◽  
T. Hashino ◽  
G. J. Tripoli ◽  
E. W. Eloranta

Abstract. Numerical simulations were carried out in a high-resolution two-dimensional framework to increase our understanding of aerosol indirect effects in mixed-phase stratiform clouds. Aerosol characteristics explored include insoluble particle type, soluble mass fraction, influence of aerosol-induced freezing point depression and influence of aerosol number concentration. Simulations were analyzed with a focus on the processes related to liquid phase microphysics, and ice formation was limited to droplet freezing. Of the aerosol properties investigated, aerosol insoluble mass type and its associated freezing efficiency was found to be most relevant to cloud lifetime. Secondary effects from aerosol soluble mass fraction and number concentration also alter cloud characteristics and lifetime. These alterations occur via various mechanisms, including changes to the amount of nucleated ice, influence on liquid phase precipitation and ice riming rates, and changes to liquid droplet nucleation and growth rates. Alteration of the aerosol properties in simulations with identical initial and boundary conditions results in large variability in simulated cloud thickness and lifetime, ranging from rapid and complete glaciation of liquid to the production of long-lived, thick stratiform mixed-phase cloud.


Author(s):  
Paulo Bisi dos Santos Jr. ◽  
Haroldo Jorge da Silva Ribeiro ◽  
Armando Costa Ferreira ◽  
Caio Campos Ferreira ◽  
Lucas Pinto Bernar ◽  
...  

In this work, the cross-linked PMMA-based dental resins scraps were submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps was analyzed by TG/DTG to guide the operating conditions in pilot scale. The pyrolysis experiments carried out in a reactor of 143L, at 345, 405, and 420°C, 1.0 atmosphere. The reaction liquid products obtained at 345°C, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of liquid products obtained at 345°C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405°C, 50, 70, and 130 minutes, and at 420°C, 40, 50, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420°C, respectively, showing a smooth sigmoid behavior, decreasing with increasing temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage deviations between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA at 20 °C. The GC-MS identified in the reaction liquid products at 345, 405, and 420°C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA between 83.454 and 98.975% (area.). For all the depolymerization experiments, the concentrations of MMA in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA. The optimum operating conditions to achieve high MMA concentrations, as well as elevated yields of liquid reaction products were 345 °C and 80 minutes.


We have measured the kinematic viscosity of glycerol-water mixtures, for glycerol mass fractions ranging from 0 to 1, in the temperature range 10-50 °C. The measurements were made by using a series of Ubbelohde viscometers. Apart from comprehensiveness and comparative accuracy the present measurements expose serious errors in the limited data that were earlier available on such mixtures. It is shown that all the data can be reasonably represented by the empirical correlation (In ν m - In ν w )/(In ν g - In ν w ) = x g [1 + (1 - x g ) { a + bx g + cx g 2 }], where ν w , v g and ν m are the kinematic viscosities of water, glycerol and the mixture respectively and x g is the mass fraction of glycerol in the mixture. The constants a, b and c are tabulated in the paper as functions of temperature. This correlation can now be used at a given temperature to tailor make a mixture of prescribed kinematic viscosity. While this paper is addressed, principally, to fluid dynamicists these results should be of interest to physicists studying the liquid state and physical chemists interested in mixtures.


2020 ◽  
Vol 93 (6) ◽  
pp. 2228-2231
Author(s):  
Yang Li ◽  
Fenghai Li ◽  
Mingjie Ma ◽  
Bing Yu ◽  
Chaoyue Zhao ◽  
...  

1946 ◽  
Vol 24f (5) ◽  
pp. 369-379 ◽  
Author(s):  
Jesse A. Pearce

Preliminary investigations showed a slow rate of production of hexachloroethane from chlorine-saturated liquid tetrachloroethane. The addition of some materials that often accelerate similar reactions was not effective here. However, rapid production was obtained by chlorinating tetrachloroethane in the presence of ultra-violet light. The effective wave-lengths appeared to lie between 3150 Å and 3540 Å, and the temperature coefficient between 75° and 100 °C. was 1.10. The result indicated that production of hexachloroethane from chlorine-saturated liquid tetrachloroethane was feasible. For the same conditions of illumination and temperature hexachloroethane was produced from chlorine-saturated pentachloroethane at a rate two and one-half times as fast as that in chlorine-saturated tetrachloroethane.


1981 ◽  
Vol 21 (04) ◽  
pp. 480-492 ◽  
Author(s):  
F.M. Orr ◽  
A.D. Yu ◽  
C.L. Lien

Abstract Phase behavior of CO2/Crude-oil mixtures which exhibit liquid/liquid (L/L) and liquid/ liquid/vapor (L/L/V) equilibria is examined. Results of single-contact phase behavior experiments for CO2/separator-oil mixtures are reported. Experimental results are interpreted using pseudoternary phase diagrams based on a review of phase behavior data for binary and ternary mixtures of CO2 with alkanes. Implications for the displacement process of L/L/V phase behavior are examined using a one-dimensional finite difference simulator. Results of the analysis suggest that L/L and L/L/V equilibria will occur for CO2/crude-oil mixtures at temperatures below about 120 degrees F (49 degrees C) and that development of miscibility occurs by extraction of hydrocarbons from the oil into a CO2-rich liquid phase in such systems. Introduction The efficiency of a displacement of oil by CO2 depends on a variety of factors, including phase behavior of CO2/crude-oil mixtures generated during the displacement, densities and viscosities of the phases present, relative permeabilities to individual phases, and a host of additional complications such as dispersion, viscous fingering, reservoir heterogeneities, and layering. It generally is acknowledged that phase behavior and attendant compositional effects on fluid properties strongly influence local displacement efficiency, though it also is clear that on a reservoir scale, poor vertical and areal sweep efficiency (caused by the low viscosity of the displacing CO2) may negate the favorable effects of phase behavior.Interpretation of the effects of phase behavior on displacement efficiency is made difficult by the complexity of the behavior of CO2/crude-oil mixtures. The standard interpretation of CO2 flooding phase behaviour, given first by Rathmell et al. is that CO2 flooding behaves much like a vaporizing gas drive, as described originally by Hutchinson and Braun. During a flood, vaporphase CO2 mixes with oil in place and extracts light and intermediate hydrocarbons. After multiple contacts, the CO2-rich phase vaporizes enough hydrocarbons to develop a composition that can displace oil efficiently, if not miscibly. The picture presented by Rathmell et al. appears to be consistent with phase behavior observed for CO2/ crudeoil mixtures as long as the reservoir temperature is high enough. Table 1 summarizes data reported for CO2/crude-oil mixtures. Of the 10 systems studied, all those at temperatures above 120 degrees F (50 degrees C) show only L/V equilibria while those below 120 degrees F exhibit L/L/V separations (Stalkup also reports two phase diagrams that are qualitatively similar to the other low-temperature diagrams but does not give temperatures). Thus, at temperatures not too far above the critical temperature of CO2 [88 degrees F (31 degrees C)], mixtures of CO2 and crude oil exhibit multiple liquid phases, and at some pressures L/L/V equilibria are observed. It has not been established whether Rathmell et al.'s interpretation of the process mechanism can be extended to cover the more complex phase behavior of low-temperature CO2/crude-oil mixtures. In a recent paper, Metcalfe and Yarborough argued critical temperature CO2 floods behave more like condensing gas drives, whereas Kamath et al. concluded that an increase in the solubility of liquid-phase CO2 in crude oil at temperatures near the critical temperature of CO2 should cause more efficient displacements of oil by CO2. SPEJ P. 480^


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6109
Author(s):  
Zhu-Hua Zhou ◽  
Sheng-Qiang Song ◽  
Robert Cromarty ◽  
Yi-Liang Chen ◽  
Zheng-Liang Xue

Improving the strength of grey cast iron wheel hubs will improve the safety of automobiles and have a great significance for energy saving and environmental protection. This paper systematically compares the calculation results of Python-based precipitation calculation and JmatPro software simulation with experiments. The results show that with a low mass fraction of niobium (0.098%) cuboid Niobium Carbide (NbC) precipitates do not form in the liquid phase; however, an elongated NbC niobium-rich phase may form during the solidification process and in the solid phase. However, cuboid NbC precipitates can be precipitated from the liquid phase when the niobium mass fraction is higher (0.27%, 0.46%). These results indicate that with the increasing niobium content the amount, particle size, and initial precipitation temperature of niobium carbide precipitated in the matrix structure will increase. According to the observation and statistical analysis of the microstructure, it is found that tensile strength will be improved with an increase in niobium content due to the refinement of the graphite and pearlite interlamellar spacing. In this paper, adding less than 0.32% of Nb to grey cast iron is recommended, considering the comprehensive cost and the effect of niobium in the material structure.


1988 ◽  
Vol 43 (6) ◽  
pp. 1303-1309 ◽  
Author(s):  
J.L. Chevalier ◽  
P. Petrino ◽  
Y. Gaston-Bonhomme

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