Xenon viscosity

Helium and Xenon viscosity and thermal conductivity values impact pressure drop and heat transfer calculations... 

Figure 2 graphically represents the results of the xenon viscosity comparison and shows the deviation of the semi-empirical method of calculating xenon viscosity from the empirically derived DIPPR curve fit recommended in this paper. Figure 2 shows that NIST results track well with DIPPR results. Xenon semi-empirical values deviate from DIPPR values by as much as 4.0% at 1400 K. 

Adequate helium and xenon pure eomponent viseosity and thermal conduetivity data exist to allow the use of curve fits of experimental data. The method recommended to calculate the viscosity and thermal conductivity of pure hehum and pme xenon is to use equations provided by the Design Institute for Physical Property Data (DIPPR) (Daubert et al., 1992). These equations were produced from curve fits of experimental data and include a quahty estimate with each correlation. The quality estimate represents the average rehability of data plus error from regression. DIPPR indicates less than 3% error for hehum and xenon viscosity and less than 5% error for hehum and xenon thermal conductivity. 

Values extracted and in some cases rounded off from ttose cited in RaLinovict (ed.), Theimophysical Propeities of Neon, Ai gon, Kiypton and Xenon, Standards Press, Moscow, 1976. Ttis source contains values for tte compressed state for pressures up to 1000 bar, etc. t = triple point. Above tbe sobd line tbe condensed phase is solid below it, it is liquid. Tbe notation 5.646. signifies 5.646 X 10 . At 83.8 K, tbe viscosity of tbe saturated liquid is 2.93 X 10 Pa-s = 0.000293 Ns/ui . Tbis book was published in English translation by Hemisphere, New York, 1988 (604 pp.). 

Xenon is an odourless, colourless, non-explosive gas present in the atmospheres of both Earth and Mars in concentrations of approximately 0.08 ppm. Its density is approximately three times and its viscosity twice that of nitrous oxide. Like other noble gases, such as helium and argon, its outer electron shell contains the maximum number of electrons (8) making the molecule highly stable chemically. Despite this, its anaesthetic activity indicates that xenon binds to cell proteins and cell membrane constituents. 

In Fig. 16 the heat-treated sampie(l) is obtained by heating poly-DSP crystals (a) up to 330°C at a scanning speed of 15°C/min. Then, the sample is cooled immediately to room temperature. The intrinsic viscosity of the original as-polymerized poly-DSP (2.1-2.9) is reduced (0.55-0.59) in sample (1). An X-ray pattern of sample (1) shows slight but definite differences when compared to that erf the original as-polymerized polymer and, in addition, the pattern agrees exactly with that ot the medium-sized polymer crystals (c), which are obtained by photopolymerization of DSP crystals upon irradiation with a xenon lamp for 50 min. DSC curves of sample (1) and polymer crystals (c) are also very similar to each other. From these results, it is concluded that the high... 

The presence of extensive backbone scission during photo-oxidative degradation has been demonstrated by molecular weight (Mn) determination, based on solution viscosities. PET with an initial f n of -20,000 decreased to ll+,000 after 600 hr xenon arc irradiation (2 ). PmPiPA with an initial Mn of -1+0,000 decreased to -10,000 after 1+0 hr of xenon arc irradiation ( ). The actual extent of backbone scission is even more startling when it is remembered that degradation has occurred only in the irradiated surface layer (surface layer will be of the order of 1000, i.e., oligomer in each case. 

To calculate micelle size and diffusion coefficient, the viscosity and refractive index of the continuous phase must be known (equations 2 to 4). It was assumed that the fluid viscosity and refractive index were equal to those of the pure fluid (xenon or alkane) at the same temperature and pressure. We believe this approximation is valid since most of the dissolved AOT is associated with the micelles, thus the monomeric AOT concentration in the continuous phase is very small. The density of supercritical ethane at various pressures was obtained from interpolated values (2B.). Refractive indices were calculated from density values for ethane, propane and pentane using a semi-empirical Lorentz-Lorenz type relationship (25.) Viscosities of propane and ethane were calculated from the fluid density via an empirical relationship (30). Supercritical xenon densities were interpolated from tabulated values (21.) The Lorentz-Lorenz function (22) was used to calculate the xenon refractive indices. Viscosities of supercritical xenon (22)r liquid pentane, heptane, decane (21) r hexane and octane (22.) were obtained from previously determined values. 

The values in these tables were generated from the NIST REFPROP software (Lemmon, E. W, McLinden, M. O., and Huber, M. L., NIST Standard Reference Database 23 Reference Fluid Thermodynamic and Transport Properties—REFPROP, National Institute of Standards and Technology, Standard Reference Data Program, Gaithersburg, Md., 2002, Version 7.1). The primary source for the thermodynamic properties is Lemmon, E. W, and Span, R., Short Fundamental Equations of State for 20 Industrial Fluids, / Chem. Eng. Data 51(3) 785-850, 2006. The source for viscosity and thermal conductivity is McCarty, R. D., Correlations for the Thermophysical Properties of Xenon, National Institute of Standards and Technology, Boulder, Colo., 1989. 

The helium/xenon coolant will be compared relative to some other common gasses. The properties that will be examined are viscosity, thermal conductivity, specific heat and density. 

The first major systematic study of PET photochemical degradation was begun by Day and Wiles in the early 1970s [9-15. Samples were irradiated using carbon-arc and xenon-arc light sources, and their degradation followed by means of tensile properties, intrinsic viscosities, infrared (IR) absorption and fluorescence emission. 

Yaws, C. 2001. Matheson Gas Data Book, 7th ed. Parsippany, NJ Matheson TriGas New York McGraw-Hill. The Matheson Gas Data Book contains individnal sections with property data on over 150 indnstrial gaseons elements and componnds (from acetylene to xenon). Data include, thermodynamic properties, IR spectra, vapor pressnre-temperature curves, Henry s Law constants, explosion limits, and viscosity. 

Effects other than those of purely viscometric origin were seen to be significant in a schematic study by McHugh and co-workers of the free radical decomposition of cumene hydroperoxide [48], and subsequent oxidation of cumene (isopropyl benzene) [49, 50] in a range of supercritical and liquid solvents. The effective non-catalysed rate coefficients for cumene hydroperoxide decomposition in non-polarisable supercritical fluids (krypton, xenon) were greater than that for non-polar liquid cyclohexane, as expected a priori on the basis of viscosities. Yet, liquid 1-octene and 1-hexanol gave similar... 

It subsequently proved advantageous to develop expressions for universal curves based on experimental results for the correlation of dense fluid transport properties. This is discussed fully in Chapter 10 with respect to xenon, for which accurate diffusion data are available, in addition to viscosity measurements, up to high densities. In the case of diffusion, there is very satisfactory agreement between the exact hard-sphere results and experimental data. 

Berg, R. E Moldover, M. R. (1990). Critical exponent for the viscosity of carbon dioxide and xenon. J. Chem. Phys., 93,1926-1938. 

Harris, K. R. (1992). The self-diffusion coefficient and viscosity of the hard-sphere fluid revised A comparison with experimental data for xenon, methane, ethene and trichloromethane. Mol. Phys., 77,1153-1167. 

Hanley, H. J. M. (1974). The viscosity and thermal conductivity coefficients of dilute argon, liypton, and xenon. J. Phys. Chem. Ref. Data, 2,619-642. 

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