Viscosity and Specific Weight

The kinematic viscosity of MEM containing aqueous electrolytes at different concentrations of MEM and ZnBt2 and at different temperatures has been studied [68] (see Table 8). 

Kinematic viscosities of aqueous electrolyte phases containing Et N Br and Bu4N Br and various concentrations of ZnBt2 were studied by Cedzynska [77]. Ionic conductivity of bromine storing phases was estimated [56] by applying the 

Pisarzhevski-Walden equation to measured values of the dynamic viscosity. However, use of this relation is only correct for solutions in the limit of zero concentration and no change in solution mechanism. 

Eustace [75] reported a dynamic viscosity of 25 cP a pure MEMBr complex phase at 23 °C. (The specific weight was 2.3 g cm ). 

Typical specific weights of bromine storing complex phases between 10 and 70°C at bromine concentrations in the range of 1-4 mol/mol complexing agent lie around 2.45 0.1 gcm Densities as a function of temperature at various bromine contents of a number of quaternary ammonium salts were given by Gerold [56]. 

Viscosities and specific weights of complexes and the corresponding aqueous phases, with the aim of simulating realistic battery conditions with MEPiMEM ratio of 1 1, 3 1, and 6 1 in the electrolyte at 50, 75, and 100% SOC, were studied in a temperature range between 10 and 50 °C [81]. Kinematic viscosities between 5 X 10 and 30 x 10 m s of the complex phases were found. 

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A summary of the results obtained from GPC/DV on the first day and the third day after solution preparation is shown in Table II. For Red Oak and RO PO, the number average molecular weight decreased by approximately 6% from the first day to the third day. However, the intrinsic viscosities increased. According to traditional polymer solution theory (42), the product of intrinsic viscosity and molecular weight yields the hydrodynamic volume specifically, it has been shown that the molecular weight that... 

TAegradation of a polymer can be evaluated by its rate of decomposi-tion. This consists of dehydrochlorination, change in color, electrical resistance, viscosity, solubility, specific weight, and infrared spectrum. The factors influencing the rate of destruction are ... 

For purposes of computation we used parameters obtained by Ebinger Sleep (1998) for the East African plume. The material properties assumed are a viscosity, h = 0.3x 10 Pas thermal diffusivity k = 0.8 x 10 m s , and specific weight contrast 200 Nm . The scaling constant is = 1/16. The starting plume head volume in the infinite radial model is g = 0.2 x 10 m , which yields Apond = 39 km. The finite widths Ro and Xq are assumed to be 250 km. This... 

If is considered to be a universal constant, the average dimensions of polymer molecules in solution can be drived simply from their intrinsic viscosities and molecular weights. More specifically, the natural, or unperturbed, dimensions of the polymer chain can be estimated from the knowledge of intrinsic viscosity in a theta solvent (Kurata and Stockmayer, 1963 Stockmayer and Fixman, 1963). 

Polymer solutions are never ideal since dissolved macromolecules influence each other even at very low concentration. On the other hand, a reliable correlation of solution viscosity and molecular weight is only possible if the dissolved macromolecules are not affected by mutual interactions they must be actually independent of each other. Therefore, the viscosity of polymer solutions should be determined at infinite dilution. However, such measurements are impossible in practice. So one works at an as low as possible polymer concentration and extrapolates the obtained values to zero concentration. To do so, the elution time measurements are not only carried out for one single polymer concentration but for varying polymer concentrations (e.g., 10, 5, 2.5, 1.25 g/1). For each solution, the value of the reduced specific viscosity is figured out (the data will make evident that this quantity is clearly concentration-dependent even at the lowest possible polymer... 

Equation (8.21) describes the relationship between viscosity and molecular weight. Since molecular weight is related to the size of the polymer chain, Eq. (8.21) also describes the relationship between [q] and N (the number of links in a polymer chain) or [q] and (R ) (the mean-square end-to-end distance). This has stimulated a great deal, interest over the last 40 years as to how they are related. More specifically, what are the meaning of K and a ... 

Hultin (77) has derived an expression for the enzymic depolymerization of hyaluronic acid based on Staudinger s (182) equation relating specific viscosity and molecular weight. This equation permits the calculation of a microunit for enzymic activity. The formula was applied to data published by Madinaveitia and Quibell (112) and Swyer and Emmens (183). The values obtained showed fairly good agreement for the higher substrate concentrations. 

The constant of proportionality (/r) is called viscosity. The dimensions of viscosity can be found from Eq. (5.3) to be [E TZ" ]. In the English system of units, the unit of viscosity is called the Rc5m (after Rc5molds) and equals one lb sec/in. In the metric system, the unit of viscosity is the Poise (after Poiseuille) and equals one dyne sec/cm. One Re m equals 68,950 Poise. Representative values of viscosity (p) and specific weight (/) are given in Table 5.1. 

T able 5.1. Representative Values of Viscosity (p) and Specific Weight f)... 

The steady-state model used in RTO typically is obtained either from fundamental knowledge of the plant or from experimental data. It utilizes the plant operating conditions for each unit such as temperature, pressure, and feed flow rates to predict properties such as product yields (or distributions), production rates, and measurable product characteristics (e.g., purity, viscosity, and molecular weight). The economic model involves the costs of raw materials, values of products, and costs of production as functions of operating conditions, projected sales figures, and so on. An objective function is specified in terms of these quantities in particular, operating profit over some specific period of time can be expressed as... 

The different cuts obtained are collected their initial and final distillation temperatures are recorded along with their weights and specific gravities. Other physical characteristics are measured for the light fractions octane number, vapor pressure, molecular weight, PONA, weight per cent sulfur, etc., and, for the heavy fractions, the aniline point, specific gravity, viscosity, sulfur content, and asphaltene content, etc. 

Equation (2.61) predicts a 3.5-power dependence of viscosity on molecular weight, amazingly close to the observed 3.4-power dependence. In this respect the model is a success. Unfortunately, there are other mechanical properties of highly entangled molecules in which the agreement between the Bueche theory and experiment are less satisfactory. Since we have not established the basis for these other criteria, we shall not go into specific details. It is informative to recognize that Eq. (2.61) contains many of the same factors as Eq. (2.56), the Debye expression for viscosity, which we symbolize t . If we factor the Bueche expression so as to separate the Debye terms, we obtain... 

Most hydrocarbon resins are composed of a mixture of monomers and are rather difficult to hiUy characterize on a molecular level. The characteristics of resins are typically defined by physical properties such as softening point, color, molecular weight, melt viscosity, and solubiHty parameter. These properties predict performance characteristics and are essential in designing resins for specific appHcations. Actual characterization techniques used to define the broad molecular properties of hydrocarbon resins are Fourier transform infrared spectroscopy (ftir), nuclear magnetic resonance spectroscopy (nmr), and differential scanning calorimetry (dsc). 

The viscosity of a fluid arises from the internal friction of the fluid, and it manifests itself externally as the resistance of the fluid to flow. With respect to viscosity there are two broad classes of fluids Newtonian and non-Newtonian. Newtonian fluids have a constant viscosity regardless of strain rate. Low-molecular-weight pure liquids are examples of Newtonian fluids. Non-Newtonian fluids do not have a constant viscosity and will either thicken or thin when strain is applied. Polymers, colloidal suspensions, and emulsions are examples of non-Newtonian fluids [1]. To date, researchers have treated ionic liquids as Newtonian fluids, and no data indicating that there are non-Newtonian ionic liquids have so far been published. However, no research effort has yet been specifically directed towards investigation of potential non-Newtonian behavior in these systems. 

Proper control of the properties of drilling mud is very important for their preparation and maintenance. Although oil-base muds are substantially different from water-base muds, several basic tests (such as specific weight, API funnel viscosity, API filtration, and retort analysis) are run in the same way. The test interpretations, however, are somewhat different. In addition, oil-base muds have several unique properties, such as temperature sensitivity, emulsion stability, aniline point, and oil coating-water wettability that require other tests. Therefore, testing of water and oil-base muds will be considered separately. 

The unavoidable addition of solids comes from the continual influx of drilled cuttings into the active mud system. Undesirable solids increase drilling cost because they reduce penetration rate through their effect on mud specific weight and mud viscosity. 

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