PREDICTING STEADY AND OSCILLATORY SHEAR RHEOLOGICAL PROPERTIES OF CMC/GUAR BLENDS USING THE BIRD-CARREAU CONSTITUTIVE MODEL

The Bird-Carreau constitutive model, a five parameter semi-empirical set of equations, was used to predict the steady shear viscosity η, the dynamic viscosity η', and the out-of-phase component of the complex viscosity divided by frequency η"/ω, for aqueous blends of sodium carboxymethylcellulose (CMC) and guar gum. The five Bird-Carreau constants were derived from equations which correlate the constants to concentration and molecular weight of the CMC/guar blends. Blends of ratios 3:1, 2:1, 1:1, 1:2, and 1:3 by weight were studied in concentrations of 0.5, 0.75, 1.0, and 1.5% by weight. For most blends the model accurately predicted the experimental η and η' data in the frequency/shear rate range of 0.1–100 s^-1 and the experimental η"/ω data in the frequency/shear rate range of 1.0–100 s⁻¹.     

Sugar Content Measurement in Fruit Tissue Using Water Peak Suppression in High Resolution 1H Magnetic Resonance

Sugar content of muskmelon tissue was measured using 200 MHz ¹H magnetic resonance (MR). Single pulse resolved water and sugar resonances, but both were broadened. The sugar peak from low sugar (≦8.0%) samples was not detectable with the single pulse. Selective saturation to suppress the water peak was inefficient. The T₁ of water was almost twice that of sugar. Therefore, inversion-recovery (IR) pulse sequences could be applied for water suppression. Separation of the sugar peak was remarkably improved allowing its detection in low sugar (1.8%) samples. Measured sugar correlated linearly with peak intensity (r≧0.94). Results suggest that ¹H MR could be used to measure sugar in intact fruits and vegetables.     

Inhomogeneity-Packing Density Relations in Binary hwders

A theoretical procedure for determining the specific volume of an inhomogeneous binary mixture having a large radius ratio is presented. The procedure is based on the hypothesis that the Furnas model holds on a local level. The methodology developed is demonstrated using two hypothetical compositional distribution functions. In one case the compositional distribution describes changes that occur from a completely unmixed to a completely mixed state. The second utilizes the normal distribution for describing smaller compositional variations.     

Optimal technique for estimating the reachable set of a controlled n-dimensional linear system

The reachable set from a given point of a controlled dynamical system is the set of all states to which the system can be driven from that point in a finite time by the allowed controls. A technique is presented Tor estimating the reachable set from the asymptotically-stable origin of a class of n-dimensional linear systems under bounded control. The technique is an optimal version of a Lyapunov method, and provides an (over-)estimate of the full reachable set; it involves the minimization of a quadratic constraint, followed by the maximization of a quadratic form subject to this constraint. The non-linear optimization problems can be routinely solved by means of computer algebra and commonly available computer software. In general, the technique produces a much-improved estimate of the reachable set compared to that given by the standard Lyapunov method. Another advantage of the technique is that it is truly applicable to higher-dimensional systems (n ≥ 3). Since the estimate produced is in the convenient form of an n-dimensional ellipsoid, projections of the estimate onto any space of dimension ≤ n — 1 can be readily found. Problems of two, three, and four dimensions are solved to illustrate the technique.     

ORDINAL POSITION AND APPROVAL MOTIVATION.

THE MARLOWE-CROWNE SOCIAL DESIRABILITY SCALE, A MEASURE OF NEED FOR APPROVAL MOTIVATION, WAS ADMINISTERED IN A GROUP SETTING TO A SAMPLE OF UNIVERSITY FRESHMEN. THE SAMPLE CONSISTED OF 80 1ST- AND 110 LATTER-BORN MALES AND 67 1ST- AND 92 LATTER-BORN FEMALES. SIGNIFICANT MAIN EFFECTS FOR SEX (P     

Predicting Steady and Oscillatory Shear Rheological Properties of CMC and Guar Gum Blends from Concentration and Molecular Weight Data

The steady shear and oscillatory shear Theological properties of aqueous solutions of sodium carboxymethylcellulose (CMC), guar gum and CMC/guar blends of ratios 3:1, 2:1, 1:1, 1:2, and 1:3 by weight were measured in the concentration range of 0.5, 0.75, 1.0, and 1.5% by weight. For the CMC/guar systems, the zero-shear rate viscosity, η₀, time constants λ₁ and λ₂ and the slopes of the non-Newtonian region of the log η vs log λ and log η′ vs log ω curves, ? S_η and ? S_η, can be related to concentration and molecular weight.     

SOME EFFECTS OF FLUID PROPERTIES AND LOCATION ON MIXING INDICES FOR FLOW NEAR DROPS†

The flow field and mixing behavior surrounding a rising drop were simulated using the SOLA-VOF computer code. The effects of kinematic viscosity, interracial tension, drop density and spatial location on the mixing behavior and several mixing indices were studied as a function of time. Two mixing indices, one based upon material line extension and rate variations in material line extension and the other based upon a Lagrangian correlation coefficient and a Lagrangian time scale, were shown to be directly related to the fluid mechanics causing the mixing. Another index, the scale of segregation, was found to be inadequate in describing the mixing since its scale was too large to discern small scale mixing behavior.     

Retardation by Glandless Cottonseed Flour of Lipid Oxidation and Discoloration in Raw Ground Beef Containing Salt

Salt (NaCl) was added to raw ground beef at levels of 0, 0.5, 1, 2 or 3% of the weight of the meat and defatted glandless cottonseed flour (GCF) was added at 0 or 3% levels. Patties were made with these mixes and stored for 3 or 6 days at 4°C or for 30 or 60 days at –20°C. Lipid oxidation (TBA values) in samples stored at 4° and –20°C and discoloration in samples stored at 4°C were determined. In samples made with salt only, TBA values within each storage period for each storage temperature increased with increasing salt levels up to 2%; increasing salt from 2 to 3% decreased TBA values. GCF markedly reduced TBA values at each salt level. Discoloration of samples stored at 4°C was also decreased by GCF.