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Turbidity, definition

Cr 4- 0.67 Na Slight brownish-yellow color and turbidity Definite turbidity... [Pg.512]

Discussion. The turbidity of a dilute barium sulphate suspension is difficult to reproduce it is therefore essential to adhere rigidly to the experimental procedure detailed below. The velocity of the precipitation, as well as the concentration of the reactants, must be controlled by adding (after all the other components are present) pure solid barium chloride of definite grain size. The rate of solution of the barium chloride controls the velocity of the reaction. Sodium chloride and hydrochloric acid are added before the precipitation in order to inhibit the growth of microcrystals of barium sulphate the optimum pH is maintained and minimises the effect of variable amounts of other electrolytes present in the sample upon the size of the suspended barium sulphate particles. A glycerol-ethanol solution helps to stabilise the turbidity. The reaction vessel is shaken gently in order to obtain a uniform particle size each vessel should be shaken at the same rate and the same number of times. The unknown must be treated exactly like the standard solution. The interval between the time of precipitation and measurement must be kept constant. [Pg.729]

Equation (li ) can be used to calculate uncorrected diameter averages. For the number, surface, volume, specific surface, weight and turbidity diameter averages (their definitions have been stated elsewhere (11,12), the following relations can be derived ... [Pg.65]

In a practical sense, stability of a dispersion ofttimes is accompanied by a retarded separation of the phases. Unfortunately, a quantitative definition cannot be based on this rate of separation because of the overwhelming influence of density, viscosity, and thermal effects. In short, a kinetic criterion, such as sedimentation rate, is not as likely to portray stability as one based on thermodynamic considerations. In this latter category are sediment volumes, turbidity, consistency, and electrical behavior. [Pg.93]

Since the scattering due to dust is negligible relative to the very large scattering from colloidal suspensions, procedure (b) is inherently attractive. Using the definition of turbidity t and the interrelation between r and R90, the calibration constant of the instrument is given by... [Pg.173]

Introduce 100ml of ether under test into a Nessler tube, passing the sample thru a filter if it has any visible turbidity. Cap tbe tube with a transparent cover and place it in the "comparator", while side-by-side with it is placed one of the standards. Report as the color the number of the standard that most nearly matches the sample. In the event that the color lies midway between two standards, report tbe darker of the two. If, owing to differences In hue berw the sample and the standards, a definite match cannot be obtd, report the range ovet which an apparent match is ohtd, making a note that it is "off-hue ... [Pg.60]

The flocculation value is the minimum concentration required for turbidity in a definite time. [Pg.59]

The measurements of water quality parameters (oxidation-reduction potential, pH, temperature, conductivity, dissolved oxygen, and turbidity) and the collection of field screening data with field portable instruments and test kits constitute a substantial portion of field work. Field measurements, such as pH, stand on their own as definitive data used for the calculations of solubility of chemical species and chemical equilibrium in water, whereas others serve as indicators of well stabilization or guide our decision-making in the field. Table 3.8 shows the diversity of field measurement... [Pg.166]

Fluorescent indicator — A substance that shows definite changes in fluorescence with a change in pH. This kind of indicator is especially useful for the titration of opaque, highly turbid, or deeply colored solutions. A long-wavelength ultraviolet lamp in a dimly lighted room provides the best environment for titrations involving fluorescent indicators [i]. [Pg.276]

Water Quality. This characteristic (i.e., turbidity) is usually difficult to interpret in the bottle test and consequently to correlate with plant behavior. Clear water is definitely the desired result. Complications, however, arise when solids are present in the crude oil. Therefore, it is necessary to remove the solids with the water, along with any oil adsorbed on these... [Pg.352]

The term liquid crystal was first applied to compounds that, unlike most compounds that melt in a single step at a definite temperature, show one or more well-defined phases between the solid and the true liquid. Otto Lehmann in 1888 was contacted by Friedrich Reinitzer who had observed that crystalline cholesteryl benzoate, on heating, seemed to have two melting points.At 145.5° C a cloudy liquid forms that, on further heating, changes sharply to a clear liquid at 178.5° C. On cooling the reverse order of phases was found. The turbid liquid is doubly refracting, like the anisotropic crystals described in Chapter 5, hence the... [Pg.661]

Troponin T binds to troponin C irrespective of Ca " concentration (Grabarek et al, 1981 Tanokura et al., 1983). The mixture of troponin T and C is turbid in the absence of Ca " and becomes transparent in the presence of Ca " (Ebashi et al., 1973 Ebashi, 1974a,b). This increase in turbidity in the absence of Ca was interpreted as a change of conformation of the troponin T-C complex and a subsequent formation of aggregates. The Ca " concentration necessary for clearing the turbidity is definitely higher than that for the regulation of contractile interaction. [Pg.30]


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See also in sourсe #XX -- [ Pg.268 ]




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