Transparency and turbidity

Testing waters for transparency and turbidity is done for orientation purposes. The transparency depends on the colour and any turbidity of the water. The turbidity is caused by suspended or colloidally dissolved inorganic and/or organic substances. Apart from sludge particles, silicic acid, ferric and aluminium hydroxide, organic colloids, bacteria and plankton are possible. The determining process should be carried out immediately after sampling, and certainly not more than 24 hours afterwards at the latest. 

For the simple visual test for turbidity, a colourless clear glass bottle 

A measurement can also be made by comparing the turbidity of the water with that of a series of dilutions of a kieselguhr standard suspension (1.00 g 

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Fig. 25a, b. Correlation between transparency and calculated [6, 201] dispersion erf (1) x 103 of composition distribution of terpolymer molecules, prepared at complete conversion, for the reference i-th monomer in the system (acrylonitrile + a-methylstyrene + styrene) (a) and (methyl methacrylate + methacrylonitrile + styrene (b). Open and dark circles denote transparent and turbid terpolymeriza-tion products in the experiments by Slocombe [128]... 

Fig. 26. The Gibbs-Rooze-boom triangle for the weight composition of (styrene + methyl acrylate + heptyl acrylate) terpolymer, prepared under Regime II (see Fig. 24) at complete conversion. Open and dark circles denote transparent and turbid terpolymer, respectively, and figures above the circles denote the theoretical value of...

Prior to the addition of the silica precursor (TEOS), the acidic copolymer solution appears transparent and the SANS data shows that the copolymer forms spherical micelles of size 7.1 nm (figure 1-a). After the addition of TEOS, the solution becomes immediately turbid. Most probably, it is because TEOS is hydrophobic and forms an emulsion droplets under stirring when added to the solution [3], Then, the opacity increases with time (figure 1-b), until a thick white precipitate forms after about 23 minutes (figure 1-c). 

I - Yellow, isotropic, transparent and homogeneous Ai - Dark yellow, birefringent and turbid large scale structure... 

Fig. 41a and b. Elastomer in the l.c. state a unstretched, macroscopically disordered and turbid b stretched, macroscopically ordered and transparent. The samples are layered on a perforated black background... 

Gels may appear transparent or turbid based on the type of gelling agent used. They exhibit different physical properties, namely, imbibition, swelling, syneresis, and... 

Appearance. Acetone sfaall. be colorless, transparent and show no turbidity when... 

Transparency or turbidity is often measured on site with a coupled electrode for the measurement of temperature and dissolved oxygen (more and more measured by optical sensor or optrode). For Rhode Island Volunteers, complementary determinations (pH, alkalinity, TP, chl-a, Ca, Mg, Na and Cl) are carried out in a laboratory and results are statistically similar to those collected by professionals (Herron, 2006). 

When the temperature of the solution is again lowered, we can observe that the solution which was limpid and transparent becomes turbid. Then, if the temperature remains constant, a meniscus appears after some time and separates two phases in the sample. We have demixtion, and this is the second characteristic effect. Precise measurements of the demixtion temperature have been made, in particular by the Japanese school. 

An example of application of three-way PCA is a data set from the Venice lagoon. In it, 11 chemical variables (chlorophyll-a, total suspended matter, water transparency, fluorescence, turbidity, suspended solids, NH4, NOj", P, COD, and BOD5) have been measured monthly in 13 sampling sites (see Figure 5.5) during the period May 1987 to December 1990, for a total of 44 months. 

The relationships of Tr-CFP, P-CFP, and DIN-CFP in the YS and ECS mixed water are the direct proportion, i.e., the CFP increases while the Tr (transparency), P, and DIN concentrations increases (Fig. 3.22). The mixed region is characterized by a more violent hydrodynamic condition, which causes turbidity and low transparency of seawater. Furthermore, the nutrients in the mixed region water far away from land are poor from terrestrial input. Besides, the mixed region water was diluted by the saline and oligotrophic waters from the ECS. Therefore, the factors controlled CFP in the YS and ECS mixed water were low transparency and nutrients (such as P and DIN). 

There is an industrial distinction between transparent and translucent materials. Transparent bodies transmit up to more than 90% they are still mostly clear even for large thicknesses. Translucent bodies have light trans-mittances of less than 90% and are only clear for small thicknesses. They are also called contact clear, since the material is indeed turbid but appears clear as a packaging material when in contact with the contents. 

The optical properties of the nanocomposites are of much interest too. The same materials could be either transparent or opaque depending on certain conditions. For example in Figure 19 we see transparency, plot (a), and turbidity, plot (c), of the material in dependence of the frequency of the current apphed. 

Figure 4 shows typical variations of the dielectric relaxation with water content as recorded along a line stretched across I( /o) and directed towards the 100% water vertex of the pseudo-ternary phase diagram, that is for systems characterized with a fixed ratio of combined surface-active agents to hexadecane and enriched gradually with water. While dielectric relaxation phenomena are hardly detectable at low water contents, systems characterized with higher water contents exhibit striking dielectric relaxations, the dielectric increment (e - e ) increasing drastically as p approaches the critical value corresponding to the transparent-to-turbid transition. The increase in (G - e ) results from the drastic increase in the low frequency permittivity whose variations with p are plotted in Figure 5a. While at low water contents, increases slowly and almost linearly with p, it displays a divergent behavior in the vicinity of the border line F. Simi-...

The size of the particles in a microemulsion is in the range of tens of nanometers whereas in pulsions this is on the order of micrometers. As a consequence, microemulsions are transparent and annlsions are turbid. 

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