Pigment level

Ermakov IV, McClane RW, Gellermann W, and Bernstein PS (2001b), Resonant Raman detection of macular pigment levels in the living human retina, Opt. Lett. 26 202-204. 

Dilatancy occurs less frequently in pigmented systems. In flush pastes or pigment concentrates, which are formulated at high pigment levels, shearing may produce an increase in viscosity ip As the pigment concentration reaches the vicinity of the critical pigment volume concentration, and even more so if this point is ex-... 

This paper provides the basic information for spec-trophotometric determination of nitrosyl and total heme pigment levels in cured meats. 

Pigment levels given in mg/m2 leaf area and in mg/g dry weight (dw). Values measured are those from fully developed leaves in June, 2000. Pigment levels within one leaf usually vary by <3%, and pigment ratios vary by <1%. Abbreviations a + b total chlorophylls a and b x + c, xanthophylls and carotenes (total carotenoids). 

Fig. 12.12. Macular pigment levels measured with spatially integrated Raman detection in about 100 volunteer subjects ranging in age between 20 and 50 years. Each circle represents a subject s MP concentration. MP levels can vary strongly between subjects...

Increasing the levels of Cab-O-Si1 and/or pigment in the print paste does not alter the plastic viscosity, but it increases the Bingham yield stress. The paste thus has a greater "shear thinning" character at higher Cab-O-Sil or pigment levels. 

Figure 11. Effect of pigment level on skinniness ratings of polyester/cotton, 50/50 fabrics printed with radiation-curable system (2.5% Graphtol Blue 6825, 15% acrylo-urethane oligomer (MW 6000), 79% monomer mixture EP-4 (80%) and v-pyrol (20%), 3% Cab-O-Sil, and 3% vicure 10. Then required amount of...

It is possible to conduct predictive irritation assays in man as only a small area of the skin needs to be tested (provided that systemic toxicity is low and informed consent is obtained). Patch test responses generally heal rapidly, within a week or so. More severe reactions should be evaluated periodically over a longer period to determine how the inflammatory response is resolved. Some subjects may develop changes in pigmentation level at the test site following severe responses. It... 

Many workers (8, 85, 105, 117) have reported on the effect of bleaching time and temperature on bleached oil properties. Data presented in Figures 22 and 23, from Taylor (8), are typical. As shown, pigment levels drop quickly (Figure 22) for the first 15-20 minutes of the bleach, during which time they reach equilibrium conditions and then begin to level off. 

The amount of titanium dioxide and its type affects the permeability of the coating. With increased permeability, the corrosion protection of a steel substrate is decreased. The pigment level was increased from 6.4 to 28 vol% and produced a corresponding reduction in corrosion resistance. In this study, the type and quantity of titanium dioxide did not have an effect on the adhesion of the coating to the substrate. Figure 19.8 provides the reason for this lack of effect on adhesion. In this study, a set of coatings was analyzed for their adhesion to... 

Solid masterbatching consists of a high concentration of pigment in a carrier. The carrier can be the plastic with which it is to be compounded, a similar plastic or low molecular weight carriers. The ideal is a masterbatch which is miscible and dispersible with all types of plastic. The pigment level has conventionally been 10-20%. Recently more concentrated masterbatches with 40-60% pigment, usually in a carrier, have been made for use at an approximately 1% addition level. 

For all the reasons cited previously, pigment analysis constitutes a real analytical challenge. To take this challenge, one must have a diversified number of analytical procedures able to rapidly and precisely quantify the different pigment levels in samples. Addressing these issues is never straightforward. With some samples, like bottled waters, analysis is very simple. 

The pigmentation of silicones with aluminum in the preparation of a heat-resistant paint is, however, atypical. Course-ground aluminum paste is employed at the rate of 2 Ib/gal. unless service temperatures of 500-600 °C are to be maintained. If the more severe, higher temperature conditions are to be experienced, 2.9 to 3.0 Ib/gal. of vehicle is an appropriate pigmentation level. This high aluminum level is necessary to provide for the sufficiently high temperature formation of the silicon-oxygen-aluminum protective barrier. 

Many applications of dispersions require a number of properties in the end use which can be achieved by the addition of fillers, pigments, leveling enhancement additives, flow improvement additives, and other additives. For example, cold flow (creep) properties of the coating can be reduced by the addition of fillers such as fiberglass. Additives should be mixed only by mild stirring to avoid coagulation of PTFE. 

Figure 3. The effect of 10 M monuron on pigment content and ethane generation of flax cotyledons incubated at 30 Wm. Pigment levels are expressed as a percentage of the levels at 0 h. Key carotenes, xanthophylls, A/ chlorophyll, B, and ethane generation, O ( %).

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