Whiteness index

Figure 10.28 Effect of temperature on the whiteness index of linen bleached using urea-activated hydrogen peroxide [243], Treated with 7 g/l hydrogen peroxide and 8 g/l urea for 150 min at pH 6 and 50 1 liquor ratio...

Figure 10.38 Effect of treatment time on the alkali solubility and Jaquemart whiteness index of wool bleached with 2-vol. hydrogen peroxide at 40 °C and 50 °C [259,264]...

Reproduction of cross and cube—present stimulus illustrations shown below. You can copy them onto a 3-by-5-inch, unlined, white index card. Allow the patient to copy the designs one at a time onto a blank sheet of paper. Drawing performance can be compared to samples (see figure E-2) to derive rough estimates of the patient s constructional ability. 

Bleaching of wool is necessary for the enhancement of whiteness and lustre. Using proteolytic enzymes alone [99] or in combination with peroxide [100], the degree of whiteness and hydrophilicity of the fibres are increased, comjjared with the oxidative treatment alone [99]. Serine protease stable to hydrogen peroxide is active in an alkaline medium and its activity increases with increasing peroxide level [94]. Higher whiteness index is caused by the decolourising action of the enzyme on natural colorants present in the wool fibre [100]. 

Cationic actives interact with anionic fluorescent brighteners and reduce their whitening efficacy [2,26], Whether this is visually perceptible or not varies among reports. Crutcher et al. [32] and Wilson [33] conclude that, after a larger number of cumulative launderings, the loss is visually perceptible. On the contrary, Baumert and Cox Crews report that the decrease of whiteness index is significant, but not visually perceptible [34],... 

The whiteness index of softened fabrics depends on the fabric softener treatment, on the number of launderings, and on the fabric type. Dryer softeners significantly improve the whiteness index of cotton [34],... 

RLATT color-coding employed in file 6ad2.p4p White indexed for first domain... 

Figure 5.1 Evolution of the scientific and technological productivity in the zeolite field, measured as the number of papers (grey) or patents (white) indexed in ISl Web of Knowledge per year under the topic zeolit. Copyright Thomson Reuters 2009. All rights reserved...

Figure 19.19 Whiteness index of chitosan-treated cotton fabric as a function of molecular weight and concentration.

Whiteness index Any of several numerical indices used to indicate the degree of whiteness examples are the following ... 

The determination of carbon and nitrogen utilization profiles can be performed in broth or pour plates seeded with the microorganism of interest. Success using these techniques require that fungi be in pure culture and that carbon and nitrogen sources be free of contamination. To interpret the broth method (Anonymous, 1984), a finely ruled white index card is placed behind the tube and the degree to which haze/turbid-ity hampers visualization is noted. Relative growth may be scored as follows ... 

BTCA), SMPU finishing does not markedly affect the mechanical strength and whiteness index of the fabric. To some extent SMPU finishing on cotton increases the mechanical strength of fabrics. Repeated washing experiments showed that the wrinkle-free effect of SMPU emulsion treated fabric can last for hundreds of laundering cycles. ... 

Drier %of active drier Incubation Time (days) Dust free drying (h) Tack-free drying (h) Total drying time (h) Hardness (s/K) 5 days Skin formation Whiteness Index... 

As an added bonus, most available colorimeters and spectrophotometers calculate the yellowness index (ASTM D1925) and the whiteness index. ASTM D 2244 describes the standard method for instrumental evaluation of color differences of opaque materials in detail. 

Once washed, the swatches are read on a Hunter Lab Colorimeter for reflectance (L), redness/greenness (a), and yeUowness/blueness (b) values. The reflectance is used to calculate percent soil removed (% SR) which ranges from 0 to 100. Whiteness index (Wl) [17] and yellowness index (Y2) can also be determined. The whiteness scale ranges from 0 (black) to 100 (white). The yellowness index ranges from positive (yellow) to negative (blue). To determine how much soil is removed from the fabric, see Figure 2. 

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