Circular of the Bureau of Standards no. 478:

Judd, Deane B.

doi:10.6028/nbs.circ.478

Cited by 7 publications

(5 citation statements)

References 81 publications

(124 reference statements)

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“…The yellowness of the fabric was expressed in terms of the yellowness index [2()~ y.i. = 10) (Rx-Rz)/ Ry (adapted from Judd [10]), where Rx, Ry, and Rz are the reflectances obtained using the CIE tristimulus filters FMX/C, FM~'/C, and FMZ/C, respectively. It should be noted that the yellowness indexes quoted in this work were obtained using only a single layer of fabric, so that the results could be compared directly with those in an earlier study [20], and the values are therefore lower than those obtained using infinitely thick samples of the same wool.…”

Section: Introductionmentioning

confidence: 99%

Photo-Oxidation Mechanisms in Wool. A Study of the Photoprotective Effect of a Thiourea/Formaldehyde Treatment

Leaver

1978

Textile Research Journal

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Mixtures of thiourea and formaldehyde, when applied to natural protein fibers such as wool or silk, are known to inhibit the photo-oxidation and discoloration of these materials in sunlight. This paper examines the mechanisms underlying the photostabilization of wool by thiourea/formaldehyde (TUF). The photostabilization depends markedly on the spectral composition of the light source and involves a combination of processes which include quenching of uv-induced singletand triplet-excited species in wool and sensitization of the fiber to photobleaching in visible light. The photoyellowing behavior is closely related to the intrinsic luminescence properties of the fiber, and the role of the excited species in the photo-oxidation of wool are discussed.

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Section: Introductionmentioning

confidence: 99%

Photo-Oxidation Mechanisms in Wool. A Study of the Photoprotective Effect of a Thiourea/Formaldehyde Treatment

Leaver

1978

Textile Research Journal

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“…Two excellent presentations of colorimetry are to be found in Judd (59,60) with many applications of the International Commission on Illumination (ICI) system to color measurement, color specification, and color mixture and to systems based on the primaries of the Young-Helmholtz, Ladd Franklin, and Hering theories of color vision. His discussions of indices of hue, lightness, and saturation, of whiteness measurements, and of ma terial standards of color show how the colorimetrist approaches problems of color with quantitative and instrumental methods.…”

mentioning

confidence: 99%

Vision

Helson¹

1952

Annu. Rev. Psychol.

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“…Most modern measurements are conducted using visible spectroscopic instrumentation operating either in transmittance or reflectance mode that records spectral data in the visible region. Color results are normally reported using reduced "color space" values such as the Commission International de l'Eclairage (CIE) L*, a*, b* (also referred to as CIELAB) or the Hunter L, a, b values (also known as Hunter Lab), which are derived from the fundamental tristimulus values [6][7][8][9], which themselves are obtained by multiplying the measured visible spectra by standard functions. The CIELAB and Hunter Lab color spaces are the most commonly used in pharmaceutical applications.…”

Section: Introductionmentioning

confidence: 99%

A Systematic Method Development Strategy for Quantitative Color Measurement in Drug Substances, Starting Materials, and Synthetic Intermediates

et al. 2011

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The color of active pharmaceutical ingredients (APIs) can be a critical quality attribute for pharmaceutical products. Color variation can be indicative of contaminants, chemical impurities, solid-state form impurities, or degradation products. The color of the pharmaceutical materials is typically specified and determined using visual appearance testing. To avoid the inherent subjectivity of visual appearance testing, to understand the link between the color and the process parameters, and to facilitate quality agreements between customers and vendors of chemical starting materials, quantitative color measurements utilizing visible spectroscopic methods are increasingly needed. In this work, a systematic method development strategy (MDS) is described to assist with the development of robust and rugged quantitative color measurement methods based on a science-and risk-based approach aligned with quality-bydesign principles. The MDS is illustrated using typical scenarios encountered in method development through several examples including a method developed for 2,3-dimethyl-2H-indazol-6-amine, a starting material in the commercial synthesis of pazopanib hydrochloride API.Flowcharts and examples are presented to illuminate key decision points in the MDS process including selection of (1) solution-state versus solid-state spectroscopic method, (2) optimal color space for reporting color measurement results, and (3) appropriate method risk assessment and control to ensure successful method implementation.General guidance is also provided to facilitate the discussion for setting quantitative color specifications.

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Circular of the Bureau of Standards no. 478:

Cited by 7 publications

References 81 publications

Photo-Oxidation Mechanisms in Wool. A Study of the Photoprotective Effect of a Thiourea/Formaldehyde Treatment

Photo-Oxidation Mechanisms in Wool. A Study of the Photoprotective Effect of a Thiourea/Formaldehyde Treatment

Vision

A Systematic Method Development Strategy for Quantitative Color Measurement in Drug Substances, Starting Materials, and Synthetic Intermediates

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