Maya Blue, a pigment used by the Mayas in Yucatan, is remarkably stable: the color is not destroyed by hot concentrated mineral acids or by heating to about 250 degrees C. The principal constituent is the colorless mineral attapulgite. It is proposed that the pigment is an adsorption complex of attapulgite and natural indigo; a synthetic equivalent may be prepared from attapulgite and either in...

…………………………………………………………………………….v TABLE OF CONTENTS……………………………………………………………….vi LIST OF TABLES…………………………………………………………………….. vii LIST OF FIGURES……………………………………………………………………. viii I. INTRODUCTION…………………………………………………….. 1 II. LITERATURE REVIEW……………………………………………... 5 A. Mixing and Dispersions…………………………………………... 6 B. Grinding/Milling and Dispersants………………………………… 9 C. Pigments………………………………………………………….. 12 D. E...

The red pigment in the eyes of the squid, blue crab, and horseshoe crab becomes photosensitive when treated with formalin, and bleaches in the light. The resulting change in density is approximately symmetrical around a maximum at 480 mmicro in the blue green. This difference absorption spectrum is in rough agreement with the spectral sensitivity of the cephalopod eye and differs only slightly ...

1. Oxidation-reduction potential methods have been applied to a study of the blue-purple pigment present in solution in the blood and in the tissue cells of the nudibranch Chromodoris zebra. 2. The blue-purple pigment and its yellow reduction product form a reversible system whose E(o)' = x0.102 volts at pH 7.0 and whose valence change from oxidant to reductant appears to be one. 3. The system ...

PURPOSE Salamander retinas are known to contain at least three cone pigments and two rod pigments. The purpose of this study was to clone and characterize the visual pigments from salamander cones. METHODS cDNA fragments of cone pigments were amplified from a salamander retina cDNA library by PCR using a pair of primers with consensus for visual pigments. These fragments were cloned and used ...

In a comparison of two selective media for Ps. aeruginosa containing 0.03% cetrimide, stronger fluorescence was obtained from growth on the medium prepared with King's medium B as the base (CTA 2); although Ps. aeruginosa was not isolated more frequently from burns on this medium than from cetrimide agar made with a Lemco base (CTA 1), results were easier to assess and there were fewer cases of...

We present a simple and intriguing device that generates highly circularly polarized white light. It comprises white polymer light-emitting diodes (WPLEDs) attached to a wideband cholesteric liquid crystal (CLC) reflector with a wide photonic bandgap (PBG) covering the visible range. The degree of circular polarization realized is very high over the visible range. The wide PBG was realized by i...

A technique for mass-marking fish was evaluated that forces fluorescent pigment into dermal tissue with compressed air. A five month trial was conducted where mark retention, readability, and marking mortality were evaluated with six fish species that represent a variety of taxonomic groups. Approximately 100 of each species were marked; a percentage with fluorescent sprayed pigment and visible...