New research provides the first direct evidence for the Gulf Stream blender effect, identifying a new mechanism of mixing water across the swift-moving current. The results have important implications for weather, climate ...
Earth Sciences
Jul 6, 2020
0
3829
(Phys.org)—For the past 17 years, spiro-OMeTAD, has been keeping a secret. Despite intense research efforts, its performance as the most commonly used hole-transporting material in perovskite and dye-sensitized solar cells ...
Light can be directed in different directions, usually also back the same way. Physicists from the University of Bonn and the University of Cologne have, however, succeeded in creating a new one-way street for light. They ...
General Physics
Nov 14, 2019
1
13125
It has often been said that solar cells are like artificial versions of the photosynthetic apparatuses found in plants, such as leaves, since both harvest sunlight. But nature's leaves can do something that most solar cells ...
"King Solomon made for himself the carriage; he made it of wood from Lebanon. Its posts he made of silver, its base of gold. Its seat was upholstered with purple, its interior inlaid with love." (Song of Songs 3:9-10)
Archaeology
Jan 28, 2021
31
2246
Researchers have developed a new enhanced DNA imaging technique that can probe the structure of individual DNA strands at the nanoscale. Since DNA is at the root of many disease processes, the technique could help scientists ...
Nanophysics
Jun 17, 2016
0
2607
Using Earth-abundant materials, EPFL scientists have built the first low-cost system for splitting CO2 into CO, a reaction necessary for turning renewable energy into fuel.
Energy & Green Tech
Jun 5, 2017
10
1790
How much information can you get from a speck of purple pigment, no bigger than the diameter of a hair, plucked from an Egyptian portrait that's nearly 2,000 years old? Plenty, according to a new study. Analysis of that speck ...
Analytical Chemistry
Nov 20, 2020
1
254
By formulating positively charged fluorescent dyes into a new class of materials called small-molecule ionic isolation lattices (SMILES), a compound's brilliant glow can be seamlessly transferred to a solid, crystalline state, ...
Materials Science
Aug 6, 2020
0
2853
A Tunisian man has pieced together bits of a local secret linked to ancient emperors: how to make a prized purple dye using the guts of a sea snail.
Archaeology
Jul 26, 2020
2
1739
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber.
Both dyes and pigments appear to be colored because they absorb some wavelengths of light more than others. In contrast with a dye, a pigment generally is insoluble, and has no affinity for the substrate. Some dyes can be precipitated with an inert salt to produce a lake pigment, and based on the salt used they could be aluminum lake, calcium lake or barium lake pigments.
Dyed flax fibers have been found in the Republic of Georgia dated back in a prehistoric cave to 36,000 BP. Archaeological evidence shows that, particularly in India and Phoenicia, dyeing has been widely carried out for over 5000 years. The dyes were obtained from animal, vegetable or mineral origin, with no or very little processing. By far the greatest source of dyes has been from the plant kingdom, notably roots, berries, bark, leaves and wood, but only a few have ever been used on a commercial scale.
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