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Chromogenic
In chemistry, the term chromogen refers to a colourless (or faintly coloured) chemical compound that can be converted by chemical reaction into a compound which can be described as "coloured" (a chromophore). There is no universally agreed definition of the term. Various dictionaries give the following definitions: * A substance capable of conversion into a pigment or dye. * Any substance that can become a pigment or coloring matter, a substance in organic fluids that forms colored compounds when oxidized, or a compound, not itself a dye, that can become a dye. * Any substance, itself without color, giving origin to a coloring matter. In biochemistry the term has a rather different meaning. The following are found in various dictionaries. * A precursor of a biochemical pigment * A pigment-producing microorganism * Any of certain bacteria that produce a pigment * A strongly pigmented or pigment-generating organelle, organ, or microorganism. Applications in chemistry *In chromogenic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromogenic Photography
Chromogenic photography is photography that works by a chromogen forming a conventional silver image and then replacing it with a dye image. Most films and papers used for color photography today are chromogenic, using three layers, each providing their own subtractive color. Some chromogenic films provide black-and-white negatives, and are processed in standard color developers (such as the C-41 process). In this case, the dyes are a neutral color. Description Chromogenic film or paper contains one or many layers of silver halide (AgX) emulsion, along with dye couplers that, in combination with processing chemistry, form visible dyes. In processing, the silver image of each layer is first developed. In concert with the dye couplers in each layer, the process subsequently forms dyes only in those areas where silver is present. In full-color chromogenic materials, multiple layers of emulsion are sensitized to different wavelengths of light. Three layers are usually present, gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dye Coupler
Dye coupler is present in Chromogen, chromogenic photographic film, film and photographic paper, paper used in photography, primarily color photography. When a color developer Redox, reduces ionized (exposed) silver halide crystals, the developer is oxidized, and the oxidized molecules react with dye coupler molecules to form a dye ''in situ.'' The silver image is removed by subsequent bleach and Photographic fixer, fix processes, so the final image will consist of the dye image. Dye coupler technology has seen considerable advancement since the beginning of modern color photography. Major film and paper manufacturers have continually improved the stability of the image dye by improving couplers, particularly since the 1980s, so that Archive, archival properties of images are enhanced in newer color papers and films. Generally speaking, dye couplers for paper use are given more emphasis on the image permanence than those for film use, but some modern films (such as Fujifilm, Fujic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during chemical reaction, reactions with other chemical substance, substances. Chemistry also addresses the nature of chemical bonds in chemical compounds. In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both Basic research, basic and Applied science, applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken or new bonds formed or both. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromophore
A chromophore is the part of a molecule responsible for its color. The word is derived . The color that is seen by our eyes is that of the light not Absorption (electromagnetic radiation), absorbed by the reflecting object within a certain wavelength spectrum of visible spectrum, visible light. The chromophore is a region in the molecule where the energy difference between two separate molecular orbitals falls within the range of the visible spectrum (or in informal contexts, the spectrum under scrutiny). Visible light that hits the chromophore can thus be absorbed by exciting an electron from its ground state into an excited state. In biological molecules that serve to capture or detect light energy, the chromophore is the Moiety (chemistry), moiety that causes a conformational change in the molecule when hit by light. Conjugated pi-bond system chromophores Just like how two adjacent p-orbitals in a molecule will form a pi-bond, three or more adjacent p-orbitals in a molec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochemistry
Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all List of life sciences, areas of the life sciences are being uncovered and developed through biochemical methodology and research.#Voet, Voet (2005), p. 3. Biochemistry focuses on understanding the chemical basis that allows biomolecule, biological molecules to give rise to the processes that occur within living Cell (biology), cells and between cells,#Karp, Karp (2009), p. 2. in turn relating greatly to the understanding of tissue (biology), tissues and organ (anatomy), organs as well as organism structure and function.#Miller, Miller (2012). p. 62. Biochemistry is closely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Film
Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and image resolution, resolution of the film. Film is typically segmented in ''frames'', that give rise to separate photographs. The emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a very short exposure (photography), exposure to the image formed by a camera lens is used to produce only a very slight chemical change, proportional to the amount of light absorbed by each crystal. This creates an invisible latent image in the emulsion, which can be chemically photographic processing, developed into a visible photograph. In addition to visible light, all films are sensitive to ultraviolet light, X-rays, gamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Paper
Photographic paper is a coated paper, paper coated with a light-sensitive chemical, used for making photographic prints. When photographic paper is exposed to light, it captures a latent image that is then Photographic developer, developed to form a visible image; with most papers the image density from exposure can be sufficient to not require further development, aside from fixing and clearing, though latent exposure is also usually present. The light-sensitive layer of the paper is called the emulsion, and functions similarly to photographic film. The most common chemistry used is Gelatin silver print, gelatin silver, but other alternatives have also been used. The print image is traditionally produced by interposing a Negative (photography), photographic negative between the light source and the paper, either by direct contact with a large negative (forming a contact print) or by projecting the shadow of the negative onto the paper (producing an enlargement). The initial light ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver Halide
A silver halide (or silver salt) is one of the chemical compounds that can form between the Chemical element, element silver (Ag) and one of the halogens. In particular, bromine (Br), chlorine (Cl), iodine (I) and fluorine (F) may each combine with silver to produce silver bromide (AgBr), silver chloride (AgCl), silver iodide (AgI), and four forms of silver fluoride, respectively. As a group, they are often referred to as the silver halides, and are often given the pseudo-chemical notation AgX. Although most silver halides involve silver atoms with oxidation states of +1 (Ag+), silver halides in which the silver atoms have oxidation states of +2 (Ag2+) are known, of which silver(II) fluoride is the only known stable one. Silver halides are light-sensitive chemicals, and are commonly used in photographic film and paper. Applications Light sensitivity Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide cry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyes
Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy (DyE song), Fantasy" from his first album ''Taki 183 (album), Taki 183''. This video became popular, attracting over 65 million views, 49 million of those within two years. Discography Albums *''Taki 183 (album), Taki 183'' (2011) *''Cocktail Citron'' (2014) *''Inside Out (2018)'' *''MySpace (2024)'' EPs *''Imperator'' (2009) *''Emo Machine'' (2017) References External linksDyE at Myspace French musicians Living people Year of birth missing (living people) {{France-musician-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runyon Classification
The Timpe and Runyon classification of nontuberculous mycobacteria is based on the rate of growth, production of yellow pigment and whether this pigment was produced in the dark or only after exposure to light. It was introduced by Ernest Runyon in 1959. On these bases, the nontuberculous mycobacteria are divided into four groups. The first three groups are classified as "Slowly growing Mycobacteria" and the fourth group as "Rapid Growers". Slowly growing Mycobacteria Runyon I: Photochromogens Runyon I organisms ( photochromogens) are slow growing, and produce a yellow-orange pigment when exposed to light. The group includes ''Mycobacterium kansasii'', ''Mycobacterium intermedium'', ''Mycobacterium marinum'', ''Mycobacterium asiaticum'', and ''Mycobacterium simiae''. '' Mycobacterium szulgai'' is a photochromogen when grown at 24 degrees, and a scotochromogen at 37 degrees. In contrast, Runyon classifications III through IV are considered ''nonphotochromogens'', in that expos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacteria
''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis ('' M. tuberculosis'') and leprosy ('' M. leprae'') in humans. The Greek prefix ''myco-'' means 'fungus', alluding to this genus' mold-like colony surfaces. Since this genus has cell walls with a waxy lipid-rich outer layer containing high concentrations of mycolic acid, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types. Mycobacterial species are generally aerobic, non-motile, and capable of growing with minimal nutrition. The genus is divided based on each species' pigment production and growth rate. While most ''Mycobacterium'' species are non-pathogenic, the genus' characteristic complex cell wall contributes to evasion from host defenses. Microbiology Morphology Mycobacteria are aerobic with 0.2-0.6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
