The CMYK color model is a subtractive color model, based on the CMY color model, used in color printing, is used to describe the printing process itself. CMYK refers to the four ink plates used in some color printing: cyan, magenta and key; the CMYK model works by or masking colors on a lighter white, background. The ink reduces the light; such a model is called subtractive because inks "subtract" the colors red and blue from white light. White light minus red leaves cyan, white light minus green leaves magenta, white light minus blue leaves yellow. In additive color models, such as RGB, white is the "additive" combination of all primary colored lights, while black is the absence of light. In the CMYK model, it is the opposite: white is the natural color of the paper or other background, while black results from a full combination of colored inks. To save cost on ink, to produce deeper black tones and dark colors are produced by using black ink instead of the combination of cyan and yellow. With CMYK printing, halftoning allows for less than full saturation of the primary colors.
Magenta printed with a 20% halftone, for example, produces a pink color, because the eye perceives the tiny magenta dots on the large white paper as lighter and less saturated than the color of pure magenta ink. Without halftoning, the three primary process colors could be printed only as solid blocks of color, therefore could produce only seven colors: the three primaries themselves, plus three secondary colors produced by layering two of the primaries: cyan and yellow produce green and magenta produce blue and magenta produce red, plus layering all three of them resulting in black. With halftoning, a full continuous range of colors can be produced. To improve print quality and reduce moiré patterns, the screen for each color is set at a different angle. While the angles depend on how many colors are used and the preference of the press operator, typical CMYK process printing uses any of the following screen angles: The "black" generated by mixing commercially practical cyan and yellow inks is unsatisfactory, so four-color printing uses black ink in addition to the subtractive primaries.
Common reasons for using black ink include: In traditional preparation of color separations, a red keyline on the black line art marked the outline of solid or tint color areas. In some cases a black keyline was used when it served as both a color indicator and an outline to be printed in black because the black plate contained the keyline; the K in CMYK represents the keyline or black plate sometimes called the key plate. Text is printed in black and includes fine detail, so to reproduce text or other finely detailed outlines, without slight blurring, using three inks would require impractically accurate registration. A combination of 100% cyan and yellow inks soaks the paper with ink, making it slower to dry, causing bleeding, or weakening the paper so much that it tears. Although a combination of 100% cyan and yellow inks should, in theory absorb the entire visible spectrum of light and produce a perfect black, practical inks fall short of their ideal characteristics and the result is a dark muddy color that does not quite appear black.
Adding black ink absorbs more light and yields much better blacks. Using black ink is less expensive than using the corresponding amounts of colored inks; when a dark area is desirable, a coloured or gray CMY "bedding" is applied first a full black layer is applied on top, making a rich, deep black. A black made with just CMY inks is sometimes called a composite black; the amount of black to use to replace amounts of the other ink is variable, the choice depends on the technology and ink in use. Processes called under color removal, under color addition, gray component replacement are used to decide on the final mix. CMYK or process color printing is contrasted with spot color printing, in which specific colored inks are used to generate the colors appearing on paper; some printing presses are capable of printing with both four-color process inks and additional spot color inks at the same time. High-quality printed materials, such as marketing brochures and books include photographs requiring process-color printing, other graphic effects requiring spot colors, finishes such as varnish, which enhances the glossy appearance of the printed piece.
CMYK are the process printers which have a small color gamut. Processes such as Pantone's proprietary six-color Hexachrome expand the gamut. Light, saturated colors cannot be created with CMYK, light colors in general may make visible the halftone pattern. Using a CcMmYK process, with the addition of light cyan and magenta inks to CMYK, can solve these problems, such a process is used by many inkjet printers, including desktop models. Comparisons between RGB displays and CMYK prints can be difficult, since the color reproduction technologies and properties are different. A computer monitor mixes shades of red and blue light to create color pictures. A CMYK printer instead uses light-absorbing cyan and yellow inks, whose colors are mixed using dithering, halftoning, or some other optical technique. Simil
The term chromic acid is used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide. This kind of chromic acid may be used as a cleaning mixture for glass. Chromic acid may refer to the molecular species, H2CrO4 of which the trioxide is the anhydride. Chromic acid features chromium in an oxidation state of +6, it is a corrosive oxidising agent. Molecular chromic acid, H2CrO4, has much in common with sulfuric acid, H2SO4. Both are classified as strong acids. H2CrO4 ⇌ − + H+The pKa for the equilibrium is not well characterized. Reported values vary between about −0.8 to 1.6. The value at zero ionic strength is difficult to determine because half dissociation only occurs in acidic solution, at about pH 0, that is, with an acid concentration of about 1 mol dm−3. A further complication is that the ion − has a marked tendency to dimerize, with the loss of a water molecule, to form the dichromate ion, 2−: 2 − ⇌ 2− + H2O log KD = 2.05.
Furthermore, the dichromate can be protonated: − ⇌ 2− + H+ pK = 1.8The pK value for this reaction shows that it can be ignored at pH > 4. Loss of the second proton occurs in the pH range 4–8, making the ion − a weak acid. Molecular chromic acid could in principle be made by adding chromium trioxide to water. CrO3 + H2O ⇌ H2CrO4but in practice the reverse reaction occurs when molecular chromic acid is dehydrated; this is. At first the colour changes from orange to red and deep red crystals of chromium trioxide precipitate from the mixture, without further colour change; the colours are due to LMCT transitions. Chromium trioxide is the anhydride of molecular chromic acid, it is a Lewis acid and can react with a Lewis base, such as pyridine in a non-aqueous medium such as dichloromethane. Dichromic acid, H2Cr2O7 is the protonated form of the dichromate ion and can be seen as the product of adding chromium trioxide to molecular chromic acid. 2− + 2H+ ⇌ H2Cr2O7 ⇌ H2CrO4 + CrO3It is present in chromic acid cleaning mixtures along with the mixed chromosulfuric acid H2CrSO7.
Chromic acid is an intermediate in chromium plating, is used in ceramic glazes, colored glass. Because a solution of chromic acid in sulfuric acid is a powerful oxidizing agent, it can be used to clean laboratory glassware of otherwise insoluble organic residues; this application has declined due to environmental concerns. Furthermore, the acid leaves trace amounts of paramagnetic chromic ions — Cr — that can interfere with certain applications, such as NMR spectroscopy; this is the case for NMR tubes. Chromic acid was used in the instrument repair industry, due to its ability to "brighten" raw brass. A chromic acid dip leaves behind a bright yellow patina on the brass. Due to growing health and environmental concerns, many have discontinued use of this chemical in their repair shops, it was used in hair dye under the name Melereon. It is used as a bleach in white photographic reversal processing. Chromic acid is capable of oxidizing many kinds of organic compounds and many variations on this reagent have been developed: Chromic acid in aqueous sulfuric acid and acetone is known as the Jones reagent, which will oxidize primary and secondary alcohols to carboxylic acids and ketones while affecting unsaturated bonds.
Pyridinium chlorochromate is generated from chromium pyridinium chloride. This reagent converts primary alcohols to the corresponding aldehydes. Collins reagent is an adduct of chromium pyridine used for diverse oxidations. Chromyl chloride, CrO2Cl2 is a well-defined molecular compound, generated from chromic acid. Oxidation of methylbenzenes to benzoic acids. Oxidative scission of indene to homophthalic acid. Oxidation of secondary alcohol to ketone and nortricyclanone. In organic chemistry, dilute solutions of chromic acid can be used to oxidize primary or secondary alcohols to the corresponding aldehydes and ketones. Tertiary alcohol groups are unaffected; because of the oxidation is signaled by a color change from orange to a blue-green, chromic acid is used as a qualitative analytical test for the presence of primary or secondary alcohols. In oxidations of alcohols or aldehydes into carboxylic acids, chromic acid is one of several reagents, including several that are catalytic. For example, nickel salts catalyze oxidations by bleach.
Aldehydes are easily oxidised to carboxylic acids, mild oxidising agents are sufficient. Silver compounds have been used for this purpose; each oxidant offers disadvantages. Instead of using chemical oxidants, electrochemical oxidation is possible. Hexavalent chromium compounds are carcinogenic. For this reason, chromic acid oxidation is not used on an industrial scale except in the aerospace industry. Chromium trioxide and chromic acids are strong oxidisers and may react violently if mixed with oxidisable organic substances. Fires or explosions may result. Chromic acid burns are treated with a dilute sodium thiosulfate solution. Alcohols from Carbonyl Compounds: Oxidation-Reduction and Organometallic Compounds International Chemical Safety Card 1194 NIOSH Pocket Guide to Chemical Hazards. "#0138". National Institute for Occupational Safety and Health. IARC
William Francis Denehy is an American former professional baseball pitcher and coach. Denehy threw and batted right-handed, stood 6 ft 3 in tall, weighed 200 lb, he was born in Connecticut. The second-ever Middletown Little League alumnus to play Major League Baseball, he signed with the New York Mets out of high school for a $20,000 bonus and made his professional debut with the Auburn Mets of the New York–Penn League in 1965, he led the league in wins with 13, the following season won nine of 11 decisions with the Double-A Williamsport Mets of the Eastern League, compiling a stellar 1.97 earned run average. In 1967, Denehy made 15 Major League appearances for the Mets, dropping seven of eight decisions with an ERA of 4.67. The 1967 Mets finished in tenth and last place, the fifth cellar-dwelling team in the expansion club's six-year history. On November 27, 1967, the Mets traded Denehy to the Washington Senators for the Senators' manager, Gil Hodges, in the middle of a multi-year contract he had signed as Washington's skipper.
The Mets' managerial post was open after the late-season departure of Wes Westrum, team officials began negotiations with the Senators to release Hodges from his contract, which still had a year to run. Hodges was a New York baseball legend as the power-hitting and Gold Glove-fielding first baseman for the Brooklyn Dodgers of the 1950s, he had become a year-round resident of Brooklyn, in the twilight of his playing career was an original Met, starting at first base in their maiden NL game in 1962. On May 23, 1963, the Mets had traded Hodges to Washington for centerfielder Jimmy Piersall, Hodges retired as an active player to become the Senators' manager. Although the expansion-era Senators had themselves never posted a winning record since their 1961 inception, the team had shown steady season-to-season improvement since Hodges' appointment as manager. During the three-week-long winter interleague trading period in effect, the Mets agreed to send Denehy and $100,000 as compensation for Washington's release of Hodges from his contract.
While Hodges brought home an improved, but still ninth-place, Mets' team in 1968, Denehy pitched in only three innings for the 1968 Senators and spent most of the season in the minor leagues. The following season, Denehy remained in Triple-A and was traded in June to the Cleveland Indians' organization. Meanwhile, in his second year as the Mets' manager, Hodges led the "1969 Miracle Mets" to the team's first National League and World Series championships. Denehy returned to the Majors with the 1971 Detroit Tigers, appearing in 31 games, all but one of them in relief, compiling an 0–3 mark with an ERA of 4.22 in 49 innings. All told, Denehy appeared in 49 Major League games, winning one and losing ten with an ERA of 4.56 in 1042⁄3 innings pitched. He retired after the 1973 season. For two seasons, Denehy served as the pitching coach for the Double-A Bristol Red Sox. In the 1983 season, he served a third season as pitching coach in the Red Sox minor league system, this time with the Red Sox new affiliate, the New Britain Red Sox.
From the start of the 1985 season until the middle of the 1987 season, Denehy was the head college baseball coach of the Hartford Hawks. Following an April 1987 game against Connecticut in which two bench-clearing brawls broke out, Denehy was fired for making inflammatory remarks made about Connecticut's team and Connecticut assistant coach Mitch Pietras. Under Denehy, the Hawks had a 17–79 record. Denehy has worked in real estate and radio and taught golf. Denehy began losing his eyesight in 2005 and, as of 2018, is blind with no vision in his right eye and glaucoma and macular holes in his left, he has received multiple grants from the Baseball Assistance Team to assist in paying for eye surgeries as he is ineligible for a pension from Major League Baseball under pre-1980 rules. Career statistics and player information from MLB, or Baseball-Reference, or Baseball-Reference