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Chlorine-releasing Compounds
Chlorine-releasing compounds, also known as chlorine base compounds, is jargon to describe certain chlorine-containing substances that are used as disinfectants and bleaches. They include the following chemicals: sodium hypochlorite (active agent in bleach), chloramine, halazone, and sodium dichloroisocyanurate. They are widely used to disinfect water and medical equipment, and surface areas as well as bleaching materials such as cloth. The presence of organic matter can make them less effective as disinfectants. They come as a liquid solution, or as a powder that is mixed with water before use. Side effects if contact occurs may include skin irritation and chemical burns to the eye. They may also cause corrosion and therefore may require being rinsed off. Specific compounds in this family include sodium hypochlorite, monochloramine, halazone, chlorine dioxide, and sodium dichloroisocyanurate. They are effective against a wide variety of microorganisms including bacterial s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bleach
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to a dilute solution of sodium hypochlorite, also called "liquid bleach". Many bleaches have broad spectrum bactericidal properties, making them useful for disinfecting and sterilizing. They are used in swimming pool sanitation to control bacteria, viruses, and algae, and in many places where sterile conditions are required. They are also used in many industrial processes, notably in the bleaching of wood pulp. Bleaches also have other minor uses like removing mildew, killing weeds, and increasing the longevity of cut flowers. Bleaches work by reacting with many colored organic compounds, such as natural pigments, and turning them into colorless ones. While most bleaches are oxidizing agents (chemicals that can remove electrons from other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Spores
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., not an offspring). It is a stripped-down, dormant form to which the bacterium can reduce itself. Endospore formation is usually triggered by a lack of nutrients, and usually occurs in gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries. There are many reports of spores remaining viable over 10,000 years, and revival of spores millions of years old has been claimed. There is one report of viable spores of ''Bacillus marismortui'' in salt crystals approximately 250 million years old. When the environment becomes more favorable, the endospore can reactivate itself into a vegetative state. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromophore
A chromophore is the part of a molecule responsible for its color. The color that is seen by our eyes is the one not absorbed by the reflecting object within a certain wavelength spectrum of 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. 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 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 molecule can form a conjugated pi-system. In a conjugated pi-system, electrons are able to capture certain photons as the electrons resonate along a certain distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Bond
A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing of electrons as in covalent bonds. The strength of chemical bonds varies considerably; there are "strong bonds" or "primary bonds" such as covalent, ionic and metallic bonds, and "weak bonds" or "secondary bonds" such as dipole–dipole interactions, the London dispersion force and hydrogen bonding. Strong chemical bonding arises from the sharing or transfer of electrons between the participating atoms. Since opposite electric charges attract, the negatively charged electrons surrounding the nucleus and the positively charged protons within a nucleus attract each other. An electron positioned between two nuclei will be attracted to both of them, and the nuclei will be attracted toward electrons in this position. This attraction constitu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Carotene
Beta (, ; uppercase , lowercase , or cursive Greek, cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiodental fricative while in borrowed words is instead commonly transcribed as μπ. Letters that arose from beta include the Roman letter and the Cyrillic letters and . Name Like the names of most other Greek letters, the name of beta was adopted from the acrophony, acrophonic name of the corresponding letter in Phoenician, which was the common Semitic languages, Semitic word ''*bait'' ('house'). In Greek, the name was ''bêta'', pronounced in Ancient Greek. It is spelled βήτα in modern monotonic orthography and pronounced . History The letter beta was derived from the Phoenician alphabet, Phoenician letter beth . Uses Algebraic numerals In the system of Greek numerals, beta has a value of 2. Such use is denote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compounds. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli. Economic impact In 2006, around 7.4 million tons of inorganic, organic, and special pigments were marketed worldwide. Estimated at around US$14.86 billion in 2018 and will rise at over 4.9% CAGR from 2019 to 2026. The global demand for pigments was roughly US$20.5 billion in 2009. According to an April 2018 report by ''Bloomberg Businessweek'', the estimated value of the pigment industry globally is $30 billion. The value of titanium dioxide – used to enhance the white brightness of many products – was placed at $13.2 billion per year, while the color Ferrari red is valued at $300 million each year. Physical principles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mildew
Mildew is a form of fungus. It is distinguished from its closely related counterpart, mould, largely by its colour: moulds appear in shades of black, blue, red, and green, whereas mildew is white. It appears as a thin, superficial growth consisting of minute hyphae (fungal filaments) produced especially on living plants or organic matter such as wood, paper or leather. Both mould and mildew produce distinct offensive odours, and both have been identified as the cause of certain human ailments. In horticulture, mildew is either species of fungus in the order Erysiphales, or fungus-like organisms in the family ''Peronosporaceae''. It is also used more generally to mean mould growth. In Old English, mildew meant honeydew (a substance secreted by aphids on leaves, formerly thought to distill from the air like dew), and later came to mean mould or fungus. Mildew grows on damp cloth, leather, or on plants, and growing on leaves can damage the plant. Household varieties The term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laundry
Laundry refers to the washing of clothing and other textiles, and, more broadly, their drying and ironing as well. Laundry has been part of history since humans began to wear clothes, so the methods by which different cultures have dealt with this universal human need are of interest to several branches of scholarship. Laundry work has traditionally been highly gendered, with the responsibility in most cultures falling to women (formerly known as laundresses or washerwomen). The Industrial Revolution gradually led to mechanized solutions to laundry work, notably the washing machine and later the tumble dryer. Laundry, like cooking and child care, is still done both at home and by commercial establishments outside the home. The word "laundry" may refer to the clothing itself, or to the place where the cleaning happens. An individual home may have a laundry room; a utility room includes but is not restricted to the function of washing clothes. An apartment building or student hal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweat
Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distributed over much of the body and are responsible for secreting the watery, brackish sweat most often triggered by excessive body temperature. The apocrine sweat glands are restricted to the armpits and a few other areas of the body and produce an odorless, oily, opaque secretion which then gains its characteristic odor from bacterial decomposition. In humans, sweating is primarily a means of thermoregulation, which is achieved by the water-rich secretion of the eccrine glands. Maximum sweat rates of an adult can be up to 2–4 liters per hour or 10–14 liters per day (10–15 g/min·m2), but is less in children prior to puberty. Evaporation of sweat from the skin surface has a cooling effect due to evaporative cooling. Hence, in hot weather, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linen
Linen () is a textile made from the fibers of the flax plant. Linen is very strong, absorbent, and dries faster than cotton. Because of these properties, linen is comfortable to wear in hot weather and is valued for use in garments. It also has other distinctive characteristics, notably its tendency to wrinkle. Linen textiles appear to be some of the oldest in the world; their history goes back many thousands of years. Dyed flax fibers found in a cave in Southeastern Europe (present-day Georgia) suggest the use of woven linen fabrics from wild flax may date back over 30,000 years. Linen was used in ancient civilizations including Mesopotamia and ancient Egypt, and linen is mentioned in the Bible. In the 18th century and beyond, the linen industry was important in the economies of several countries in Europe as well as the American colonies. Textiles in a linen weave texture, even when made of cotton, hemp, or other non-flax fibers, are also loosely referred to as "linen". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor percentages of waxes, fats, pectins, and water. Under natural conditions, the cotton bolls will increase the dispersal of the seeds. The plant is a shrub native to tropical and subtropical regions around the world, including the Americas, Africa, Egypt and India. The greatest diversity of wild cotton species is found in Mexico, followed by Australia and Africa. Cotton was independently domesticated in the Old and New Worlds. The fiber is most often spun into yarn or thread and used to make a soft, breathable, and durable textile. The use of cotton for fabric is known to date to prehistoric times; fragments of cotton fabric dated to the fifth millennium BC have been found in the Indus Valley civilization, as well as fabric remnants dated back ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Health System
Health, according to the World Health Organization, is "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity".World Health Organization. (2006)''Constitution of the World Health Organization''– ''Basic Documents'', Forty-fifth edition, Supplement, October 2006. A variety of definitions have been used for different purposes over time. Health can be promoted by encouraging healthful activities, such as regular physical exercise and adequate sleep, and by reducing or avoiding unhealthful activities or situations, such as smoking or excessive stress. Some factors affecting health are due to individual choices, such as whether to engage in a high-risk behavior, while others are due to structural causes, such as whether the society is arranged in a way that makes it easier or harder for people to get necessary healthcare services. Still, other factors are beyond both individual and group choices, such as genetic disorders. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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