Health and Vitamins essays

Health and Vitamins essays Vitamins are everything and nothing. One all the high-pressure advertising and Farfetched claims and stripped away, vitamins emerge as what they really are: everyday Chemicals found in minuscule amounts in almost everything you eat. Vitamins are so Common that it is almost impossible to get them out of food. The closest anyone has come so far to vitamins-free dishes in white flour, white rice, white cornmeal, white sugar, and all the other are to much of a process for food. Even more important, if you keep up all the vitamins you need each day in a pile, that pile would be smaller then period at the end of this sentence. To look at it another way, divide an 1000 parts: your maximum vitamins requirement is a mere 7 of those parts every 24 hours. You could store all the vitamins you need each year in a thimble-and still Everybody really needs vitamins. They play an indispensable role in millions of everyday chemical reaction that occur in the body. Every important event, from digestion to reproduction to ready to walking, requires one vitamin or another. If you were to eat a diet totally lacking in vitamins, your life expectancy would be measured in weeks, if not Back in 1940 when the German Luftwaffe was destroying London by relentless and methodical bombing, the Royal Air Force suddenly got the upper hand, particularly in high air battle. The rigidly censored British newspaper gleefully revealed to all the world that the British advantage was the result of feeding carrots supposedly rich in vitamin A to the fighter pilots to prevent night blindness. From that moment on, a generation of American youngsters were conscientiously overdosed with raw carrots to protect them from night blindness, a disease that has not been a serious threat since the year 1349, when an epidemic occurred in Holland. Even more important, the newspaper ...

Eutectic Definition and Examples

Eutectic Definition and Examples A eutectic system is a homogeneous, solid mixture of two or more substances that form a super-lattice; the mixture either melts or solidifies at a lower temperature than the melting point of any of the individual substances. The phrase most commonly refers to a mixture of alloys. A eutectic system only forms when there is a specific ratio between the components. The word comes from the Greek words eu, meaning good or well and tecsis, meaning melting. Examples of Eutectic Systems Several examples of eutectic systems or eutectoids exist, in metallurgy and in various other fields. These mixtures typically have useful properties that are not possessed by any single constituent substance: Sodium chloride and water form a eutectoid when the mixture is 23.3% salt by mass with a eutectic point at -21.2 degrees Celsius. The system is used to make ice cream and to melt ice and snow.The eutectic point of the mixture of ethanol and water is nearly pure ethanol. The value means there is a maximum proof or purity of alcohol that can be obtained using distillation.Eutectic alloys are often used for soldering. A typical composition is 63% tin and 37% lead by mass.Eutectoid glassy metals exhibit extreme corrosion resistance and strength.Inkjet printer ink is a eutectic mixture, permitting printing at a relatively low temperature.Galinstan is a liquid metal alloy (composed of gallium, indium, and tin) used as a low-toxicity replacement for mercury. Related Terms Concepts and terms related to eutectic systems include: Eutectoid: Eutectoid refers to a homogeneous solid mixture that forms from cooling two or more melted metals to a certain temperature.Eutectic Temperature or Eutectic Point: The eutectic temperature is the lowest possible melting temperature for all of the mixing ratios of the component substances in a eutectoid. At this temperature, the super-lattice will release all of its components and the eutectic system will melt into a liquid as a whole. Contrast this with a non-eutectic mixture, in which each component will solidify into a lattice at its own specific temperature until the whole material eventually becomes solid.Eutectic Alloy: A eutectic alloy is an alloy formed from two or more components that exhibits eutectic behavior. A eutectic alloy melts at a distinct temperature. Not all binary alloys form eutectic alloys. For example, gold-silver does not form a eutectoid, as the valence electrons are not compatible with super-lattice formation.Eutectic Percentage Ratio: This is defi ned as the relative composition of the components of a eutectic mixture. The composition, particularly for binary mixtures, is often shown on a phase diagram. Hypoeutectic and Hypereutectic: These terms apply to compositions that could form a eutectoid, but do not have the appropriate ratio of component substances. A hypoeutectic system has a smaller percentage of ÃŽ ² and a greater percentage of ÃŽ ± than a eutectic composition, while a hypereutectic system has a greater percentage of ÃŽ ± and a lower percentage of ÃŽ ² than a eutectic composition.