This usage was adopted by Wilbur Olin Atwater, a professor at Wesleyan University, in 1887, in an influential article on the energy content of food. In 1879, Marcellin Berthelot distinguished between gram-calorie and kilogram-calorie, and proposed using "Calorie", with capital "C", for the large unit. He proposed calling the "large" unit "kilocalorie", but the term did not catch on until some years later. physician Joseph Howard Raymond, in his classic 1894 textbook A Manual of Human Physiology. The same term was used for the "small" unit by Pierre Antoine Favre (chemist) and Johann T. The term (written with lowercase "c") entered French and English dictionaries between 18. It was first introduced by Nicolas Clément, as a unit of heat energy, in lectures on experimental calorimetry during the years 1819–1824. The term "calorie" comes from Latin calor 'heat'. The precise equivalence between calories and joules has varied over the years, but in thermochemistry and nutrition it is now generally assumed that one (small) calorie ( thermochemical calorie) is equal to exactly 4.184 J, and therefore one kilocalorie (one large calorie) is 4184 J or 4.184 kJ. However, the kcal is not officially part of the International System of Units (SI), and is regarded as obsolete, having been replaced in many uses by the SI derived unit of energy, the joule (J), or the kilojoule (kJ) for 1000 joules. In physics and chemistry the word calorie and its symbol usually refer to the small unit the large one being called kilocalorie (kcal). Some authors recommend the spelling Calorie and the symbol Cal (both with a capital C) if the large calorie is meant, to avoid confusion however, this convention is often ignored. It is generally used in publications and package labels to express the energy value of foods in per serving or per weight, recommended dietary caloric intake, metabolic rates, etc. In nutrition and food science, the term calorie and the symbol cal may refer to the large unit or to the small unit in different regions of the world. Thus, 1 large calorie is equal to 1000 small calories. The small calorie or gram calorie is defined as the amount of heat needed to cause the same increase in one milliliter of water. The large calorie, food calorie, dietary calorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter of water by one degree Celsius (or one kelvin). The calorie is a unit of energy that originated from the caloric theory of heat. A 710-millilitre (24 US fl oz) energy drink with 330 large calories For other uses, see KCAL (disambiguation) and Calorie (disambiguation). "kcal" redirects here this article is about the unit of energy.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |