ThermodynamicsのA-Zガイド、熱&アンプ、質量移動、流体工学
English Русский 中文 Português Español Français Deutsch 概要 編集委員会 連絡先 アクセス Begell House
View in A-Z Index

The calorie is a unit measure of the quantity of heat; 1cal=4.1868 Joule (J).

Before the universal adoption of the SI systems, the calorie was included in the dimensions of some functions which characterize thermodynamic and translational properties of substances and heat transfer processes. These functions are: internal energy, enthalpy, the Gibbs energy (isobaric-isothermal potential), the Helmholtz energy (isochoric-isothermal potential), the partial molar Gibbs energy (chemical potential), entropy, heat capacity, heat conduction and heat transfer coefficients.

Historically, the calorie has been defined as the quantity of heat required for heating up 1 g of distilled water at atmospheric pressure by 1°C. The reason for the discrepancy in the value of calorie— which existed in literature (in particular, the so-called thermochemical calorie, 1cal=4.1840 J)—is due to the temperature dependence of the heat capacity of water. At present, the Joule, which represents the energy measurement unit in the SI system, is most frequently used in measurements and tabulations of the functions mentioned above.

表示回数: 23089 記事追加日: 2 February 2011 記事最終修正日: 8 February 2011 ©著作権 2010-2021 トップへ戻る
A-Z索引 著者/編集者 意味マップ ビジュアルギャラリー 寄稿 Guest