Application programming interface

In computer programming, an application programming interface (API) is a set of routines, protocols, and tools for building software and applications.

An API expresses a software component in terms of its operations, inputs, outputs, and underlying types, defining functionalities that are independent of their respective implementations, which allows definitions and implementations to vary without compromising the interface. A good API makes it easier to develop a program by providing all the building blocks, which are then put together by the programmer.

An API may be for a web-based system, operating system, or database system, and it provides facilities to develop applications for that system using a given programming language. As an example, a programmer who develops apps for Android may use an Android API to interact with hardware, like the front camera of an Android-based device.

In addition to accessing databases or computer hardware like hard disk drives or video cards, an API can ease the work of programming GUI components. For example, an API can facilitate integration of new features into existing applications (a so-called "plug-in API"). An API can also assist otherwise distinct applications with sharing data, which can help to integrate and enhance the functionalities of the applications.

Api (mountain)

Api is the highest peak in the Yoka Pahar Section of Gurans Himal, part of the Himalayas in the extreme northwest corner of Nepal, near the borders of India and Tibet. It is a little-known peak in a rarely visited part of the Himalayas, but it rises dramatically over the low surrounding terrain.

Notable features

Although low in elevation among the major mountains of Nepal, Api is exceptional in its rise above local terrain; the surrounding valleys are significantly lower than those surrounding most higher Himalayan peaks.

Climbing history

The Api region was visited by Westerners in 1899, 1905, and 1936, but the peak was not attempted until 1953 on a visit by W. H. Murray a Scottish Mountaineer with John Tyson. This attempt was unsuccessful, as was another, by Italians, in 1954 which resulted in the death of two expedition members.

The first ascent of Api occurred in 1960. The Doshisha Alpine Society of Japan successfully completed the Northwest Face route attempted by the 1954 party.

API gravity

The American Petroleum Institute gravity, or API gravity, is a measure of how heavy or light a petroleum liquid is compared to water: if its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks.

API gravity is thus an inverse measure of a petroleum liquid's density relative to that of water (also known as specific gravity). It is used to compare densities of petroleum liquids. For example, if one petroleum liquid is less dense than another, it has a greater API gravity. Although mathematically, API gravity is a dimensionless quantity, see the formula below, it is referred to as being in 'degrees'. API gravity is gradated in degrees on a hydrometer instrument. API gravity values of most petroleum liquids fall between 10 and 70 degrees.

History of development

In 1916, the U.S. National Bureau of Standards accepted the Baumé scale, which had been developed in France in 1768, as the U.S. standard for measuring the specific gravity of liquids less dense than water. Investigation by the U.S. National Academy of Sciences found major errors in salinity and temperature controls that had caused serious variations in published values. Hydrometers in the U.S. had been manufactured and distributed widely with a modulus of 141.5 instead of the Baumé scale modulus of 140. The scale was so firmly established that, by 1921, the remedy implemented by the American Petroleum Institute was to create the API gravity scale, recognizing the scale that was actually being used.