Work (electrical)

Electrical work is the work done on a charged particle by an electric field. The equation for 'electrical' work is equivalent to that of 'mechanical' work:

where

The electrical work per unit of charge, when moving a negligible test charge between two points, is defined as the voltage between those points.

Overview

Qualitative overview

Particles that are free to move, if positively charged, normally tend towards regions of lower voltage (net negative charge), while if negatively charged they tend to shift towards regions of higher voltage (net positive charge).

However, any movement of a positive charge into a region of higher voltage requires external work to be done against the field of the electric force, work equal to that electric field would do in moving that positive charge the same distance in the opposite direction. Similarly, it requires positive external work to transfer a negatively charged particle from a region of higher voltage to a region of lower voltage.

The electric force is a conservative force: work done by a static electric field is independent of the path taken by the charge. There is no change in the voltage (electric potential) around any closed path; when returning to the starting point in a closed path, the net of the external work done is zero. The same holds for electric fields.

Work of art

A work of art, artwork, art piece, piece of art or art object is an aesthetic physical item or artistic creation. Apart from "work of art", which may be used of any work regarded as art in its widest sense, including works from literature and music, these terms apply principally to tangible, portable forms of visual art:

Used more broadly, the term is less commonly applied to:

Work (The 2 Bears song)

"Work" is a single by London-based musical duo The 2 Bears. It was released on 1 January 2012 as a Digital download in the United Kingdom. The song features on their debut studio album Be Strong.

Music video

A music video to accompany the release of "Work" and was uploaded to YouTube on 12 January 2012 at a total length of three minutes and fourteen seconds.

Track listing

Chart performance

Release history

References

Film (Polish magazine)

Film is a monthly Polish magazine devoted to cinema. It has been in publication since 1946, originally as a bimonthly publication. The founders were Jerzy Giżycki, Zbigniew Pitera, Tadeusz Kowalski, and Leon Bukowiecki.

Since September 2012, the editor-in-chief has been Tomasz Raczek. Previous editors have included Maciej Pawlicki, Lech Kurpiewski, Igor Zalewski and Robert Mazurek, Agnieszka Różycka, Marcin Prokop and Jacek Rakowiecki.

In January 2007, Film was purchased by Platforma Mediowa Point Group (PMPG).

Editorial staff

References

External links

Official website (Polish)

Lubrication theory

In fluid dynamics, lubrication theory describes the flow of fluids (liquids or gases) in a geometry in which one dimension is significantly smaller than the others. An example is the flow above air hockey tables, where the thickness of the air layer beneath the puck is much smaller than the dimensions of the puck itself.

Internal flows are those where the fluid is fully bounded. Internal flow lubrication theory has many industrial applications because of its role in the design of fluid bearings. Here a key goal of lubrication theory is to determine the pressure distribution in the fluid volume, and hence the forces on the bearing components. The working fluid in this case is often termed a lubricant.

Free film lubrication theory is concerned with the case in which one of the surfaces containing the fluid is a free surface. In that case the position of the free surface is itself unknown, and one goal of lubrication theory is then to determine this. Surface tension may then be significant, or even dominant. Issues of wetting and dewetting then arise. For very thin films (thickness less than one micrometre), additional intermolecular forces, such as Van der Waals forces or disjoining forces, may become significant.

List of film periodicals

Film periodicals combine discussion of individual films, genres and directors with in-depth considerations of the medium and the conditions of its production and reception. Their articles contrast with film reviewing in newspapers and magazines which principally serve as a consumer guide to movies.

Magazines and trade publications

Scholarly journals

References

Bibliography