Rolling

Rolling is a type of motion that combines rotation (commonly, of an axially symmetric object) and translation of that object with respect to a surface (either one or the other moves), such that, if ideal conditions exist, the two are in contact with each other without sliding.

Rolling where there is no sliding is referred to as pure rolling. By definition, there is no sliding when the instantaneous velocity of the rolling object in all the points in which it contacts the surface is the same as that of the surface; in particular, for a reference plane in which the rolling surface is at rest, the instantaneous velocity of the point of contact of the rolling object is zero.

In practice, due to small deformations near the contact area, some sliding and energy dissipation occurs. Nevertheless, the resulting rolling resistance is much lower than sliding friction, and thus, rolling objects, typically require much less energy to be moved than sliding ones. As a result, such objects will more easily move, if they experience a force with a component along the surface, for instance gravity on a tilted surface, wind, pushing, pulling, or torque from an engine. Unlike most axially symmetrical objects, the rolling motion of a cone is such that while rolling on a flat surface, its center of gravity performs a circular motion, rather than linear motion. Rolling objects are not necessarily axially-symmetrical. Two well known non-axially-symmetrical rollers are the Reuleaux triangle and the Meissner bodies. The oloid and the sphericon are members of a special family of developable rollers that develop their entire surface when rolling down a flat plane. Objects with corners, such as dice, roll by successive rotations about the edge or corner which is in contact with the surface.

Leukocyte extravasation

Leukocyte extravasation, less commonly called diapedesis, is the movement of leukocytes out of the circulatory system and towards the site of tissue damage or infection. This process forms part of the innate immune response, involving the recruitment of non-specific leukocytes. Monocytes also use this process in the absence of infection or tissue damage during their development into macrophages.

Overview

Leukocyte extravasation occurs mainly in post-capillary venules, where haemodynamic shear forces are minimised. This process can be understood in several steps, outlined below as "chemoattraction", "rolling adhesion", "tight adhesion" and "(endothelial) transmigration". It has been demonstrated that leukocyte recruitment is halted whenever any of these steps is suppressed.

White blood cells (leukocytes) perform most of their functions in tissues. Functions include phagocytosis of foreign particles, production of antibodies, secretion of inflammatory response triggers (histamine and heparin), and neutralization of histamine. In general, leukocytes are involved in the defense of an organism and protect it from disease by promoting or inhibiting inflammatory responses. Leukocytes use the blood as a transport medium to reach the tissues of the body. Here is a brief summary of each of the four steps currently thought to be involved in leukocyte extravasation:

Rolling (metalworking)

In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform. The concept is similar to the rolling of dough. Rolling is classified according to the temperature of the metal rolled. If the temperature of the metal is above its recrystallization temperature, then the process is known as hot rolling. If the temperature of the metal is below its recrystallization temperature, the process is known as cold rolling. In terms of usage, hot rolling processes more tonnage than any other manufacturing process, and cold rolling processes the most tonnage out of all cold working processes.Roll stands holding pairs of rolls are grouped together into rolling mills that can quickly process metal, typically steel, into products such as structural steel (I-beams, angle stock, channel stock, and so on), bar stock, and rails. Most steel mills have rolling mill divisions that convert the semi-finished casting products into finished products.

Substance

Substance may refer to:

Music

See also

Substance 1987

Substance (also known as Substance 1987) is a compilation album by English alternative dance band New Order, released in August 1987 by Factory Records. It compiles all of the band's singles at that point in their 12-inch versions, along with their respective B-side tracks. The then-newly released non-album single "True Faith" is also featured, along with its B-side "1963".

Substance was released on vinyl, double CD, double cassette and Digital Audio Tape. It sold over one million copies and became New Order's most popular and critically acclaimed album.

Songs

While Substance presents a sizeable collection of singles, there are many omissions and differences to be found from the original single releases:

Substance (Joy Division album)

Substance is a singles compilation album by the post-punk band Joy Division, released on Factory Records in 1988. It is the companion to a similar singles compilation by their subsequent band New Order, also entitled Substance. It peaked at #7 in the UK album chart and #146 on the Billboard 200, the band's only chart appearance in the United States. It also reached #15 in New Zealand and #53 in Australia in August 1988.

Content

Substance compiles the four singles released by the band that did not appear on albums - "Transmission", "Komakino", "Love Will Tear Us Apart", and "Atmosphere" - as well as their B-sides. It also collects tracks released on extended play singles, the band's first release An Ideal for Living, and two samplers issued by Factory Records, A Factory Sample and Earcom 2: Contradiction. The single "Atmosphere" had been originally issued in France as "Licht und Blindheit" with "Dead Souls" on the B-side. Following the death of Ian Curtis, it was reissued as a posthumous B-side of the "She's Lost Control" single in an alternate version from the track that had previously appeared on Unknown Pleasures. The vinyl version omits the single "Komakino" and does not include the complete titles from the extended plays. Later CD pressings issued by London Records contain a previously unreleased mix of "She's Lost Control" that is slightly different from the original single release. More guitar is featured within the song, the synthesizer melody is shortened and starts at a later point, and the ending of the song is extended by 15 seconds and doesn't fade out.