Barrier

A barrier or barricade is a physical structure which blocks or impedes something.

Barrier may also refer to:

Physical

Roadway

Crowd and noise control

Barrier (computer science)

In parallel computing, a barrier is a type of synchronization method. A barrier for a group of threads or processes in the source code means any thread/process must stop at this point and cannot proceed until all other threads/processes reach this barrier.

Many collective routines and directive-based parallel languages impose implicit barriers. For example, a parallel do loop in Fortran with OpenMP will not be allowed to continue on any thread until the last iteration is completed. This is in case the program relies on the result of the loop immediately after its completion. In message passing, any global communication (such as reduction or scatter) may imply a barrier.

Dynamic barriers

Classic barrier constructs define the set of participating processes/threads statically. This is usually done either at program startup or when a barrier like the Pthreads barrier is instantiated. This restricts the possible applications for which barriers can be used.

To support more dynamic programming paradigms like fork/join parallelism, the sets of participants have to be dynamic. Thus, the set of processes/threads participating in a barrier operation needs to be able to change over time. X10 introduced the concept of clocks for that purpose, which provide a dynamic barrier semantic. Building on clocks, phasers have been proposed to add even more flexibility to barrier synchronization. With phasers it is possible to express data dependencies between the participating processes explicitly to avoid unnecessary over-synchronization.

Barrier isolator

Barrier isolator is a general term that includes two types of devices: Isolators and Restricted Access Barriers (RABS). Both are devices that provide a physical and aerodynamic (air overpressure) barrier between the external clean room environment and a work process. The isolator design is the more dependable of the two barrier design choices, as it prevents contamination hazards by achieving a more comprehensive separation of the processing environment from the surrounding facility. Nonetheless, both Isolator and RABS designs are contemporary approaches developed over the last 35 years and a great advancement over designs of the 1950s-70s that were far more prone to microbial contamination problems.

Barrier and Isolator designs are used throughout the industries, from sterile injectable drug filling to cytotoxic sterile drug compounding to electronics manufacturing to orange juice filling. Pharmaceutical industry and pharmacy compounding isolators are used for maintaining sterility of a drug, and that is the focus of this article. This type of strict design and control is important when producing sterile medicines because consumers receiving injections, surgical irrigants, or other "parenterally"-administered drugs are often highly vulnerable to infection. As a result, contaminated drugs have caused grave (e.g., permanent injury, death) consequences for the consumer. The sterility of other dosage forms, such as ophthalmics, is similarly important, as blindness or partial loss of vision has occurred due to intrinsically contaminated eye medications.

ASAP

ASAP may refer to: As Soon As Possible.

Music and television

Technology and internet

Institutions, Organizations or Programs

ASAP (band)

ASAP was a band created by guitarist and vocalist Adrian Smith of Iron Maiden fame. ASAP released an album in 1989 entitled Silver and Gold. A.S.A.P. stands for "Adrian Smith and Project", and the full name of the band is incorporated within the band logo, with each word written in tiny font underneath the corresponding letter in the abbreviation.

History

Adrian Smith formed the band in 1989 when Iron Maiden was taking a year break after spending almost a year on the road for the Seventh Son of a Seventh Son album tour in 1988. The band had its origin in Urchin, a band Smith fronted in the 1970s. Andy Barnett, Dave Colwell and Richard Young played with Smith in various incarnations of Urchin, which was disbanded in 1981 when Smith joined Iron Maiden.

Further foundations for the band were laid out in late 1985 when Iron Maiden were taking a break after their massive world tour in support of their album Powerslave. Bored with the lull in band's activity as they prepared to record a new album, Adrian Smith and Nicko McBrain started playing on their own to pass the time, and they soon formed a full band which included Colwell and Barnett. Along with some other musicians they knew, they went to play a one-off gig at London's Marquee Club under the name of "The Entire Population of Hackney". At the show, the band performed mostly original material, including the songs "Silver And Gold" (which would later become the title track of their only album, "Fighting Man", "School Days" and "When She's Gone" (all of which would later be recorded by ASAP and released as B-sides to its singles) at the show, as well as three songs that would later be recorded by Iron Maiden ("Juanita", "Reach Out" and "That Girl").

ASAP (Bardot song)

"ASAP" is a pop / R&B song performed by former Australian pop group Bardot, and was the first single from their second album Play It Like That (2001).

History

The fast tempo R&B track is about a partner's interfering mother. "ASAP" was Bardot's second single in the UK.

Track listing

Australian CD single

UK CD single

Charts

References