Air conditioning

Air conditioning (often referred to as A/C or AC) is the process of altering the properties of air (primarily temperature and humidity) to more comfortable conditions, typically with the aim of distributing the conditioned air to an occupied space such as a building or a vehicle to improve thermal comfort and indoor air quality. In common use, an air conditioner is a device that lowers the air temperature. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants.

In the most general sense, air conditioning can refer to any form of technology that modifies the condition of air (heating, cooling, (de-)humidification, cleaning, ventilation, or air movement). However, in construction, such a complete system of heating, ventilation, and air conditioning is referred to as heating, ventilation, and air conditioning (HVAC -as opposed to AC).

History

The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. In Ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.

Toyota A engine

The A Series engines are a family of inline-four internal combustion engines with displacement from 1.3 L to 1.8 L produced by Toyota Motor Corporation. The series has cast iron engine blocks and aluminum cylinder heads.

The development of the series began in the late 1970s, when Toyota wanted to develop a completely new engine for the Toyota Tercel, successor of Toyota's K engine. The goal was to achieve good fuel efficiency and performance as well as low emissions with a modern design. The A-series includes the first mass-production DOHC, four-valve-per-cylinder engine, the 4A-GE, and a later version of the same motor was one of the first production five-valve-per-cylinder engines.

Toyota joint venture partner Tianjin FAW Xiali still produces the 1.3 L 8A and recently resumed production of the 5A.

1A

The 1.5 L 1A was produced between 1978 and 1980. All variants were belt-driven 8-valve counter-flow SOHC engine with a single, twin-barrel downdraft carburetor.

1A-C

Applications:

A1C

A1C may refer to:

Agenda for Change

Agenda for Change (AfC) is the current National Health Service (NHS) grading and pay system for all NHS staff, with the exception of doctors, dentists and some senior managers. It covers more than 1 million people and harmonises their pay scales and career progression arrangements across traditionally separate pay groups, in the most radical change since the NHS was founded.

It came into operation on 1 December 2004, following agreement between the unions, employers and governments involved.

Job evaluation

The AfC system allocates posts to set pay bands by giving consideration to aspects of the job, such as the skills involved, under an NHS Job Evaluation Scheme. There are nine numbered pay bands subdivided into points, similar to the old alphabetic Whitley Council 'grades' pay scales. A set of national job profiles has been agreed to assist in the process of matching posts to pay bands. All staff will either be matched to a national job profile, or their job will be evaluated locally. In theory, AfC is designed to evaluate the job rather than the person in it, and to ensure equity between similar posts in different areas. In reality it has been implemented differently in different places, and some posts have been graded very differently from similar jobs elsewhere, despite the supposedly tighter definitions. Around 5% of staff have appealed their gradings, but again the appeals process varies from site to site. Current indications suggest that lower bandings are being used in London and Scotland than elsewhere in the country.

Fairchild Republic A-10 Thunderbolt II

The Fairchild Republic A-10 Thunderbolt II is an American twin-engine, straight wing jet aircraft developed by Fairchild-Republic in the early 1970s. It entered service in 1976, and is the only United States Air Force production-built aircraft designed solely for close air support, including attacking tanks, armored vehicles, and other ground targets.

The A-10 was designed around the 30 mm GAU-8 Avenger rotary cannon that is its primary armament. The A-10's airframe was designed for durability, with measures such as 1,200 pounds (540 kg) of titanium armor to protect the cockpit and aircraft systems, enabling it to absorb a significant amount of damage and continue flying. Its short takeoff and landing capability permits operation from airstrips close to the front lines, while its simple design enables maintenance at forward bases with limited facilities. The A-10A single-seat variant was the only version built, though one A-10A was converted to an A-10B twin-seat version. In 2005, a program was begun to upgrade remaining A-10A aircraft to the A-10C configuration.