HVAC

HVAC (heating, ventilating, and air conditioning; also heating, ventilation, and air conditioning) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. Refrigeration is sometimes added to the field's abbreviation as HVAC&R or HVACR, (heating,ventilating and air-conditioning & Refrigeration) or ventilating is dropped as in HACR (such as the designation of HACR-rated circuit breakers).

HVAC is important in the design of medium to large industrial and office buildings such as skyscrapers, onboard vessels, and in marine environments such as aquariums, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.

Ventilating or ventilation (the V in HVAC) is the process of "exchanging" or replacing air in any space to provide high indoor air quality which involves temperature control, oxygen replenishment, and removal of moisture, odors, smoke, heat, dust, airborne bacteria, and carbon dioxide. Ventilation removes unpleasant smells and excessive moisture, introduces outside air, keeps interior building air circulating, and prevents stagnation of the interior air.

Heater (disambiguation)

Heater is an object that emits heat.

Heater may also refer to:

In electronics:

In music:

In other fields:

Targetmaster

Targetmaster is a subline of the Transformers toyline that include Nebulan sidekicks who can transform into the Transformers' weapons.

1987 Targetmasters

The first Targetmasters assortment, released in 1987, included six new characters, and five existing ones from the 1986 line, whose toys were slightly remolded with larger peg holes to hold their new weapons, as well as an additional peg hole for each remold to mount its weapon in vehicle mode. In 2003, one of the two Japanese-exclusive Targetmasters from 1987 was added to the Autobot ranks. Unfortunately, the Targetmaster weapon he shares with Decepticon Cyclonus, also share names. To further add to the confusion, the printed names of Stepper and Artfire's weapon/partners in Japan are swapped. Cyclonus's partner Nightstick is called Nebulon (the name Fracas is erroneously given on Scourge's box) and paired with Stepper. Scourge's partner Fracas is called Nightstick and paired with Artfire.

The smaller Targetmaster partners were easily lost making them highly collectable and demand high prices on the secondary market.

Katana

Historically, katana (刀) were one of the traditionally made Japanese swords (日本刀, nihontō) that were used by the samurai of feudal Japan. Modern versions of the katana are sometimes made using non-traditional materials and methods. The katana is characterized by its distinctive appearance: a curved, slender, single-edged blade with a circular or squared guard and long grip to accommodate two hands.

History

The production of swords in Japan is divided into specific time periods:

The first use of "katana" (gatana) as a word to describe a long sword that was different from a tachi occurs as early as the Kamakura Period (1185–1333). These references to "uchigatana" and "tsubagatana" seem to indicate a different style of sword, possibly a less costly sword for lower-ranking warriors. The evolution of the tachi into the katana seems to have started during the early Muromachi period (1337 to 1573). Starting around the year 1400, long swords signed with the "katana" signature were made. This was in response to samurai wearing their tachi in what is now called "katana style" (cutting edge up). Japanese swords are traditionally worn with the signature facing away from the wearer. When a tachi was worn in the style of a katana, with the cutting edge up, the tachi's signature would be facing the wrong way. The fact that swordsmiths started signing swords with a katana signature shows that some samurai of that time period had started wearing their swords in a different manner.

Katana (disambiguation)

Katana is Japanese for backsword and often refers to uchigatana, especially in English. For a list of fictional katana, see Katanas in fiction. Katana may also refer to:

Dreamcast

The Dreamcast (Japanese: ドリームキャスト, Hepburn: Dorīmukyasuto) is a home video game console released by Sega on November 27, 1998 in Japan, September 9, 1999 in North America, and October 14, 1999 in Europe. It was the first in the sixth generation of video game consoles, preceding Sony's PlayStation 2, Nintendo's GameCube and Microsoft's Xbox. The Dreamcast is Sega's final home console, marking the end of the company's 18 years in the console market.

In contrast to the expensive hardware of the unsuccessful Sega Saturn, the Dreamcast was designed to reduce costs with "off-the-shelf" components, including a Hitachi SH-4 CPU and an NEC PowerVR2 GPU. Released in Japan to a subdued reception, the Dreamcast enjoyed a successful U.S. launch backed by a large marketing campaign, but interest in the system steadily declined as Sony built hype for the upcoming PlayStation 2. Sales did not meet Sega's expectations despite several price cuts, and the company continued to incur significant financial losses. After a change in leadership, Sega discontinued the Dreamcast on March 31, 2001, withdrawing from the console business and restructuring itself as a third-party publisher. 9.13 million Dreamcast units were sold worldwide.