There are currently 34 names in this directory beginning with the letter U.
Universal Camouflage Pattern also referred to unofficially as ACUPAT (Army Combat Uniform Pattern) or Digital Camouflage (digicam), is a digital military camouflage pattern formerly used in the United States Army’s Army Combat Uniform.
Or Ultra High Frequency are radio frequencies between 300 MHz and 3 GHz propagating mainly by line of sight. They are used for TV broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones, etc.
An all-purpose knife traditionally used by Inuit, Yupik, and Aleut women for virtually every application that requires cutting, from skinning animals to cutting hair, cutting ice for igloo construction as well as a weapon.
The innermost and darkest part of a shadow, where the light source is completely blocked. An observer in the umbra experiences a total eclipse.
United Nations Convention on the Law of the Sea is an international agreement that defines rights and responsibilities of nations with respect to their use of the oceans, guidelines for businesses, the environment and marine resources. However, the UN has no direct operational role in the implementation of the Convention.
Upcycling is another form of recycling when waste material is converted into new materials. Turning used plastic bottles into planters would be an example of upcycling.
A small scale current of rising air, often within a cloud. A mass of warm air will be less dense than the surrounding region, and will rise reaching air that is either warmer or less dense than itself. Drafts can also be created by low pressure regions which attract air from the surrounding area, which move towards the centre and then rise, creating an updraft.
Type of ocean current caused by waves breaking on the shore so that water from previous waves runs underneath them, creating a gentle current that runs back out to sea.
Kind of ultraviolet rays that comes from the Sun. They penetrate deep into the dermis, the skin’s thickest layer and exposure can lead to skin aging and suppression of the immune system. Prolonged exposure can lead to skin cancer. 95% of UV rays that reach the surface of the Earth is UV-A rays.
UV-B rays burn the superficial layers of skin. The intensity of UV-B rays vary by season, location and time of day, with 10am to 4pm being peak hours. Sunburned skin doesn’t just feel awful, it can cause permanent damage over time. 5% of UV rays that reach the surface of the Earth is UV-B rays.
A type of ultraviolet ray that does not reach the surface of the Earth since it is absorbed by the ozone layer in the atmosphere.
Lightweight, one or two seater fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional 3-axis control aircraft with ailerons, elevator and rudder, calling the former “microlight” and the latter “ultralight”.
Kind of radiation from the Sun. Excessive exposure to UV rays results in sunburn and can lead to skin cancers. About 10% of sunlight comprises UV rays of which a third reaches the Earth’s surface. The higher the altitude, more the UV rays. These rays comprises UV-A rays, UV-B rays and UV-C rays.
Universal Transverse Mercator
Converting the curvature of the Earth into a flat surface like in a map brings about distortions in calculations, particular longitudes. To overcome this problem, the Universal Transverse Mercator system was developed which divides the Earth between 80°S and 84°N latitude into 60 zones, each 6° of longitude and 8° of latitude. Zone 1 covers longitude 180° to 174° W; zone numbering increases eastward to zone 60, which covers longitude 174° to 180° E. A combination of the zone and the latitude band defines a grid zone.
Unmanned Aerial Vehicle (UAV)
Commonly known as a drone it is an aircraft without a human pilot aboard and can be controlled by an operator located on the ground or in another vehicle, or fully autonomously, by onboard computers. They are increasingly being used in civil and recreational applications by police, film makers and drone racers.
The area above the ground water level or water table where soil pores are not fully saturated, although some water may be present.
Or urban slacklining combines different styles of slacklining and is practiced in urban areas. A type of urbanlining is timelining, where one tries to stay on a slackline for as long as possible without falling down. Another type is streetlining, that combines street workout power moves with the slackline’s dynamic, shaky, bouncy feeling. Main focus are static handstands, super splits, planche, front lever, back lever, one arm handstand and other interesting extreme moves that are evolving in street workout culture.
Also known as Great Bear, it is the third largest constellation in the sky and lies in the northern celestial hemisphere visible throughout the year. Its most recognisable grouping is of seven bright stars known as the Big Dipper used as a pointer towards the Pole Star or Polaris.
Also known as the Little Bear, it is a constellation in the northern sky. The tail may be seen as the handle of a ladle, hence the North American name, Little Dipper. It is important for navigation because of Polaris which is the brightest star in the constellation and marks the tail of the constellation.
A community or society that possesses nearly perfect qualities. Often means something that is unachievable.
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