Pound (mass) in the context of "RAF Bomber Command"

Troy weight is a system of units of mass whose origin is uncertain. By far the most common troy unit is the troy ounce (oz t), the standard mass unit for precious metals in industry and in trade; it equals 31.1034768 grams. The troy weight units are the grain, the pennyweight (24 grains), the troy ounce (20 pennyweights), and the troy pound (12 troy ounces). The troy grain is equal to the grain unit of the avoirdupois and apothecaries' systems, but the troy ounce is heavier than the avoirdupois ounce, and the troy pound is lighter than the avoirdupois pound.

Grammage and basis weight, in the pulp and paper industry, are the area density of a paper product, that is, its mass per unit of area. Two ways of expressing the area density of a paper product are commonly used:

• Expressed in grams (g) per square metre (g/m), regardless of its thickness (caliper) (known as grammage). This is the measure used in most parts of the world. It is often notated as gsm on paper product labels and spec sheets.
• Expressed in terms of the mass per number of sheets of a specific paper size (known as basis weight). The convention used in the United States and a few other countries using US-standard paper sizes is pounds (lb) per ream of 500 (or in some cases 1000) sheets of a given (raw, still uncut) basis size. The traditional British practice is pounds per ream of 480, 500, 504, or 516 sheets of a given basis size. Japanese paper is expressed as the weight in kilograms (kg) per 1,000 sheets.

Enceladus is the sixth-largest moon of Saturn and the 18th largest in the Solar System. It is about 500 kilometres (310 miles) in diameter, about a tenth of that of Saturn's largest moon, Titan. It is covered by clean, freshly deposited snow hundreds of meters thick, making it one of the most reflective bodies of the Solar System. Consequently, its surface temperature at noon reaches only −198 °C (75.1 K; −324.4 °F), far colder than a light-absorbing body would be. Despite its small size, Enceladus has a wide variety of surface features, ranging from old, heavily cratered regions to young, tectonically deformed terrain.

Enceladus was discovered on August 28, 1789, by William Herschel, but little was known about it until the two Voyager spacecrafts, Voyager 1 and Voyager 2, flew by Saturn in 1980 and 1981. In 2005, the spacecraft Cassini started multiple close flybys of Enceladus, revealing its surface and environment in greater detail. In particular, Cassini discovered water-rich plumes venting from the south polar region. Cryovolcanoes near the south pole shoot geyser-like jets of water vapour, molecular hydrogen, other volatiles, and solid material, including sodium chloride crystals and ice particles, into space, totalling about 200 kilograms (440 pounds) per second. More than 100 geysers have been identified. Some of the water vapour falls back as snow, now several hundred metres thick; the rest escapes and supplies most of the material making up Saturn's E ring. According to NASA scientists, the plumes are similar in composition to comets. In 2014, NASA reported that Cassini had found evidence for a large south polar subsurface ocean of liquid water with a thickness of around 10 km (6 mi). The existence of Enceladus's subsurface ocean has since been mathematically modelled and replicated.

The international yard and pound are two units of measurement that were the subject of an agreement among representatives of six nations signed on 1 July 1959: Australia, Canada, New Zealand, South Africa, the United Kingdom and the United States. The agreement defined the yard as exactly 0.9144 meters and the avoirdupois pound as exactly 0.45359237 kilograms.

In physics and engineering, mass flow rate is the rate at which mass of a substance changes over time. Its unit is kilogram per second (kg/s) in SI units, and slug per second or pound per second in US customary units. The common symbol is ${\displaystyle {\dot {m}}}$ (pronounced "m-dot"), although sometimes ${\displaystyle \mu }$ (Greek lowercase mu) is used.

Sometimes, mass flow rate as defined here is termed "mass flux" or "mass current".Confusingly, "mass flow" is also a term for mass flux, the rate of mass flow per unit of area.

Avoirdupois (/ˌævərdəˈpɔɪz, ˌævwɑːrdjuːˈpwɑː/; abbreviated avdp.) is a measurement system of weights that uses pounds and ounces as units. It was first commonly used in the 13th century AD and was updated in 1959.

In 1959, by international agreement among countries that used the pound as a unit of mass, the International Avoirdupois Pound was fixed at the modern definition of exactly 0.45359237 kilograms.. It remains the everyday system of weights used in the United States, and is still used, in varying degrees, in everyday life in the United Kingdom, Canada, Australia, and some other former British colonies, despite their official adoption of the metric system.

The apothecaries' system, or apothecaries' weights and measures, is a historical system of mass and volume units that were used by physicians and apothecaries for medical prescriptions, and also sometimes by scientists. The English version of the system is closely related to the English troy system of weights, the pound and grain being exactly the same in both. It divides a pound into 12 ounces, an ounce into 8 drachms, and a drachm into 3 scruples of 20 grains each. This exact form of the system was used in the United Kingdom; in some of its former colonies, it survived well into the 20th century. The apothecaries' system of measures is a similar system of volume units based on the fluid ounce. For a long time, medical recipes were written in Latin, often using special symbols to denote weights and measures.

The use of different measure and weight systems depending on the purpose was an almost universal phenomenon in Europe between the decline of the Roman Empire and metrication. This was connected with international commerce, especially with the need to use the standards of the target market and to compensate for a common weighing practice that caused a difference between actual and nominal weight. In the 19th century, most European countries or cities still had at least a "commercial" or "civil" system (such as the English avoirdupois system) for general trading, and a second system (such as the troy system) for precious metals such as gold and silver. The system for precious metals was usually divided in a different way from the commercial system, often using special units such as the carat. More significantly, it was often based on different weight standards.

The ounce (/ˈaʊns/) is any of several different units of mass, weight, or volume and is derived almost unchanged from the uncia, an Ancient Roman unit of measurement.

The avoirdupois ounce (exactly 28.349523125 g) is 1⁄16 avoirdupois pound; this is the United States customary and British imperial ounce. It is primarily used in the United States.