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Ullage
Ullage or headspace is the unfilled space in a container, particularly with a liquid. Etymology The word ''ullage'' comes from the Latin word ''oculus'', used by the Romans to refer to a barrel cork hole. This word was, in turn, taken in medieval French as ''oeil'', from which a verb ''ouiller'' was created, meaning to fill a barrel to full capacity. Around 1300, the word ''ouillage'' was created by the Normans to refer to the amount of liquid needed to fill a barrel to capacity. Alcoholic beverages In winemaking, ''ullage'' came to refer to any amount by which a barrel is unfilled, perhaps because some of the contents have been used. It is also applied to the unfilled air space at the top of a bottle of wine, which in this case is essential to allow for expansion of the contents as the temperature changes. By further extension, in brewing and beer retail, ''ullage'' is the residue of beer left in a barrel that has been emptied. When calculating tax returns and the like, license ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ullage Motor
Ullage motors (also known as ullage engines or ullage rockets) are relatively small, independently fueled rocket engines that may be fired prior to main engine ignition, when the vehicle is in a zero-g situation. The resulting acceleration causes liquid in the rocket's main tanks to settle towards the aft end, ensuring uninterrupted flow to the fuel and oxidizer pumps. Description Cryogenic-liquid-fueled rockets keep their propellants in insulated tanks. These tanks are never completely filled to allow for expansion. In micro-gravity conditions the cryogenic liquids are without a free surface existing in a slushy state between solid, liquid, and gas. In this mixed state, ullage gases may be sucked into the engines, which is undesirable, as it displaces useful propellant, reduces efficiency, and may damage the engines. Small rocket engines, called "ullage motors", are sometimes used to settle the propellant prior to the main engine ignition to allow the formation of a temporary f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the Roman Republic it became the dominant language in the Italian region and subsequently throughout the Roman Empire. Even after the fall of Western Rome, Latin remained the common language of international communication, science, scholarship and academia in Europe until well into the 18th century, when other regional vernaculars (including its own descendants, the Romance languages) supplanted it in common academic and political usage, and it eventually became a dead language in the modern linguistic definition. Latin is a highly inflected language, with three distinct genders (masculine, feminine, and neuter), six or seven noun cases (nominative, accusative, genitive, dative, ablative, and vocative), five declensions, four verb conjug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cereal
A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more food energy worldwide than any other type of crop and are therefore staple crops. They include wheat, rye, oats, and barley. Edible grains from other plant families, such as buckwheat, quinoa and chia, are referred to as pseudocereals. In their unprocessed whole grain form, cereals are a rich source of vitamins, minerals, carbohydrates, fats, oils, and protein. When processed by the removal of the bran and germ the remaining endosperm is mostly carbohydrate. In some developing countries, grain in the form of rice, wheat, millet, or maize constitutes a majority of daily sustenance. In developed countries, cereal consumption is moderate and varied but still substantial, primarily in the form of refined and processed grains. Because of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Surface Effect
The free surface effect is a mechanism which can cause a watercraft to become unstable and capsize. It refers to the tendency of liquids — and of unbound aggregates of small solid objects, like seeds, gravel, or crushed ore, whose behavior approximates that of liquids — to move in response to changes in the attitude of a craft's cargo holds, decks, or liquid tanks in reaction to operator-induced motions (or sea states caused by waves and wind acting upon the craft). When referring to the free surface effect, the condition of a tank that is not full is described as a "slack tank", while a full tank is "pressed up". Stability and equilibrium In a normally loaded vessel any rolling from perpendicular is countered by a righting moment generated from the increased volume of water displaced by the hull on the lowered side. This assumes the center of gravity of the vessel is relatively constant. If a moving mass inside the vessel moves in the direction of the roll, this counters th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailing
Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, windsurfer, or kitesurfer), on ''ice'' (iceboat) or on ''land'' (land yacht) over a chosen course, which is often part of a larger plan of navigation. From prehistory until the second half of the 19th century, sailing craft were the primary means of maritime trade and transportation; exploration across the seas and oceans was reliant on sail for anything other than the shortest distances. Naval power in this period used sail to varying degrees depending on the current technology, culminating in the gun-armed sailing warships of the Age of Sail. Sail was slowly replaced by steam as the method of propulsion for ships over the latter part of the 19th century – seeing a gradual improvement in the technology of steam through a number of stepwise developments. Steam allowed scheduled services that ran at higher average speeds than sai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulk Cargo
Bulk cargo is commodity cargo that is transported unpackaged in large quantities. Description Bulk cargo refers to material in either liquid or granular, particulate form, as a mass of relatively small solids, such as petroleum/ crude oil, grain, coal, or gravel. This cargo is usually dropped or poured, with a spout or shovel bucket, into a bulk carrier ship's hold, railroad car/ railway wagon, or tanker truck/ trailer/semi-trailer body. Smaller quantities can be boxed (or drummed) and palletised; cargo packaged in this manner is referred to as breakbulk cargo. Bulk cargo is classified as liquid or dry. The Baltic Exchange is based in London and provides a range of indices benchmarking the cost of moving bulk commodities, dry and wet, along popular routes around the seas. Some of these indices are also used to settle Freight Futures, known as FFA's. The most famous of the Baltic indices is the Baltic Dry Indices, commonly called the BDI. This is a derived funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Stability
Ship stability is an area of naval architecture and ship design that deals with how a ship behaves at sea, both in still water and in waves, whether intact or damaged. Stability calculations focus on centers of gravity, centers of buoyancy, the metacenters of vessels, and on how these interact. History Ship stability, as it pertains to naval architecture, has been taken into account for hundreds of years. Historically, ship stability calculations relied on rule of thumb calculations, often tied to a specific system of measurement. Some of these very old equations continue to be used in naval architecture books today. However, the advent of calculus-based methods of determining stability, particularly Pierre Bouguer's introduction of the concept of the metacenter in the 1740s ship model basin, allow much more complex analysis. Master shipbuilders of the past used a system of adaptive and variant design. Ships were often copied from one generation to the next with only minor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vapor
In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. Herring, ''General Chemistry'', Prentice-Hall, 8th ed. 2002, p. 483–86. which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature. A vapor is different from an aerosol. An aerosol is a suspension of tiny particles of liquid, solid, or both within a gas. For example, water has a critical temperature of , which is the highest temperature at which liquid water can exist. In the atmosphere at ordinary temperatures gaseous water (known as water vapor) will condense into a liquid if its partial pressure is increased sufficiently. A vapor may co-exist with a liquid (or a solid). When this is true, the two phases will be in equilibrium, and the gas-partial pressure will be equal to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relief Valve
A relief valve or pressure relief valve (PRV) is a type of safety valve used to control or limit the pressure in a system; pressure might otherwise build up and create a process upset, instrument or equipment failure, or fire. The pressure is relieved by allowing the pressurized fluid to flow from an auxiliary passage out of the system. The relief valve is designed or set to open at a predetermined set pressure to protect pressure vessels and other equipment from being subjected to pressures that exceed their design limits. When the set pressure is exceeded, the relief valve becomes the " path of least resistance" as the valve is forced open and a portion of the fluid is diverted through the auxiliary route. In systems containing flammable fluids, the diverted fluid (liquid, gas or liquid-gas mixture) is either recaptured by a low pressure, high-flow vapor recovery system or is routed through a piping system known as a ''flare header'' or ''relief header'' to a central, elevated g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Of Federal Regulations
In the law of the United States, the ''Code of Federal Regulations'' (''CFR'') is the codification of the general and permanent regulations promulgated by the executive departments and agencies of the federal government of the United States. The CFR is divided into 50 titles that represent broad areas subject to federal regulation. The CFR annual edition is published as a special issue of the '' Federal Register'' by the Office of the Federal Register (part of the National Archives and Records Administration) and the Government Publishing Office. In addition to this annual edition, the CFR is published online on the Electronic CFR (eCFR) website, which is updated daily. Background Congress frequently delegates authority to an executive branch agency to issue regulations to govern some sphere. These statutes are called "enabling legislation." Enabling legislation typically has two parts: a substantive scope (typically using language such as "The Secretary shall promulgate r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Maritime Organization
The International Maritime Organization (IMO, French: ''Organisation maritime internationale'') is a specialised agency of the United Nations responsible for regulating shipping. The IMO was established following agreement at a UN conference held in Geneva in 1948 and the IMO came into existence ten years later, meeting for the first time in 1959. Headquartered in London, United Kingdom, IMO currently has 175 Member States and three Associate Members. The IMO's primary purpose is to develop and maintain a comprehensive regulatory framework for shipping and its remit today includes maritime safety, environmental concerns, legal matters, technical co-operation, maritime security and the efficiency of shipping. IMO is governed by an assembly of members which meets every two years. Its finance and organization is administered by a council of 40 members elected from the assembly. The work of IMO is conducted through five committees and these are supported by technical subcommi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Control System
A reaction control system (RCS) is a spacecraft system that uses thrusters to provide attitude control and translation. Alternatively, reaction wheels are used for attitude control. Use of diverted engine thrust to provide stable attitude control of a short-or-vertical takeoff and landing aircraft below conventional winged flight speeds, such as with the Harrier "jump jet", may also be referred to as a reaction control system. Reaction control systems are capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is also capable of providing torque to allow control of rotation ( roll, pitch, and yaw). Reaction control systems often use combinations of large and small ( vernier) thrusters, to allow different levels of response. Uses Spacecraft reaction control systems are used for: * attitude control during different stages of a mission; * station keeping in orbit; * close maneuvering during docking procedures; * con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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