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Science And Technology Of The Han Dynasty
The Han dynasty (206 BCE – 220 CE) of early imperial China, divided between the eras of Western Han (206 BCE – 9 CE, when the capital was at Chang'an), the Xin dynasty of Wang Mang (r. 9–23 CE), and Eastern Han (25–220 CE, when the capital was at Luoyang, and after 196 CE at Xuchang), witnessed some of the most significant advancements in premodern Chinese science and technology. There were great innovations in metallurgy. In addition to Zhou-era China's (c. 1046 – 256 BCE) previous inventions of the blast furnace and cupola furnace to make pig iron and cast iron, respectively, the Han period saw the development of steel and wrought iron by use of the finery forge and puddling process. With the drilling of deep boreholes into the earth, the Chinese used not only derricks to lift brine up to the surface to be boiled into salt, but also set up bamboo-crafted pipeline transport systems which brought natural gas as fuel to the furnaces. Smelting techniques ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wrought Iron
Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag Inclusion (mineral), inclusions (up to 2% by weight), which give it a wood-like "grain" that is visible when it is etched, rusted, or bent to structural failure, failure. Wrought iron is tough, malleable, ductile, corrosion resistant, and easily forge welding, forge welded, but is more difficult to welding, weld electrically. Before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron. It was given the name ''wrought'' because it was hammered, rolled, or otherwise worked while hot enough to expel molten slag. The modern functional equivalent of wrought iron is Carbon steel#Mild or low-carbon steel, mild steel, also called low-carbon steel. Neither wrought iron nor mild steel contain enough carbon to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Drill
A seed drill is a device used in agriculture that sows seeds for crops by positioning them in the soil and burying them to a specific depth while being dragged by a tractor. This ensures that seeds will be distributed evenly. The seed drill sows the seeds at the proper seeding rate and depth, ensuring that the seeds are covered by soil. This saves them from being eaten by birds and animals, or being dried up due to exposure to the sun. With seed drill machines, seeds are distributed in rows; this allows plants to get sufficient sunlight, nutrients, and water from the soil. Before the introduction of the seed drill, most seeds were planted by hand broadcasting, an imprecise and wasteful process with a poor distribution of seeds and low productivity. Use of a seed drill can improve the ratio of crop yield (seeds harvested per seed planted) by as much as nine times. The use of seed drill saves time and labor. Some machines for metering out seeds for planting are called planters. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plowshare
In agriculture, a plowshare ( US) or ploughshare ( UK; ) is a component of a plow (or plough). It is the cutting or leading edge of a moldboard which closely follows the coulter (one or more ground-breaking spikes) when plowing. The plowshare itself is often a hardened blade dressed into an integral moldboard (by the blacksmith) so making a unified combination of plowshare and moldboard, the whole being responsible for entering the cleft in the earth (made by the coulter's first cutting-through) and turning the earth over. In well-tilled terrain the plowshare may do duty without a preceding coulter. In modern plows both coulter and plowshare are detachable for easy replacement when worn or broken. History Triangular-shaped stone ploughshares are found at the sites of Chinese Majiabang culture dated to 3500 BC around Lake Tai. Ploughshares have also been discovered at the nearby Liangzhu and Maqiao sites roughly dated to the same period. The British archaeologist David R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tillage
Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoeing, and raking. Examples of draft-animal-powered or mechanized work include ploughing (overturning with moldboards or chiseling with chisel shanks), rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks (teeth). Tillage that is deeper and more thorough is classified as primary, and tillage that is shallower and sometimes more selective of location is secondary. Primary tillage such as ploughing tends to produce a rough surface finish, whereas secondary tillage tends to produce a smoother surface finish, such as that required to make a good seedbed for many crops. Harrowing and rototilling often combine primary and secondary tillage into one operation. "Tillage" can also mean the lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bellows
A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtight cavity which can be expanded and contracted by operating the handles, and fitted with a valve allowing air to fill the cavity when expanded, and with a tube through which the air is forced out in a stream when the cavity is compressed. xford English Dictionary, 2nd ed: bellows/ref> It has many applications, in particular blowing on a fire to supply it with air. The term "bellows" is used by extension for a flexible bag whose volume can be changed by compression or expansion, but not used to deliver air. For example, the light-tight (but not airtight) bag allowing the distance between the lens and film of a folding photographic camera to be varied is called a bellows. Etymology "Bellows" is only used in plural. The Old English name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterwheel
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets arranged on the outside rim forming the driving car. Water wheels were still in commercial use well into the 20th century but they are no longer in common use. Uses included milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fibre for use in the manufacture of cloth. Some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a water wheel is called a mill race. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace. Waterwheels were used for various purposes from ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Natural gas is colorless and odorless, so odorizers such as mercaptan (which smells like sulfur or rotten eggs) are commonly added to natural gas supplies for safety so that leaks can be readily detected. Natural gas is a fossil fuel and non-renewable resource that is formed when layers of organic matter (primarily marine microorganisms) decompose under anaerobic conditions and are subjected to intense heat and pressure underground over millions of years. The energy that the decayed organisms originally obtained from the sun via photosynthesis is stored as chemical energy within the molecules of methane and other hydrocarbons. Natural gas can be burned fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipeline Transport
Pipeline transport is the long-distance transportation of a liquid or gas through a system of pipes—a pipeline—typically to a market area for consumption. The latest data from 2014 gives a total of slightly less than of pipeline in 120 countries of the world. The United States had 65%, Russia had 8%, and Canada had 3%, thus 76% of all pipeline were in these three countries. ''Pipeline and Gas Journals worldwide survey figures indicate that of pipelines are planned and under construction. Of these, represent projects in the planning and design phase; reflect pipelines in various stages of construction. Liquids and gases are transported in pipelines, and any chemically stable substance can be sent through a pipeline. Pipelines exist for the transport of crude and refined petroleum, fuels – such as oil, natural gas and biofuels – and other fluids including sewage, slurry, water, beer, hot water or steam for shorter distances. Pipelines are useful for transporting water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantities in seawater. The open ocean has about of solids per liter of sea water, a salinity of 3.5%. Salt is essential for life in general, and saltiness is one of the basic human tastes. Salt is one of the oldest and most ubiquitous food seasonings, and is known to uniformly improve the taste perception of food, including otherwise unpalatable food. Salting, brining, and pickling are also ancient and important methods of food preservation. Some of the earliest evidence of salt processing dates to around 6,000 BC, when people living in the area of present-day Romania boiled spring water to extract salts; a salt-works in China dates to approximately the same period. Salt was also prized by the ancient Hebrews, Greeks, Romans, Byzantines, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brine
Brine is a high-concentration solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of solutions used for brining foods) up to about 26% (a typical saturated solution, depending on temperature). Brine forms naturally due to evaporation of ground saline water but it is also generated in the mining of sodium chloride. Brine is used for food processing and cooking (pickling and brining), for de-icing of roads and other structures, and in a number of technological processes. It is also a by-product of many industrial processes, such as desalination, so it requires wastewater treatment for proper disposal or further utilization (fresh water recovery). In nature Brines are produced in multiple ways in nature. Modification of seawater via evaporation results in the concentration of salts in the residual fluid, a characteristic geologic deposit call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derrick
A derrick is a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its guys. Most derricks have at least two components, either a guyed mast or self-supporting tower, and a boom hinged at its base to provide articulation, as in a ''stiffleg'' derrick. The most basic type of derrick is controlled by three or four lines connected to the top of the mast, which allow it both to move laterally and cant up and down. To lift a load, a separate line runs up and over the mast with a hook on its free end, as with a crane. Forms of derricks are commonly found aboard ships and at docking facilities. Some large derricks are mounted on dedicated vessels, and known as floating derricks and sheerlegs. The term derrick is also applied to the framework supporting a drilling apparatus in an oil rig. The derrick derives its name from a type of gallows named after Thomas Derrick, an Elizabethan era English executioner. Types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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