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Defile
Defile may refer to: * To make dirty or impure * Defile (geography), in geography, a narrow pass or gorge between mountains * Defile (military), to march off in a line * The Defile, a pass between Suess Glacier and Nussbaum Riegel in Victoria Land, Antarctica * Battle of the Defile or Battle of the Pass, 731 battle between the Umayyads and Turks See also * File (other) * Contamination * Pollution {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defile (geography)
In geography, a defile is a narrow pass or gorge between mountains or hills. The term originates from a military description of a route through which troops can march only in a narrow column or with a narrow front. On emerging from a defile (or something similar) into open country, soldiers are said to "debouch". Background In a traditional military formation, soldiers march in ranks (the depth of the formation is the number of ranks) and files (the width of the formation is the number of files), so, if a column of soldiers approaches a narrow pass, the formation must narrow, and so the files on the outside must be ordered to the rear (or to some other position) so that the column has fewer files and more ranks. The French verb for this order is ''défiler'', from which the English verb comes, as does the physical description for a valley that forces this manoeuvre. Defiles of military significance can also be formed by other physical features that flank a pass or path and cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of The Defile
The Battle of the Defile or Battle of the Pass ( ar, وقعة الشعب, Waqʿat al-Shʿib) was fought in the Takhtakaracha Pass (in modern Uzbekistan) between a large army of the Umayyad Caliphate and the Turkic Türgesh khaganate over three days in July 731 CE. The Türgesh had been besieging Samarkand, and Samarkand's commander, Sawra ibn al-Hurr al-Abani, had sent a request for relief to the newly appointed governor of Khurasan, Junayd ibn Abd al-Rahman al-Murri. Junayd's 28,000-strong army was attacked by the Türgesh in the pass, and although the Umayyad army managed to extricate itself and reach Samarkand, it suffered enormous casualties; Sawra's 12,000 men, who had been commanded to attack the Türgesh from the rear in a relief effort, were almost annihilated. The battle, for which one of the most detailed accounts of the entire Umayyad era survives in the ''History'' of al-Tabari, halted or reversed Muslim expansion into Central Asia for a decade. The losses suffere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirty
Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debris: scattered pieces of waste or remains * Dust: a general powder of organic or mineral matter * Filth: foul matter such as excrement * Grime: a black, ingrained dust such as soot * Soil: the mix of clay, sand, and humus which lies on top of bedrock. The term 'soil' may be used to refer to unwanted substances or dirt that are deposited onto surfaces such as clothing. Exhibitions and studies A season of artworks and exhibits on the theme of dirt was sponsored by the Wellcome Trust in 2011. The centrepiece was an exhibition at the Wellcome Collection showing pictures and histories of notable dirt such as the great dust heaps at Euston and King's Cross in the 19th century and the Fresh Kills landfill which was once the world's largest landfill. Cleaning When things are dirty, they are usuall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impurity
In chemistry and materials science, impurities are chemical substances inside a confined amount of liquid, gas, or solid, which differ from the chemical composition of the material or compound. Firstly, a pure chemical should appear thermodynamically in at least one chemical phase and can also be characterized by its one-component-phase diagram. Secondly, practically speaking, a pure chemical should prove to be homogeneous (i.e., will show no change of properties after undergoing a wide variety of consecutive analytical chemical procedures). The perfect pure chemical will pass all attempts and tests of further separation and purification. Thirdly, and here we focus on the common chemical definition, it should not contain any trace of any other kind of chemical species. In reality, there are no absolutely 100% pure chemical compounds, as there is always some minute contamination. Indeed, as detection limits in analytical chemistry decrease, the number of impurities detected tend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defile (military)
Marching refers to the organized, uniformed, steady walking forward in either rhythmic or route-step time; and, typically, it refers to overland movements on foot of military troops and units under field orders. Marching is often performed to march music and is typically associated with military and civilian ceremonial parades. It is a major part of military basic training in most countries and usually involves a system of drill commands. Purpose It is said that many ancient empires first developed marching as a way to move troops from one place to another without them getting mixed up with other troops. A soldier learning to march to drum cadences, martial music and shouted commands is considered an essential element of teaching military discipline. In the United States Marine Corps, close order drill is used to promote exercise, obeying orders, discipline, esprit de corps, confidence, and leadership. Military paces In the military venue there are various rhythmic mili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Defile
The Defile () is a narrow ice-free passageway between the terminus of Suess Glacier and the talus-covered slope of Nussbaum Riegel in Taylor Valley, Victoria Land. It was charted and descriptively named by the British Antarctic Expedition, 1910–13, under Robert Falcon Scott Captain Robert Falcon Scott, , (6 June 1868 – c. 29 March 1912) was a British Royal Navy officer and explorer who led two expeditions to the Antarctic regions: the ''Discovery'' expedition of 1901–1904 and the ill-fated ''Terra Nov .... References Mountain passes of Victoria Land McMurdo Dry Valleys {{McMurdoDryValleys-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File (other)
File or filing may refer to: Mechanical tools and processes * File (tool), a tool used to ''remove'' fine amounts of material from a workpiece **Filing (metalworking), a material removal process in manufacturing ** Nail file, a tool used to gently abrade away and shape the edges of fingernails and toenails Documents * An arranged collection of documents *Filing (legal), submitting a document to the clerk of a court Computing * Computer file, a resource for storing information ** file URI scheme ** (command), a Unix program for determining the type of data contained in a computer file *File system, a method of storing and organizing computer files and their data *Files by Google, an Android app *Files (Apple), an Apple app Other uses * File (formation), a single column of troops one in front of the other * File (chess), a column of the chessboard * Filé powder, a culinary ingredient used in Cajun and Creole cooking * Filé (band), a Cajun musical ensemble from Louisiana, U.S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contamination
Contamination is the presence of a constituent, impurity, or some other undesirable element that spoils, corrupts, infects, makes unfit, or makes inferior a material, physical body, natural environment, workplace, etc. Types of contamination Within the sciences, the word "contamination" can take on a variety of subtle differences in meaning, whether the contaminant is a solid or a liquid, as well as the variance of environment the contaminant is found to be in. A contaminant may even be more abstract, as in the case of an unwanted energy source that may interfere with a process. The following represent examples of different types of contamination based on these and other variances. Chemical contamination In chemistry, the term "contamination" usually describes a single constituent, but in specialized fields the term can also mean chemical mixtures, even up to the level of cellular materials. All chemicals contain some level of impurity. Contamination may be recognized or not a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
