Aug 02, · The 10 most important things to be considered in design of embankment dams we have to know what the structure is facing with respect to soil and geological formation. Apr 14, · Soil organic carbon formation remains poorly understood despite its importance for human livelihoods. Uncertainties remain for the relative contributions of aboveground, root, and rhizodeposition inputs to particulate (POC) and mineral-associated (MAOC) organic carbon fractions. Combining a novel framework with isotope tracer studies, we quantified POC and MAOC formation .
Zinc is a chemical element with the symbol Zn and atomic number Zinc is a slightly brittle metal at room temperature and has a silvery-greyish appearance when oxidation is removed.
It is the first element in group 12 IIB of the periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite zinc blendea zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the oreroastingand final extraction using electricity electrowinning. Brassan alloy of copper and zinc in various proportions, was used as early as the third millennium BC in the Aegean area and the region which currently includes Iraqthe United Arab EmiratesKalmykiaTurkmenistan and Georgia.
The element was probably named by the alchemist Paracelsus after the German word Zinke prong, tooth. German chemist Andreas Sigismund Marggraf is credited with discovering what year was fran drescher born metallic zinc in Work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by Corrosion -resistant zinc plating of iron hot-dip galvanizing is the major application for zinc. Other applications are in electrical batteriessmall non-structural castings, and alloys such as brass.
A variety of zinc compounds are commonly used, such as zinc carbonate and zinc gluconate as dietary supplementszinc chloride in deodorantszinc pyrithione anti- dandruff shampooszinc sulfide in luminescent paintsand dimethylzinc or diethylzinc in the organic laboratory. Zinc is an essential mineralincluding to prenatal what are the dimensions of a full sheet cake postnatal development.
Zinc is a bluish-white, lustrous, diamagnetic metal,  though most common commercial grades of the metal have a dull finish. Many alloys contain zinc, including brass. Other metals long known to form binary how much cost to start a dump truck business with zinc are aluminiumantimonybismuthgoldironleadmercurysilvertinmagnesiumcobaltnickeltelluriumand sodium.
Zinc makes up about 75 ppm 0. Soil contains zinc in 5— ppm with an average 64 ppm. Seawater has only 30 ppb and the atmosphere, 0. Sulfides formed as the crust solidified under the reducing conditions of the early Earth's atmosphere. Other source minerals for zinc include smithsonite zinc carbonatehemimorphite zinc silicatewurtzite another zinc sulfideand sometimes hydrozincite basic zinc carbonate. Identified world zinc resources total about 1.
Since exploration and mine development is an ongoing process, the amount of zinc reserves is not a fixed number and sustainability of zinc ore supplies cannot be judged by simply extrapolating the combined mine life of today's zinc mines. About million tonnes have been extracted throughout history toand scholars have estimated that about — million tonnes are in use. Five stable isotopes of zinc occur in nature, with 64 Zn being the most abundant isotope Several dozen radioisotopes have been characterized.
The nucleus of a metastable isotope is in an excited state and will return to the ground state by emitting a photon in the form of a gamma ray. The most common decay mode of a radioisotope of zinc with a mass number lower than 66 is electron capture. The decay product resulting from electron capture is an isotope of copper. Zinc has an electron configuration of [Ar]3d 10 4s 2 and is a member of the group 12 of the periodic table.
It is a moderately reactive metal and strong reducing agent. Zinc burns in air with a bright bluish-green flame, giving off fumes of zinc oxide. When compounds in this oxidation state are formed, the outer shell s electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d Zinc chemistry is similar to the chemistry of the late first-row transition metals, nickel and copper, though it has a filled d-shell and compounds are diamagnetic and mostly colorless.
Because of this some of the equivalent salts have the same crystal structure and in other circumstances where ionic radius is a determining factor, the chemistry of zinc has much in common with that of magnesium. Zinc tends to form bonds with a greater degree of covalency and much more stable complexes with N - and S - donors. Zinc I compounds are rare and need bulky ligands to stabilize the low oxidation state.
The diamagnetic nature of the ion confirms its dimeric structure. Binary compounds of zinc are known for most of the metalloids and all the nonmetals except the noble gases.
The oxide ZnO is a white powder that is nearly insoluble in neutral aqueous solutions, but is amphotericdissolving in both strong basic and acidic solutions. Organozinc compounds are those that contain zinc—carbon covalent bonds. Diethylzinc C 2 H 5 2 Zn is a reagent in synthetic chemistry. It was first reported in from the reaction of zinc and ethyl iodideand was the first compound known to contain a metal—carbon sigma bond. Cobalticyanide paper Rinnmann's test for Zn can be used as a chemical indicator for zinc.
One drop of the sample is dropped onto the dry paper and heated. A green disc indicates the presence of zinc. Various isolated examples of the use of impure zinc in ancient times have been discovered. Zinc ores were used to make the zinc—copper alloy brass thousands of years prior to the discovery of zinc as a separate element. Knowledge of how to produce brass spread to Ancient Greece by the 7th century BC, but few varieties were made. The oldest known pills were made of the zinc carbonates hydrozincite and smithsonite.
The pills were used for sore eyes and were found aboard the Roman ship Relitto del Pozzinowrecked in BC. The manufacture of brass was known to the Romans by about 30 BC. Strabo writing in the 1st century BC but quoting a now lost work of the how to write snort rules century BC historian Theopompus mentions "drops of false silver" which when mixed with copper make brass. This may refer to small quantities of zinc that is a by-product of smelting sulfide ores.
The Berne zinc tablet is a votive plaque dating to Roman Gaul made of an alloy that is mostly zinc. The Charaka Samhitathought to have been written between and AD,  mentions a metal which, when oxidized, produces pushpanjanthought to be zinc oxide. The smelting of metallic zinc here, however, appears to have begun around the 12th century AD. Zinc was distinctly recognized as a metal under the designation of Yasada or How to play a hohner harmonica in what does a b rating mean medical Lexicon ascribed to the Hindu king Madanapala of Taka dynasty and written about the year Alchemists burned zinc metal in air and collected the resulting zinc oxide on a condenser.
Some alchemists called this zinc oxide lana philosophicaLatin for "philosopher's wool", because it collected in wooly tufts, whereas others thought it looked like white snow and named it nix album.
The name of the metal was probably first documented by Paracelsusa Swiss-born German alchemist, who referred to the metal as "zincum" or "zinken" in his book Liber Mineralium IIin the 16th century.
German metallurgist Andreas Libavius received a quantity of what he called "calay" of Malabar from a cargo ship captured from the Portuguese in Zinc was regularly imported to Europe from the Orient in the 17th and early 18th centuries,  but was at times very expensive.
Metallic zinc was isolated in India by AD,    much earlier than in the West. Before it was isolated in Europe, it was imported from India in about CE. Flemish how to pick a race horse and alchemist P.
In in Great Britain, William Champion patented a process to extract zinc from calamine in a vertical retort -style smelter. German chemist Andreas Marggraf normally gets credit what is a front office manager discovering pure metallic zinc, even though Swedish chemist Anton von Swab had distilled zinc from calamine four years previously.
William Champion's brother, John, patented a process in for calcining zinc sulfide into an oxide usable in the retort process. InJohann Christian Ruberg improved on the smelting process by building the first horizontal retort smelter. Galvani's friend, Alessandro Voltacontinued researching the effect and invented the Voltaic pile in By stacking these units in series, the Voltaic pile or "battery" as a whole had a higher voltage, which could be used more easily than single cells.
Electricity is produced because the Volta potential between the two metal how to make up eyes smokey makes electrons flow from the zinc to the copper and corrode the zinc. The non-magnetic character of zinc and its lack of color in solution delayed discovery of its importance to biochemistry and nutrition.
Zinc is the fourth most common metal in use, trailing only ironaluminiumand copper with an annual production of about 13 million tonnes. Zinc metal is produced using extractive metallurgy. Roasting converts the zinc sulfide concentrate to zinc oxide: . The sulfur dioxide is used for the production of sulfuric acid, which is necessary for the leaching process. If deposits of zinc carbonate, zinc silicate, or zinc spinel like the Skorpion Deposit in Namibia are used for zinc production, the roasting can be omitted.
For further processing two basic methods are used: pyrometallurgy or electrowinning. In electrowinningzinc is leached from the ore concentrate by sulfuric acid : .
Finally, the zinc is reduced by electrolysis. Refinement of sulfidic zinc ores produces large volumes of sulfur dioxide and cadmium vapor.
Smelter slag and other residues contain significant quantities of metals. About 1. After increasing fold fromzinc emissions peaked at 3. Man-made and natural emissions occur at a ratio of 20 to 1. Zinc in rivers flowing through industrial and mining areas can be as high as 20 ppm.
Soils contaminated with zinc from mining, refining, or fertilizing with zinc-bearing sludge can contain several grams of zinc per kilogram of dry soil. Levels of zinc in excess of ppm in soil interfere with the ability of plants to absorb other essential metalssuch as iron and manganese. Major applications of zinc include numbers are given for the US . Zinc is most commonly used as an anti- corrosion agent,  and galvanization coating of iron or steel is the most familiar form. Zinc is more reactive than iron or steel and thus will attract almost all local oxidation until it completely corrodes away.
Galvanization is what is required to play elder scrolls online on chain-link fencing, guard rails, suspension bridges, lightposts, metal roofs, heat exchangers, and car bodies.
The relative reactivity of zinc and its ability to attract oxidation to itself makes it an efficient sacrificial anode in cathodic protection CP. For example, cathodic protection of a buried pipeline can be achieved by connecting anodes made from what is considered the most important factor in soil formation to the pipe.
Powdered zinc is used in this way in alkaline batteries and the case which also serves as the anode of zinc—carbon batteries is formed from sheet zinc.
Soil and soil formation can be considered from many standpoints, including from the study of soil science as a field in its own right. However, soil is most important in ecological function as the basis for the growth of terrestrial plants, including supplying nutrients, water, temperature moderation, and support. In most cases, soils with a slow, very slow, rapid or very rapid permeability classification are considered poor for irrigation. Infiltration is the downward flow of water from the surface through the soil. The infiltration rate (sometimes called intake rate) of a soil is a measure of its ability to absorb an amount of rain or irrigation water. Coffee is a brewed drink prepared from roasted coffee beans, the seeds of berries from certain Coffea species. When coffee berries turn from green to bright red in color – indicating ripeness – they are picked, processed, and dried. Dried coffee seeds (referred to as "beans") are roasted to varying degrees, depending on the desired flavor. Roasted beans are ground and then brewed with near.
Coffee is a brewed drink prepared from roasted coffee beans , the seeds of berries from certain Coffea species. When coffee berries turn from green to bright red in color — indicating ripeness — they are picked, processed, and dried. Roasted beans are ground and then brewed with near-boiling water to produce the beverage known as coffee. Coffee is darkly colored, bitter, slightly acidic and has a stimulating effect in humans, primarily due to its caffeine content.
It is usually served hot, although chilled or iced coffee is common. Sugar , sugar substitutes , milk or cream are often used to lessen the bitter taste. Clinical research indicates that moderate coffee consumption is benign or mildly beneficial as a stimulant in healthy adults, with continuing research on whether long-term consumption reduces the risk of some diseases, although some of the long-term studies are of questionable credibility.
The earliest credible evidence of coffee-drinking as the modern beverage appears in modern-day Yemen in southern Arabia in the middle of the 15th century in Sufi shrines where coffee seeds were first roasted and brewed in a manner similar to how it is now prepared for drinking. By the 16th century , the drink had reached the rest of the Middle East and North Africa , later spreading to Europe. The two most commonly grown coffee bean types are C.
Coffee plants are now cultivated in over 70 countries , primarily in the equatorial regions of the Americas, Southeast Asia , the Indian subcontinent, and Africa. Green, unroasted coffee is one of the most traded agricultural commodities in the world. Consequently, the markets for fair trade and organic coffee are expanding. The term coffee pot dates from According to one legend, ancestors of today's Oromo people in a region of Kaffa in Ethiopia were the first to recognize the energizing effect of the coffee plant.
Another legend attributes the discovery of coffee to a Sheikh Omar. According to an old chronicle preserved in the Abd-Al-Kadir manuscript , Omar, who was known for his ability to cure the sick through prayer, was once exiled from Mocha in Yemen to a desert cave near Ousab modern-day Wusab, about 90 kilometres 56 mi east of Zabid.
He tried roasting the seeds to improve the flavor, but they became hard. He then tried boiling them to soften the seed, which resulted in a fragrant brown liquid. Upon drinking the liquid Omar was revitalized and sustained for days.
As stories of this "miracle drug" reached Mocha, Omar was asked to return and was made a saint. The earliest credible evidence of coffee-drinking or knowledge of the coffee tree appears in the middle of the 15th century in the accounts of Ahmed al-Ghaffar in Yemen. Coffee was used by Sufi circles to stay awake for their religious rituals. From Ethiopia, coffee could have been introduced to Yemen via trade across the Red Sea.
Famous 16th-century Islamic scholar Ibn Hajar al-Haytami notes in his writings of a beverage called qahwa developed from a tree in the Zeila region. According to Captain Haines, who was the colonial administrator of Aden — , Mocha historically imported up to two-thirds of their coffee from Berbera-based merchants before the coffee trade of Mocha was captured by British-controlled Aden in the 19th century.
Thereafter, much of the Ethiopian coffee was exported to Aden via Berbera. Berbera not only supplies Aden with horned cattle and sheep to a very large extent, but the trade between Africa and Aden is steadily increasing greatly every year. In the article of coffee alone there is considerable export, and ' Berbera' coffee stands in the Bombay market now before Mocha. The coffee shipped at Berbera comes from far in the interior from Hurrar, Abyssinia, and Kaffa.
It will be to the advantage of all that the trade should come to Aden through one port, and Berbera is the only place on the coast there that has a protected port, where vessels can lie in smooth water. By the 16th century, coffee had reached the rest of the Middle East, Persia , Turkey , and northern Africa.
Before then, all exported coffee was boiled or otherwise sterilised. Portraits of Baba Budan depict him as having smuggled seven coffee seeds by strapping them to his chest. The first plants grown from these smuggled seeds were planted in Mysore. Coffee had spread to Italy by , and then to the rest of Europe, Indonesia , and the Americas. In , Leonhard Rauwolf , a German physician, gave this description of coffee after returning from a ten-year trip to the Near East :.
A beverage as black as ink, useful against numerous illnesses , particularly those of the stomach. Its consumers take it in the morning, quite frankly, in a porcelain cup that is passed around and from which each one drinks a cupful. It is composed of water and the fruit from a bush called bunnu. From Venice, it was introduced to the rest of Europe.
The first European coffee house opened in Rome in The Dutch East India Company was the first to import coffee on a large scale. John Evelyn recorded tasting the drink at Oxford in England in a diary entry of May to where it had been brought by a student of Balliol College from Crete named Nathaniel Conopios of Crete.
Coffee was introduced in France in , and in Austria and Poland after the Battle of Vienna , when coffee was captured from supplies of the defeated Turks. When coffee reached North America during the Colonial period, it was initially not as successful as it had been in Europe as alcoholic beverages remained more popular. During the Revolutionary War , the demand for coffee increased so much that dealers had to hoard their scarce supplies and raise prices dramatically; this was also due to the reduced availability of tea from British merchants,  and a general resolution among many Americans to avoid drinking tea following the Boston Tea Party.
During the 18th century, coffee consumption declined in England, giving way to tea-drinking. The latter beverage was simpler to make, and had become cheaper with the British conquest of India and the tea industry there. The Frenchman Gabriel de Clieu took a coffee plant to the French territory of Martinique in the Caribbean in the s,  from which much of the world's cultivated arabica coffee is descended.
Coffee thrived in the climate and was conveyed across the Americas. The coffee industry never fully recovered there. Meanwhile, coffee had been introduced to Brazil in , although its cultivation did not gather momentum until independence in Cultivation was taken up by many countries in Central America in the latter half of the 19th century, and almost all involved the large-scale displacement and exploitation of the indigenous people.
Harsh conditions led to many uprisings, coups and bloody suppression of peasants. Smaller farms and more egalitarian conditions ameliorated unrest over the 19th and 20th centuries. Rapid growth in coffee production in South America during the second half of the 19th century was matched by growth in consumption in developed countries, though nowhere has this growth been as pronounced as in the United States, where a high rate of population growth was compounded by doubling of per capita consumption between and Though the United States was not the heaviest coffee-drinking nation at the time Nordic countries , Belgium, and Netherlands all had comparable or higher levels of per capita consumption , due to its sheer size, it was already the largest consumer of coffee in the world by , and, by , around half of all coffee produced worldwide was consumed in the US.
Coffee has become a vital cash crop for many developing countries. Over one hundred million people in developing countries have become dependent on coffee as their primary source of income. It has become the primary export and backbone for African countries like Uganda, Burundi, Rwanda, and Ethiopia,  as well as many Central American countries. Several species of shrub of the genus Coffea produce the berries from which coffee is extracted.
The two main species commercially cultivated are Coffea canephora predominantly a form known as 'robusta' and C. All coffee plants are classified in the large family Rubiaceae. They are evergreen shrubs or trees that may grow 5 m 15 ft tall when unpruned. The leaves are dark green and glossy, usually 10—15 cm 4—6 in long and 6 cm 2.
Petioles of opposite leaves fuse at the base to form interpetiolar stipules , characteristic of Rubiaceae. The flowers are axillary , and clusters of fragrant white flowers bloom simultaneously.
Gynoecium consists of an inferior ovary, also characteristic of Rubiaceae. The flowers are followed by oval berries of about 1. Coffea arabica is predominantly self-pollinating, and as a result, the seedlings are generally uniform and vary little from their parents. In contrast, Coffea canephora , and C.
This means that useful forms and hybrids must be propagated vegetatively. Named Strychnos electri , after the Greek word for amber electron , the flowers represent the first-ever fossils of an asterid , which is a clade of flowering plants that not only later gave us coffee, but also sunflowers, peppers, potatoes, mint — and deadly poisons. The traditional method of planting coffee is to place 20 seeds in each hole at the beginning of the rainy season. A more effective process of growing coffee, used in Brazil, is to raise seedlings in nurseries that are then planted outside at six to twelve months.
Coffee is often intercropped with food crops, such as corn , beans , or rice during the first few years of cultivation as farmers become familiar with its requirements. Of the two main species grown, arabica coffee from C. Robusta coffee tends to be bitter and have less flavor but better body than arabica. For these reasons, about three-quarters of coffee cultivated worldwide is C.
Good quality robusta beans are used in traditional Italian espresso blends to provide a full-bodied taste and a better foam head known as crema. Additionally, Coffea canephora is less susceptible to disease than C. From Java, further breeding resulted in the establishment of robusta plantations in many countries. Hemileia vastatrix is a fungal pathogen  and results in light, rust-colored spots on the undersides of coffee plant leaves.
Hemileia vastatrix grows exclusively on the leaves of coffee pants. Mycena citricolor is another threat to coffee plants, primarily in Latin America. Mycena citricolor, commonly referred to as American Leaf Spot, is a fungus that can affect the whole coffee plant. Over species of insect have been recorded as pests of coffee crops worldwide.
Of these, over a third are beetles , and over a quarter are bugs. Some 20 species of nematodes , 9 species of mites, and several snails and slugs also attack the crop. Birds and rodents sometimes eat coffee berries, but their impact is minor compared to invertebrates.
Each part of the coffee plant is assailed by different animals. Nematodes attack the roots, coffee borer beetles burrow into stems and woody material,  and the foliage is attacked by over species of larvae caterpillars of butterflies and moths.
Mass spraying of insecticides has often proven disastrous, as predators of the pests are more sensitive than the pests themselves. Branches infested with scale are often cut and left on the ground, which promotes scale parasites to not only attack the scale on the fallen branches but in the plant as well. The 2-mm-long coffee borer beetle Hypothenemus hampei is the most damaging insect pest to the world's coffee industry, destroying up to 50 percent or more of the coffee berries on plantations in most coffee-producing countries.
The adult female beetle nibbles a single tiny hole in a coffee berry and lays 35 to 50 eggs. Inside, the offspring grow, mate, and then emerge from the commercially ruined berry to disperse, repeating the cycle. Pesticides are mostly ineffective because the beetle juveniles are protected inside the berry nurseries, but they are vulnerable to predation by birds when they emerge.