Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as an element in nature, it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels, by the mid-18th century, Swedish chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite contained a new element, johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon. Manganese phosphating is used for rust and corrosion prevention on steel, ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers, Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries. In biology, manganese ions function as cofactors for a variety of enzymes with many functions.
Manganese enzymes are essential in detoxification of superoxide free radicals in organisms that must deal with elemental oxygen. Manganese functions in the complex of photosynthetic plants. The element is a trace mineral for all known living organisms but is a neurotoxin. In larger amounts, and apparently with far greater effectiveness through inhalation, Manganese is a silvery-gray metal that resembles iron. It is hard and very brittle, difficult to fuse, Manganese metal and its common ions are paramagnetic. Manganese tarnishes slowly in air and oxidizes like iron in water containing dissolved oxygen, naturally occurring manganese is composed of one stable isotope, 55Mn. Eighteen radioisotopes have been isolated and described, the most stable being 53Mn with a half-life of 3.7 million years, 54Mn with a half-life of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the radioactive isotopes have half-lives of less than three hours, and the majority of less than one minute. Manganese has three meta states, Manganese is part of the iron group of elements, which are thought to be synthesized in large stars shortly before the supernova explosion.
53Mn decays to 53Cr with a half-life of 3.7 million years, because of its relatively short half-life, 53Mn is relatively rare, produced by cosmic rays impact on iron. Manganese isotopic contents are combined with chromium isotopic contents and have found application in isotope geology
The Areni-1 cave complex is located near the Areni village in southern Armenia along the Arpa River. In 2010, it was announced that the earliest known shoe was found at the site, in January 2011, the earliest known winery in the world was announced to have been found. Also in 2011, the discovery of a straw skirt dating to 3900 BC was reported, in 2009, the oldest brain was discovered
A canyon or gorge is a deep cleft between escarpments or cliffs resulting from the erosive activity of a river over geologic timescales. A canyon may refer to a rift between two peaks, such as those in ranges including the Rocky Mountains, the Alps. Usually a river or stream and erosion carve out such splits between mountains, examples of mountain-type canyons are Provo Canyon in Utah or Yosemite National Park in Californias Sierra Nevada. Canyons within mountains, or gorges that have an opening on one side are called box canyons. Slot canyons are very narrow canyons, often with smooth walls, steep-sided valleys in the seabed of the continental slope underwater are referred to as submarine canyons. Unlike canyons on land, submarine canyons are thought to be formed by turbidity currents, the word canyon is Spanish in origin, with the same meaning. The word canyon is used in North America while the words gorge and ravine are used in Europe and Oceania, though gorge. In the United States, place names generally use canyon in the southwest and gorge in the northeast, in Canada, a gorge is usually narrow while a ravine is more open and often wooded.
The military-derived word defile is occasionally used in the United Kingdom, most canyons were formed by a process of long-time erosion from a plateau or table-land level. The cliffs form because harder rock strata that are resistant to erosion, Canyons are much more common in arid than in wet areas because physical weathering has a more localized effect in arid zones. The wind and water from the combine to erode and cut away less resistant materials such as shales. The freezing and expansion of water serves to help form canyons, water seeps into cracks between the rocks and freezes, pushing the rocks apart and eventually causing large chunks to break off the canyon walls, in a process known as frost wedging. Canyon walls are formed of resistant sandstones or granite. Sometimes large rivers run through canyons as the result of geological uplift. These are called entrenched rivers, because they are unable to alter their course. In the United States, the Colorado River in the Southwest, Canyons often form in areas of limestone rock.
As limestone is soluble to an extent, cave systems form in the rock. When these collapse, a canyon is left, as in the Mendip Hills in Somerset and Yorkshire Dales in Yorkshire, England
Bow and arrow
The bow and arrow is a projectile weapon system that predates recorded history and is common to most cultures. Archery is the art, practice, or skill of applying it, a bow is a flexible arc that shoots aerodynamic projectiles called arrows. A string joins the two ends of the bow and when the string is drawn back, the ends of the bow are flexed, when the string is released, the potential energy of the flexed stick is transformed into the kinetic energy of the arrow. Archery is the art or sport of shooting arrows from bows, today and arrows are used primarily for hunting and for the sport of archery. Someone who makes bows is known as a bowyer, and one who makes arrows is a fletcher —or in the case of the manufacture of arrow heads. The bow and arrow appears around the transition from the Upper Paleolithic to the Mesolithic, at the site of Nataruk in Turkana County, obsidian bladelets found embedded in a skull and within the thoracic cavity of another skeleton, suggest the use of stone-tipped arrows as weapons.
After the end of the last glacial period, use of the bow seems to have spread to every inhabited continent, including the New World, the oldest extant bows in one piece are the elm Holmegaard bows from Denmark which were dated to 9,000 BCE. High-performance wooden bows are made following the Holmegaard design. Microliths discovered on the south coast of Africa suggest that arrows may be at least 71,000 years old, the bow was an important weapon for both hunting and warfare from prehistoric times until the widespread use of gunpowder in the 16th century. Organised warfare with bows ended in the mid 17th century in Europe, the British upper class led a revival of archery from the late 18th century. Sir Ashton Lever, an antiquarian and collector, formed the Toxophilite Society in London in 1781, under the patronage of George, the basic elements of a bow are a pair of curved elastic limbs, traditionally made from wood, joined by a riser. Both ends of the limbs are connected by a known as the bow string.
By pulling the string backwards the archer exerts compressive force on the section, or belly, of the limbs as well as placing the outer section, or back. While the string is held, this stores the energy released in putting the arrow to flight. The force required to hold the string stationary at full draw is used to express the power of a bow. Other things being equal, a draw weight means a more powerful bow. The various parts of the bow can be subdivided into further sections, the topmost limb is known as the upper limb, while the bottom limb is the lower limb. At the tip of each limb is a nock, which is used to attach the bowstring to the limbs, the riser is usually divided into the grip, which is held by the archer, as well as the arrow rest and the bow window
Belgium, officially the Kingdom of Belgium, is a sovereign state in Western Europe bordered by France, the Netherlands, Germany and the North Sea. It is a small, densely populated country which covers an area of 30,528 square kilometres and has a population of about 11 million people. Additionally, there is a group of German-speakers who live in the East Cantons located around the High Fens area. Historically, the Netherlands and Luxembourg were known as the Low Countries, the region was called Belgica in Latin, after the Roman province of Gallia Belgica. From the end of the Middle Ages until the 17th century, Belgium is a federal constitutional monarchy with a parliamentary system of governance. It is divided into three regions and three communities, that exist next to each other and its two largest regions are the Dutch-speaking region of Flanders in the north and the French-speaking southern region of Wallonia. The Brussels-Capital Region is a bilingual enclave within the Flemish Region. A German-speaking Community exists in eastern Wallonia, Belgiums linguistic diversity and related political conflicts are reflected in its political history and complex system of governance, made up of six different governments.
Upon its independence, declared in 1830, Belgium participated in the Industrial Revolution and, during the course of the 20th century, possessed a number of colonies in Africa. This continuing antagonism has led to several far-reaching reforms, resulting in a transition from a unitary to a federal arrangement during the period from 1970 to 1993. Belgium is a member of the Eurozone, NATO, OECD and WTO. Its capital, hosts several of the EUs official seats as well as the headquarters of major international organizations such as NATO. Belgium is a part of the Schengen Area, Belgium is a developed country, with an advanced high-income economy and is categorized as very high in the Human Development Index. A gradual immigration by Germanic Frankish tribes during the 5th century brought the area under the rule of the Merovingian kings, a gradual shift of power during the 8th century led the kingdom of the Franks to evolve into the Carolingian Empire. Many of these fiefdoms were united in the Burgundian Netherlands of the 14th and 15th centuries, the Eighty Years War divided the Low Countries into the northern United Provinces and the Southern Netherlands.
The latter were ruled successively by the Spanish and the Austrian Habsburgs and this was the theatre of most Franco-Spanish and Franco-Austrian wars during the 17th and 18th centuries. The reunification of the Low Countries as the United Kingdom of the Netherlands occurred at the dissolution of the First French Empire in 1815, although the franchise was initially restricted, universal suffrage for men was introduced after the general strike of 1893 and for women in 1949. The main political parties of the 19th century were the Catholic Party, French was originally the single official language adopted by the nobility and the bourgeoisie
Khorixas is a town of 6,000 inhabitants in southern Kunene Region, Namibia. It was previously the capital of the Damaraland bantustan prior to Namibias independence and it is located in Khorixas Constituency. Most of the inhabitants are from the Damara ethnic group, the town is located near to an important deposit of petrified wood and the Twyfelfontein valley, known for its rock art. The regional hospital and some regional offices are still located in Khorixas. There are six schools and one branch of University of Namibia in Khorixas, Versteende Wood as the biggest primary school, the unemployment rate in town is estimated to be around 70%. Donkerhoek, the informal settlement, has neither water nor electricity. Khorixas is governed by a council that currently has seven seats. In May 2005, UDF removed Marta Claasen as mayor following internal council elections in which she collaborated with SWAPO councillors in order for her to obtain the position of mayor and she was expelled from the party and replaced on the council by Efraim Gariseb. UDF had four seats on the council and SWAPO had three.
Immanuel ǁGaroeb, of UDF, became acting mayor, Claasen claimed that she was replaced because of her stance on corruption and mismanagement. In the 2010 local authority election, a total of 2,788 votes were cast in the town, UDF won with approximately 58% of the vote. Of the two other parties seeking votes in the election, SWAPO received approximately 39% of the vote, Khorixas has a semi-arid climate, with warm to hot summers and mild winters. It borders on a desert climate, the average annual precipitation is 233 mm. The Robber Chanties, which in August 2010 played in the Northern Stream Division One and sought promotion the Namibia Premier League, are based in Khorixas
A chalice is a goblet or footed cup intended to hold a drink. In general religious terms, it is intended for drinking during a ceremony, chalices are often made of precious metal, and they are sometimes richly enamelled and jewelled. The gold goblet was symbolic for family and tradition, the ancient Roman calix was a drinking vessel consisting of a bowl fixed atop a stand, and was in common use at banquets. Chalices have been used since the early church, because of Jesus command to his disciples to Do this in remembrance of me. And Pauls account of the Eucharistic rite in 1 Corinthians 11, 24-25, the vessels used in this important act of worship were highly decorated and treated with great respect. A number of examples of chalices have a large bowl. Over time, the size of the bowl diminished and the base became larger for better stability, over time, official church regulations dictated the construction and treatment of chalices. Some religious traditions still require that the chalice, at least on the inside of the cup, in Western Christianity, chalices will often have a pommel or node where the stem meets the cup to make the elevation easier.
In Roman Catholicism, chalices tend to be tulip-shaped, and the cups are quite narrow, Roman Catholic priests will often receive chalices from members of their families when first ordained. In Eastern Christianity, chalices will often have icons enameled or engraved on them, in Orthodoxy and Eastern Catholicism, all communicants receive both the Body of Christ and the Blood of Christ. To accomplish this, a portion of the Lamb is placed in the chalice, for this reason, eastern chalices tend to have larger, rounded cups. In the Russian Orthodox Church, the faithful will kiss the foot of the chalice after receiving Holy Communion. In other traditions, they kiss the cup. Although Orthodox monks are not permitted to hold personal possessions, the permit a hieromonk to keep a chalice. In the early and medieval church, when a deacon was ordained, early written accounts of the ordination of deaconesses reflect this practice. In the West the deacon carries the chalice to the altar at the offertory, in the East, the priest carries the chalice and the deacon carries the paten.
Only wine, water and a portion of the Host are permitted to be placed in the chalice, the chalice is considered to be one of the most sacred vessels in Christian liturgical worship, and it is often blessed before use. Among the Eastern Churches there are varying practices regarding blessing, in some traditions the very act of celebrating the Sacred Mysteries is the only blessing necessary, in others, there is a special rite of blessing
Cave paintings are painted drawings on cave walls or ceilings, mainly of prehistoric origin, to some 40,000 years ago in Eurasia. The exact purpose of the Paleolithic cave paintings is not known, evidence suggests that they were not merely decorations of living areas since the caves in which they have been found do not have signs of ongoing habitation. They are located in areas of caves that are not easily accessible. Some theories hold that cave paintings may have been a way of communicating with others, the paintings are remarkably similar around the world, with animals being common subjects that give the most impressive images. Humans mainly appear as images of hands, mostly hand stencils made by blowing pigment on a hand held to the wall. The earliest known cave paintings/drawings of animals are at least 35,000 years old and are found in Pettakere cave on the island of Sulawesi in Indonesia, previously it was believed that the earliest paintings were in Europe. The earliest non-figurative rock art dates back to approximately 40,000 years ago, nearly 340 caves have now been discovered in France and Spain that contain art from prehistoric times.
But subsequent technology has made it possible to date the paintings by sampling the pigment itself, the choice of subject matter can indicate chronology. For instance, the reindeer depicted in the Spanish cave of Cueva de las Monedas places the drawings in the last Ice Age. The oldest date given to a cave painting is now a pig that has a minimum age of 35,400 years old at Pettakere cave in Sulawesi. Indonesian and Australian scientists have dated other non-figurative paintings on the walls to be approximately 40,000 years old, the method they used to confirm this was dating the age of the stalactites that formed over the top of the paintings. The art is similar in style and method to that of the Indonesian caves as there were hand stencils and this date coincides with the earliest known evidence for Homo sapiens in Europe. Because of the cave arts age, some scientists have conjectured that the paintings may have made by Neanderthals. The earliest known European figurative cave paintings are those of Chauvet Cave in France and these paintings date to earlier than 30,000 BCE according to radiocarbon dating.
Some researchers believe the drawings are too advanced for this era, the radiocarbon dates from these samples show that there were two periods of creation in Chauvet,35,000 years ago and 30,000 years ago. In 2009, cavers discovered drawings in Coliboaia Cave in Romania, an initial dating puts the age of an image in the same range as Chauvet, about 32,000 years old. Some caves probably continued to be painted over a period of thousands of years. This was created roughly between 10,000 and 5,500 years ago, and painted in rock shelters under cliffs or shallow caves, though individual figures are less naturalistic, they are grouped in coherent grouped compositions to a much greater degree
The enterprising, sea-based Phoenician civilization spread across the Mediterranean between 1500 BC and 300 BC. Their civilization was organized in city-states, similar to those of Ancient Greece, perhaps the most notable of which were Tyre, Arvad and Carthage. Each city-state was an independent unit, and it is uncertain to what extent the Phoenicians viewed themselves as a single nationality. In terms of archaeology, language and religion there was little to set the Phoenicians apart as markedly different from other Semitic Canaanites. The Phoenicians were the first state-level society to make use of alphabets. By their maritime trade, the Phoenicians spread the use of the alphabet to Anatolia, North Africa, and Europe, where it was adopted by the Greeks, the name Phoenicians, like Latin Poenī, comes from Greek Φοίνικες. The word φοῖνιξ phoînix meant variably Phoenician person, Tyrian purple, the word may be derived from φοινός phoinós blood red, itself possibly related to φόνος phónos murder.
Beekes has suggested a Pre-Greek origin of the ethnonym, the oldest attested form of the word in Greek may be the Mycenaean po-ni-ki-jo, po-ni-ki, possibly borrowed from Ancient Egyptian fnḫw Asiatics, although this derivation is disputed. The folk-etymological association of Φοινίκη with φοῖνιξ mirrors that in Akkadian which tied kinaḫni, the land was natively known as knʿn and its people as the knʿny. In the Amarna tablets of the 14th century BC, people from the region called themselves Kenaani or Kinaani, the ethnonym survived in North Africa until the 4th century AD. Herodotus account refers to the myths of Io and Europa, according to the Persians best informed in history, the Phoenicians began the quarrel. The Greek historian Strabo believed that the Phoenicians originated from Bahrain, Herodotus believed that the homeland of the Phoenicians was Bahrain. The people of Tyre in South Lebanon in particular have long maintained Persian Gulf origins, there is little evidence of occupation at all in Bahrain during the time when such migration had supposedly taken place.
Canaanite culture apparently developed in situ from the earlier Ghassulian chalcolithic culture, Byblos is attested as an archaeological site from the Early Bronze Age. The Late Bronze Age state of Ugarit is considered quintessentially Canaanite archaeologically, fernand Braudel remarked in The Perspective of the World that Phoenicia was an early example of a world-economy surrounded by empires. The high point of Phoenician culture and sea power is usually placed c, archaeological evidence consistent with this understanding has been difficult to identify. A unique concentration in Phoenicia of silver hoards dated between 1200 and 800 BC, contains hacksilver with lead isotope ratios matching ores in Sardinia and Spain. This metallic evidence agrees with the memory of a western Mediterranean Tarshish that supplied Solomon with silver via Phoenicia
Henties Bay is a coastal city in the Erongo Region of western Namibia. It is located 70 km north of Swakopmund and is an important holiday settlement,70 kilometres to the north of the town is the seal colony of Cape Cross. The town has about 8,000 inhabitants and owns 121 square kilometres of land, the mayor of Henties Bay is Aila Haufiku. Bartolomeu Dias sailed along the Atlantic coast in 1488, near the area of todays Henties Bay he discovered such an abundance of fish that he named this coastline Praia das Sardinhas, Coast of Fish. The fresh water source was first discovered by Schutztruppe soldiers in 1886, in 1920, a minerals prospector stayed overnight. After tasting the water he was said to be healed from an affliction, the namesake of the town is major Hendrik Henty Stefanus van der Merwe who discovered the place in 1929 while looking for water. He had been hunting a rhinoceros in the hinterland of the Namibian coast near the Brandberg in order to collect a reward from a museum in Pennsylvania that was in search of a rhino skeleton.
After shooting the rhino and scraping meat from the bones, water resources of the expedition diminished and forced the party to load the decomposing carcass and they chose to head into the direction of the Atlantic coast and reached it close to Cape Cross. From there van der Merwe and his fellows searched southwards for the mouth of Omaruru River, a few miles south of the mouth they discovered a deep sand valley with reed grass growing in it, advertising the presence of fresh water. Van der Merwe liked the place and after delivering the bones and collecting his reward, the place became known as Henty se baai and developed into a holiday hideout, mainly because of the abundance of fish at this spot. In 1951 the South–West Africa Administration mandated to South Africa, proclaimed erven in the Omaruru riverbed that were available for rent, the first shop was established during that time. A lighthouse was erected to guide ships along the dangerous Namibian coast, in the 1960s mining holes were dug after diamonds had been found in the area on a few occasions. A few years mining was abandoned due to lack of success.
In 1966 it was decided that the riverbed must not be settled in, a hotel was built one year later, and the town began to develop. The town is predominantly a tourist destination for anglers and 4x4 enthusiasts and its property market has expanded significantly since the late 1990s, particularly for upmarket holiday accommodation. Henties Bay is situated in the National West Coast Recreation Area but there are few restrictions, particularly for driving off-road on the beach and this lures tourists into the area but puts a burden on the sensitive environment. Specifically in danger are the fields which take decades to recover from tracks cut through them. Henties Bay is governed by a council that currently has seven seats
A mountain is a large landform that stretches above the surrounding land in a limited area, usually in the form of a peak. A mountain is steeper than a hill. Mountains are formed through tectonic forces or volcanism and these forces can locally raise the surface of the earth. Mountains erode slowly through the action of rivers, weather conditions, a few mountains are isolated summits, but most occur in huge mountain ranges. High elevations on mountains produce colder climates than at sea level and these colder climates strongly affect the ecosystems of mountains, different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains tend to be used less for agriculture and more for resource extraction and recreation, the highest mountain on Earth is Mount Everest in the Himalayas of Asia, whose summit is 8,850 m above mean sea level. The highest known mountain on any planet in the Solar System is Olympus Mons on Mars at 21,171 m, there is no universally accepted definition of a mountain.
Elevation, relief, steepness and continuity have been used as criteria for defining a mountain, whether a landform is called a mountain may depend on local usage. The highest point in San Francisco, California, is called Mount Davidson, notwithstanding its height of 300 m, Mount Scott outside Lawton, Oklahoma is only 251 m from its base to its highest point. Whittows Dictionary of Physical Geography states Some authorities regard eminences above 600 metres as mountains, in addition, some definitions include a topographical prominence requirement, typically 100 or 500 feet. For a while, the US defined a mountain as being 1,000 feet or taller, any similar landform lower than this height was considered a hill. However, the United States Geological Survey concludes that these terms do not have technical definitions in the US, using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, and 14% of Africa. As a whole, 24% of the Earths land mass is mountainous, there are three main types of mountains, volcanic and block.
All three types are formed from plate tectonics, when portions of the Earths crust move, compressional forces, isostatic uplift and intrusion of igneous matter forces surface rock upward, creating a landform higher than the surrounding features. The height of the feature makes it either a hill or, if higher and steeper, major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity. Volcanoes are formed when a plate is pushed below another plate, at a depth of around 100 km, melting occurs in rock above the slab, and forms magma that reaches the surface. When the magma reaches the surface, it builds a volcanic mountain. Examples of volcanoes include Mount Fuji in Japan and Mount Pinatubo in the Philippines, the magma does not have to reach the surface in order to create a mountain, magma that solidifies below ground can still form dome mountains, such as Navajo Mountain in the US