Sunshine duration
Sunshine duration or sunshine hours is a climatological indicator, measuring duration of sunshine in given period for a given location on Earth expressed as an averaged value over several years. It is a general indicator of cloudiness of a location, thus differs from insolation, which measures the total energy delivered by sunlight over a given period. Sunshine duration is expressed in hours per year, or in hours per day; the first measure indicates the general sunniness of a location compared with other places, while the latter allows for comparison of sunshine in various seasons in the same location. Another often-used measure is percentage ratio of recorded bright sunshine duration and daylight duration in the observed period. An important use of sunshine duration data is to characterize the climate of sites of health resorts; this takes into account the psychological effect of strong solar light on human well-being. It is used to promote tourist destinations. If the Sun were to be above the horizon 50% of the time for a standard year consisting of 8,760 hours, apparent maximal daytime duration would be 4,380 hours for any point on Earth.
However, there are physical and astronomical effects. Namely, atmospheric refraction allows the Sun to be still visible when it physically sets below the horizon. For that reason, average daytime is longest in polar areas, where the apparent Sun spends the most time around the horizon. Places on the Arctic Circle have the longest total annual daytime, 4,647 hours, while the North Pole receives 4,575; because of elliptic nature of the Earth's orbit, the Southern Hemisphere is not symmetrical: the Antarctic Circle, with 4,530 hours of daylight, receives five days less of sunshine than its antipodes. The Equator has a total daytime of 4,422 hours per year. Given the theoretical maximum of daytime duration for a given location, there is a practical consideration at which point the amount of daylight is sufficient to be treated as a "sunshine hour". "Bright" sunshine hours represent the total hours when the sunlight is stronger than a specified threshold, as opposed to just "visible" hours. "Visible" sunshine, for example, occurs around sunrise and sunset, but is not strong enough to excite the sensor.
Measurement is performed by instruments called sunshine recorders. For the specific purpose of sunshine duration recording, Campbell–Stokes recorders are used, which use a spherical glass lens to focus the sun rays on a specially designed tape; when the intensity exceeds a pre-determined threshold, the tape burns. The total length of the burn trace is proportional to the number of bright hours. Another type of recorder is the Jordan sunshine recorder. Newer, electronic recorders have more stable sensitivity than that of the paper tape. In order to harmonize the data measured worldwide, in 1962 the World Meteorological Organization defined a standardized design of the Campbell–Stokes recorder, called an Interim Reference Sunshine Recorder. In 2003, the sunshine duration was defined as the period during which direct solar irradiance exceeds a threshold value of 120 W/m². Sunshine duration follows a general geographic pattern: subtropical latitudes have the highest sunshine values, because these are the locations of the eastern sides of the subtropical high pressure systems, associated with the large-scale descent of air from the upper-level tropopause.
Many of the world's driest climates are found adjacent to the eastern sides of the subtropical highs, which create stable atmospheric conditions, little convective overturning, little moisture and cloud cover. Desert regions, with nearly constant high pressure aloft and rare condensation—like North Africa, the Southwestern United States, Western Australia, the Middle East—are examples of hot, dry climates where sunshine duration values are high; the two major areas with the highest sunshine duration, measured as annual average, are the central and the eastern Sahara Desert—covering vast desert countries such as Egypt, Libya and Niger—and the Southwestern United States. The city claiming the official title of the sunniest in the world is Yuma, with over 4,000 hours of bright sunshine annually, but many climatological books suggest there may be sunnier areas in North Africa. In the belt encompassing northern Chad and the Tibesti Mountains, northern Sudan, southern Libya, Upper Egypt, annual sunshine duration is estimated at over 4,000 hours.
There is a smaller, isolated area of sunshine maximum in the heart of the western section of the Sahara Desert around the Eglab Massif and the Erg Chech, along the borders of Algeria and Mali where the 4,000-hour mark is exceeded, too. Some places in the interior of the Arabian Peninsula receive 3,600–3,800 hours of bright sunshine annually; the largest sun-baked region in the world is North Africa. The sunniest month in the world is December in Eastern Antarctica, with 23 hours of bright sun daily. Conversely, higher latitudes lying in stormy westerlies have much cloudier and more unstable and rainy weather, have the lowest values of sunshine duration annually. Temperate oceanic climates like those in northwestern Europe, the western coast of Canada, areas of New Zealand's South Island are examples of cool, wet, humid climates where cloudless sunshine duration values are low; the areas with the lowest sunshine duration annually lie over the polar oceans, as well as parts of northern Europe, southern Alaska, northern Russia, areas near the Sea of
Lusaka
Lusaka is the capital and largest city of Zambia. One of the fastest developing cities in southern Africa, Lusaka is in the southern part of the central plateau at an elevation of about 1,279 metres; as of 2010, the city's population was about 1.7 million. Lusaka is the centre of both commerce and government in Zambia and connects to the country's four main highways heading north, south and west. English is the official language of the city, Nyanja and Bemba are common. Lusaka was the site of a village named after its Chief Lusaka, according to history, was located at Manda Hill, near where the Zambia's National Assembly building now stands. In the Nyanja language, Manda means graveyard; the area was expanded by European settlers in 1905 with the building of the railway. In 1935, due to its central location, its situation on the railway and at the crossroads of the Great North Road and Great East Road, it was chosen to replace Livingstone as the capital of the British colony of Northern Rhodesia.
After the federation of Northern and Southern Rhodesia in 1953, it was a centre of the independence movement amongst some of the educated elite that led to the creation of the Republic of Zambia. In 1964, Lusaka became the capital of the newly independent Zambia. In recent years, Lusaka has become a popular urban settlement for tourists alike, its central nature and fast growing infrastructure sector have increased donor confidence and as such Zambians are seeing signs of development in the form of job creation, etc. It is thought that with proper and effective economic reforms, Lusaka as well as Zambia as a whole will develop considerably. Lusaka is home to a diverse community of foreign nationals, many of whom work in the aid industry as well as diplomats, representatives of religious organisations and some business people; as the national capital, Lusaka is the seat of the legislative and judicial branches of government, epitomized by the presence of the National Assembly, the State House, the High Court.
The Parliament is situated at the Parliament complex. The city is the capital of Lusaka Province, the smallest and most populous of the country's nine provinces, forms an administrative district run by Lusaka City Council. In 2007, the mayor was Steven Chilatu, the deputy mayor was Mary Phiri. List of mayors: F. Payne 1954–55. H. K. Mitchell 1955–56 Ralph Rich 1956–57 H. F. Tunaley 1957–58 H. K. Mitchell 1958–60 Jack Fischer 1960–61 Richard Sampson 1962–63 S. H. Chilesh 1964–65 W. Banda 1965–69 Fleefort Chirwa 1969–71? Simon C. Mwewa up to 1982List of Governors Simon C. Mwewa 1982 to 1983 Donald C. Sadoki Michael Sata Rupiah Banda Bautius Kapulu Lt. Muyoba – up to 1991List of Mayors – Multi-party era John Chilambwe 1993–94 Fisho Mwale 1994–96 Gilbert R. Zimba Local Government Administrator – 1996–99 Patricia Nawa Patrick Kangwa John Kabungo Levy Mkandawire Stephen Mposha Christine Nakazwe Stephen Chilatu Robert Chikwelete Daniel Chisenga Mulenga Sata Wilson Chisala Kalumba – 2016 – May 2018 Miles Sampa – July 2018 – present Zambia's largest institution of learning, the University of Zambia, is based in Lusaka.
Other universities and colleges located in Lusaka include: University of Lusaka, Zambia Open University, Chainama Hills College, Evelyn Hone College, Zambia Centre for Accountancy Studies University, National Institute of Public Administration, Cavendish University, Lusaka Apex Medical University and DMI-St. Eugene University. Lusaka has some of the finest schools in Zambia, including the American International School of Lusaka, International School of Lusaka, Rhodes Park School, the Lusaka International Community School, the French International School, the Italian international School, the Lusaka Islamic Cultural and Educational Foundation, the Chinese International School, Baobab College. Rhodes Park School is not an international school, though there is a large presence of Angolans, Congolese, South Africans, Chinese; the children of the late President, Levy Mwanawasa as well as the children of Vice-President George Kunda, attend the Rhodes Park School. Other well known schools located in Lusaka include: Matero Boys' Secondary School, Roma Girls' Secondary School, Munali Boys' and Girls' Secondary Schools, Chudleigh House School, Kabulonga Boys' and Girls' Secondary Schools, Lake Road PTA School, David Kaunda Technical School, Ibex Hill School and St. Mary's Secondary School.
Most major world religions are represented in Lusaka with the outstanding majority belonging to Christianity, a large number belonging to Protestant churches. Attractions include Lusaka National Museum, the Political Museum, the Zintu Community Museum, the Freedom Statue, the Zambian National Assembly, the Agricultural Society Showgrounds, the Moore Pottery Factory, the Lusaka Playhouse theatre, two cinema, a cenotaph, a golf club, the Lusaka Central Sports Club, Kalimba Reptile Park, Monkey Pools and the zoo and botanical gardens of the Munda Wanga Environmental Park; the city is home to the University of Zambia. Along Great East Road are three of the largest shopping malls in Zambia: Arcades shopping mall, Eastpark shopping mall and Manda Hill shopping mall, revamped and is home to international stores such as Shoprite and Woolworths, a new movie theatre and many others; the city centre includes several blocks west of Cairo Road, around which lie the New City Market and Kamwala Market, a major shopping area, as well
Zinc
Zinc is a chemical element with symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. In some respects zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state, the Zn2+ and Mg2+ ions are of similar size. Zinc has five stable isotopes; the most common zinc ore is sphalerite, a zinc sulfide mineral. The largest workable lodes are in Australia and the United States. Zinc is refined by froth flotation of the ore and final extraction using electricity. Brass, an alloy of copper and zinc in various proportions, was used as early as the third millennium BC in the Aegean, the United Arab Emirates, Kalmykia and Georgia, the second millennium BC in West India, Iran, Syria and Israel/Palestine. Zinc metal was not produced on a large scale until the 12th century in India, though it was known to the ancient Romans and Greeks; the mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, as early as the 9th century AD when a distillation process was employed to make pure zinc.
Alchemists burned zinc in air to form what they called "philosopher's wool" or "white snow". The element was named by the alchemist Paracelsus after the German word Zinke. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746. Work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron is the major application for zinc. Other applications are in electrical batteries, small non-structural castings, alloys such as brass. A variety of zinc compounds are used, such as zinc carbonate and zinc gluconate, zinc chloride, zinc pyrithione, zinc sulfide, dimethylzinc or diethylzinc in the organic laboratory. Zinc is an essential mineral, including to postnatal development. Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, diarrhea.
Enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc may cause ataxia and copper deficiency. Zinc is a bluish-white, diamagnetic metal, though most common commercial grades of the metal have a dull finish, it is somewhat less dense than iron and has a hexagonal crystal structure, with a distorted form of hexagonal close packing, in which each atom has six nearest neighbors in its own plane and six others at a greater distance of 290.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. Above 210 °C, the metal can be pulverized by beating. Zinc is a fair conductor of electricity. For a metal, zinc has low melting and boiling points; the melting point is the lowest of all the d-block metals aside from cadmium. Many alloys contain zinc, including brass. Other metals long known to form binary alloys with zinc are aluminium, bismuth, iron, mercury, tin, cobalt, nickel and sodium.
Although neither zinc nor zirconium are ferromagnetic, their alloy ZrZn2 exhibits ferromagnetism below 35 K. A bar of zinc generates a characteristic sound when bent, similar to tin cry. Zinc makes up about 75 ppm of Earth's crust. Soil contains zinc in 5–770 ppm with an average 64 ppm. Seawater has only 30 ppb and the atmosphere, 0.1–4 µg/m3. The element is found in association with other base metals such as copper and lead in ores. Zinc is a chalcophile, meaning the element is more to be found in minerals together with sulfur and other heavy chalcogens, rather than with the light chalcogen oxygen or with non-chalcogen electronegative elements such as the halogens. Sulfides formed as the crust solidified under the reducing conditions of the early Earth's atmosphere. Sphalerite, a form of zinc sulfide, is the most mined zinc-containing ore because its concentrate contains 60–62% zinc. Other source minerals for zinc include smithsonite, hemimorphite and sometimes hydrozincite. With the exception of wurtzite, all these other minerals were formed by weathering of the primordial zinc sulfides.
Identified world zinc resources total about 1.9–2.8 billion tonnes. Large deposits are in Australia and the United States, with the largest reserves in Iran; the most recent estimate of reserve base for zinc was made in 2009 and calculated to be 480 Mt. Zinc reserves, on the other hand, are geologically identified ore bodies whose suitability for recovery is economically based at the time of determination. 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 extrapolating the combined mine life of today's zinc mines; this concept is well supported by data from the United States Geol
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth from an ore body, vein, reef or placer deposit. These deposits form a mineralized package, of economic interest to the miner. Ores recovered by mining include metals, oil shale, limestone, dimension stone, rock salt, potash and clay. Mining is required to obtain any material that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or water. Mining of stones and metal has been a human activity since pre-historic times. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, final reclamation of the land after the mine is closed. De Re Metallica, Georgius Agricola, 1550, Book I, Para. 1Mining operations create a negative environmental impact, both during the mining activity and after the mine has closed.
Hence, most of the world's nations have passed regulations to decrease the impact. Work safety has long been a concern as well, modern practices have improved safety in mines. Levels of metals recycling are low. Unless future end-of-life recycling rates are stepped up, some rare metals may become unavailable for use in a variety of consumer products. Due to the low recycling rates, some landfills now contain higher concentrations of metal than mines themselves. Since the beginning of civilization, people have used stone and metals found close to the Earth's surface; these were used to make early weapons. Flint mines have been found in chalk areas where seams of the stone were followed underground by shafts and galleries; the mines at Grimes Graves and Krzemionki are famous, like most other flint mines, are Neolithic in origin. Other hard rocks mined or collected for axes included the greenstone of the Langdale axe industry based in the English Lake District; the oldest-known mine on archaeological record is the Ngwenya Mine in Swaziland, which radiocarbon dating shows to be about 43,000 years old.
At this site Paleolithic humans mined hematite to make the red pigment ochre. Mines of a similar age in Hungary are believed to be sites where Neanderthals may have mined flint for weapons and tools. Ancient Egyptians mined malachite at Maadi. At first, Egyptians used the bright green malachite stones for ornamentations and pottery. Between 2613 and 2494 BC, large building projects required expeditions abroad to the area of Wadi Maghareh in order to secure minerals and other resources not available in Egypt itself. Quarries for turquoise and copper were found at Wadi Hammamat, Tura and various other Nubian sites on the Sinai Peninsula and at Timna. Mining in Egypt occurred in the earliest dynasties; the gold mines of Nubia were among the largest and most extensive of any in Ancient Egypt. These mines are described by the Greek author Diodorus Siculus, who mentions fire-setting as one method used to break down the hard rock holding the gold. One of the complexes is shown in one of the earliest known maps.
The miners crushed the ore and ground it to a fine powder before washing the powder for the gold dust. Mining in Europe has a long history. Examples include the silver mines of Laurium. Although they had over 20,000 slaves working them, their technology was identical to their Bronze Age predecessors. At other mines, such as on the island of Thassos, marble was quarried by the Parians after they arrived in the 7th century BC; the marble was shipped away and was found by archaeologists to have been used in buildings including the tomb of Amphipolis. Philip II of Macedon, the father of Alexander the Great, captured the gold mines of Mount Pangeo in 357 BC to fund his military campaigns, he captured gold mines in Thrace for minting coinage producing 26 tons per year. However, it was the Romans who developed large scale mining methods the use of large volumes of water brought to the minehead by numerous aqueducts; the water was used for a variety of purposes, including removing overburden and rock debris, called hydraulic mining, as well as washing comminuted, or crushed and driving simple machinery.
The Romans used hydraulic mining methods on a large scale to prospect for the veins of ore a now-obsolete form of mining known as hushing. They built numerous aqueducts to supply water to the minehead. There, the water stored in large tanks; when a full tank was opened, the flood of water sluiced away the overburden to expose the bedrock underneath and any gold veins. The rock was worked upon by fire-setting to heat the rock, which would be quenched with a stream of water; the resulting thermal shock cracked the rock, enabling it to be removed by further streams of water from the overhead tanks. The Roman miners used similar methods to work cassiterite deposits in Cornwall and lead ore in the Pennines; the methods had been developed by the Romans in Spain in 25 AD to exploit large alluvial gold deposits, the largest site being at Las Medulas, where seven long aqueducts tapped local rivers and sluiced the deposits. Spain was one of the most important mining regions, but all regions of the Roman Empire were exploited.
In Great Britain the natives had mined minerals for millennia, but after the Roman conquest, the scale of the operations increased as the Romans needed Britannia's resources gold, silver
Homo heidelbergensis
Homo heidelbergensis is an extinct species or subspecies of archaic humans in the genus Homo, which radiated in the Middle Pleistocene from about 700,000 to 300,000 years ago, known from fossils found in Southern Africa, East Africa and Europe. African H. heidelbergensis has several subspecies. The subspecies are Homo heidelbergensis heidelbergensis, Homo heidelbergensis daliensis, Homo rhodesiensis, Homo heidelbergensis steinheimensi; the derivation of Homo sapiens from Homo rhodesiensis has been proposed, but is obscured by a fossil gap from 400–260 kya. The species was named Homo heidelbergensis due to the skeleton's first discovery near Heidelberg, Germany; the first discovery—a mandible—was made in 1907 by Otto Schoetensack. The skulls of this species share features with both Homo erectus and the anatomically modern Homo sapiens; the Sima de los Huesos cave at Atapuerca in northern Spain holds rich layers of deposits where excavations were still in progress as of 2018. H. Heidelbergensis was dispersed throughout Southern Africa as well as Europe.
Its exact relation both to the earlier Homo antecessor and Homo ergaster, to the lineages of Neanderthals and modern humans is unclear. Homo sapiens has been proposed as derived from H. heidelbergensis via Homo rhodesiensis, present in East and North Africa from around 400,000 years ago. The correct assignment of many fossils to a particular chronospecies is difficult and differences in opinion ensue among paleoanthropologists due to the absence of universally accepted dividing lines between Homo erectus, Homo heidelbergensis, Homo rhodesiensis and Neanderthals, it is uncertain whether H. heidelbergensis is ancestral to Homo sapiens, as a fossil gap in Africa between 400,000 and 260,000 years ago obscures the presumed derivation of H. sapiens from H. rhodesiensis. Genetic analysis of the Sima de los Huesos fossils seems to suggest that H. heidelbergensis in its entirety should be included in the Neanderthal lineage, as "pre-Neanderthal" or "archaic Neanderthal" or "early Neanderthal", while the divergence time between the Neanderthal and modern lineages has been pushed back to before the emergence of H. heidelbergensis, to about 600,000 to 800,000 years ago, the approximate time of disappearance of Homo antecessor.
The delineation between early H. heidelbergensis and H. erectus is unclear. Given the evidence, it means there is no direct evidence that suggest the Homo heidelbergensis is related to modern-day humans. H. heidelbergensis is thought to be derived from Homo antecessor, around 800,000 to 700,000 years ago. The oldest-known fossil classified as H. heidelbergensis dates to around 600,000 years ago, but the flint tools found in 2005 at Pakefield near Lowestoft in Suffolk with teeth from the water vole Mimomys savini, a key dating species, suggest human presence in England at 700,000 years ago, assumed to correspond to a transitional form between H. antecessor and H. heidelbergensis. Fifty prehistoric hominid footprints up to nearly one million years old were discovered in Happisburgh, England, they are members of Homo antecessor that lived from 1.2 million to 800,000 years ago. In Europe, H. heidelbergensis is taken to have given rise to H. neanderthalensis at 240,000 years ago. Homo sapiens most derived from H. rhodesiensis after around 300,000 years ago.
A morphological separation of a European and an African branch of H. heidelbergensis during the Wolstonian Stage and Ipswichian Stage, the last of the prolonged Quaternary glacial periods, has been argued based on the evidence of the Atapuerca skull in Spain and the Kabwe skull in modern-day Zambia. Neither the derivation of H. heidelbergensis from H. erectus, nor the derivation of anatomically modern humans and Neanderthals from H. heidelbergensis, are clear-cut and are the object of debate. Both H. erectus and H. heidelbergensis are described as polytypic species, which went through a number of population bottlenecks and associated In the summary of Hublin, Middle Pleistocene humans in Eurasia underwent a succession of population bottlenecks due to glaciations. The "Western Eurasian clade" derived form H. rhodesiensis or H. heidelbergensis sensu lato diverge at MIS 12 but coalesce as late as MIS 5, suggesting a division between Eurasian H. heidelbergensis and H. neanderthalensis before MIS 11.
A fossil gap in Africa between 400 and 260 kya obscures the presumed derivation of H. sapiens from H. rhodesiensis. Chris Stringer argues for Homo heidelbergensis as an independent chronospecies. A 2013 genetic study on the Sima de los Huesos fossils classified them as H. heidelbergensis or "early Neanderthal". For more than half a century, many experts were reluctant to accept Homo heidelbergensis as a separate taxon due to the rarity of specimens, which prevented sufficient informative morphological comparisons and the distinction of H. heidelbergensis from other known human species. The species name "heidelbergensis" only experienced a renaissance with the many discoveries of Middle Pleistocene fossils since the 1990s; the paleontology institute at Heidelberg University, where the type specimen is kept since 1908, as late as 2010 still classified it as Homo erectus heidelbergensis, i.e. categorizing it as a Homo erectus subspecies. This was changed to Homo heidelbergensis, accepting the categorization as separate species, in 2015."Rhodesian Man" (Kab
Titanium
Titanium is a chemical element with symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, high strength. Titanium is resistant to corrosion in sea water, aqua regia, chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, was named by Martin Heinrich Klaproth after the Titans of Greek mythology; the element occurs within a number of mineral deposits, principally rutile and ilmenite, which are distributed in the Earth's crust and lithosphere, it is found in all living things, water bodies and soils. The metal is extracted from its principal mineral ores by the Hunter processes; the most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include a component of smoke screens and catalysts. Titanium can be alloyed with iron, aluminium and molybdenum, among other elements, to produce strong, lightweight alloys for aerospace, industrial processes, agri-food, medical prostheses, orthopedic implants and endodontic instruments and files, dental implants, sporting goods, mobile phones, other applications.
The two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. In its unalloyed condition, titanium is less dense. There are two allotropic forms and five occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant. Although they have the same number of valence electrons and are in the same group in the periodic table and zirconium differ in many chemical and physical properties; as a metal, titanium is recognized for its high strength-to-weight ratio. It is a strong metal with low density, quite ductile and metallic-white in color; the high melting point makes it useful as a refractory metal. It is paramagnetic and has low electrical and thermal conductivity. Commercially pure grades of titanium have ultimate tensile strength of about 434 MPa, equal to that of common, low-grade steel alloys, but are less dense. Titanium is 60% denser than aluminium, but more than twice as strong as the most used 6061-T6 aluminium alloy.
Certain titanium alloys achieve tensile strengths of over 1,400 MPa. However, titanium loses strength when heated above 430 °C. Titanium is not as hard as some grades of heat-treated steel. Machining requires precautions, because the material can gall unless sharp tools and proper cooling methods are used. Like steel structures, those made from titanium have a fatigue limit that guarantees longevity in some applications; the metal is a dimorphic allotrope of an hexagonal α form that changes into a body-centered cubic β form at 882 °C. The specific heat of the α form increases as it is heated to this transition temperature but falls and remains constant for the β form regardless of temperature. Like aluminium and magnesium, titanium metal and its alloys oxidize upon exposure to air. Titanium reacts with oxygen at 1,200 °C in air, at 610 °C in pure oxygen, forming titanium dioxide, it is, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation.
When it first forms, this protective layer continues to grow slowly. Atmospheric passivation gives titanium excellent resistance to corrosion equivalent to platinum. Titanium is capable of withstanding attack by dilute sulfuric and hydrochloric acids, chloride solutions, most organic acids. However, titanium is corroded by concentrated acids; as indicated by its negative redox potential, titanium is thermodynamically a reactive metal that burns in normal atmosphere at lower temperatures than the melting point. Melting is possible only in a vacuum. At 550 °C, it combines with chlorine, it reacts with the other halogens and absorbs hydrogen. Titanium is one of the few elements that burns in pure nitrogen gas, reacting at 800 °C to form titanium nitride, which causes embrittlement; because of its high reactivity with oxygen and some other gases, titanium filaments are applied in titanium sublimation pumps as scavengers for these gases. Such pumps inexpensively and reliably produce low pressures in ultra-high vacuum systems.
Titanium is the ninth-most abundant element in the seventh-most abundant metal. It is present as oxides in most igneous rocks, in sediments derived from them, in living things, natural bodies of water. Of the 801 types of igneous rocks analyzed by the United States Geological Survey, 784 contained titanium, its proportion in soils is 0.5 to 1.5%. Common titanium-containing minerals are anatase, ilmenite, perovskite and titanite. Akaogiite is an rare mineral consisting of titanium dioxide. Of these minerals, only rutile and ilmenite have economic importance, yet they are difficult to find in high concentrations. About 6.0 and 0.7 million tonnes of those minerals were mined in 2011, respectively. Signi
Central Province, Zambia
Central Province is one of Zambia's ten provinces. The provincial capital is Kabwe, the home of the Mulungushi Rock of Authority. Central Province has an area of 94,394 km, it has six districts. The total area of forest in the province is 9,095,566 ha, it has a national park and three game management areas; as of 2010, Central Province had a population of 1,307,111, comprising 10.05% of the total Zambian population. The literacy rate stood at 70.90% against a national average of 70.2%. Bemba was the most spoken language with 31.80% speaking it, Lala was the majority clan in the province, comprising 20.3% of population. Central Province contains 20.64% of the total area of cultivated land in Zambia and contributes 23.85% of the total agricultural production in the country, with wheat being the major crop. The Ikubi Lya Loongo festival during July and Ichibwela Mushi festival during September are the major festivals celebrated in the province. Kafue National Park, the country's largest, is shared with Southern and North-Western Provinces, other natural areas include Blue Lagoon National Park, Kasanka National Park, the Bangweulu Wetlands, South Luangwa National Park, the Lunsemfwa and Lukusashi river valleys and Lukanga Swamp.
Central Province is considered the birthplace of the national movement of Zambia. The United National Independence Party was founded in Kabwe by Kenneth Kaunda, who became the first President of Zambia and remained in office from 1964 to 1991; the provincial capital is home of the Mulungushi Rock of Authority. This is a historic site, an isolated flat-topped hill, where in 1960, UNIP met for the first time, away from the eye of the colonial administration, it is still used for political gatherings, but the open air assemblies have been replaced by a conference centre built nearby at Mulungushi University. The Mulungushi River gives its name to many historical policies and organizations; the 1968 Mulungushi Declaration proclaimed the country as a socialist nation. Mulungushi Hall in the capital is the venue for most international conventions; the city of Kapiri Mposhi was a historic site during the post-colonial era fight against White minorities. As of 2013, before a part of Chibombo District, was declared a district on its own by the President, Michael Sata.
It is to the "East Of Chibombo". As of 2015, before a part of Kapiri Mposhi District, was declared a district on its own, with a proposal for it to become Zambia's new capital city, it is to the "West Of Kapiri Mposhi". As of February 2018, National Planning and Development Minister Alexander Chiteme declared that this plan was still being appraised and no final decision had yet been made. Adding Ngabwe District and Chisamba District to the earlier mentioned six districts brings the total to eight districts as of February 2018. Central Province shares a border with eight other provinces; the total area of forest in the province is 9,095,566 ha. The province has three game management areas. There are six districts in the province; the province has fertile soil conducive for the growth of maize. Lukanga Swamp has been identified by the International Monetary Fund as a potential place for a fishing industry. Precious metals are found in the Mkushi area, gold in Mumbwa, coal in Kapiri Mposhi. Lukanga Swamp is a permanent swamp covering 1,850 km2 at the mouths and along the Lukanga and Kafue rivers.
It contains many lagoons like Lake Suye. TAZARA, the Tanzania-Zambia railway line, has a major terminal in the city, it provides connectivity to the port in Tanzania from Zambia. According to the 2010 Zambian census, Central Province had a population of 1,307,111, comprising 10.05% of the total Zambian population of 13,092,666. There were 648,465 males and 658,646 females, making the sex ratio 1,016 females for every 1,000 males, compared to the national average of 1,028; the literacy rate stood at 70.90% against a national average of 70.2%. 74.87% of people lived in rural areas, while 25.13% lived in urban areas. The total area of the province is 94,394 km2 and the population density was 13.80 per km2. The decadal population growth of the province was 2.60%. The median age in the province at the time of marriage was 20.6. The average household size was 5.5, with the average size of families headed by women being 4.8 and 5.8 for families headed by men. In the province, 54.30% were eligible to vote.
The unemployment rate was 12.70%. The total fertility rate was 6.3, the complete birth rate was 6.1, the crude birth rate was 36.0, the child–woman ratio at birth was 785, the general fertility rate was 156, the gross reproduction rate was 2.5, the net reproduction rate was 1.8. The labour force constituted 52.20% of the total population. Out of the labour force, 62.7% were men and 42.2% were women. The annual growth rate of the labour force was 2.2%. Bemba was the most spoken language with 31.80% speaking it. The total population in the province with albinism stood at 3,007; the life expectancy at birth stood at 52 compared to the national average of 51. Lala was the largest clan in comprising 20.3 % of population. The provincial administration is set up purely for administrative purposes; the province is headed by a minister appointed by the President and there are ministries of central government for each province. The administrative head of the province is the Permanent Secretary, appointed by the President.
There is a Deputy Permanent Secretary, heads of government departments and civil servants at the provincial level. Central P
Zambia
About 75 km east-southeast of Kabwe, Zambia, the Lunsemfwa River cuts a 500m deep gash, known as The Wonder Gorge, through the lip of the Muchinga Escarpment (viewed from Bell’s Point). The antenna atop the Taipei 101 skyscraper, the world’s second-tallest building, would just protrude above the rim of this gorge.
Kabwe travel guide from Wikivoyage
