China, officially the Peoples Republic of China, is a unitary sovereign state in East Asia and the worlds most populous country, with a population of over 1.381 billion. The state is governed by the Communist Party of China and its capital is Beijing, the countrys major urban areas include Shanghai, Beijing, Shenzhen and Hong Kong. China is a power and a major regional power within Asia. Chinas landscape is vast and diverse, ranging from forest steppes, the Himalaya, Karakoram and Tian Shan mountain ranges separate China from much of South and Central Asia. The Yangtze and Yellow Rivers, the third and sixth longest in the world, Chinas coastline along the Pacific Ocean is 14,500 kilometers long and is bounded by the Bohai, East China and South China seas. China emerged as one of the worlds earliest civilizations in the basin of the Yellow River in the North China Plain. For millennia, Chinas political system was based on hereditary monarchies known as dynasties, in 1912, the Republic of China replaced the last dynasty and ruled the Chinese mainland until 1949, when it was defeated by the communist Peoples Liberation Army in the Chinese Civil War.
The Communist Party established the Peoples Republic of China in Beijing on 1 October 1949, both the ROC and PRC continue to claim to be the legitimate government of all China, though the latter has more recognition in the world and controls more territory. China had the largest economy in the world for much of the last two years, during which it has seen cycles of prosperity and decline. Since the introduction of reforms in 1978, China has become one of the worlds fastest-growing major economies. As of 2016, it is the worlds second-largest economy by nominal GDP, China is the worlds largest exporter and second-largest importer of goods. China is a nuclear weapons state and has the worlds largest standing army. The PRC is a member of the United Nations, as it replaced the ROC as a permanent member of the U. N. Security Council in 1971. China is a member of numerous formal and informal multilateral organizations, including the WTO, APEC, BRICS, the Shanghai Cooperation Organization, the BCIM, the English name China is first attested in Richard Edens 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa.
The demonym, that is, the name for the people, Portuguese China is thought to derive from Persian Chīn, and perhaps ultimately from Sanskrit Cīna. Cīna was first used in early Hindu scripture, including the Mahābhārata, there are, other suggestions for the derivation of China. The official name of the state is the Peoples Republic of China. The shorter form is China Zhōngguó, from zhōng and guó and it was applied to the area around Luoyi during the Eastern Zhou and to Chinas Central Plain before being used as an occasional synonym for the state under the Qing
Gian Lorenzo Bernini
Gian Lorenzo Bernini was an Italian sculptor and architect. While a major figure in the world of architecture, he was the sculptor of his age. Bernini was a figure in the emergence of Roman Baroque architecture along with his contemporaries, the architect Francesco Borromini. Early in their careers they had all worked at the time at the Palazzo Barberini, initially under Carlo Maderno and, following his death. Later on, they were in competition for commissions, Peters Basilica, completed under Pope Paul V with the addition of Madernos nave and facade and finally re-consecrated by Pope Urban VIII on 18 November 1626, after 150 years of planning and building. Berninis design of the Piazza San Pietro in front of the Basilica is one of his most innovative, during his long career, Bernini received numerous important commissions, many of which were associated with the papacy. At an early age, he came to the attention of the nephew, Cardinal Scipione Borghese. Although he did not fare so well during the reign of Innocent X, under Alexander VII, he again regained pre-eminent artistic domination.
Bernini and other artists fell from favor in neoclassical criticism of the Baroque, the art historian Howard Hibbard concludes that, during the seventeenth century, there were no sculptors or architects comparable to Bernini. Bernini was born in Naples in 1598 to Angelica Galante and Mannerist sculptor Pietro Bernini and he was the sixth of their thirteen children. Gianlorenzo Bernini was the definition of childhood genius and he was “recognized as a prodigy when he was only eight years old, he was consistently encouraged by his father, Pietro. His precocity earned him the admiration and favor of powerful patrons who hailed him as ‘the Michelangelo of his century’” and his father was so impressed by his son’s obvious talent that he took him to Rome to showcase him to the cardinals and Pope. Bernini was presented before Pope Paul V, for whom he did a sketch of Saint Paul, once he was brought to Rome, he never left. “For Bernini there could be only one Rome, ‘You are made for Rome, ’ said Pope Urban VIII to him, ‘and Rome for you’”.
It was in world of 17th century Rome and religious power. Under the patronage of the wealthy and most powerful Cardinal Scipione Borghese. By the time he was twenty-two, he was considered talented enough to have given a commission for a papal portrait. Berninis reputation, was established by four masterpieces
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate. The Mohs scale of hardness, based on scratch hardness comparison. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite, aragonite will change to calcite at 380–470 °C, and vaterite is even less stable. Calcite is derived from the German Calcit, a term coined in the 19th century from the Latin word for lime and it is thus etymologically related to chalk. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, prisms, or various scalenohedra. Calcite exhibits several twinning types adding to the variety of observed forms and it may occur as fibrous, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form and its fracture is conchoidal, but difficult to obtain. It has a defining Mohs hardness of 3, a gravity of 2.71.
Color is white or none, though shades of gray, orange, green, violet, calcite is transparent to opaque and may occasionally show phosphorescence or fluorescence. A transparent variety called Iceland spar is used for optical purposes, acute scalenohedral crystals are sometimes referred to as dogtooth spar while the rhombohedral form is sometimes referred to as nailhead spar. Single calcite crystals display an optical property called birefringence and this strong birefringence causes objects viewed through a clear piece of calcite to appear doubled. The birefringent effect was first described by the Danish scientist Rasmus Bartholin in 1669, at a wavelength of ~590 nm calcite has ordinary and extraordinary refractive indices of 1.658 and 1.486, respectively. Between 190 and 1700 nm, the refractive index varies roughly between 1.9 and 1.5, while the extraordinary refractive index varies between 1.6 and 1.4. Calcite, like most carbonates, will dissolve with most forms of acid, calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations.
Although calcite is fairly insoluble in water, acidity can cause dissolution of calcite. Ambient carbon dioxide, due to its acidity, has a slight solubilizing effect on calcite, calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. On a landscape scale, continued dissolution of calcium carbonate-rich rocks can lead to the expansion and eventual collapse of cave systems, high-grade optical calcite was used in World War II for gun sights, specifically in bomb sights and anti-aircraft weaponry
Afghanistan, officially the Islamic Republic of Afghanistan, is a landlocked country located within South Asia and Central Asia. It has a population of approximately 32 million, making it the 42nd most populous country in the world. It is bordered by Pakistan in the south and east, Iran in the west, Turkmenistan and Tajikistan in the north and its territory covers 652,000 km2, making it the 41st largest country in the world. The land served as the source from which the Kushans, Samanids, Ghaznavids, Khiljis, Hotaks, the political history of the modern state of Afghanistan began with the Hotak and Durrani dynasties in the 18th century. In the late 19th century, Afghanistan became a state in the Great Game between British India and the Russian Empire. Following the Third Anglo-Afghan War in 1919, King Amanullah unsuccessfully attempted to modernize the country and it remained peaceful during Zahir Shahs forty years of monarchy. A series of coups in the 1970s was followed by a series of wars that devastated much of Afghanistan.
The name Afghānistān is believed to be as old as the ethnonym Afghan, the root name Afghan was used historically in reference to a member of the ethnic Pashtuns, and the suffix -stan means place of in Persian. Therefore, Afghanistan translates to land of the Afghans or, more specifically in a historical sense, the modern Constitution of Afghanistan states that he word Afghan shall apply to every citizen of Afghanistan. An important site of historical activities, many believe that Afghanistan compares to Egypt in terms of the historical value of its archaeological sites. The country sits at a unique nexus point where numerous civilizations have interacted and it has been home to various peoples through the ages, among them the ancient Iranian peoples who established the dominant role of Indo-Iranian languages in the region. At multiple points, the land has been incorporated within large regional empires, among them the Achaemenid Empire, the Macedonian Empire, the Indian Maurya Empire, and the Islamic Empire.
Archaeological exploration done in the 20th century suggests that the area of Afghanistan has been closely connected by culture and trade with its neighbors to the east, west. Artifacts typical of the Paleolithic, Neolithic, urban civilization is believed to have begun as early as 3000 BCE, and the early city of Mundigak may have been a colony of the nearby Indus Valley Civilization. More recent findings established that the Indus Valley Civilisation stretched up towards modern-day Afghanistan, making the ancient civilisation today part of Pakistan, Afghanistan, in more detail, it extended from what today is northwest Pakistan to northwest India and northeast Afghanistan. An Indus Valley site has found on the Oxus River at Shortugai in northern Afghanistan. There are several smaller IVC colonies to be found in Afghanistan as well, after 2000 BCE, successive waves of semi-nomadic people from Central Asia began moving south into Afghanistan, among them were many Indo-European-speaking Indo-Iranians.
These tribes migrated further into South Asia, Western Asia, the region at the time was referred to as Ariana
Pamukkale, meaning cotton castle in Turkish, is a natural site in Denizli Province in southwestern Turkey. The city contains hot springs and travertines, terraces of carbonate minerals left by the flowing water and it is located in Turkeys Inner Aegean region, in the River Menderes valley, which has a temperate climate for most of the year. The ancient Greco-Roman city of Hierapolis was built on top of the castle which is in total about 2,700 metres long,600 m wide and 160 m high. It can be seen from the hills on the side of the valley in the town of Denizli,20 km away. Tourism is and has been a major industry, people have bathed in its pools for thousands of years. As recently as the century, hotels were built over the ruins of Hierapolis. An approach road was built from the valley over the terraces, when the area was declared a World Heritage Site, the hotels were demolished and the road removed and replaced with artificial pools. Wearing shoes in the water is prohibited to protect the deposits, pamukkales terraces are made of travertine, a sedimentary rock deposited by water from the hot springs.
In this area, there are 17 hot water springs in which the ranges from 35 °C to 100 °C. When the water, supersaturated with carbonate, reaches the surface, carbon dioxide de-gasses from it. The depositing continues until the carbon dioxide in the water balances the carbon dioxide in the air, calcium carbonate is deposited by the water as a soft jelly, but this eventually hardens into travertine. In this museum, alongside historical artifacts from Hierapolis, there are artifacts from Laodiceia, Tripolis, Attuda. In addition to these, the museum has a section devoted to artifacts found at Beycesultan Hüyük that includes some of the most beautiful examples of Bronze Age craft. Artifacts from the Caria and Lydia regions are on display in this museum, the museum’s exhibition space consists of three closed areas of the Hierapolis Bath and the open areas in the eastern side which are known to have been used as the library and gymnasium. The artifacts in open space are mostly marble and stone. Hierapolis is broken down into ruins and it is recognized as a World Heritage Site together with Hierapolis.
Hierapolis-Pamukkale was made a World Heritage Site in 1988, the underground volcanic activity which causes the hot springs forced carbon dioxide into a cave, which was called the Plutonium, which here means place of the god Pluto. This cave was used for religious purposes by priests of Cybele, tadpoles can be found in the pools
Tufa is a variety of limestone formed when carbonate minerals precipitate out of ambient temperature water. Geothermally heated hot springs sometimes produce similar carbonate deposits known as travertine, Tufa is sometimes referred to as travertine. It should not be confused with hot spring travertine, Mono Lakes tufa is thermogene, according to Pentecost. Tufa, which is calcareous, should not be confused with tuff and fossil tufa deposits abound with wetland plants, as such many tufa deposits are characterised by their large macrobiological component and are highly porous. Tufa forms either in fluvial channels or in lacustrine settings and Pedley provide a review of tufa systems worldwide. Deposits can be classified by their depositional environment, Pedley provides an extensive classification system, which includes the following classes of fluvial tufa, Spring – Deposits form on emergence from a spring/seep. Barrages often contain a significant detrital component, composed of organic material, lacustrine tufas are generally formed at the periphery of lakes and build up phytoherms and stromatolites.
Oncoids are common in these environments, while fluvial and lacustrine systems make up the bulk of tufa systems worldwide, there are several other important tufa environments. Although sometimes regarded as a distinct carbonate deposit, calcareous sinter formed from ambient temperature water can be considered a sub-type of tufa, calcareous speleothems may be regarded as a form of calcareous sinter. They lack any significant macrophyte component due to the absence of light, Tufa columns are an unusual form of tufa typically associated with saline lakes. They are distinct from most tufa deposits in that lack any significant macrophyte component. Some tufa columns may form from hot-springs and therefore actually be a form of travertine. It is generally thought that such features form from CaCO3 precipitated when carbonate rich source waters emerge into alkaline soda lakes and they have been found in marine settings. Tufa deposits form an important habitat for a diverse flora and diatoms are well represented.
The porosity of the deposits creates a wet habitat ideal for these plants, modern tufa is formed from alkaline waters, supersaturated with calcite. On emergence, waters degas CO2 due to the lower atmospheric pCO2, since carbonate solubility decreases with increased pH, precipitation is induced. Supersaturation may be enhanced by leading to a reduction in pCO2, for example increased air-water interactions at waterfalls may be important. Recently it has demonstrated that microbially induced precipitation may be more important than physico-chemical precipitation
Semuc Champey is a natural monument in the department of Alta Verapaz, near the Qeqchi Maya town of Lanquín. It consists of a natural 300 m limestone bridge, under which passes the Cahabón River, atop the bridge is a series of stepped, turquoise pools, a popular swimming attraction. Although it can be difficult to get to, Semuc is becoming more and more popular with travelers, Semuc Champey Photos and Overview
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine.
Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, granular, or massive, depending on the method of formation.
Crystals of calcite, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
St. Peter's Square
St. Peters Square is a large plaza located directly in front of St. Peters Basilica in the Vatican City, the papal enclave inside Rome, directly west of the neighbourhood or rione of Borgo. Both the square and the basilica are named after Saint Peter, an apostle of Jesus, at the centre of the square is an ancient Egyptian obelisk, erected at the current site in 1586. Gian Lorenzo Bernini designed the square almost 100 years later, including the massive Tuscan colonnades, four columns deep, a granite fountain constructed by Bernini in 1675 matches another fountain designed by Carlo Maderno in 1613. Bernini had been working on the interior of St, there were many constraints from existing structures. The massed accretions of the Vatican Palace crowded the space to the right of the basilicas façade, the colossal Tuscan colonnades, four columns deep, frame the trapezoidal entrance to the basilica and the massive elliptical area which precedes it. The ovato tondos long axis, parallel to the basilicas façade, the elliptical center of the piazza, which contrasts with the trapezoidal entrance, encloses the visitor with the maternal arms of Mother Church in Berninis expression.
On the south side, the colonnades define and formalize the space, on the north side, the colonnade masks an assortment of Vatican structures, the upper stories of the Vatican Palace rise above. The obelisk was erected at Heliopolis, Egypt, by an unknown pharaoh. The Emperor Augustus had the moved to the Julian Forum of Alexandria, where it stood until 37 AD, when Caligula ordered the forum demolished. He had it placed on the spina which ran along the center of the Circus of Nero, the Vatican Obelisk is the only obelisk in Rome that has not toppled since ancient Roman times. During the Middle Ages, the ball on top of the obelisk was believed to contain the ashes of Julius Caesar. Fontana removed the ancient metal ball, now in a Rome museum, Christopher Hibbert writes that the ball was found to be solid. Though Bernini had no influence in the erection of the obelisk, he did use it as the centerpiece of his magnificent piazza, the paving is varied by radiating lines in travertine, to relieve what might otherwise be a sea of cobblestones.
In 1817 circular stones were set to mark the tip of the shadow at noon as the sun entered each of the signs of the zodiac. Below is a view of St. Peters Square from the cupola which was taken in June,2007, St. Peters Square today can be reached from the Ponte SantAngelo along the grand approach of the Via della Conciliazione. The spina which once occupied this grand avenue leading to the square was demolished ceremonially by Benito Mussolini himself on October 23,1936 and was demolished by October 8,1937. St. Peters Basilica was now visible from the Castel SantAngelo. After the spina, almost all the south of the passetto were demolished between 1937 and 1950, obliterating one of the most important medieval and renaissance quarters of the city
The Atlantic in palaeoclimatology was the warmest and moistest Blytt-Sernander period, pollen zone and chronozone of Holocene northern Europe. The climate was warmer than today. It was preceded by the Boreal, with a similar to today’s, and was followed by the Subboreal. Because it was the warmest period of the Holocene, the Atlantic is often referenced more directly as the Holocene climatic optimum, the Atlantic is equivalent to Pollen Zone VII. Sometimes a Pre-atlantic or early Atlantic is distinguished, on the basis of an early dividing cold snap, other scientists place the Atlantic entirely after the cold snap, assigning the latter to the Boreal. The period is still in the process of definition, which would end at the well-known 6.2 ka BC -cold-event. Or one single Atlantic period is defined, starting at that just mentioned cold-event, after a lake-level criterion, Kul’kova and others define the Atlantic as running from 8000 to 5000 BP. Each period has its distinctive ratios of species, according to the ice-core criterion it is extremely difficult to find a clear boundary, because the measurements still differ too much and alignments are still under construction.
Many find a decline of temperature significant enough after 4800 BC, another criterion comes from bio-stratigraphy, the elm-decline. However, this appears in different regions between 4300 and 3100 BC, the Atlantic was a time of rising temperature and marine transgression on the islands of Denmark and elsewhere. The sea rose to 3 m above its present level by the end of the period, the oysters found there required lower salinity. Tides of up to 1 m were present, lake levels in all north Europe were generally higher, with fluctuations. The temperature rise had the effect of extending southern climates northward in a short period. The treelines on northern mountains rose by 600 to 900 m and they did not replace the species that were there, but shifted the percentages in their favor. Across middle Europe, the forests were replaced by climax or old growth deciduous ones. The dense canopy theory, has been questioned recently by F. Vera and hazel require more light than is allowed by the dense canopy.
Vera hypothesizes that the lowlands were more open and that the low frequency of grass pollen was caused by the browsing of large herbivores, such as Bos primigenius and Equus ferus. During the Atlantic period the temperate zone forests of south and central Europe extended northward to replace the boreal mixed forest